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[Display omitted] In the adsorption process of functionalized layered double hydroxide (LDH) to target pollutants it, is essential to investigate the role of functional groups. In this work, 2‑mercaptoethane sulfonic acid (MS) was used as an intercalation modifier to prepare functionalized NiFe-LDH by solvothermal method. The interfacial interaction between the functional groups and the NiFe-LDH surface was studied via molecular dynamics simulation. During the intercalation process, the more negatively charged sulfonic acid group tends to self-assemble electrostatically with the LDH laminate, while the sulfhydryl group is involved in complexing heavy metal ions. The adsorption experiments showed that the adsorption performance of the adsorbent for the three ions of Cd2+, Mn2+, and Co2+ at 298.15 K was 266.16 mg/g, 175.60 mg/g, and 106.56 mg/g, respectively, which were 10 times, 8.7 times, and 4.9 times higher than that of unmodified NiFe-LDH. Meanwhile, Multiwfn wavefunction analysis combined Visual Molecular Dynamics (VMD) was applied to analyze and visualize the reaction active sites & the interactions between MS and NiFe-LDH, and the complexation of the functional group of MS with metal ions, to insight the role of the functional groups in MS molecule, and to reveal the cause that the adsorption capacity of modified NiFe-LDH for heavy metals greatly improves from the view of atoms. [ABSTRACT FROM AUTHOR]

The corresponding adsorption mechanism of the adsorbent in the process of adsorbing phosphate. As shown, three adsorption mechanisms of the adsorbent in the process of adsorbing phosphate: 1: The combination of PO 4 3− and La3+ produces LaPO 4 with smaller Ksp. 2: H 2 PO 4 − and HPO 4 2− enters the interlayer through a substitution reaction with OH− between the LDH layers to realize the adsorption of phosphate. 3: The electrostatic mutual attraction between quercetin and phosphate realizes the adsorption of phosphate. [Display omitted] Severe water eutrophication due to large releases of phosphorus has become a worldwide environmental problem. Adsorption active sites is less of traditional adsorbents in the phosphorus removal process resulting in low removal efficiency, so the new high-efficiency phosphorus removal adsorbents become an effective way to solve the problem. In this work, quercetin modified MnFe layered double hydrotalcite three-dimensional composites structures encapsulated by lanthanum (La(III)) nanoparticles (QLa@MnFe-LDH) were successfully prepared by a classical hydrothermal method. The results of the adsorption experiments show that La(III) nanosphere-encapsulated MnFe-LDH provides a more adequate binding site for phosphate adsorption. The adsorption performance of QLa@MnFe-LDH for phosphate was outstanding, the maximum adsorption capacity was 346.5 mg/g at 298.15 K, which was 300 % higher than that of MnFe-LDH. Moreover, QLa@MnFe-LDH retained its high adsorption capacity (>315.5 mg/g) over a wide range of pH (4.0 ∼ 7.0). The active sites of the reactions were predicted by Multiwfn and Visual Molecular Dynamics (VMD), and novel visualization studies of weak interactions were applied to theoretical studies. The modified MnFe-LDH encapsulated by La nanospheres has a strong adsorption capacity for phosphate adsorption. Therefore, the modified QLa@MnFe-LDH was expected to become an effective adsorption material for phosphorus removal. [ABSTRACT FROM AUTHOR]

Highly efficient multifunctional adsorbent successfully realizes the removal of Cr ions from wastewater. The adsorbent is easily separated from the water to avoid secondary pollution. [Display omitted] • A novel 3D multifunctional composite magnetic adsorbent material has been successfully synthesized and applied for the removal of Cr(VI) from solution. • The composite adsorbent enables efficient capture and reduction of Cr(VI) under full light exclusion conditions. • The exceptional recyclability mitigates the issue of secondary contamination from the adsorbent. Designing a magnetic adsorbent material that is both reducible and has strong adsorption properties is significant in reducing Cr(VI) ion pollution. Herein, a 3D multifunctional composite adsorbent for Cr(VI) ions was obtained by using Fe 3 O 4 surface-arrayed magnesium iron layered double hydroxides (Mg/Fe-LDH) micro sheets as a substrate with in situ growth of Cu 2 O nanoparticles (Cu 2 O NPs) on their surfaces. Under dark conditions, adsorption capacity of the Cu 2 O@LDH@Fe 3 O 4 for Cr(VI) was up to 218.82 mg·g−1, surpassing that of Cu 2 