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Electrochromic supercapacitors have drawn enormous attention due to their ability to monitor the charge and discharge processes through color changes of electroactive materials. However, there are few work on small organic molecules as active materials for all-solid-state electrochromic supercapacitors. Herein, we reported two novel multifunctional symmetric viologens (TPA-bpy and CZ-bpy), which showed different solvatochromic, electrochromic, electroluminochromic and energy storage behaviors despite their similar chemical structures. The different performances between these two viologens were attributed to the difference in the intramolecular charge transfer capability and the solubility in organic solvents. Devices containing TPA-bpy displayed faster response time and higher coloration efficiency due to the introduction of packing-disruptive and three-dimensional triarylamine groups. Moreover, devices containing TPA-bpy also showed energy storage characteristics with an obvious color change from purple to yellow. It showed a wide voltage window (2.0 V), long discharge time (230.3 s at 0.01 mA cm−2), and excellent cycling stability with 90% capacitance retention after 6,000 cycles. The work provides a new and convenient strategy towards the development of novel electrochromic capacitive materials.

Developing low-cost, highly efficient and robust photocatalystic hydrogen evolution system is a promising solution to environmental and energy crisis. Herein, a Z-scheme Cu3P/ZnIn2S4 heterojunction photocatalyst was successfully constructed for the first time via a facile solution-phase hybridization method. The optimized Cu3P/ZIS composite exhibited the highest H2 production rate of 2561.1 μmol g−1 h−1 under visible light irradiation (>420 nm), which was 5.2 times greater than that of bare ZnIn2S4 and even exceeded the photocatalytic performance of Pt/ZIS composite. The apparent quantum yield of 10 wt% Cu3P/ZnIn2S4 can reach 22.3% at 420 nm. The huge boost of photocatalytic hydrogen evolution activity is ascribed to the formation of heterojunction with the built in electric field within Cu3P/ZnIn2S4 and Z-scheme charge carriers transfer pathway, which result in efficient separation and migration of charge carriers. In addition, both experimental and theoretical calculation confirmed that the charge-carriers transfer pathway of Cu3P/ZnIn2S4 photocatalyst follows the Z-scheme mechanism instead of conventional type-Ⅱ heterojunction mechanism. This work is considered helpful for getting a great deal of insight into constructing high-activity and cost-effective transition metal phosphides (TMPs) based photcatalytic hydrogen production system and rationally designing Z-scheme heterojunction photocatalyst.

Global warming and energy shortage are two major stumbling blocks on the road of human social progress, and have gradually aroused a sense of crisis. Artificial photosynthesis is a two-pronged solution to both problems. However, due to the harsh reaction conditions and low efficiency, traditional semiconductors cannot achieve this. Two-dimensional (2D) materials with larger specific surface areas, lower carrier migration distances, more active surface atoms, and higher elastic strain tolerance play a critical role in the solar to chemical energy conversion scheme, and provide a novel methodology for the synthesis of fine chemicals. This review details the principles of photocatalytic reduction of CO2, and highlights the reduction pathways and product selectivity via experimental methods and theoretical calculations. The state-of-the-art achievements of 2D materials in the field of photocatalytic reduction of CO2 are summarized, mainly including material structure, characteristics, and modification strategies to improve the performance of CO2 reduction. And the research on the combination of 2D materials and single atoms is emphasized. Moreover, bottlenecks and challenges in the design and application of 2D materials, as well as prospects of the future development direction, will be highlighted in order to seek new breakthroughs by exploring new materials design solutions.

