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We elucidate the successful harnessing of the atomistic "pump-driven" effect to engineer a potent internal electric field (IEF) within transition metal oxides (TMOs). This IEF acts as a dynamic catalyst for charge transfer, significantly bolstering reaction kinetics and, consequently, augmenting the efficacy of hybrid capacitive deionization (HCDI) systems. [Display omitted] • Successful synthesis of the MoS 2 @MnO 2 heterostructure. • Atomic-level "pump-driven" effect induces a strong inherent electric field. • Meticulous design enhances directional electron transfer and charge efficiency. • Enhanced desalination capacity and rate compared to pristine MnO 2. • Leveraging empirical and computational insights enriches understanding. In addressing the limitations imposed by the inherently low electronic conductivity and substantial ion transfer resistance of transition metal oxides (TMOs) in hybrid capacitive deionization (HCDI) applications, this study delineates a pioneering approach through the fabrication of a MoS 2 /MnO 2 heterostructure, leveraging manganese dioxide (MnO 2) as a model system. The investigation underscores the essentiality of constructing high-quality interfaces to act as conduits for directional charge flow, a critical but formidable challenge for enhancing desalination efficacy in electrode materials. By harnessing an atomistic "pump-driven" mechanism, the MoS 2 /MnO 2 heterostructure demonstrably facilitates the promotion of desalination processes, underscored by the establishment of a potent local electric field (IEF) aimed at commanding charge dynamics. Empirical and computational analyses coalesce to unveil the preferential electron transfer from MoS 2 to MnO 2 , a phenomenon precipitated by charge redistribution. This orchestrated charge flow not only augments electronic and ionic transfer efficiencies but also emboldens the MoS 2 /MnO 2 heterostructure with enhanced desalination capabilities. The results show that MoS 2 /MnO 2 demonstrates superior HCDI performance compared to MnO 2 in a 500 mg L-1 NaCl solution at 1.2 V, with SRC of 33.21 mg g-1 and SRR of 1.50 mg g-1 min-1. The elucidation of this charge-guided dynamic, achieved through meticulous manipulation of the electronic microstructure and the IEF at the atomic scale, presents a novel paradigm for material science. This research presents an innovative approach for realizing robust charge-guided dynamics through the deliberate manipulation of the electronic microstructure and IEF of materials, employing an atomic-level "pump-driven" effect. This strategy opens new avenues for extending these principles to a broad array of advanced materials. [ABSTRACT FROM AUTHOR]

Channel-aligned regulation of photoelectrode within the bulk structure to generate eminent light absorbance and high-level pollutant adsorption is pivotal but challenging for realizing high-performance photofuel cell (PFC) system. Here we demonstrated for the first time the capability of an expansion-flow-modulated DIW 3D printing for controllably constructing porous microlattice photoelectrode with multiscale well-interconnected oriented channels and vertical alignment of photoactive graphene nanosheets, which facilitated remarkable light spreading/absorption and highly efficient pollutant diffusion/trapping, thereby enabling an assembled vertically-aligned PFC (VAPFC) with prominent photoelectric conversion capability for wastewater pollutants under sunlight. [Display omitted] • Porous microlattice photoelectrode was consistently constructed through a controllable and scalable expansion-flow-modulated DIW 3D printing strategy. • 3DP photoelectrode featured multiscale well-interconnected oriented channels and vertical alignment of photoactive graphene nanosheets. • The unique architecture of photoelectrode enabled remarkable light spreading/absorption and highly efficient pollutant diffusion/trapping. • Assembled VAPFC exhibited an impressive photoelectric conversion capability for wastewater pollutants under sunlight. Channel-aligned regulation of photoelectrode within the bulk structure to generate eminent light absorbance and high-level pollutant adsorption is pivotal but challenging for realizing high-performance photofuel cell (PFC) system. Herein, we demonstrated an effective and scalable expansion-flow-modulated direct ink writing (DIW) 3D printing strategy for controllably constructing microlattice photoelectrode, with multiscale well-interconnected oriented channels built by layer-by-layer highly-regular assembly of filaments and vertical alignment of graphene nanosheets within filaments as well as uniform coupling of abundant photoactive nanoparticles to highly ordered channel walls. The unique architectural features enabled high-speed and effective diffusion/trapping of wastewater pollutants throughout the entire photoelectrode, and meanwhile facilitated ready spreading of incident light into the photoelectrode interior to yield high light absorption. As a result, an integrated 3D-printed vertically-aligned PFC (3DP VAPFC) assembled with as-fabricated photoelectrode exhibited its powerful capability for efficiently converting wastewater pollutants into electric energy under sunlight, with remarkable cycling stability and maximum power density of 0.11 mW cm−2. This work opens a promising route for architecting advanced photoelectrode toward PFC devices with highly efficient degradation and electricity generation of pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • MBiC@tE achieves an efficient F- electrosorption capacity of 37.9 mg F - gelectrode-1. • Fluoride was removed by the synergistic roles during capacitive control process. • Bismuth active units induced Faradaic redox reaction and increased pseudocapacitance. • The complex carbon framework ensured electrical double layer capacitance. • Insights into the phase transition of bismuth during the electrosorption. Remediation of fluoride in groundwater through electrosorption to cope with its high charge density and the smallest anion radius remains a promising strategy. Composite carbon materials obtained by calcining metal–organic frameworks contribute to the performance of conventional fluoride electrosorption systems. This study provides a redox-active electrode (MBiC@tE) that incorporates the Faradaic ion trapping effect for fluoride removal. Under potential control, MBiC@tE reversibly traps/releases fluoride anions from the aqueous solution through the combined roles of Faradaic pseudocapacitance and electrical double layer capacitance, with an electrosorption capacity of approximately 37.9 mg F - g electrode -1. The target contaminant anions are directly involved in the Faradaic reaction on the bismuth sites, with the formation of Bi-F bond excited by an electric field, thus resulting in the removal of fluoride as a consequence of the generation of insoluble substance (BiF 3). Furthermore, as expected (Bi 0 + 3F- ⇌ BiF 3 + 3e-), the working electrode exhibits good reversibility and maintains a high fluoride removal capacity even after multiple cycles. This study presents a comprehensive elucidation on the synergistic roles of Faradaic effect and electrical double layer capacitance induced by the electric field, and offers profound insights into the phase transition of bismuth and its affinity for fluoride during the electrosorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluoride (FL) is abundant in the earth's environment and is often discharged into aquifers. • Fluorosis is the outcome of continuous exposure to FL concentrations of more than 4 ppm. • CM for FLR have a long lifespan and are highly resistant to harsh conditions. • EDI for FLR shows a reduction in labor costs and no chemicals required for resin regeneration. • MCDI offers significant potential for the removal of organic pollutants including fluoride. One of the biggest issues facing the globe today is fluoride poisoning of water, which is a severe risk to the well-being of people since water is essential for consumption from both natural and man-made sources. Fluoride in water can be removed using a variety of methods, although the issue is still not completely solved. Because of its ionic size and reactivity, fluoride can be hard to remove from water-based solutions using traditional electrochemical, precipitation, and adsorption methods. One of the latest innovations that has been shown to be highly successful in bringing fluoride levels down to the required levels is the use of membranes. This review discusses fluoride and its characteristics, sources, impacts on the environment and humans, fluoride measurement techniques, and fluoride applications. The efficacy of different types of membrane separation processes are covered with respect to techniques developed, advantages and drawbacks of defluoridation processes. This review critically examines membrane-based techniques for different defluoridation processes including nanofiltration (NF), reverse osmosis (RO), membrane distillation (MD), electrodialysis (ED), and forward osmosis (FO). Furthermore, the study addresses developments in ceramic membranes, electrodeionization and membrane capacitive deionization, hybrid membrane techniques, and life cycle assessment (LCA) for membrane-based defluoridation process. The work meets the SDGs goal #6 of clean water supply. [ABSTRACT FROM AUTHOR]

• A knittable fiber-shaped capacitive pressure sensor was prepared. • The knittable sensor can be seamlessly incorporated into garment. • The knittable sensor showed a sensitivity of 0.04 kPa−1 in low pressure range. • The sensor's easy-integration facilitates real-time rehabilitation monitoring. The integration of sensors into clothes offers significant convenience for monitoring the rehabilitation of patients. However, conventional flat sensors face challenges in achieving seamless integration due to their incompatibility with clothing. Here, we created a knittable fiber-shaped capacitive pressure sensor designed for long-term monitoring of shoulder movements of patients with rotator cuff injuries. This innovative sensor incorporates copper wires and silver conductive fibers as electrodes, with a polyvinylidene fluoride (PVDF) composite fiber membrane containing zeolite imidazolate framework (ZIF-8) particles as the dielectric layer. The resultant sensor can be seamlessly while non-invasively incorporated into the garment of patents due to its exceptionally flexibility. After optimizing the number of Cu wires (4) and electrospinning time of PVDF (8 min), the knittable sensor showed a sensitivity of 0.04 kPa−1 in the range of 2–8 kPa, 10 times higher than that without ZIF-8 (0.003 kPa−1). Beyond its applications in monitoring shoulder movement across various directions and degrees, this sensor has proven its ability in monitoring breath or recording weight when encompassed into a mask or a carpet, respectively. Via integrated in daily wearings, this sensor holds immense potential in the fields of rehabilitation monitoring and personal health management due to its remarkable sensitivity and flexibility. [ABSTRACT FROM AUTHOR]