O, Mg/Fe-LDH@Fe 3 O 4 , and Mg/Fe-LDH by factors of 1.39, 4.41, and 8.32 respectively. Surprisingly, the removal of Cr(VI) was as high as 76.16 % by the Cu 2 O@LDH@Fe 3 O 4 (C initial = 200 mg/L, pH = 3). Kinetic, isotherm, and thermodynamic results reveal that the removal of Cr(VI) by the Cu 2 O@LDH@Fe 3 O 4 is consistent with the pseudo-second-order kinetic model of spontaneous monomolecular layer chemisorption. Density functional theory (DFT) calculations show that HCrO 4 - has a lower energy band gap and is more easily reduced by Cu 2 O. Therefore, the reason for the adsorbent having more removal effect under acidic conditions was revealed. The XPS and FT-IR experimental mechanism analysis results indicated that Cr(VI) is immobilized on the Cu 2 O@LDH@Fe 3 O 4 surface through electrostatic interactions, followed by reduction to Cr(III) by Cu 2 O NPs, which is subsequently adsorbed on the surface of the Cu 2 O@LDH@Fe 3 O 4. This novel adsorbent structure and unique Cr(VI) removal mechanism provide new ideas for the design of future adsorbents. [ABSTRACT FROM AUTHOR]

Honeycomb nitrogen-doped porous carbon (NPC) was prepared for supercapacitor applications by hydrothermal carbonization and KOH activation process. This process used glucose as the carbon source and trans-1, 2-cyclohexane diamine tetraacetic acid as the nitrogen source. It can both control the morphology and improve the electrical performances of the as-achieved NPC. The porous carbon electrode offers improved electrochemical properties with a capacitance as high as 423 F/g at 0.5 A/g. There was excellent cycling stability with 92.5% capacitance retention after 5000 cycles at 10 A/g current density as well as good rate performance with 300 F/g even at 20 A/g. This is due to the hierarchical porous structure, high specific surface area, numerous nitrogen groups, and good electrical conductivity. Moreover, the symmetric supercapacitor based on the porous carbon materials in neat DLC301 electrolyte delivers a high energy density of 58.75 Wh/kg and an excellent power density of 250 W/kg. Two assembled supercapacitors were connected and utilized for the driving recorder to work normally for 15 s. These satisfactory electrochemical properties indicate that the honeycomb 3D porous carbon has good prospects as an electrode for supercapacitors. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped 3D hierarchical porous carbons (3DNHPCs) are prepared in a green strategy. • Tertiary porous structure and surface-exposed active sites accelerate ion insertion. • Superior desalination capacity and rapid desalination rate are achieved. • Ultrahigh water recovery and productivity are acquired. Exploiting a sustainable and effective strategy for fabricating 3D N-doped hierarchical porous carbon (3DNHPC) for capacitive deionization (CDI) is a huge challenge for desalination. The traditional methods often adopt expensive precursors, complex routes and strong corrosive activators that are harmful for its practical application. Herein, a novel green double organic salt activation strategy is developed that utilizes lotus stem (LS) with a regular 3D macroarray structure to acquire 3DNHPC x. Different from single C 6 H 5 K 3 O 7 or Na 2 EDTA activation, 3DNHPC x obtained under double organic salt co-activation exhibits a suitable micro-meso-macro porous structure with a high BET surface area (S BET) of 2256.2 m2/g, a large pore volume of 1.02 cm3/g, a remarkable mesoporous volume of 0.41 cm3/g and 1.31 % N content. Its unique tertiary pore structure and copious surface-exposed active sites facilitate the ions rapid insertion and extraction from the micropores. The assembled CDI cells achieve a superior salt removal capability of 25.36 mg/g as well as a splendid volumetric adsorption capacity (VAC) of 6.21 mg/cm3 and an ultrafast average salt removal rate of 7.84 mg/g/min. Meanwhile, 3DNHPC 11 maintain 89.4 % adsorption capacity after 50 cycles. Besides, 3DNHPC 11 obtains a high water recovery (WR) of 82.2 % and high productivity of 290 g NaCl /g C /(h m2) or 108.1 g NaCl /cm3 C /(h m2). This work sheds light on one way to design economical and eco-friendly 3DNHPCs for high-performance CDI desalination. [ABSTRACT FROM AUTHOR]