Summary The future of sustainable energy supply demands innovative breakthroughs in the design of cheap and durable catalysts for efficient electrochemical water splitting. Distinct from the conventional doping, defecting, and nanostructuring strategy, we develop a simple and feasible electric-strain way to trigger electrocatalyst's structural phase transition via regulating carrier distribution, realizing an excellent hydrogen evolution reaction (HER) performance. Herein, thanks to the intrinsic noncentrosymmetric polarization of our designed Janus MoReS3 nanostructures, large numbers of carriers are energetically pulled into the catalyst's interior to generate electric strain, leading to the deformation of the charged MoReS3 nanosheets and transition from T′ phase to another reversible atomic configuration (T″ phase) with higher catalytic activity and faster carrier transfer. The electric-strain-generated T″-MoReS3 shows HER performances in excess of a commercial Pt/C electrode at large current densities, reaching a current density of 150 mA cm−2 at an overpotential of 189 mV.

The porous structure composed of non-metal elements of covalent organic frameworks (COFs) contributes to a large surface area and multifunction, rendering COFs a brilliant material for energy storage. Unfortunately, the low conductivity of most COFs limits their application in batteries. Herein, we fabricate COF-derived nitrogen-doped porous carbon (NPC) using nitrogen-rich COF-JLU2 as precursors by a simple carbonization for potassium-ion batteries (PIBs) and aluminum (Al) batteries for the first time. The computational results suggest that NPC has an enhanced conductivity and optimized electron density distribution. NPC could overcome the low conductivity of COF and thus further optimize its electrochemical performance in PIBs and Al batteries. It displays an excellent stability even after 2500 cycles (as the anode for PIBs) and 30000 cycles (as the cathode for Al batteries) with a high Coulombic efficiency. This fascinating study may be extended in other COFs for energy storage applications.

One of vital issues that inhibit photoactivity of metal–organic frameworks is the poor electrical conductivity. In this work, one-dimensional mixed-valence iron chains are used to improve this poor...

Structural modulation of catalytic nanostructures and fundamental understanding of their active sites at the atomic scale are important for predicting and improving the catalytic properties of nanostructures. Here, we prepared quasi-one-dimensional (1D) metal molybdenum (Mo) chains confined in atom-thick molybdenum disulfide (MoS2), referred henceforth as Mo/MoS2 nanosheets, and evaluated their hydrogen evolution reaction (HER) properties. The experiment and theoretical calculations show that the quasi-1D Mo chain with unsaturated coordination exhibits high HER activity. The unsaturated Mo sites in the chains increase the carrier density and facilitate the diffusion of hydrogen along the chains, mimicking an atomic scale reactor which leads to an experimentally observed enhanced catalytic performance. Within the framework of Volmer-Tafel model, the calculated kinetic barrier for H2 evolution is only 0.48 eV for Mo/MoS2, which is significantly lower than that for the Pt (111) surface (∼0.8 eV). In particular, Mo/MoS2 nanosheets supported on reduced graphene oxide (Mo/MoS2/RGO) outperformed commercial Pt on glassy carbon (Pt/C) in the practically meaningful high-current region (>140 mA cm−2) in 0.5 M H2SO4 solution and (15 mA cm−2) in 1.0 M NaOH solution, demonstrating that the Mo/MoS2/RGO could potentially replace Pt catalysts in practical HER systems. Additionally, this study provides crucial insights into the role of active centers in catalysis through a model-structure-performance relationship, thus pointing the way to a commercially viable technology for HER.

A broad bandgap and detrimental recombination of photoexcited h+-e− pairs are fatal deficiencies for using the g-C3N4 visible light water splitting. Herein, a sea-urchin-structure g-C3N4 (CNSC) with ∼2.0 eV bandgap was prepared using a hydrothermal strategy. It is important to note that CNSC can efficiently suppress h+-e− pair recombination and has a narrow bandgap which can utilize more visible light. Conventional g-C3N4 has a ∼2.7 eV bandgap and valence band (VB) potential of +1.83 V vs. NHE but the VB of CNSC is +1.55 V. As a result, CNSC does not create H2O2, which can passivate g-C3N4. Density functional theory (DFT) confirms that C N, C O, and OH groups in the CNSC shift the d-band centre of Pt closer to Fermi level, leading to better stabilization of adsorbate and higher catalytic performance. Photo-depositing Pt on the CNSC, 3 wt% Pt/CNSC produces H2 and O2 evolution rate (HER and OER) of 41.5 and 20.3 μmol g-1 h-1 (apparent quantum efficiency: 0.43% at 420 ± 10 nm), respectively, 30 times greater than HER of 2 wt% Pt/bulk g-C3N4 in overall water splitting under visible-light (λ ≥ 420 nm). This work provides an innovative approach to construct hierarchical nanostructure g-C3N4 with narrow bandgap and paves the pathway for development of water splitting photocatalysts.