[Display omitted] • Core-shell heterostructured CoFe@NiFe PBA is successfully synthesized. • Encapsulation of CoFe PBA with NiFe PBA shell alleviates dissolution of the core material during Na+ insertion/extraction. • Favorable hydrophilicity and large specific surface area of the shell material promotes accessibility of electrolyte ions. • Higher electrical conductivity of the shell material enhances charge transfer on the electrode. Rational design of stable and high-capacity faradaic electrode materials is crucial for enhancing the desalination performance of hybrid capacitive deionization (HCDI). In this work, to fully exploit the advantages of high-capacity CoFe Prussian blue analogs (PBA) and structurally stable NiFe PBA, a core–shell heterostructured CoFe@NiFe PBA is successfully synthesized by a two-step co-precipitation method. The construction of the core–shell heterostructure not only suppresses dissolution of the CoFe PBA core, but also facilitates fast charge transfer and efficient ion diffusion during Na+ ions insertion/extraction. With an optimal NiFe PBA shell thickness of 30 nm, the core–shell structured PBA electrode demonstrates outstanding cycling performance with a capacity retention of 72.6 % over 10,000 charge/discharge cycles. Moreover, when utilized as the cathode material in HCDI, the core–shell heterostructured PBA exhibits intriguing desalination performance, including a high desalination capacity of 49 mg g−1 and excellent desalination stability over 200 cycles (77.7 %). This paper presents a straightforward strategy for designing core–shell heterostructured PBA electrode, with the potential to advance the development of high-performance capacitive desalination. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel two-stage FCDI (TS-FCDI) configuration is proposed. • PANI-CC-AC freestanding electrode construction by one-pot ectropolymerization method. • Secondary ion transfer between the two types of electrodes improves the desalination performance of TS-FCDI. • Role of the two types of electrodes in deionization process was comprehensive analyzed. The desalination of seawater/wastewater utilizing flow-electrode capacitive deionization (FCDI) has received significant interest. However, challenges like the low electrical conductivity of flow electrode and excessive energy consumption have prevented the scaling up of desalination operations. To overcome these issues, this study introduces a new FCDI system termed the two-stage FCDI (TS-FCDI) system, in which desalination modules are equipped with freestanding and flow electrode. The TS-FCDI system offers a graded desalination module design that produces an average salt removal rate (ASRR) of 113 µg cm2·min−1. However, the TS-FCDI system requires substantially reduced infrastructure investment, device size, and energy expenses. Notably, the design allows for the simultaneous operation of freestanding and flow electrode and enables the transport of ions and charges in the electrode region. Experimental evidence from multiple device configurations (CDI, FCDI, and TS-FCDI) supports this claim. Notably, the TS-FCDI system shows about twice the desalination performance over FCDI, with approximately 50 h of single-cycle (SC) operation. This enhancement links the freestanding electrode with the flow electrode, enabling the device to be well-suited for practical applications. The continuous flow of electrode particles in contact with the freestanding electrode initiates secondary ion transport, merging two different types of electrodes to enhance the active space of the electrode, effectively improving ion adsorption performance. In summary, the results of this study indicate the potential of the TS-FCDI system as a suitable desalination technology for scaling up applications. [ABSTRACT FROM AUTHOR]

• The leaf-liked structure of CoP/FeP is in situ constructed by a simple strategy. • The CoP/FeP enables strong adsorption of H and weak adsorption of O 2 on Co. • The synergy between FeP and CoP induces abundant active sites and efficient mass transfer. • The CoP/FeP exhibits superior OER/HER performance in alkaline solution. Development of non-noble bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are of great significance under alkaline electrolytes for overall water splitting. In this work, CoP/FeP has been designed and constructed in situ on carbon fiber paper by using the bimetallic metal organic frameworks (MOFs) synthesis strategy. The heterogeneous CoP/FeP displays excellent catalytic activities in both HER and OER of the fully hydrolyzed semi-reaction. Remarkably, CoP/FeP is applied as the bifunctional electrode in anode and cathode to construct an overall water splitting apparatus, resulting in the low cell voltage and excellent stability. The exceptional electrocatalytic performance may be mainly attributed to the heterogeneous interface, which constructs a built-in electric field to provide electron to Co with electron-rich structure, resulting in the strong adsorption of H and weak adsorption of O 2 on Co. This study provides an effective and controllable method for the design of self-supporting bimetal phosphide catalysts. [ABSTRACT FROM AUTHOR]

• K 2 FeO 4 is first utilized for the solid-phase oxidation of pitch by a high-energy ball mill. • The solid-phase reaction mechanism involving in oxidation and condensation was revealed. • Advanced pitch-based porous carbon (H-CBPF) was prepared by a solid–liquid synergistic strategy. • The synergistic effect improves both the porous geometric configuration and O content of H-CBPF. • H-CBPF delivers an excellent salt adsorption capacity and a superior charge efficiency. To address limited desalination capacity and insufficient charge efficiency for carbon materials in capacitive deionization (CDI), a solid–liquid synergistic oxidation strategy of potassium pertechnetate (VI) for pitch was proposed to construct porous carbon with a reasonable pore structure and high reactive surface. On the one hand, K 2 FeO 4 is first utilized for the solid-phase oxidation (SPO) of pitch by a high-energy ball mill, introducing rich oxygen-containing groups such as ether bonds. Meanwhile, dehydro-condensation reactions occurred during SPO, resulting in the formation of the oxidized pitch with a high degree of condensation. Importantly, the pyrolysis yield of the oxidized pitch is as high as 46.9 % at 800 °C, almost twice that of the pristine pitch, meaning that the oxidized pitch with high polymer degree and rich C-O bridge bonds facilitates the carbon fixation and emission reduction during carbonization. On the other hand, the self-oxidation of K 2 FeO 4 in aqueous solution forms bifunctional activators (KOH and Fe(OH) 3) for the preparation of pitch-based porous carbon. Benefiting from the crosslinking structure of oxidized pitch and the multi-effective activation, the prepared porous carbon (H-CBPF) exhibits a robust layered stacking topology with a high surface area and oxygen content. Thereby, it can deliver an excellent salt adsorption capacity (SAC) of 22.1 mg g−1 with an average desalination rate of 1.89 mg g−1 min−1 and a high charge efficiency of 85 % at 1.2 V in 500 mg L-1 NaCl solution. This work opens up a green and economical route for the preparation of pitch-derived porous carbon for high-performance CDI. [ABSTRACT FROM AUTHOR]

[Display omitted] • The sandwich structure NPC/NiMn-LDH/MXene is elaborately designed for Cl- capture. • The NPC/NiMn-LDH/MXene electrode presents optimized Cl- diffusion kinetics. • The NPC/NiMn-LDH/MXene//NPC cell showcases exceptional Cl- removal performance. • DFT results validate NPC/NiMn-LDH/MXene facilitates interfacial charge transfer. Layered double hydroxides (LDHs) have been recognized as prospective two-dimensional capacitive deionization (CDI) faradaic materials for Cl- capture, offering tunable interlayer distance, high anion exchange capacity, and reversible ion intercalation/deintercalation ability. However, the self-stacking tendency, poor electrical conductivity, and undesired stability of LDHs nanosheets severely impede ion migration and active sites accessibility, leading to unsatisfactory CDI performance. Herein, we present an elaborately designed three-dimensional sandwich structural composite N-doped porous carbon spheres/NiMn-layered double hydroxide/MXene (NPC/NiMn-LDH/MXene) to efficiently capture Cl- as the CDI anode. In this assembly, MXene not only ensures excellent electrical conductivity for rapid ion transfer but also serves as a robust substrate for the uniform dispersion of NiMn-LDH nanosheets. Moreover, NiMn-LDH effectively inhibits the agglomeration of MXene and provides substantial storage capacity for ion accommodation. The conductive intermedium NPC establishes interconnected conductive channels, enriching accessible charge transport pathways, resulting in an accelerated ion diffusion kinetics. Accordingly, the NPC/NiMn-LDH/MXene electrode demonstrated predominant specific capacitance (265 F g-1), lower ion transfer resistance, and an optimized Cl- diffusion coefficient (7.95 × 10-17 cm2 s−1). In an asymmetrical CDI cell assembly, the NPC/NiMn-LDH/MXene//NPC cell delivered outstanding Cl- removal capacity (43.5 mg g−1), swift salt removal rate (12.5 mg g−1 min−1), efficient energy utilization (0.183 kWh kg−1-NaCl), and remarkable cyclic adsorption/desorption stability (89.6 % retention rate). Additionally, density functional theory (DFT) calculations validated that the sandwich construction of NPC/NiMn-LDH/MXene facilitated interfacial charge transfer from NPC and MXene to NiMn-LDH, accelerated ion transfer rate, and reduced ion migration energy, resulting in accessible ion diffusion kinetics and smooth Cl- shuttle. This unique approach enriches ion transfer pathways by leveraging the distinctive structural characteristics of faradaic materials, providing valuable insights for further developments in CDI technology. [ABSTRACT FROM AUTHOR]

• A novel capacitive deionization with a three-phase architecture (T-CDI) was proposed. • Cathodic oxygen reduction was enhanced in T-CDI without affecting desalination. • SAC value and H 2 O 2 generation were 14.91 mg/g and 25.55 mg/L, respectively. • Simultaneous desalination and organics control was achieved by T-CDI/UV. • Applicability of T-CDI in long-term operation was investigated. Cathodic oxygen reduction, as a Faradaic side reaction, has been proven to be thermodynamically favorable for H 2 O 2 generation in capacitive deionization (CDI), which may provide a greener manner for organics control alongside desalination. However, the low levels of dissolved oxygen (DO) in saline water and its potential Faradaic degradation of carbon-based electrodes limit the H 2 O 2 generation in the conventional CDI (C-CDI). Herein, a novel three-phase CDI architecture (T-CDI) was proposed to simultaneously achieve stable desalination and supplementary H 2 O 2 generation. Unlike C-CDI architecture, T-CDI was open-ended at the cathode side, where porous nickel foam was used as current collector and air diffusion layer. Accordingly, a stable gas–liquid-solid three-phase interface was created inside the cathode, thus enhancing the diffusion and utilization of atmospheric air and preventing the damaging effects of excessive DO on the electrode. A stable electrosorption and electrocatalysis performance for T-CDI was obtained by regulating electrode hydrophilic-hydrophobic properties, comparing with other CDI configurations, and altering operating conditions. The salt adsorption capacity and H 2 O 2 accumulative concentration were 14.91 mg/g and 25.55 mg/L, respectively. Furthermore, the simultaneous desalination and organics control in T-CDI were investigated with the assistance of UV irradiation (T-CDI/UV). When treating NaCl and sulfamethazine (SMR) mixture solution, T-CDI/UV significantly reduced the irreversible electrode organic fouling and improved the desalination stability. Additionally, the potentially hazardous SMR was effectively removed alongside desalination. Finally, the long-term operation of T-CDI demonstrated that the generated H 2 O 2 cannot induce an additional substantial deterioration in desalination stability. The techno-economic assessment showed T-CDI was economically competitive compared with C-CDI. This study provides insights into the synergy of non-Faradaic and Faradaic processes and further diversifies the application of CDI in water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • A CNT-CeO 2 electrode is fabricated to selectively remove F− in mixed ion solutions. • CNTs increase the conductivity of the electrode and hinder the aggregation of CeO 2. • Pseudo-capacitance behavior of F– entering CeO 2 was observed first time by EQCM. • The energy consumption for treating actual groundwater using scaled-up equipment is low at approximately 0.2 kWh/m3. Selective capacitive deionization (SCDI) is a promising process for preferentially removing specific ions from waters with complex compositions. The selectivity towards certain species in CDI is most frequently achieved through novel electrode materials with high affinities towards targeted species. In this study, we investigate the selective removal of fluoride ions from groundwater containing concentrated co-existing chloride ions. A carbon nanotube-CeO 2 (CNT-CeO 2) electrode is employed for the electro-sorption of fluoride ions. Our findings are compelling: when processing a mixed F−/Cl− solution comprising 10 mg/L F− and 100 mg/L Cl−, the CNT-CeO 2 electrode is seen to reduce the concentration of F− ions to 1.5 mg/L in just 150 min, amounting to an 85 % F− removal efficiency, while the Cl− removal efficiency remains below 2 %. Importantly, this translates to a F−/Cl− separation factor of up to 4.16 when using the CeO 2 -based electrodes, which is 40 times higher than that achieved with conventional activated carbon (AC) electrodes. Furthermore, the energy consumption for treating actual groundwater using scaled-up equipment is impressively low at approximately 0.2 kWh/m3. The high affinity of CNT-CeO 2 towards fluoride is attributed to the intercalation Faraday capacitance initiated by the reaction between F− with CeO 2 , as verified by the electrochemical quartz crystal microbalance (EQCM). Moreover, EQCM results show a substantial increase in both mass and current as the potential increased beyond 0.8 V vs Ag/AgCl, implying that the current surge is not a result of water splitting but rather the adsorption of F− onto the CNT-CeO 2 electrode. The addition of CNTs substantially increases the conductivity of CeO 2 electrodes and restricts the aggregation of CeO 2 , thereby accelerating ion diffusion and promoting selective adsorption characteristics. Importantly, our electro-driven approach demonstrates excellent adsorption–desorption over 20 cycles. This comprehensive study advances the technological development of selective CDI, while providing new insights for fluoride removal in groundwater. [ABSTRACT FROM AUTHOR]