High conductivity NiCo 2 S 4 (NCS) nanosheets in situ grown in porous nitrogen-doped reduced graphene oxide (PN-rGO) materials were successfully prepared via a simple hydrothermal method. A synergistic effect between the NCS and PN-rGO matrix is observed on the electrochemical performance of the composites. PN-rGO/NCS exhibits an equivalent ultralow diffusion resistance and charge transfer resistance (0.16 Ω), ultrahigh specific capacitance (1,687 F g−1 at a current density of 0.5 A g−1), and an excellent rate capability (1,478 F g−1 at a current density of 10 A g−1). The asymmetric supercapacitor (ASC) is designed with PN-rGO/NCS as the positive electrode and active carbon as the negative electrode. The ASC device exhibits a high capacitance (355.5 F g−1 at a current density of 1 A g−1). Density functional theory calculations show PN-rGO/NCS to increase the electrical conductivity of the material, and concomitantly the electrochemical performance. The data suggest that the PN-rGO/NCS hybrid structure can be considered as a future supercapacitor electrode material. Image, graphical abstract [ABSTRACT FROM AUTHOR]

[Display omitted] • Composition of dual-emitting fluorescent probes was achieved by utilizing Eu and Tb as bimetallic centers. • First proposed dual-emission ratio sensor constructed with diaminoterephthalic acid. • Emission color conversion by adjusting the doping ratio of Eu and Tb. • The probe enables ratiometric sensing of furacilin and has excellent sensitivity and low detection limits. Lanthanide metal–organic frameworks (LnMOFs) have substantial potential in luminescence due to their unique antenna effect. Nevertheless, the single emission is susceptible to pseudo-signals caused by external environmental conditions, which significantly threaten the accurate measurement of the concentration. In this case, we prepared a dual-emission fluorescent probe {Eu x Tb 1-x (NH 2 -BDC) 3 (DMF) 4 ·2DMF} ∞ (NH 2 -BDC = Diaminoterephthalic acid, DMF = N , N -dimethylformamide). The stable dual-emission signal provides a superior signal output for detecting nitrofurazone (NFZ), which is detected by the probe with excellent fluorescence for 0–10 μM NFZ. In the investigation of the detection mechanism, it is speculated that NFZ incorporates with probe to generate a novel complex. Furthermore, The UV absorption curves of the novel complexes and NFZ overlap extensively with those of the probe. The addition of NFZ attenuates the characteristic luminescence of Eu and Tb by competing for the absorption of the excitation light of the probe. The probe has exhibits rapid response, excellent sensitivity, visual detection and a meagre detection limit (LOD = 0.013 μ M) for the detection of NFZ. This work not only broadens the application of LnMOFs in the field of ratiometric detection but also provides a favorable fluorescent probe for the quantitative detection of NFZ. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrate-mediated organic salt activation strategy was proposed to fabricate high-yield-high-performance NHPC. • Tertiary porous structure and surface-exposed active sites facilitated salt ion removal. • The splendid desalination capability and rapid desalination kinetics were acquired. • The universality and commerciality for NHPCX y were further investigated. Developing a green and facile strategy for high-yield preparing N-doped hierarchical porous carbon (NHPC) for capacitive deionization (CDI) is a huge challenge for desalination. So far, there are limited reports on high-yield NHPC synthesis. Herein, a novel nitrate (NaNO 3 , KNO 3 , Zn(NO 3) 2 and NH 4 NO 3)-mediated-organic salt activation strategy was exploited to construct NHPCX y (X = Na, K, Zn, NH 4 ; Y(nitrate ratio) = 1, 3, 5). Thereinto, C 6 H 5 K 3 O 7 served as activator and nitrate acted as assisted-activator and foaming agent. Compared with C 6 H 5 K 3 O 7 activation, NHPCNa 3 acquired by NaNO 3 -C 6 H 5 K 3 O 7 co-activation achieved 35.5% high yield and depicted 3D macroarray structures with high specific surface area (S BET) of 1912.2 m2/g, large pore volume (V pore) of 1.56 cm3/g and 1.21 % N content. Its tertiary pore structure and rich surface-exposed active sites favored the ions rapid insertion and extraction from the micropores. The final NHPCNa 3 delivered an excellent salt adsorption capacity (SAC) of 19.74 mg/g. Moreover, it exhibited 14.61 mg/g high SAC at 15.5 mg/cm2 and only showed 9.4% SAC drop after 50 cycles. While using diverse biomass precursors, it obtained an optimal SAC of 23.16 mg/g. NHPCK 3 , NHPCZn 3 and NHPC(NH 4) 3 also presented the feature of high-yield-high-performance. The high yield came from the foaming effect of nitrate and the property difference may be ascribed to the different cations. This work provides one span-new green universality strategy to design high-yield-high-performance NHPCs in commercial-grade CDI applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • High dispersion