Solar energy-driven semiconductor photocatalysis has gathered increasing interest in the field of energy and environmental applications. However, a vital problem that limits its application is that photocatalysis requires a continuous light source to perform redox reaction. The ability of keeping catalytic activity in the dark has been the ultimate goal for the wide application of photocatalysis. More and more efforts have been paid to develop photocatalysts to perform photocatalytic reactions under both light and dark conditions, which is so called “round-the-clock photocatalytic system” (RTCPS). RTCPS with an ability of energy storage can work well under both daytime and nighttime, which widely used in the removal of heavy metal ion, the degradation of organic pollutant, disinfection and hydrogen generation. The important potential of RTCPS necessitate timely reviews of the recent advances to streamline efforts. Thus, this review aimed to summarize the recent advances in RTCPS, including the mechanism, characterization techniques and applications. Moreover, future challenge and research direction on the mechanistic study, material design and potential applications are also discussed.

We report an in situ alloying strategy for obtaining homogeneous (Bi,Sb) alloy nanoparticles from (Bi,Sb)2S3 nanotubes for the exceptional anode of potassium ion batteries (KIBs). The operando X-ray diffraction results, along with transmission electron microscopy and energy-dispersive X-ray spectroscopy mappings, successfully reveal the phase evolution of this material, which is (Bi,Sb)2S3 → (Bi,Sb) → K(Bi,Sb) → K3(Bi,Sb) during the initial discharge and K3(Bi,Sb) → K(Bi,Sb) → (Bi,Sb) in the charging process. The in situ alloying strategy produces a synergistic effect and brings an outstanding electrochemical performance. It achieves ultrahigh discharge capacities of 611 mAh g-1 at 100 mA g-1 (0.135C) and 300 mAh g-1 at 1000 mA g-1 (1.35C) and retains a capacity as high as 353 mAh g-1 after 1000 cycles at 500 mA g-1 (0.675C) with a Coulombic efficiency close to 100%. In addition, the KIBs full cell, which is composed of this anode and a perylenetetracarboxylic dianhydride cathode, reaches an initial discharge capacity as high as 276 mAh g-1 at 500 mA g-1 and maintains 207 mAh g-1 after 100 cycles.

To acquire remarkable cathode materials for lithium-sulfur batteries with ultrahigh utilization of active materials and superior cycling stability, we firstly employ carboxylated carbon nanotubes to prepare the NiCo2S4@CNTs/S for lithium-sulfur batteries via a simple hydrothermal method, following by a low temperature annealing. The NiCo2S4@CNTs presents a unique structure, which possesses thin branches filled with densely packed small leaves where a large number of micropores distribute. In the novel superstructure, carboxylated carbon nanotubes can effectively improve the electronic transportation capacity and conductivity of the cathode material. In lithium-sulfur batteries, bimetal sulfides have a strong adsorption of the polysulfides, effectively suppressing the diffusion of lithium polysulfides. The NiCo2S4@CNTs/S electrode shows a capacity of 788 mA h g−1 at the current density of 0.5 C and 758 mA h g−1 at 2 C. Even after 1000 cycles at the current density of 0.6 C the capacity only decays by 0.0489% each cycle. It should be notes that most of Coulombic efficiency of the NiCo2S4@CNTs/S electrode is about 99%, regardless of the current density. More importantly, the NiCo2S4@CNTs can exhibit an outstanding capability of absorbing lithium polysulfides, which provides a promising strategy for preparing advanced lithium-sulfur batteries.