Bithmush-impregnated carbon nanofiber aerogel with a rational "multi-layer protection" shell was unprecendently prepared and used as chloride chloride-capturing electrode to trigger fast and ultra-durable faradic capacitive deionization. [Display omitted] • Bi nanoclusters impregnated carbon nanofiber aerogel (Bi NCs@CNFAs) was prepared. • Bi NCs@CNFAs was unprecedently introduced in faradic capacitive deionization (FDI). • The multi-layer protection design could prevent structural changes of Bi NCs@CNFAs. • The ultrasmall and even distributed Bi nanoclusters enable fast pseudo-capacitance. • The desalination rate/durability of our FDI outperforms most reported systems. Faradic-based capacitive deionization (FDI) has been recognized as one of the most promising technologies to solve the freshwater crisis, yet was hindered mostly by the relatively low desalination rate and sluggish long-term stability of its anode materials. Through careful analysis, the origin of the slow desalination rate was determined to be the faradic diffusion and mass transfer, while the poor cycling stability could be originated from the volumetric expansion of the redox-active material as well as structural damage caused by the uneven stress during multicycle operation. Herein, we developed a Bi nanocluster (NCs) embedded in carbon nanofiber aerogels (Bi NCs@CNFAs) nanostructure as chloride-capturing electrodes for FDI. The essence of this work lies in the design of the "multi-layer protection" shell that could not only limit the volumetric expansion of the Bi NCs (inner protection layer) but also alleviate the stress caused by potential structure changes (outer buffer layer). As a result, the Bi NCs@CNFAs-based FDI display ultra-fast desalination kinetics (0.524 mg g−1 s−1) with remarkable long-term stability (only 8 % reduction over 250 cycles), significantly outperformed the highest value reported in the literature so far. This study is interesting because it exemplifies the significance of problem-driven strategy (nanocluster-induced surface-driven capacitance to address slow desalination kinetics; rigid carbon shell to suppress the volumetric expansion of Bi NCs; CNFAs scaffold to address potential structural damage and aggregation) to improve the desalination performance of FDI, which could further motivate advancements of highly effective desalination systems in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • LVP@2C exhibited a maximum Li+ adsorption capacity of 25.8 mg g−1 in 200 mg L−1 of Li+ ion solution. • The LVP@2C maintained a high retention rate of 78 % even after 50 cycles. • The selectivity coefficient of LVP@2C is 444.7 and 351.2 at Mg/Li ratios of 1:5 and Na/Li ratios of 1:15. • The LVP@2C displayed excellent lithium extraction performance in natural Tibet salt lake brine. • The Li+ adsorption and desorption behavior is due to V reversible synergistic valence transitions. Recently, with the rapid development of lithium-ion batteries and electric vehicles, the demand for lithium resources in the world has undoubtedly greatly intensified. Based on the advantages of high selectivity and low energy consumption, capacitive deionization (CDI) technology is well-suited for the selective extraction of lithium resources from salt lakes. Herein, carbon-coated Li 3 V 2 (PO 4) 3 (LVP@C) is developed as a cathode electrode for the first time by using a hybrid CDI device to selectively extract Li+ ions from salt lake brine, due to its high theoretical capacity and excellent cycling capacity. The electrochemical (de)intercalation mechanism of Li+ ions in the LVP@C has been evaluated by electrochemical, X-ray photoelectron spectroscopy (XPS), and in-situ X-ray diffraction (XRD) techniques, demonstrating a reversible transition of the V valence state during electrosorption/desorption based on Faradaic redox reaction. The optimized LVP@2C delivers a maximum Li+ electrosorption capacity of 25.8 mg g−1, and still maintains a high retention of 78 % even after 50 cycles. The LVP@2C has lithium selectivity coefficients of 444.7 and 351.2 at high Mg-Li ratios of 1:5 and high Na-Li ratios of 1:15. Density Functional Theory (DFT) calculations further reveal that the selective electrosorption mechanism in the LVP@2C electrode is mostly ascribed to the smaller hydrated ionic radius and lower ionic diffusion energy barrier of Li+ ions in comparison with Mg2+ ions. Finally, the effectiveness evaluation of the lithium selective extraction from the brine of a natural salt lake in Tibet indicates that the LVP@2C has highly selective electrosorption of lithium (α (Li/Mg) = 187.50, α (Li/K) = 136.11, α (Li/Na) = 116.88, α (Li/Ca) = 4.92) and can serve as a potential electrode for the extraction of lithium from salt lake brine. [ABSTRACT FROM AUTHOR]

A highly water-sources tolerant monolithic H+/10-CoMoB catalyst has been successfully developed by simple and efficient H+-etching corrosion engineering. The catalyst enables high water-sources adaptive hydrolysis of borohydrides. Moreover, NaBH 4 -based H 2 supply system with this catalyst has achieved full drive of 100 W fuel cell using different water-sources. [Display omitted] • CoMoB based catalyst with high water-sources adaptability has been developed. • The catalyst has great borohydride hydrolysis activity in natural water-sources. • H 2 generator with the catalyst drives 100 W fuel cell using various water-sources. High water-source adaptability is meaningful to the popularization of hydrolysis of borohydrides as portable hydrogen generation technique. Herein, the key catalyst that can enable high water-sources adaptive hydrolysis of borohydrides is successfully developed for the first time. The as-prepared monolithic CoMoB based catalyst has outstanding catalytic activity with high hydrogen generation rate of the 3.0 L min−1 g−1 at 25 °C and low activation energy of 38.7 kJ mol−1 toward the hydrolysis of NaBH 4 using deionized water. More importantly, the catalyst exhibits distinguished durability toward hydrolysis of borohydrides in various water, including deionized water, lake water, and even seawater benefiting from its unique structure and gas scouring effect. Furthermore, an efficient NaBH 4 -based H 2 supply system is developed with the catalyst and this system successfully achieves full drive of 100 W fuel cell using different sources of water. This study may provide a new protocol to develop portable H 2 generation system with high water source adaptability in wild environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel edge-N doped hierarchical carbons were firstly reported for P electrosorption. • The edge-N strategy endowed more accessible active centers and conductive efficiency. • The LNPC900 electrode showed a superior phosphate removal capacity of 533.06 mg g−1. • The system performed well in natural water purification with low P concentration. • The coupling of electrical capacitance and chemical interactions were achieved. Achieving high-efficiency removal of phosphate has been an urgent issue to combat eutrophication and meet ever-stricter emission standards. Electro-assisted adsorption, a mild electrochemical technology, demonstrated great potential for wastewater treatment owing to the merits of considerable removal performance, facile operation, and energy efficiency. Exploring and boosting the properties of electrode materials is exceedingly vital for technological advancement. In this study, the novel edge-N decorated La-doped hierarchical carbon composites (LNPCs) were developed via in-situ nucleation and one-pot pyrolysis strategy as phosphate capture electrodes. The LNPC900 electrode exhibited an ultrahigh phosphate removal capability of 533.06 mg PO 4 3- g−1 at 1.2 V, surpassing most of the reported electrode materials. Furthermore, this electrochemical system also performed well in the purification of natural river water with low phosphate concentration, where the treated concentration was below the first-class emission standard in China (0.5 mg P L−1). Comprehensive analysis and theoretical calculations indicate that the synergistic property of edge-N and small graphitic carbon nanodomains ensured more accessible active centers and conductive efficiency. The superb phosphate removal capability mainly originated from the coupling contribution of the electrical double layer capacitance, ligand exchange, and electrostatic attraction. This study possesses insight into the theoretical basis for the practical application of phosphate electrosorption and provides a new level of the technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D PAA/GO aerogel was a CDI electrode material. • The double "O" in C = O = C = O acts as a charge transfer and activation site. • The maximum UO 2 2+ adsorption capacity of PAA/GO was 898.7 mg g−1. • DFT explores mechanisms of action. The extraction of uranium is crucial for sustaining a consistent nuclear fuel cycle, yet the task of isolating uranyl ions from aqueous solutions presents formidable challenges. Herein, a PAA/GO aerogel was developed using polyacrylic acid-functionalized graphene, wherein the C = O = C = O segment's dual oxygen served both as electrodes for capacitive deionization and as sites for charge transfer and uranyl capture, effectively purifying uranium mine wastewater. Furthermore, under the stringent experimental conditions set at 298 K and a pH of 5.5, the PAA/GO composite demonstrated an impressive adsorption capacity of 898.7 mg g−1. When this composite was further amalgamated into the CDI architecture, it exhibited an impressive 92 % uranium extraction from genuine mine effluent at an unwavering potential of 0.9 V. Through density functional theory (DFT) analyses, the adsorption energies of [UO 2 (H 2 O) 5 ]2+ with the PAA/GO composite involving C = O = C = O ligands displayed the highest value compared with PAA and PAA/GO composite (involving monodentate and bidentate ligands). The Bader charge analysis further indicating the greatest charge loss in the uranium ion. In conclusion, the novel PAA/GO aerogel 3D framework with its specific C = O = C = O regional chain sets a pioneering standard in uranium extraction techniques, showcasing unprecedented efficiency in UO 2 2+ removal from aqueous solutions. [ABSTRACT FROM AUTHOR]