and stable attachment of LDH on nitrogen and sulfur doped porous carbon (NSPC). • The synergistic effect of LDH and NSPC enhances the adsorption of heavy metal ions. • The adsorption mechanism was attributed to surface complexation. Layered double hydroxides (LDHs) composites (NSPC@LDH) were successfully prepared on nitrogen and sulfur-doped porous carbon (NSPC) by a simple co-precipitation method. The synergistic effect between the modified porous carbon and LDH enhanced its adsorption performance. Compared with pure LDH, the composite had a larger specific surface area (188.78 m2/g) and pore structure with a smaller crystallite size (4.56 nm). The porous carbon carrier effectively mitigated the aggregation effect of LDH. The maximum adsorption capacities of NSPC@LDH for Zn2+ (100 ppm) and Cu2+ (100 ppm) were 125.7 mg/g and 137.5 mg/g, respectively, which were 2.85 and 2.39 times the original LDH. The XRD and XPS studies of the adsorbent after adsorption revealed that surface complexation and physical adsorption played a dominant role in the removal of Zn2+ and Cu2+, and the introduction of N, S heteroatoms provided more active centers for heavy metal ions. Moreover, after five desorption cycles, NSPC@LDH still exhibited high removal efficiency. The results indicated that the synthesized NSPC@LDH composites have great potential for removing Zn2+ and Cu2+ from aqueous solutions. [ABSTRACT FROM AUTHOR]

[Display omitted] • "Pre-embedded seed then growth" ensures the stability of the adsorbent structure. • Co-doping of dual-functional components exhibits effective synergistic adsorption. • Theoretical calculations of ligand exchange and hydrogen bonding mechanisms. • Adsorbents that degrade after adsorbing phosphates have fertilizer effect. • Proposing a closed-loop design from waste utilization to treatment and final reuse. Recovering and reusing of phosphorus (P) in wastewater is the optimal solution to address mineral shortages and eutrophication. Here, the layered double hydroxides (LDHs) grown on wood-derived aerogels (WAs) were prepared after screening the powdered precursors and named La/MgFe-LDH(LS)@WAs. The intricate pore structure and surface morphology of the WAs formed a fibrous network with ultra-low density, good strength and elasticity, allowing for uniform loading. The sample exhibited excellent adsorption capacity of 139.5 mg P/g at pH 4.0, and over 100.0 mg P/g within a wide pH range (3.0–8.0). Thomas and Yoon-Nelson models could effectively describe the dynamic adsorption process. Microscopic morphology and textural characteristics of the samples were characterized and molecular dynamics (MD) simulations and theoretical calculations based on density functional theory (DFT) were used to study the interaction mechanisms. The coordination bonds and weak interactions between the active component LS and La(OH) 3 with phosphates were characterized using interaction region indicator (IRI) and independent gradient model based on Hirshfeld molecular density partitioning (IGMH) methods. The atomic δg index mapped to the molecular structure vividly illustrated the maximum contribution of hydroxyl hydrogen to phosphate deprotonation oxygen in inter-fragment interactions on LS. Combining the formation of Me-O-P bonds characterized by X-ray photoelectron spectroscopy (XPS), the mechanism involves weak interactions (hydrogen bond) and chemical adsorption via ligand exchange. High removal efficiency was demonstrated in real wastewater. A method for waste reuse was also proposed. Plant cultivation experiments showed that La/MgFe-LDH(LS)@WAs could sustain wheat growth with slowly degrade and maintain high phosphate availability. The composite shows potential for water restoration, waste treatment, and value-added conversion in the production of controlled-release fertilizers. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-mass loading CoO@NiCo-LDH was prepared from ZIF-67 self-sacrificing template. • Irregular electrode surfaces of 3D nanochannels enable rapid reaction kinetics. • Core-shell structure enhances LDH's conductivity and Faradaic activity. • A simple one-step hydrothermal method to prepare the High-mass loading FeNi-S anode. The rapidly growing market of portable and wearable smart electronics has created strong interest in flexible electrode materials with high specific capacitance and fast charging/discharging properties. However, high mass-specific capacitance active materials are often limited by the low areal mass-loading required. High areal capacity electrodes can make more efficient use of the limited