Hydrogenation engineering has been considered as one of the promising methodologies to significantly enhance the visible light absorption and photocatalytic activities of semiconductor photocatalyst. However, hydrogenated catalyst with remarkably elevated photocatalytic activity has been commonly obtained so far under severe conditions such as high temperatures or pressures and huge doses of H2 or plasma activation with complex treatment. Here, we proposed in-situ hydrogenated ZnIn2S4 (HxZIS) obtained at room temperature under UV–vis light illumination within several hours. This extremely facile hydrogenation strategy is based on the discovered fact that H could spontaneously adsorb on the ZnIn2S4 (ZIS) surface to generate durable point defects and even surface disorder, resulting in the largely enhanced solar energy utilization of ZIS. As a result, the hydrogenation engineered the band gap from 2.42 to 1.51 eV, while the optimal bandgap was tuned to ca. 2.08 eV with a ∼10-fold photocatalytic activity promotion. This study is the first paradigm of in-situ hydrogenation of inorganic metal chalcogenide, and we believe that such a facile and general methodology will open up a new pathway to create high-efficiency photocatalyst.

Two-dimensional (2D) layered transition metal sulfide based materials are promising candidates for electrodes of lithium ion batteries (LIBs). As one of the representatives, molybdenum disulfide (MoS2), exhibits additional reversible capacity beyond their theoretical value although the lithium storage mechanism is still poorly understood. In this report, we developed a highly conducting metallic phase 1T(octahedral)-MoS2 based electrode with metal Mo atoms confined in “graphene nanoreactor” of abnormal lithium-storage sites, which delivered a high specific capacity of ~1800 mAh g−1 at 1 A g-1, about 2.6 times of its intercalation reactions value. Contrary to previous reports, a new lithium-storage mechanism for the high and ever-increasing capacity was proposed. The theoretical calculations and experiments show that a major contribution to the extra capacity in MoS2 anodes is due to Mo atoms accommodate with Li+. The Mo precipitates and their full contact with Li2S matrix enabled the reversible Mo→LixMo→Mo→1T-MoS2 reaction during charging/discharging processes. Over prolonged cycling, per Mo atomic could accommodate six Li+ ions. This new proposal could help to establish an accurate electrochemical reaction mechanism of MoS2 LIBs, which may lead to inspiration on new methods to greatly improve the performance of the MoS2 anode.

Visible-light-driven photocatalysis has been widely employed as an efficient and environment-friendly technology for organic pollutants removal from wastewaters. Herein, a novel approach of BiVO4-catalyzed sulfite under visible light irradiation (BiVO4/sulfite/vis) was established to achieve the model contaminant methyl orange (MO) removal. About 92.06% of MO could be rapidly degraded within 50 min in this new catalytic system and the reaction rate was close to 105.29-fold as high as that of BiVO4/vis system. The effects of sulfite amount, catalysis dosage, MO concentration, inorganic anions and natural organic matters (NOMs) were deeply investigated and the correspondent mechanisms were also discussed. Interestingly, the coexisting Cr(VI) at certain concentration would accelerate MO removal and further demonstrated by phenol and atrazine degradation through the Cr(VI) + organic pollutants combined pollution system. The presence of HA in BiVO4/sulfite/vis also exhibited positive effects on the degradation of organic pollutants, attributable to more OH species generation. Three-dimensional excitation-emission matrix fluorescence spectra (3D EEMs) and liquid chromatography-mass spectrometer (LC-MS) were implemented to explore MO degradation pathway. The sulfite (SO3 −) generation was confirmed by active species trapping experiments and electron spin resonance (ESR), and N2 purging reaction was also carried out to exclude the oxidative species of SO3 −. The photoinduced holes played a direct role in the SO3 − generation and the OH radical also contributed. This study provides new thoughts to improve the photodegradation of multiple organic pollutants by the introducing of sulfite or sulfite/Cr(VI).