A vertically oriented porous PVA hydrogel and PDA/CB modified 3D raised-fabric are innovatively designed as an solar evaporator to enhance the evaporation rate, conversion efficiency and self-desalting performance. [Display omitted] • A super water transport PVA hydrogel and PDA/CB modified 3D raised-fabric are innovatively designed as solar evaporators. • It exhibits high water evaporability (1.73 kg m-2h−1, 1 sun) and conversion efficiency (91.9 %). • The 3D raised-fabric solar evaporator system can be readily fabricated for scalable production. • The collected water is in full compliance with the drinking requirements of WHO and EPA. A solar evaporator with simple fabrication process, exceptional photothermal conversion efficiency and dependable continuous water evaporation holds significant potential for seawater desalination and wastewater treatment. Despite the substantial research dedicated to developing high-efficiency solar evaporators, there remains a need for additional exploration to tackle concerns such as salt crystallization, low evaporation efficiency, poor durability and stability. Here, an efficient water transport PVA hydrogel (water transport layer) and polydopamine/carbon black modified 3D raised-fabric (photothermal layer) are innovatively designed as solar evaporators. The synergistic effect between the periodic raised structure and polydopamine/carbon black results in outstanding photothermal conversion capabilities of PDA/CB@RF. Meanwhile, the porous structure of PVA hydrogel and its vertically aligned channels facilitate ion exchange and ensure a consistent water supply to the photothermal layer. This phenomenon serves to prevent the accumulation of salt in the photothermal layer, thereby markedly enhance the water evaporation capability of the PDA/CB@RF evaporator. The results demonstrate that the PDA/CB@RF evaporator system exhibits excellent photothermal conversion performance with its surface temperature rapidly ascending to 73.3 ℃ under 1 sun light intensity, and effectively boost the water evaporation rate (1.73 kg m-2h−1, 1 sun). Furthermore, the PDA/CB@RF evaporator exhibits excellent conversion efficiency (91.9 %) and self-desalting capability. Overall, this solar evaporator system with a 3D raised fabric design integrates light and thermal energy, consistent water evaporation and self-desalting functionalities, which makes it hold the potential to solve the pressing challenge of water shortage. [ABSTRACT FROM AUTHOR]

[Display omitted] • The development history of capacitive deionization for defluorination is introduced. • Recent advances of electrode materials have been classified and reviewed. • Defluorination mechanisms have been summarized. • Challenges for engineering applications are presented. • Future perspectives on defluorination by capacitive deionization are provided. The combined need for advanced treatment of fluoridated water and low-energy technologies has inspired researchers to develop more efficient and green methods of fluoride removal. Capacitive deionization (CDI), a novel water treatment technology, has garnered significant attention in the defluorination field due to its exceptional ion selectivity. Recent decades, CDI has achieved remarkable advancements in electrode materials, F− storage mechanisms, and the potential for engineering applications in the realm of F− removal. However, there has been a lack of reviews that highlight design strategies for electrode materials in terms of fluoride ion properties in water and provide insights into key factors for designing CDI structures with excellent performance and promise for scale applications. Herein, starting from the background of fluorine pollution in surface water, and the selective removal of fluorine heavily relies on the crucial role played by electrode materials. Accordingly, all kinds of defluorinated electrode materials are reviewed. Secondly, the defluorination mechanism is summarized especially the distinctions among these processes. Additionally, the challenges existing in the promotion of CDI defluorination to large-scale applications are firstly analyzed in depth. Finally, future research opportunities and prospects by CDI for defluorination are proposed. In summary, CDI shows great potential for removing fluoride ions from water, offering a fresh approach to sustainable water resource management and environmental protection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn dopant-reinforced NaTi 2 (PO 4) 3 possesses superior structural stability and conductivity. • The optimal NT 1.5 M 0.5 P exhibits ultrahigh salt removal capacity of 128.5 mg/g and cycle stability. • The ultrahigh durability is rooted from the solid-solution reaction induced by Mn-ions pillar. • NT 1.5 M 0.5 P||NaFeHCF rocking-chair desalination battery owns stable, rapid and low energy consumption desalination. Battery deionization (BDI) technique has attracted great attention as a potential candidate to tackle the freshwater crisis, but its application is plagued by the lack of electrode materials with large desalination capacity and excellent durability. Herein, Mn dopant-reinforced NaTi 2 (PO 4) 3 (NT 2–x M x P) composites with significantly enhanced structural stability and electronic/ionic conductivity were fabricated toward seawater desalination. Especially, the NT 1.5 M 0.5 P exhibits excellent desalination performance, affording a salt removal capacity (SRC) of 128.5 mg/g with a salt removal rate (SRR) of 18.4 mg g−1 min−1 and almost no capacity attenuation after 500 cycles. Furthermore, the NT 1.5 M 0.5 P further possesses favorable technical feasibility in different aqueous media, including desalination at various NaCl concentrations, temperature, solution pH, and natural seawater. Mechanism studies reveal that the NT 1.5 M 0.5 P undergoes a solid-solution reaction based on the reversible electrochemical reaction of the Ti4+/Ti3+ redox pair during the desalination/salination process. A rocking-chair desalination battery consisting of NT 1.5 M 0.5 P and NaFeHCF demonstrates a favorable desalination ability (average SRC of 49.4 mg/g and SRR of 1.73 mg g−1 min−1), outstanding cycling stability (92 % of capacity retention in 100 cycles), low energy consumption (0.288 kWh/kg-NaCl) and high average charging efficiency (86.9 %). This work sheds light on the rational design of advanced NASICON-type electrodes for seawater desalination with remarkable desalination capacity and long serving life. [ABSTRACT FROM AUTHOR]

• A photoinitiator-grafted polymer chain (PGPC) is synthesized. • PGPC-coated hydrogel demonstrates strong resistance to swelling and drying. • PGPC-coating preparation methods are simple and versatile. • This strategy does not leave residues in the bulk hydrogel. Currently, diverse hydrogels with multiple functionalities have attracted considerable attention. However, due to poor adaptability in real-life application scenarios for example in drying air and underwater, the hydrogels developed to date have not yet realized most of their promising applications, particularly in flexible electronics. Herein, inspired by the process of preparing the outermost layer of sugar coating on Tanghulu, a traditional Chinese winter snack, we report a dipping-ultraviolet (UV) encapsulation method for affording hydrogels with excellent water retention and anti-swelling capacity. A photoinitiator-grafted polymer chain (PGPC) with UV curing capability is prepared by 4-benzoylphenyl acrylate (ABP) and hydrophobic monomers radical polymerization, which is uncrosslinked during synthesis. After dipping and UV irradiation, the PGPC on the polyacrylamide (PAAm) hydrogel surface is cross-linked by benzophenone (BP) chemistry to form a coating network. Furthermore, the PGPC-coated hydrogel PAAm demonstrates great anti-drying properties with a weight fraction of up to 0.85 ± 0.02 after 21 h at 50 °C and anti-swelling capacity with a weight fraction of down to 1.01 ± 0.01 after 120 h in deionized water. Benefiting from the BP chemistry, the versatility of this method is demonstrated using various hydrogels such as polyvinyl alcohol (PVA) and polyzwitterionic hydrogel. As a proof-of-concept, the coated-hydrogel-based sensor shows strong signals anti-interference ability in ambient air and underwater. This work provides a promising route for encapsulating different hydrogels endowing weak hydrogels with strong environmental adaptability. [ABSTRACT FROM AUTHOR]

[Display omitted] • A parametric investigation of the electrochemical desalination cell was carried out. • The longer residence time of the flow electrode and the feed water augmented the desalination. • Surface area of carbon and redox couple play a crucial role in desalination. • A reduction of 235 mg/L of total dissolved solids in tap water was observed. Flow Electrode Capacitive Deionization (FCDI) is a promising technology that uses carbon materials as flow electrodes in aqueous conditions to enable continuous desalination. In this work, the parametric investigation of the FCDI cell was carried out for low and high surface area activated carbon. When 1 mM/1 mM ferri-/ferrocyanide redox couple in the 1 M NaCl supporting electrolyte containing the 5 wt% high surface area activated carbon and 0.5 wt% MWCNT is circulated as flow electrode at the flow rate of 8 mL/min in the electrode chamber and 0.1 mM NaCl feed water is circulated in single-pass mode at 8 mL/min, the FCDI system achieved a significant improvement in desalination performance up to 76.38 % of SRE, with a high average salt removal rate of 43.925 µg/cm2s @ 2 V, charge efficiency of 20.11 % and average energy consumption of 0.27 kWh/mol, through a thorough parametric investigation. When the FCDI cell was tested with tap water, the average salt removal rate, average energy consumption, and salt removal efficiency were calculated at 6.11 μg/cm2s, 2.46 kWh/mol, and 46.61 % respectively, resulting in the reduction of total dissolved solids of 600 mg/L at the inlet to 365 mg/L at the outlet. The combination of microporous high surface area carbon and ferro-ferri redox couple propelled the desalination performance in comparison with the macroporous low surface area carbon, maximizing the ion removal rate, which further reduced the energy consumption and operating voltage for the process. [ABSTRACT FROM AUTHOR]