internal space of these miniature devices by minimizing the volume and weight taken by current collectors and separators. Herein, a method is proposed to prepare a nickel–cobalt layered double hydroxide binder-free cathode on flexible carbon cloth with a mass loading of 20 mg cm−2. This core–shell hybrid structure prepared using a MOF self-sacrificing template, achieves a high energy density using thick electrodes while improving their slow kinetics by enhancing both the ion diffusion process and charge transfer dynamics. The areal capacitance reaches a staggering 4.42 mAh cm−2 (31.79 F cm−2) at a current density of 8 mA cm−2. Furthermore, a one-step hydrothermal method to prepare the FeNi-S anode (1.67 mAh cm−2, 2 mA cm−2) is proposed. Upon assembling with the gel electrolyte, this flexible device possesses an impressive energy density of 3.29 mW h cm−2 (3 mW cm−2). It can readily supply energy to watches, wireless e-paper, LEDs, and can be anticipated to be widely used in next-generation high-performance portable and wearable devices. [ABSTRACT FROM AUTHOR]

In recent years, metal-organic framework derivatives have been regarded as materials with great potential for water treatment applications. In this study, we employed a polyvinylpyrrolidone (PVP)-assisted copper-cobalt bimetallic zeolitic imidazole framework (ZIF) as a template to rationally design nanosheet-like mixed metal oxide embedded nitrogen-doped carbon (CuCoO-PC). CuCoO-PC exhibited excellent degradation potential towards metronidazole (MNZ) and achieved almost complete degradation within 7 min through the activation of peroxymonosulfate (PMS). Importantly, the introduction of copper into CuCoO-PC established strong interactions between copper and cobalt, accelerating the activation performance of PMS. Furthermore, PVP, rich in nitrogen atoms, formed strong coordination interactions with ZIF precursors, which effectively protected the morphological stability of ZIF at high temperature, preventing collapse and aggregation. Meanwhile, the formation of nitrogen-doped carbon networks provides a pathway for the generation of non-radical. The study found that CuCoO-PC continuously activated PMS, generating various reactive oxygen species (ROS), among which SO 4 •- and 1O 2 played decisive roles. By calculating the HOMO, LUMO, and Fukui functions, we identified the reactive sites of MNZ and proposed possible degradation pathways. CuCoO-PC demonstrated excellent catalytic performance, reduced toxicity of intermediate products, and good reusability, all of which highlight its enormous potential in practical applications. [Display omitted] • CuCoO-PC composites are prepared using PVP to enrich the nitrogen content. • CuCoO-PC/PMS system exhibits prominent catalytic performance for MNZ removal. • SO 4 •- and 1O 2 was the main active substance involved in the MNZ degradation. • CuCoO-PC was stable and effective in multiple cycles of MNZ degradation efficiency. • The most reactive site on MNZ molecule was predicted by DFT calculation. [ABSTRACT FROM AUTHOR]

Tetragonal-phase BaTiO3 powders of particle size 370 nm were synthesized by microwave sintering at 850 °C. The raw materials were BaCO3, TiO2, and alanine. SiC microspheres were used as microwave conductors. The effects of the holding time, sintering aids, and SiC addition on the preparation of BaTiO3 were investigated. The results indicate that the addition of SiC as a microwave acceptor leads to formation of microwave micro-regions. This enables uniform heating of the raw materials and decreases the calcination temperature needed to obtain BaTiO3. Alanine coordinates with Ba, and this loosens the metal–CO3 bond and promotes separation of CO2, decreases the BaCO3 decomposition temperature, and provides a higher nucleation site density. It gives an idea about the microwave solid-state synthesis of BaTiO3 powder. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped La 2 CuO 4 had been synthesized using melamine as the N precursor. • N-doped La 2 CuO 4 showed enhanced catalytic activity and stability. • Density Functional Theory (DFT) calculations were performed to verify the results. • A mechanism of phenol degradation was proposed. • The toxicity of degradation intermediates was greatly reduced. Herein, N-doped perovskite La 2 CuO 4 (LCO) (N-LCO(M)) was fabricated by sol–gel rapid calcination method using melamine (M) as N source/ligand, and applied for the catalytic wet air oxidation (CWAO) to degrade high-concentration phenol-containing simulated wastewater. The experimental results exhibited that N-LCO(M) illustrated