Exploring and designing an efficient and robust photocatalyst toward the degradation of organic pollutants under nature sunlight irradiation is a challenging research topic. The ability to maintain the photocatalytic activity in the entire daytime will be the ultimate goal for further widespread application of solar energy-driven semiconductor photocatalysis. Here, an all-day-active Z-scheme photocatalytic system is reported by employing Ag@AgI nanoparticles decorated Ag3PO4 cubes (C-Ag3PO4@Ag@AgI). By coupling the pronounced carrier separation as well as increased stability, the C-Ag3PO4@Ag@AgI is capable of performing efficient Rhodamine B (RhB) and bisphenol A (BPA) degradation under sunlight irradiation, and still persist noticeable activity when the light is very weak. The RhB (20 mg/L, 50 mL) can be completely degraded by C-Ag3PO4@Ag@AgI (30 mg) within 1 h with the average luminous power of 117.5 mW (3.14 cm2). Dramatically, the as-prepared samples can still maintain photocatalytic activity even in a cloudy day (0.2–6.7 mW). This work has offered a valuable concept of continuous pollutant removal under nature sunlight irradiation in the entire daytime, which may serve as a model system for the wide environment applications, such as the removal of low-level pollutants under weak light irradiation.

Molybdenum disulfide (MoS2) presents a promising catalyst to replace state-of the-art platinum (Pt) for hydrogen evolution reaction (HER), but it still lacks an effective way due to the catalytically inert basal plane. Herein, we report a rational design of MoS2 nanomesh that possesses evenly distributed holes and defects to make full use of the 2H-MoS2 basal planes by combining ball-milling with ultrasonic methods. The exfoliation of muti-layer MoS2 to fewer layer or enven monolayer is proceed in pure water without using any chemicals or surfactants. The great advantage of the catalyst is the monolayer, holey and defective structure, which maximizing the synergistic activity for both electrocatalytic and photocatalytic HER performances. Impressively, the MoS2 nanomesh renders outstanding electrocatalytic HER activity with an overpotential of 160 mV at a current density of 10 mV cm−2, and a small Tafel slope of 46 mV decade−1. The photocatalytic H2 evolution rate is about 4.84 mmol h−1 when working with Eosin Y as an organic photosensitizer. Additionally, this catalyst shows excellent cycle stability in the electrochemical and photocatalytic reactions. This present work put a new insight into the large-scale production of chemically active 2H MoS2-based catalysts for HER.

g-C3N4 has recently emerged as a promising photocatalyst for solar energy conversion. Nonetheless, attempts to enhance its inherently low activity are rarely based on precise molecular tunability strategy. In this study, two-type cyanamide defects-grafting g-C3N4 (CCN) was prepared through the thermal polymerization of thiourea in the presence of KCl. Stable potassium isothiocyanate (KSCN) was in situ generated via thiourea isomerization and then reacted with different amino groups ( NH2 and NH) in tri-s-triazine rings to obtain two-type cyanamide defects. Theoretical calculations and experiment results confirm that the ratio of the two-type cyanamide defects could be adjusted by KCl dosage, accompanying tunable energy levels of CCN. The charge carrier transfer and separation of CCN was greatly improved. Furthermore, the existence of cyanamide defects hindered the formation of intermolecular hydrogen bonds among g-C3N4, which facilitated the formation of porous structure and exposed more active sites for photocatalytic hydrogen evolution reaction (HER). As a result, the optimized photocatalyst (CCN-0.03) showed a high HER rate of 4.0 mmol g−1h−1, which was 5 times higher than 0.8 mmol g−1h−1 for pristine g-C3N4. And the apparent quantum efficiency reached up to 14.65% at 420 ± 10 nm. The findings deepen the understanding on precise molecular tuning of g-C3N4.