[Display omitted] • RuO 2 /CeO 2 heterojunction loaded on carbon spheres (RuO 2 /CeO 2 @C) is prepared. • Theoretical calculations investigate the electrocatalytic mechanism of RuO 2 /CeO 2 @C. • RuO 2 /CeO 2 @C exhibits durable water splitting in acidic conditions. The use of proton exchange membrane (PEM) hydrolysis technology holds promise for eco-friendly hydrogen production using renewable energy sources. However, developing efficient, cost-effective, and durable bifunctional electrocatalysts for the acidic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains challenging. Here, we synthesized RuO 2 /CeO 2 heterojunction loaded on carbon spheres (RuO 2 /CeO 2 @C) via hydrothermal and annealing techniques to address this issue. Our experiments demonstrate exceptional catalytic activity of RuO 2 /CeO 2 @C for both OER and HER, with overpotentials of 170 and 120 mV, respectively, at 10 mA/cm2 in 0.5 M H 2 SO 4. Moreover, the electrocatalyst enables overall water splitting at 1.54 V and maintains stability for over 100 h at 10 mA/cm2. Density functional theory (DFT) calculations suggest that RuO 2 /CeO 2 heterojunction modifies d-band center of Ru, balances H adsorption/desorption behavior, accelerates reaction kinetics, and lowers the energy barrier, thereby enhancing electrocatalytic activity. These findings provide valuable insights for future efficient bifunctional water splitting electrocatalyst design. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiCoAl-LDH nanosheet arrays were vertically assembled on the surface of MXene. • Conductive CNT developed tighter bridge connections between LDH nanosheet arrays. • The nanoarray structure further exposed active sites and improved ion storage. • The splendid desalination capability and remarkable stability were acquired. Layered double hydroxide (LDH) is considered as an attractive capacitive deionization (CDI) faradic material for anion (such as Cl−) capture due to its excellent anion storage capacity, highly reversible anion (de)insertion and superior chemical stability. Nevertheless, the self-stacking property and poor conductivity of LDH lead to undesirable CDI performance. Herein, the CNT@NiCoAl-LDH@MXene heterostructure with three-dimensional (3D) interconnected network was rationally designed with MXene as the conductive substrate for the uniform and vertical growth of NiCoAl-LDH nanosheet arrays and CNT as the conductive bridge for fast electron transfer. Strong chemical bonding interactions were formed at the interface of this heterostructure, creating tighter and more stable interconnections. Moreover, the specific surface area of this unique arrays structure is 4.28 and 8.62 times that of NiCoAl-LDH and MXene, respectively, effectively suppressing the aggregation of layered materials and providing more exposed active sites. Therefore, the obtained CNT@NiCoAl-LDH@MXene electrode exhibits prominent specific capacitance (179 F g−1), decreased equivalent series and transfer resistance, increased ion diffusion rate and splendid electrochemical stability (capacitance retention rate of 107.5 % after 1500 GCD cycles). Consequently, as employed for Cl− intercalation anode coupled with AC cathode for CDI, the CNT@NiCoAl-LDH@MXene//AC cell exhibited excellent Cl− removal capacity (79.5 mg g−1), higher charge efficiency (88.4 %), lower energy consumption (0.62 kWh kg−1-NaCl) and exceptional desalination capacity retention rate (96.4 % after 40 adsorption/desorption cycles). This work provides an excellent anode material selection for the enhancement of CDI performance and valuable insights for the design of 3D interconnected network heterostructure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various morphologies of core–shell tungsten oxide@carbon composite electrodes were synthesized. • The urchin-like W 18 O 49 @C HCDI cathode achieved high SAC of 32.25 mg g−1 at 1.2 V. • Excellent cycling stability over 200 cycles with negligible metal leaching was displayed. • Such core@carbon shell structure with particular morphology provides inspirations for future research. W 18 O 49 has been considered as a promising candidate for electrochemical applications, but it suffers from unsatisfactory electrical conductivity, low specific surface area, poor structural stability, and the corresponding morphology dependent capacitive deionization (CDI) performance has not been reported. Herein, we explored the novel composites of various morphologies of W 18 O 49 encapsulated by a carbon shell (W 18 O 49 @C) as hybrid capacitive deionization (HCDI) cathode for water desalination. The as-obtained W 18 O 49 @C exhibited unique structures, allowing synergistic effects of ion intercalation and electric-double-layer capacitance, fast ion penetration, rapid electron transfer, and dissolution prevention of the active core materials. Among the three morphologies of W 18 O 49 @C, urchin-like W 18 O 49 @C (UWC) presented appropriate pore size distribution, the largest specific surface area and specific capacitance, the highest degree of graphitization and carbon content, consequently achieving excellent desalination capacity. Furthermore, an outstanding cycling stability over 200 cycles as well as a high charge efficiency and a low energy consumption were displayed for the UWC electrode. This study illustrates the great promise of urchin-like core–shell tungsten oxide@carbon composite in HCDI and paves a way for rational design of highly efficient and stable electrode materials for water desalination. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic effect of Fe-N-C contribute to enhanced electrochemical reversibility. • Indirect interface contact of SiO 2 and biomass carbon prevents the formation of SiC. • "Double carbon" structured promotes the formation of stable LiF-rich SEI. • The decomposition of iron salts provides abundant defects for Li+ transport. • The LiFePO 4 ‖Fe-N-C/SiO x /C-3 full cell delivers good electrochemical performance. Fabrication of high performance silicon-based materials derived from natural biowastes plays a significant role in the green recycling of biomass resources. However, low utilization of organic component and poor lifespan hinders the its large scale applications. Herein, biomass derived SiO x /C-3 composite was encapsulated into Fe-N-C decorated carbon nanofibers network (Fe-N-C/SiO x /C-3) by a facile magnesiothermic reduction combined with electrostatic spinning strategy. The ingenious designed indirect contact biomass carbon/SiO 2 interface effectively utilizes the organic components of rice husk and prevents the formation of SiC during reduction process. HAADF-STEM and XPS characterization confirmed the presence of Fe single atoms and the formation of Fe-N coordination bonds. Benefiting from the unique carbonaceous network and catalytic effect of Fe-N-C, the Fe-N-C/SiO x /C-3 exhibit excellent lithium storage properties (832.6 mAh g−1 after 250 cycles at 0.1 A g−1). Even at high current density (1 A g−1), the electrode can still remain a capacity of 602 mAh g−1 after 1000 cycles with capacity retention of 79.4%. The ex-situ SEM and XPS characterizations demonstrated that the gradient structure consisting of inner biomass-derived carbon and flexible carbonaceous networks enhanced the overall conductivity and structural integrity of the composite. Furthermore, the catalytic effect of Fe-N-C facilitates the rapidly formation of stable LiF-rich solid electrolyte interphase (SEI) films during charge/discharge process. The assembled LiFePO 4 ‖Fe-N-C/SiO x /C-3 full cell shows excellent electrochemical performance (106.5 mAh g−1 after 100 cycles at 0.1A g−1), which provides insights into the fabrication of high performance biomass derived silicon based anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bph and hBN improve the ability of RGO sponges to store electrical charge. • Consistent high removal of contaminants in continuous and intermittent current. • Shorter OFF cycles were more effective in producing oxidizing species. • Energy consumption was reduced 2-fold using intermittent current. • Ions in the wastewater impacted positively the Bph and hBN-RGO anode performance. Borophene (Bph) and hexagonal boron nitride (hBN)-modified graphene sponge anode coupled to N-doped graphene sponge cathode were applied for electrochemical degradation of persistent organic contaminants using intermittent current. Three different ON-OFF pulse cycles were tested using low-conductivity supporting electrolyte in flow-through mode. Functionalization of the reduced graphene oxide (RGO) with Bph and hBN improved the ability of the double layer to store electrical charge, thus maintaining the generation of H 2 O 2 , O 3 , and ·OH even during the OFF cycles. Both anodes tested showed enhanced contaminant removal during shorter OFF periods (e.g. 52.5 s/52.s and 75 s/30 s ON/OFF), due to the improved retention of anode charge during the shorter OFF stages. Electrochemical removal of the target contaminants required 24 kWh m−3 in continuous current mode for both hBN-RGO and Bph-RGO anodes at 231 A/m−2, which was lowered to 11.7 and 13.5 kWh m−3 respectively, using ON-OFF pulse cycles. Electrochemical degradation pathways were elucidated in both systems using carbamazepine as a representative persistent contaminant. Flow-through reactors with both Bph- and hBN-RGO anodes removed ≥60 % of the target contaminants in a single pass using continuous current, whereas intermittent current led to somewhat decreased removal efficiencies (43–58 %) due to the scavenging effect of the wastewater matrix. Thus, halving the current ON time led to less than 20 % decrease in the removal efficiencies due to the capacitive properties of RGO. Given that switching to intermittent current decreased the energy consumption from 9.3 kWh m−3 to 4.4 kWh m−3 (Bph-RGO anode) and from 6.9 kWh m−3 to 3.6 kWh m−3 (hBN-RGO anode), higher removal of the target contaminants can be achieved by coupling sequential reactors in the intermittent current mode. [ABSTRACT FROM AUTHOR]

[Display omitted] • Adding KWCL to compost led to the highest N 2 O emissions, reaching 121.66 mg m−2. • KWCL exerted the greatest impact on the community structure of bacteria and fungi. • Denitrification was the key way for N 2 O emissions in thermophilic stage of compost. • Bacteria were identified as the main key taxa for N 2 O emissions during composting. • Environmental factors emerged as the most critical drivers of N 2 O emissions. Solid-liquid mixed composting is a novel approach for handling kitchen waste (KW). In this study, KW was employed as composting materials to explore the nitrous oxide (N 2 O) emissions and corresponding mechanisms associated with the reuse of three supplementary liquids (CK: deionized water; T1: kitchen waste composting leachate (KWCL); T2: kitchen waste leachate (KWL)) during the composting process. The analysis included N 2 O emissions, microbial community dynamics, and nitrogen metabolism pathways. The findings demonstrated that the addition of KWCL (T1) and KWL (T2) significantly increased the nutrient content in the compost. Notably, T1 exhibited significantly higher cumulative N 2 O emissions than CK and T2 (P < 0.01). Both CK and T2 demonstrated more robust microbial safety, while the addition of KWCL (T1) led to more significant alterations in the structure of bacterial and fungal communities. Denitrification was identified as the primary pathway for N 2 O emissions during the thermophilic period. Nitrous oxide reductase activity was significantly lower in T1 than in T2 (P < 0.05), and the abundance of the nos Z gene in T1 (3.39 %) was lower than that in CK (4.18 %) and T2 (4.51 %), contributing to higher N 2 O emissions. Correlation analysis revealed the vital role of bacteria in N 2 O production, while bacterial and fungal communities exhibited positive correlations with variables such as carbon-to-nitrogen ratio and total carbon. Environmental factors were identified as key drivers of N 2 O emissions (r = 0.837, P < 0.05). These findings provided valuable insights for the sustainable management and recycling of KW. [ABSTRACT FROM AUTHOR]

[Display omitted] • The activated biochar (AB) and V 2 AlC-OH x MAX phase were used for Cr(VI) removal. • The asymmetric AB//V 2 AlC-OHx possesses both EDLC and pseudocapacitive behaviors. • The SEC of AB//V 2 AlC-OH x of 47.2 mg g−1 with removal efficiency of 99 % was observed. • The conversion of 60% Cr(VI) into Cr(III) during CDI processes enhances the removal efficiency. • Excellent cyclic performance for at least 20 adsorption–desorption cycles. The development of high-value-added biomass-derived carbonaceous as electrode material from agricultural wastes has received considerable attention. In this study, the activated biochar (AB) derived from the badam tree leaves (BTL) and functionalized 2D metal-carbide materials, V 2 AlC-OH x , have been successfully synthesized by alkaline treatment and microwave-assisted hydrothermal method, respectively, and then used as the asymmetric electrode materials for capacitive deionization application to remove Cr(VI) ions from aqueous solutions. The large specific surface area and the interconnected meso- and macro-porous channels of AB provide active sites and short ion diffusion paths to accelerate ion transport and electrosorption. In addition, the highly crystalline 2D architecture of V 2 AlC-OH x offers suitable lattice fringes for electron transfer. The conversion of Cr(VI) into Cr(III) on the surface of V 2 AlC-OH x , followed by the capture of Cr(III) onto the AB cathode has triggered the enhanced removal of Cr(VI). The AB//V 2 AlC-OH x asymmetric CDI device exhibits superior deionization performance for Cr(VI) removal with a specific electrosorption capacity of 47.2 mg g−1 and removal efficiency of 99 %. Excellent cyclic performance for at least 20 adsorption–desorption cycles is also observed, indicating the excellent durability of the fabricated materials. These results demonstrate that AB and V 2 AlC-OH x are promising CDI electrodes for the removal of metal ions and other hazardous pollutants from industrial effluents. [ABSTRACT FROM AUTHOR]