enhanced phenol degradation efficiency. Thereinto, 87.9% COD degradation efficiency was achieved in simulated wastewater containing 8000 mg/L phenol, while for undoped LCO prepared with citric acid (CA) as ligand (LCO(CA)) was only 43.8%. The systematic characterizations and density functional theory (DFT) calculations were utilized to verify the above results. The results revealed that N doping favored the formation of more oxygen vacancies (*) and facilitated the charge transfer between Cu and O. More oxygen vacancies (*) reinforced the ability of N-LCO(M) to adsorb O 2 to form reactive oxygen species (O*), and meanwhile, the charge transfer between Cu and O was manifested as the redox cycle of the catalytic active metal Cu2+/Cu1+. The redox cycle also promoted the formation of O 2 − and HO, making the more exhaustive degradation of phenol. This successfully proved that N doping was core to improving the activity and stability of N-LCO(M). Moreover, a possible mechanism of phenol degradation was proposed based on the experimental results and DFT calculations. Eventually, the toxicity of the intermediate products was further evaluated by quantitative structure–activity relationship (QSAR) analysis, showing the significantly reduced toxicity of the intermediate products. Overall, the proposed CWAO technique is a green and promising wastewater treatment method. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel adsorbent of UiO-66-NH 2 @Mg(OH) 2 was prepared and characterized. • The adsorption capacity was improved significantly after modification. • Adsorption behavior and mechanism of phosphate on UNM were explored. • Multiwfn wave function methods were applied to interpret the adsorption mechanisms. • Phosphate was successfully recovered by the struvite-based method. Two serious challenges of water eutrophication and phosphorus resources exhaustion make the P recovery imperative. In this work, a novel phosphate adsorbent UiO-66-NH 2 @Mg(OH) 2 (UNM) has been synthesized by the in-situ growth of magnesium hydroxide nanosheets around UiO-66-NH 2. The batch adsorption experiments were carried out by controlling the single variate (such as pH, initial concentration, contact time, temperature and interfering anions) to explore the adsorption behaviors. And the adsorption dynamics and isotherms fit well with the pseudo-second-order (PSO) and Langmuir models, combined with the thermodynamics results, indicating a spontaneous and endothermic monolayer chemisorption process. Besides, the maximum phosphate adsorption capacity of UNM was calculated as 408.07 mg/g (≈130.39 mg P/g) at pH = 6.0, T = 298 K. A series of characterizations (XRD, FT-IR, SEM, EDS, BET, TGA, XPS, ICP-MS et. al) and quantum chemical analysis methods (ESP, ALIE and Hirshfeld surface) was applied to predict the reactive sites. The possible mechanism can be deduced as two continuous steps: the physical attraction by weak interactions and the chemical adsorption with an ion-exchange mechanism. The UNM also presented high removal efficiency in the environmental water samples and showed satisfactory reusability and excellent chemical stability in the recycling process. From the desorption effluents, we successfully recycled the struvite with 14.31% P content. Therefore, the UNM will be regarded as a promising phosphate adsorbent in practice and this work will provide inspiration and guidance for the design and preparation of high-efficiency P-removal adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel BiVO 4 /BiOBr-Ov Z-scheme heterojunction has been prepared. • The existence of oxygen vacancies leads to altering the photogenerated carrier transfer path from type-II to Z-scheme. • The internal electric field and band edge bending are explained based on the results of DFT calculations. • The mechanism of Z-scheme photocatalysis is discussed. • •O 2 − and h+ were the prominent radicals for OTC degradation. Constructing oxygen vacancies (Ov) has been widely used to enhance photocatalytic activity as a conventional and efficient approach, but its influence on the interfacial charge transfer pathway remains ambiguous. Herein, we synthesized BiVO 4 /BiOBr-Ov (BVB-Ov) photocatalysts through a facile method. Subsequently, various characterization results verified the successful preparation of BVB-Ov composites via combining BiVO 4 with BiOBr containing oxygen vacancies (BiOBr-Ov). The results of photocatalytic degradation experiments illustrated that 20% BVB-Ov exhibited the highest degradation rate (91%) for Oxytetracycline (OTC), which was much higher than that of 