The capability of palladium (Pd) nanoparticles photo-deposited on BiVO4 (BV) nanosheets support to effectively activate persulfate (PS) and degrade pharmaceutical residues amiloride (AML) in aqueous solution under visible light was investigated. The removal efficiency of AML in Pd/BV/PS/vis system reached to 96.43% within 30 min as compared to only 50.73%, 70.87% and 77.70% in BV/vis, Pd/BV/vis and BV/PS/vis respectively under the identical experimental conditions. One inherent reason for the enhanced performance was possibly owing to the fact that visible light absorption of photocatalyst was improved through the surface plasma resonance (SPR) effect of Pd nanoparticles. For another respect, the photo-induced electron-hole pairs separation rate was firstly strengthened with Pd as electron traps and then by PS oxidants as electrons acceptors. Influencing factors including PS dosage, AML concentration, humic acid (HA) concentration, coexisting anions and cations and water sources on the AML degradation in the Pd/BV/PS/vis system were explored in details. Higher photocatalytic activity was still maintained in raw wastewater containing dyes, phenols and antibiotics. More generation of oxidative species such as O2−, OH and SO4 − were verified by radical quenching experiment and electron spin resonance (ESR) test. The major products of AML decomposition were identified and the correspondent degradation pathways were also proposed. This founding allows for the construction of highly efficient BV-based photocatalysts and provides a new opportunity for the treatment of wastewater containing refractory pollutants by SO4 −-based advanced oxidation processes (AOPs).

The high carrier recombination rate and serious photocorrosion of Ag3PO4 greatly restrict its photocatalytic application. Here, we fabricated an Ag3PO4/Ti3C2 Schottky catalyst and found that Ti3C2 can greatly enhanced the catalytic activity and stability of Ag3PO4. This arises from: (i) the abundant surface hydrophilic functional groups of Ti3C2 construct strong interfacial contact with Ag3PO4, which facilitate the separation of carriers; (ii) the strong redox reactivity of surface Ti sites promote multiple electron reduction reactions to induce more OH production; and (iii) a Schottky junction formed at Ag3PO4-Ti3C2 interface timely transfer electrons to Ti3C2 surface by built-in electric field, inhibiting the photocossion of Ag3PO4 caused by photogeneration electrons. Consequently, Ag3PO4/Ti3C2 exhibited excellent photocatalytic activity and stability for the degradation of organic pollutants. Especially, the apparent rate constant of 2,4-Dinitrophenol degradation with Ag3PO4/Ti3C2 was 2.5 times that of Ag3PO4/RGO and 10 times that of Ag3PO4. The photocatalytic performance of Ag3PO4/Ti3C2 toward tetracycline hydrochloride still maintained 68.4% after 8 cycles, while Ag3PO4/RGO and Ag3PO4 only maintained 36.2% and 7.8%, respectively. Furthermore, the efficient photoreduction of Cr6+ using AgI/Ti3C2 further illustrated an enormous potential in coupling Ti3C2 with other photosensitivity semiconductor to improve their catalytic activity and stability.

Lithium–sulfur (Li–S) batteries have attracted great interest because of its high theoretical capacity (1675 mA h g–1). However, the low electrical conductivity of sulfur, dissolution of polysulfides, and structural collapse of electrode limit its practical application. Here an ultrathin honeycomb-like porous carbon derived from loofah sponge and doped with nitrogen (PCLSN) is prepared as a stable host for sulfur nanoparticles. Attributed to the integrated honeycomb structure, hierarchical porosity, ultrathin honeycomb walls, and synergistic effects between physical and chemical adsorption of polysulfides, the developed PCLSN@S cathode achieves a high initial specific capacity of 1379 mA h g–1 at 0.1 C, outstanding cyclability with a small capacity decay rate of 0.044% per cycle over 970 cycles at 2 C, excellent rate performance with a high capacity of 664 mA h g–1 at 3 C, and high sulfur content of PCLSN@S up to 76.1%. Our approach provides a promising route to design other 3D porous structures for high ...