[Display omitted] • TGH+-PD@Tb3+ for fluorescence detection of NADH in "turn-on" mode. • Green fluorescence from TGH+-PD@Tb3+@NADH solution for fluorescence detection of Maa and MST. • TGH+-PD@Tb3+ with ability to adsorb MST in aqueous environments. Hazardous substances are often found in various forms in different environments, so testing for different types of hazardous substances is necessary. In particular, the removal of pollutants from the water environment is also of great interest. In this study, TGH+-PD@Tb (1 @Tb) is successfully prepared for the fluorescence detection of sodium dehydroacetate (NADH) by "turn-on" mode. Continuously, the selective fluorescence detections of 2-methoxyaceticacid (Maa) and mesotrione (MST) are accomplished using the solution (1 @Tb@NADH) with green fluorescence by "turn-off" mode. In deionized water, the limits of detection of NADH, Maa and MST are 1.8 μM, 0.10 μM and 0.046 μM, respectively. Meanwhile, based on selectivity and anti-interference experiments, 1 @Tb and 1 @Tb@NADH maintain the ability to detect NADH, Maa and MST in their own environments of existence (bread, serum and lake water). In further exploration of the mechanism, we find that the three substrates exhibited different response mechanisms, namely antenna effect of NADH, photoinduced electron transfer (PET) of Maa, and inner filter effect (IFE) of MST. Additionally, 1 @Tb also shows good adsorption effect for MST, and the maximum adsorption capacity is 470.8 mg/g, providing reference value for MST removal from lake water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Si-CaH 2 nano-mixture with a "Raisins in Bread" structure was prepared flexibly. • High hydrogen yield (1216 mL/g) and fast hydrolysis kinetics (225 mL/(s·g)) are achieved. • The in-situ hydrolysis process was dynamically characterized under TEM. • The mechanism of rapid hydrolysis is attributed to local high concentration alkali field. Silicon is considered as a promising portable hydrolytic hydrogen production material due to its abundant raw materials, high theoretical capacity (1600 mL/g) and facile storage. However, the low hydrolysis activity and slow hydrolysis rate of silicon hinder its practical application. To address this issue, we introduced CaH 2 to form Si-based composites via a flexible ball milling method. The above composites showed ideal yield (1216 mL/g in 10 min), reaction conversion (95.5%) and fast hydrolysis kinetics (225 mL/(s·g)) in deionized water, which is one of the best hydrolysis performances of Si-based composites so far. The hydrolytic process can be divided into two steps: the splitting hydrolysis of CaH 2 and the continuous hydrolysis of Si. Combining the dynamic in-situ structural analysis with the analogue simulation, it can be confirmed that the formation of local high concentration alkali field is the key to promote the complete hydrolysis and achieve high yield and fast kinetics of the composites. The existence of lattice defects was proved and the adsorption of Si to hydroxide ion was proved by theoretical calculation. Our work provided a novel idea for the theoretical design of hydrolytic hydrogen production compounds and promoted the practical application of low cost and portable hydrolytic hydrogen production materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mesoporous NCS were synthesized by controlled self-assembly method. • NCS enriched with nitrogen-doped active sites and interconnected framework. • NCS-900 exhibited an ultra-high electrosorption capacity of 149.35 mg/g for NO 3 – at 1.2 V. • A novel stirring CDI was used to accelerate the ion mass transfer rate. Nitrate contamination in the water environment has become an increasingly serious problem. Capacitive deionization (CDI), an emerging electrochemical water treatment technique, possesses a promising potential for efficient nitrate removal. Herein, we prepared nitrogen-doped carbon spheres (NCS) by controlled self-assembly using nano-SiO 2 as a sacrificial template and constructed a novel stirring CDI (SCDI) using NCS as nitrate capture electrodes. The interconnected framework and controllable mesoporous structure of NCS-900 enhance the transfer and diffusion of nitrate ions. In addition, the defects caused by the nitrogen-doped increase the active sites of NCS-900, resulting in outstanding specific capacitive properties. SCDI system promotes mass transfer and allows them to be more uniformly distributed in solution. As a consequence, the concentration of ions near the electrode is elevated, which enhances the removal capacity and reaction rate of the process. Importantly, the SCDI system using NCS-900 as the electrode achieved an ultrahigh nitrate electrosorption capacity of 149.35 mg/g with a rapid removal rate of 7.46 mg/g/min at 1.2 V condition in 5 mM NaNO 3 solution, which was much higher than that of reported nitrate capture electrodes. The superior nitrate removal performance can be ascribed to the synergy between the novel electrode material NCS with high adsorption capacity and the reaction device SCDI with improved system dynamics. In addition, the stability and selectivity of nitrate electrosorption were maintained well in the comprehensive conditions and actual sewage. This work opens a new path for efficient nitrate removal by CDI technology. [ABSTRACT FROM AUTHOR]

• The p-n heterojunction with V o was facilely constructed by LDH self-scarification. • NiFe-MOF⊆LDH exhibited outperformed OER and ORR activities with ΔE of 0.58 V. • The tandem in situ EF reaction coupled with OER yielded the highest H 2 O 2 rate of 27.4 mmol/h used for wastewater degradation. • In situ Raman and DFT verified the electron transfer and good conductivity favourable for OER and EF. The rational design of p-n heterojunction was highly desirable to optimize charge distribution at space-charge region, tailoring the adsorption free energy of intermediate matters, and to boost the oxygen evolution reaction (OER) and in situ electro-Fenton (EF) reaction. Herein, a self-sacrificing strategy has been employed to construct the NiFe-MOF⊆LDH nanosheet arrays on carbon cloth (CC), directly using NiFe-LDH as template. NiFe-MOF⊆LDH exhibited outperformed OER activity with a lower overpotential of 196 mV and smaller Tafel slope of 48 mV dec-1(η 10). The conferred higher valence state for Ni3+ and the more carrier density to absorb more OH– ions confirmed by in-situ Raman and density functional theory (DFT) calculation endowed the excellent OER activity, which was expected to endow the self-oxygenation to support the following EF in this system without additional O 2. An electrochemical flow reactor was designed for anodic OER and cathodic EF only at low voltage of 1.6 V. Typically, the in-situ H 2 O 2 yield rate could achieve 27.4 mmol/h at cathodic ORR reaction, which was further activated by Fe2+/Fe3+ cycling for the heterogeneous Fenton reaction. This tandem reactor could remove 96% of ibuprofen (IBF) within 120 min with long-term cycle use. In a word, coupling the OER with EF in a flow reactor has possible application in the fields of sustainable energy and environmental remediation. [ABSTRACT FROM AUTHOR]

• Ionizing radiation was effective to degrade cephalosporin C in aqueous solution. • CEP-C at concentration 0.02–0.2 mM could be completely degraded at 0.4–2.0 kGy. • Antimicrobial activity to S. aureus and E. coli decreased after irradiation. • There is positive correlation between CEP-C removal and antimicrobial activity decrease. The serious threat of antimicrobial resistance to human health and ecological environment has aroused the development of potential technologies to abate antibiotics from aqueous solution. This work shows that ionizing irradiation was efficient to degrade the broad-spectrum β-lactams antibiotic, cephalosporin C (CEP-C) in aqueous solution and eliminate the antimicrobial activity. As exposed to gamma irradiation, a complete removal of CEP-C was achieved at 0.4–2.0 kGy with the initial CEP-C concentrations of 0.02–0.2 mM, while the TOC reduction at 2 kGy reached 5–28%. The CEP-C degradation rate declined with increasing the initial CEP-C concentrations and maintained at the similar levels in the pH range of 3.5–9.5. The rate constant of CEP-C degradation was reduced by around 2.2 times in the presence of t-BuOH, suggesting that OH is mainly responsible for CEP-C degradation. The intermediates formed did not exhibit the antimicrobial activity. Positive correlation between the CEP-C removal and the loss of antimicrobial activity against S. aureus and E. coli was observed in both deionized water and underground water. However, the acute toxicity increased until 5 kGy and declined with further increasing the absorbed doses. Byproducts with opened β-lactam ring and dihydrothiazine ring, as well as formic acid, acetic acid and sulfate were detected, indicating that the active position of CEP-C was destroyed by gamma irradiation. [ABSTRACT FROM AUTHOR]

• PAHs in sewage sludge-derived biochar (SSDB) can leach out in water. • Only PAHs with 2–3 ring structures are appreciably released from SSDB into water. • Increased pyrolysis temperature leads to less formation but more leaching of PAHs. • As pyrolysis temperature increases, PAHs and HOCs share similar leaching patterns. • Biochar PAH release is likely associated with the leaching of HOCs and metals. Polycyclic aromatic hydrocarbons (PAHs), a family of persistent organic pollutants with various negative health effects, are inherently formed during biochar pyrolysis. However, the knowledge regarding the leaching potentials and mechanisms of PAHs remains limited for biochar implementation to soil. In this study we evaluated the leaching behaviors of PAHs from sewage sludge-derived biochar pyrolyzed at different temperatures (300–700 °C) using the protocol of Synthetic Precipitation Leaching Procedure (SPLP) with deionized water. Leachate concentrations of sixteen U.S. Environmental Protection Agency PAHs increased with the increasing pyrolysis temperature, exhibiting an opposite pyrolytic temperature dependence with their concentrations in biochar. The total leachate PAH concentration peaked at 700 °C with 11.75 μg/L, corresponding to 15.9% of total PAHs present in biochar. PAH leaching was associated with the release of hydrophobic organic compounds (HOCs) that created a mobile phase to facilitate the mobilization of PAHs into water. The enhanced release of calcium, aluminum, and barium from the biochars with pyrolysis temperature could also favor the leaching of biochar PAHs, due to the destruction of HOCs-(metal ions)-mineral linkages, which improved the release of HOCs and HOCs-bound PAHs; and because the extent of metal cross-linking in biochar is reduced, enabling better diffusion of PAHs through the inner matrix and thus accelerating their desorption. [ABSTRACT FROM AUTHOR]

• MCDI was probed for wastewater reuse in pilot-scale using ion selective electrodes. • The coated electrodes showed better performance attributing to its low resistivity. • NO 3 − was selectively removed attributing to its high permselectivity through AEM. • Faster flow rate and lower potential enhanced NO 3 − selectivity in single-pass mode. • The flat coated layer kept organic substances from accumulating on the surface. This study investigated membrane capacitive deionization (MCDI) at a pilot-scale using ion-selective polymer-coated carbon electrodes for wastewater reuse. Several issues have been addressed to verify the suitability of MCDI for wastewater reclamation: electrosorption performance, removal efficiency and selectivity of ions present in wastewater, optimization of operating conditions, and performance degradation in long-term caused by the accumulation of organic contaminants. The coated electrodes had better adsorption capacities and charge efficiencies than the conventional MCDI system, which was attributed to their low electrical resistance induced by the thin coated layer. The pilot-scale MCDI test cell involved 50 pairs of anion- and cation-selective electrodes and achieved good removal efficiency of ions from the wastewater effluent, particularly for problematic charged impurities, such as nitrate (NO 3 −) (up to 91.08% of NO 3 − was removed). Increasing the flow rate and reducing the applied potential were shown to be efficient for achieving better water quality by enhancing the NO 3 − selectivity. Last, the 15 d operation showed good reproducibility in electrosorption and regeneration for the coated electrodes, despite the fact that high concentrations of organics were contained in the wastewater feed solution (12.4 mg/L of dissolved organic carbon). [ABSTRACT FROM AUTHOR]