20% BiVO 4 /BiOBr (71%). In addition, three possible degradation pathways were deduced from liquid chromatography-mass spectrometry (LC-MS) analysis. Photoelectrochemical, photoluminescence (PL) and time-resolved PL (TRPL) investigation revealed that 20% BVB-Ov possessed the fastest photogenerated carrier separation and transportation rate. Kelvin probe force microscopy (KPFM) technology and Density functional theory (DFT) calculations have shown that the introduction of oxygen vacancies modulated the relative positions of the Fermi levels between BiVO 4 and BiOBr. We have finally combined DFT calculations, energy band analysis, trapping experiments and electron paramagnetic resonance (EPR) results, confirming that the existence of oxygen vacancies led to altering the photogenerated carrier transfer path from type-II to Z-scheme. This work provided insights and guidelines for oxygen vacancies to coordinate interfacial charge transfer pathways. [ABSTRACT FROM AUTHOR]

[Display omitted] • The universal low carbon mass loading was used in capacitive deionization (CDI) for efficient deionized (DI) water production. • Partial desalination performance weakened with increasing carbon mass loading. • CDI cells using YEC-8–5.81 as electrodes produced DI water with a low conductivity of 1.89 μS/cm. • Carbons with a suitable micro- meso pore distribution and high specific capacitance may be a better choice. • 82.2% DI water recovery was achieved under stopped flow (SF) discharge mode. High-purity deionized (DI) water can be widely used in high-end manufacturing fields, but its efficient and energy-saving production is a huge challenge. Here, simple carbon mass loading control was developed for efficient DI water production via advanced capacitive deionization (CDI). Supercapacitor carbon (YEC-8) electrodes with diverse mass loading of 2.50, 5.81, 12.63 and 24.72 mg/cm2 were prepared for desalination. As expected, YEC-8–2.50 acquired the optimal CDI performance. High mass loading of 12.63 and 24.72 mg/cm2 not only caused an overt property drop but also serious wasted materials. Competitively, YEC-8–5.81 achieved a similar volumetric adsorption capacity (VAC) to YEC-8–2.50 as well as made up for the lack of total mass of YEC-8–2.50 and the resultant solution conductivity was as low as 1.89 μS/cm (grade III DI water). This strategy has been successfully extended to other carbon materials and carbons with suitable micro- meso pore distribution and high specific capacitance may be a better choice. Besides, the reverse effect of acetylene black (AB) mass on desalination was verified. To gain a high water recovery (W R), stopped flow (SF) discharge was introduced and realized a high W R of 82.2 %. Meanwhile, cycling tests indicated its splendid cycling stability. This study provides a universal direction for using low mass loading strategy for efficient DI water production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defect content and particle size of MOF-808 can be tuned using iron nitrate. • The modulating MOF-808 can achieve effective removal and recovery of phosphate. • Adsorption mechanisms involve electrostatic attractions and ligand exchange. In this work, a facile and green method is applied to synthesize hydrophilic MOF-808(Zr) and modulate its defect content and particle size using different amounts of iron nitrate (denoted as F) to obtain serial XF-MOF-808 ("X" implied the dosage of used F). The development of additional adsorption sites and the fine-tune of pore and particle size based on MOF-808 significantly improved phosphate adsorption performance. In particular, the 0.5F-MOF-808 shows excellent adsorption capacity (305.5 mg/g) and rapid diffusion rate (37.51 mg/g·min0.5) for phosphate at 298 K and initial pH = 6.5, outperforming pristine MOF-808 and most previously reported adsorbents. 0.5F-MOF-808 possesses a wide pH tolerance, outstanding reusability and excellent selectivity for phosphate adsorption from simulated wastewater, verified in environmental implication and regeneration experiments. Phosphate loaded on the adsorbent can be converted to struvite for agricultural fertilizer via a simple crystallization process. Compared to MOF-808, the exceptional sorption performance of 0.5F-MOF-808 is supported by decreased internal diffusion limitation, enlarged pore size and the development of new adsorption sites, which can be proved by advanced characterizations and batch adsorption experiments. This work presents a promising modification strategy of MOF materials for phosphate adsorption and recovery. [ABSTRACT FROM AUTHOR]