• DBD in air achieves complete mineralization of herbicides in water. • Mechanisms of mesotrione and metolachlor advanced oxidation by non-thermal plasma. • No reciprocal influence of mesotrione and metolachlor in atmospheric plasma treatment. The goals of this research were to i) test the ability of air non-thermal plasma to promote the degradation in water of two widespread herbicides, mesotrione and metolachlor, ii) determine the process efficiency and products for each herbicide treated individually, iii) detect and investigate any possible reciprocal effects when the two herbicides, which are often used in combination, are treated together in the same solution. The experiments were carried out using a dielectric barrier discharge (DBD) reactor to generate a strongly oxidizing non-thermal plasma above the liquid surface and induce the advanced oxidation of dissolved organic chemicals. The results of extensive HPLC (UV, MS and MS/MS) and TOC analyses show that air non-thermal plasma efficiently decomposes both herbicides, that mesotrione is considerably more reactive than metolachlor and that complete mineralization of both is achieved at sufficiently long treatment times. Treatment of metolachlor was also performed in tap water, a closer model for environmental systems, achieving the same results as found in deionized water. Detailed product and kinetic studies failed to reveal any effect attributable to reciprocal influence of mesotrione and metolachlor when treated together in the same solution. [ABSTRACT FROM AUTHOR]

• A system based on membrane rejection and electrochemical technique was developed. • MIL-101 endowed the mixed matrix membranes (MMMs) with phosphate adsorption capacity. • MMMs of capacitive deionization capacity was prepared with porous carbon cloth. • The conductive MMM performed both high selectivity and permeability. The great potential of ultrafiltration (UF) membranes for phosphate rejection has been challenged by the selectivity-permeability trade-off. Here, we propose a filtration system based on a novel dual-layer UF mixed matrix membrane (MMM) with a capacity for capacitive deionization (CDI), which was fabricated by incorporating NH 2 -MIL-101 into a polyethersulfone (PES) polymer matrix and the in-situ combination of carbon cloth (CC). The MMM exhibited an improved porosity of 85.52%, a declined water contact angle of 53.25°, and a 5.7% increase in water permeability in comparison to those of the PES membrane due to the hydrophilic and mesoporous NH 2 -MIL-101 particles. While incorporating the CC provided the non-conductive PES polymer with high electroconductivity. As an electrode, the CC/MMM exhibited a relatively high permeance of 424.63 L/h MPa m2, good antifouling performance, and remarkable phosphate rejection that reached 100% during the 2-h filtration period in the electrically-enhanced dead-end filtration cell. The removal capacity of the cell exceeded 22.51% and 74.0% for the energized CC/PES membrane and uncharged CC/MMM, respectively, due to the superior phosphate adsorption ability of NH 2 -MIL-101 and enhanced deionization capacity due to the electric field. UF MMM separation coupled with the electrochemical technique exhibited great potential to enhance the selective rejection of phosphate ions at low levels, while maintaining high membrane permeability and shortening the treatment time required by the CDI technique. [ABSTRACT FROM AUTHOR]

• Acidification of digestates caused increased fouling on aquaporin-based membranes. • Highly concentrated draw solutions caused a decline in osmotic water permeability. • Total ammonia nitrogen rejection was always ≥95.5%. • Rinsing with deionized water recovered the pristine membrane characteristics. • Fouling of aquaporin-based membranes was mild and reversible. Forward osmosis is a low-energy water treatment emerging technology, which has demonstrated improved solute rejection and low fouling propensity. In this study, the applicability of aquaporin-based forward osmosis membranes during separation of biogas digestate liquid fractions was investigated. The results showed that Total Ammonia-Nitrogen rejection was higher than 95.5% in all experiments, independently of the type of draw solution (NaCl and hide preservation effluents), experimental period and the use of feed acidification. The results also confirmed that high draw osmotic pressures (i.e. 3.5 M sodium chloride and hide preservation wastewater) combined with feed acidification had a negative effect on the membrane water permeability. Membrane rinsing after fouling was also successful in recovering the membrane initial water flux as well as removing the remaining foulants on the membrane surface. The membrane inspection results from Scanning-Electron Microscope, Energy-Dispersive X-Ray analysis and Fourier Transform Infrared–Attenuated Total Reflectance showed that fouling in this application was mild and reversible after membrane rinsing. The applicability of aquaporin-based forward osmosis membranes during separation of biogas digestate liquid fractions has been demonstrated. The results showed the potential of this technology to achieve enhanced ammonia-nitrogen rejections and low-fouling propensity. [ABSTRACT FROM AUTHOR]

• The biomimetic polypropylene (PP) tubular foams are fabricated. • Tunable hollow, rough inner and hierarchical porous structure are designed. • The inner diameter of the as-prepared foams via a fixed circle die can be adjusted. • A theoretical model is offered to explain the formation of the as-prepared foams. • The as-prepared foams exhibit ultra-high flux and separation efficiency. Inspired by nature, the biomimetic polypropylene (PP) foams with tunable hollow tubular structure, hierarchical porous structure and rough inner surface characteristics were designed and massively fabricated (with a speed exceed 0.5 m/s) via environment-friendly supercritical carbon dioxide (scCO 2) continuous extrusion foaming. Additionally, the inner diameter of the as-prepared biomimetic tubular PP foams can be easily adjusted from extreme low (∼0.4 mm) to very high (∼20.0 mm) size through a fixed 2.0 mm circle extruder die by carefully controlling the radially distributed temperature and melt viscoelasticity. Furthermore, we also theoretically analyzed the reasons of the formation of such biomimetic hierarchical tubular structure during foaming and drew up the corresponding schematic diagram. More interestingly, thanks to the above biomimetic structure, the as-prepared PP foam strips exhibited both superior absorption and filtration ability during the oil-water separation, in which the deionized water could be filtered quickly through the foam strips while the oil was absorbed in seconds. Besides, the relationship between pore size and hydrophobicity of polymer foams was theoretically analyzed by the Young-Laplace equation. More importantly, we believe that the design principles and processing strategies reported here can also be applied to other materials and it has great potential application in the environmental sewage treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • State of the art in electrosorption of organic compounds (EOC) critically reviewed. • EOC shows promise against poorly adsorbable, highly polar, and ionized pollutants. • Enhanced adsorption and active control of ad-/desorption by electric potential. • Insightful performance parameters proposed to unify rapidly growing EOC research. • EOC application for on-site regenerable adsorbers and in treatment trains discussed. The widespread contamination of water resources with emerging organic contaminants necessitates the development of sustainable and cost-effective water treatment technologies. Adsorption, as a widely used water remediation process, is hampered by severe performance limitations against ionic and hydrophilic organic contaminants. In addition, no facile on-site regeneration techniques are available. Electrosorption of organic compounds (EOC) is a promising alternative to not only improve adsorption performance, but also to facilitate adsorbent regeneration by green electricity. The number of studies on EOC has grown exponentially over the past decades. There are numerous examples showing that applied electric potentials can significantly enhance the adsorption affinity, capacity, and kinetics of conductive carbon adsorbents. However, whether these effects are specific to certain compound classes or more generally applicable remains unclear as well as the optimal criteria for designing EOC processes. Therefore, we critically evaluated the current state of the art of EOC in terms of active control of adsorption and desorption processes and the achievable effects for ionic and neutral organic compounds. Through a detailed consideration of compound speciation and surface chemistry of electrode materials, we derive mechanistic insights into the EOC process and discuss differences between electrosorption of inorganic and organic compounds. We provide definitions and propose insightful performance parameters to unify the rapidly growing EOC research. Potential application scenarios and future research directions are discussed. Overall, EOC is less likely to be a one-fits-all solution for removing contaminants, but adds a valuable tool especially for the hydrophilic and ionic organic contaminants that challenge conventional adsorption processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Supercapacitor has excellent electrochemical behavior, can be used as advanced energy storage device. • Numerous eco-efficient regulation strategies are proposed to manufacture coal-derived porous carbon. • Coal-derived porous carbon electrode exhibit superior energy/power density and remarkable rate property. • Coal-derived porous carbon achieve clean and high value-added utilization of coal resources. Large-scale consumption of renewable energy (RE) is the driving force underpinning the sustainable development of the world. However, the intermittence and randomness of its working mode leads to low energy density and high dispersion. The collaborative model of "power generation coupled with energy storage" is the main way to achieve a safe and stable supply of RE. Supercapacitor have both high energy density of secondary batteries and large power density of conventional capacitors, making up for the shortcomings of two energy storage devices, which can be used as advanced energy storage devices for RE. Electrode materials determine the comprehensive performance of supercapacitor. Porous carbon in carbonaceous materials presents rich pore structure, stable physicochemical characteristics, low price and easy industrial promotion, which is the goal pursued of human science. Coal is high in reserve and carbon content, and low cost. Preparation of functional nano carbon electrode materials from coal is expected to solve the problem of low investment and large scale manufacture. The review focus on the latest research of coal-derived porous carbon, with special attention to synthesis methods, regulation strategies, and structural optimization. The efficient application of coal-derived porous carbon for supercapacitor is discussed and further research challenges are proposed. [ABSTRACT FROM AUTHOR]

• An asymmetric integrated structure is provided to solve the problem of PA coating on the nanofiber membrane support. • Photothermal annealing technology is first applied in the construction of asymmetric integrated nanofiber support. • The prepared TFC-FO membranes have excellent structural stability and water permeability. The high surface roughness and large pore size of electrospun nanofibers (ESNF) make it impossible to form good polyamide (PA) layers through interfacial polymerization. Therefore, ESNF cannot be directly used as the supporting layer of nanofiber-supported thin film composite forward osmosis (NTFC-FO) membrane. However, its advantages of high porosity and large pore size are required for forward osmosis (FO) process. In this work, for the first time, an asymmetric integrated ESNF is constructed by introducing photothermal materials PANI into the supporting layer and using in situ photothermal annealing to controllably reduce the surface roughness and pore size of the support membrane, which not only meets the requirements of interface polymerization to form a good PA layer, but also maintains the high porosity, large pore size and structural stability of the ESNF. With this strategy, the FO membrane with highly selective PA layer and low membrane structural parameter (S) were obtained. The results shows that NTFC-FO membrane shows high water flux of 40.2 L·m−2·h−1 and low reverse salt flux of 4.9 g·m−2·h−1, and specific salt flux of J s /J w is only 0.12 with deionized water and 1.0 M NaCl solution as the feed solution and draw solution, respectively, and the FO membrane also exhibit excellent rejection to dye wastewater. It can be considered that the asymmetric integrated ESNF supporting layer constructed by the photothermal annealing strategy provides a simple and feasible method for the preparation of high-performance NTFC-FO membranes. [ABSTRACT FROM AUTHOR]

• The successful construction of nitrogen-vacancy-rich Co 2 N/CoP p-n junction. • The Co 2 N/CoP@CC delivers HER activity with the overpotential of 44 mV at 10 mA cm−2. • The built-in electric field can spontaneously enhance continuous electron transport. • The nitrogen vacancy can adjust the adsorption free energy of the intermediates. In-depth study the regulation mechanism of p-n heterogeneous interface and vacancy defects on electrocatalytic performance remains a great challenge. Herein, a nitrogen-vacancy-rich Co 2 N/CoP@CC p-n junction with enhanced HER and OER activities has been successfully developed. In detail, the Co 2 N/CoP@CC delivers HER activity comparable to the commercial Pt/C catalyst, as demonstrated by the ultra-low overpotential of 44 mV, and also shows excellent OER activity with an overpotential as low as 227 mV at 10 mA cm−2 in alkaline medium. Meanwhile, the water splitting potential of 1.5 V for the Co 2 N/CoP@CC heterojunction at 10 mA cm−2 is also achieved. DFT theoretical calculations indicate the outstanding electrocatalytic activity of Co 2 N/CoP@CC may be attributed to the synergy effect of abundant nitrogen vacancies and built-in electric field induced by rich p-n interfaces, which can effectively promote electron transfer, realize charge redistribution, adjust the adsorption/desorption free energy of the intermediates, and thus significantly enhancing the electrocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Scaling up preparation of modified catalysts by direct calcination in air. • Both defects and oxygen-containing groups contribute to performance enhancement. • Electro-Fenton for high pollutant removal kinetics in a wide pH range. • Industrializable case of 30 g catalyst synthesis theoretically for 5.4 m2 electrode. • Lab-scale demonstration for wastewater treatment with capacity of 7.2 L/h. Electro-Fenton (EF) regarded as a green substitution to traditional homogeneous Fenton, produces highly oxidizing OH through in-situ H 2 O 2 electrosynthesis and electrochemical Fe2+ regeneration. One of obstacles that hinders translation of bench-scale EF performance to water treatment practices is the difficulty of scaling up catalyst/electrode preparation in low cost while producing high performance. Here we report scalable preparation of modified carbon catalysts for high-efficiency EF by directly calcinating commercial carbonaceous materials in air. The EF with modified carbon cathode shows high kinetics of 0.296–0.569 min−1 for levofloxacin removal in much wider pH range of 3.0–6.6 using less Fe dosage compared with homogeneous Fenton. This EF system can reduce chemical oxygen demand (COD) of coking wastewater from 312.0 to 99.5 mg L−1 to satisfy wastewater discharge standard in China while consuming low electricity of 1.8–4.9 kWh kg−1 COD−1. We demonstrated the scalability of this EF process by scaling up preparative throughput of catalyst (30 g that can be processed into electrodes with total working areas of 54000 cm2), enlarging electrode size (230 cm−2) and reactor volume with wastewater treatment capacity of 7.2 L/h. This scalability demonstration of EF technology shows the promising potential of achieving low-cost advanced wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Charging time plays a decisive role in CDI performance improvement. • UQ analysis quantitively provides guidance for CDI optimization. • The pore distribution and connectivity are highlighted. Capacitive deionization (CDI) is considered to be one of the most promising technologies to deionize water with low/medium concentration. Great attention has been paid to improve its performance by optimizing electrode architectures and operation conditions. However, no guidelines are built for developing such strategies due to the nonlinear impact of the parameters concerning electrodes and operations. Therefore, our work quantitatively reveals the influence of some key parameters involving electrode characteristics, operation conditions and ion properties using the statistical analysis based on uncertainty quantification. We find the porosity solely has a small influence on all the performance metrics. But the pore might play a significant role by the pore size distribution and connectivity that greatly determine the effective diffusion coefficient of salt ions. The high diffusion coefficient obviously raises the salt adsorption by facilitating ion transport, which also reduces the energy consumption while most of the consumed energy could even be recovered. The current exerts an opposite influence by shortening the charging period in the constant current (CC) mode. The salt concentration in the inflow water increases the adsorption capacity but decreases the removal efficiency. The decreased removal efficiency requires less external energy, enabling the usage of CDI as an economic pre-treatment unit. We highlight the ion transport resistance and its influence on CDI performance by acting upon charging time in the CC mode. We also suggest the application of the constant voltage mode to the low-salinity wastewater instead of the CC mode due to the high resistance. Our work addressed the importance of proper electrode and operation condition for high desalination performance and energy efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • A ternary composite slurry by introducing AC, CB and CNT particles is proposed. • CNT and CB particles serve as bridging and filling effects, respectively. • A unique connection of charge percolation networks in AC/(CB + CNT) slurry was investigated. • Charge transfer enhanced mechanism in AC/(CB + CNT) slurry was explored by CFD simulation. • AC/(CB + CNT) slurry in FCDI exhibits a faster removal salt rate and lower molar energy consumption. Weak contact between activated carbon (AC) particles results in a poor conductivity for the electrode slurry, which limits the improved desalination performance in flow-electrode capacitive deionization (FCDI). Based on the bridging and filling effects of nanoparticles, we report a ternary composite slurry with multi-dimensional sized carbon particles by introducing the carbon nanotubes (CNT) and carbon black (CB) into AC-based slurry, namely AC/(CB + CNT) slurry. Further enhanced electrical conductivity relative to conventional pure AC slurry. By comparison analysis, FCDI system with the ternary carbon composite slurry had a faster average salt removal rate (ASAR) of 1.89 μmol cm−2 min−1 under at 1.2 V in a feed salinity of 2.0 g L−1, which is 3.27 1.92 and 1.46 times that of pure AC, AC/CB and AC/CNT slurry. In long-term operation (1800 min, U = 1.6 V), the AC/(CB + CNT) slurry exhibited a stable ASAR of 4.41 μmol cm−2 min−1 and maintained a charging efficiency (CE) of around 96% and molar energy consumption (E m) of 0.043 kWh mol−1. Electrochemical analysis and computational fluid dynamics (CFD) simulation further confirms that AC/(CB + CNT) slurry enable system with a point-to-line-to-surface connection morphology, which generates a robust charge percolation network with diverse pathway and facilitates the charge transfer. In summary, this study developed a facile strategy for increasing the slurry conductivity to provide a feasible approach in efficient desalination application. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Mn 0.6 Zn 0.4 Fe 2 O 4 catalyst was fabricated from spent Zn-Mn alkaline batteries. • Mn 0.6 Zn 0.4 Fe 2 O 4 catalyst was used to activate PMS and degrade BPA. • The active radicals generated during PMS/Mn 0.6 Zn 0.4 Fe 2 O 4 process was identified. • The role of A-site metal and Fe(III) of spinel during oxidation was examined. • The importance of surface hydroxyl groups on activation of PMS was confirmed. Abstract Spinel ferrites have shown great potential to activate peroxides for environmental remediation. In this work, a Mn-Zn ferrite catalyst was fabricated by the citrate combustion method from spent Zn-Mn alkaline batteries. The synthesized Mn 0.6 Zn 0.4 Fe 2 O 4 catalysts were applied to activate peroxomonosulfate (PMS) and degrade bisphenol A (BPA) in water. A 95.8% BPA (0.1 mM) removal was achieved at initial pH of 6.2, Mn 0.6 Zn 0.4 Fe 2 O 4 dosage of 0.2 g/L, PMS concentration of 0.5 mM, and reaction time of 60 min. The concentration of metal leaching and radical identification experiments suggested that BPA is mainly degraded by surface-adsorbed reactive radicals. Metals at A site of the spinel (AFe 2 O 4 , A = Mn and Zn) were responsible for PMS activation and Fe(III) acted as the reservoir for the surface hydroxyl groups, which substantially accelerated the degradation of BPA. The addition of Cl− improved the destruction of BPA and a NaHCO 3 concentration below 5 mM had a negligible effect on the BPA removal. When the PMS/Mn 0.6 Zn 0.4 Fe 2 O 4 process was used to treat real river water spiked with BPA, the removal of BPA was much faster than that in deionized water. This implied that the PMS/Mn 0.6 Zn 0.4 Fe 2 O 4 process may provide some new insights not only for the recycling of spent batteries, but also for removal of contaminants from wastewater. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Capacitive deionization (CDI) has emerged as a promising way to obtain freshwater. • Nitrogen-doped mesostructured carbon nanocrystals (NMCs) are useful for CDI. • NMCs show a high nitrogen content and large accessible surface area. • NMCs exhibit a high salt adsorption capacity of 20.63 mg g−1. • The salt adsorption capacity is much higher than for the typical AC benchmarks. Abstract Capacitive deionization (CDI) has emerged as a promising way to obtain freshwater from saline water, but its implementation is in its infancy and remains challenging due to the low salt adsorption capacity (SAC) of commonly used activated carbons (ACs). It is thus desirable to develop carbon electrodes that can exceed the performance of ACs benchmarks. In this work, nitrogen-doped mesostructured carbon nanocrystals (NMCs) have been developed by direct carbonization of highly ordered mesostructured polymers. Due to their mesoporous structure, high N content and large surface area, NMCs exhibit a maximum SAC of 20.63 mg g−1. This state-of-the-art carbon electrode largely surpasses common ACs. This work demonstrates the significance of the material synthetic chemistry and the importance of nanostructuring carbon materials for CDI applications. [ABSTRACT FROM AUTHOR]

Highlights • The feasibility of perchlorate selective removal by batch-mode CDI was investigated. • A one-dimensional CDI process model was developed to describe the process. • A favorably strong preferential adsorption of ClO 4 − over Cl− was observed. Abstract Capacitive deionization (CDI) has attracted increasing attention over the past decade for the facile removal of ions from aqueous solutions. Nowadays, CDI is rapidly growing and evolving, and has been applied in many aspects. One important application field is water remediation, i.e., removing ionic contaminants of concern from water. Herein, we investigated the feasibility of perchlorate removal from brackish waters by batch-mode CDI technology. Effects of various operating parameters on dynamic electrosorption processes of both perchlorate and chloride were examined. Meanwhile, a one-dimensional CDI process model for dual-anions was developed to quantitatively describe the electrosorption kinetics of perchlorate and chloride, and an excellent agreement between the modeling results and the experimental data was observed. Experimental results revealed a favorably strong preferential adsorption of ClO 4 − over Cl− in the studied CDI system under various conditions. Moreover, only slight discrepancy between adsorption-desorption cycles was found, demonstrating the good regeneration of electrodes and operational stability of the CDI cell. Finally, the scale-up studies indicated that the CDI stack with multiple pairs of electrodes could achieve a much more superior ion removal performance than the CDI cell with only one pair of electrodes. To conclude, these results showed that the CDI system was effective for perchlorate selective removal in the presence of other major ions and had potential in treatment of perchlorate-contaminated brackish water. [ABSTRACT FROM AUTHOR]