Aluminum (Al) based rechargeable batteries offer the possibilities of safety, high energy density and low cost. Graphene with excellent mechanical properties and high electronic conductivity contributes to the excellent long-term cycle stability and superior rate performance, rendering it an attractive cathode material for Al batteries. However, the synthesis process of the high quality graphene, which is high energy consumption and complex, is not appropriate for the mass application of Al batteries. In this work, we presented a cost-effective and low-temperature (600 °C) synthesis of edge-rich graphene paper for the cathode of Al batteries. The edge-rich and interconnected design of graphene could effectively improve its performance in Al batteries. A reversible capacity as high as 128 mA h g−1 was achieved at 2000 mA g−1. It also displayed a superior cycling stability, displaying no capacity decay and a Coulombic efficiency higher than 99.2% after 20,000 cycles at even a high current density of 8000 mA g−1. Significantly, this novel cathode material would present a new opportunity for the practical application of Al batteries.

Using natural minerals as persulfate activators can develop effective and economical in situ chemical oxidation technology for environmental remediation. Yet, few natural minerals can provide a high activation efficiency. Here, we demonstrate that brochantite (Cu4SO4(OH)6), a natural mineral, can be used as a persulfate activator for the rapid degradation of tetracycline hydrochloride (TC-H). Approximately 70% of TC-H was removed in Cu4SO4(OH)6/PDS within 5 min, which much higher than that of Cu3P (61.99%), CuO (29.75%), CNT (25.83%), Fe2O3, (14.48%) and MnO2 (9.76%). Experiments and theoretical calculations suggested that surface copper acts as active sites induce the production of free radicals. The synergistic effect of Cu/S promotes the cycle between Cu+/Cu2+. Sulfate radicals and hydroxyl radicals are the main reactive oxygen species that are responsible for the rapid removal of TC-H. The findings of this work show a novel persulfate/brochantite system and provide useful information for the environmental remediation.

As a recent addition to the family of van der Waals layered crystals, indium selenide (InSe) possesses unique optoelectronic and photonic properties, enabling high-performance electronic devices for broad applications. Nevertheless, the lithium storage behavior of InSe flakes is thus largely unexplored due to its low electronic conductivity and challenges associated with its exfoliation. Here, we prepare few-layered InSe flakes through liquid-phase exfoliation of wet-chemistry-synthesized layered InSe single crystals, and percolate the flakes with carbon nanotube (CNT) networks in order to form flexible anodes to store lithium (Li). We demonstrate, with the support of CNTs, that exfoliated InSe flakes possess superior Li storage capacity to bulk InSe; the capacity increases over prolonged cycling up to 1224 mA h g−1 from 520 mA h g−1, coupled with excellent rate handling properties and long-term cycling stability. The operando X-ray diffraction results suggest that the alloying of indium with Li dominates the Li storage reactions. By combining with density-functional theory calculations and post-mortem analysis, we believe that the in situ formed indium gradually reduces the domain size, forming nanoclusters which allow the accommodation of 4 Li+ per atomic indium, and leading to extra capacity beyond the traditional theoretical value. This new “nanoscluster alloying” Li storage mechanism may inspire new architectures or methods to synthesize few-layered InSe, thereby presenting broad opportunities for high-performance Li-ion battery anode technologies.

Photocatalytic degradation is an alternative method to remove pharmaceutical compounds from water, however it is hard to achieve efficient rate because of the low efficiency of photocatalysts. In this study, an efficient Z-Scheme photocatalyst was constructed by integrating graphitic carbon nitride (CN) and reduced graphene oxide (rGO) with AP via a simple facile precipitation method. Excitedly, ternary AP/rGO/CN composite showed superior photocatalytic and anti-photocorrosion performances under both intense sunlight and weak indoor light irradiation. NOF can be completely degraded in only 30 min and about 85% of NOF can be mineralized after 2 h irradiation under intensive sunlight irradiation. rGO could work not only as a sheltering layer to protect AP from photocorrosion but also as a mediator for Z-Scheme electron transport, which can protect AP from the photoreduction. This strategy could be a promising method to construct photocatalytic system with high efficiency for the removal of antibiotics under natural light irradiation.

“Memory catalysis” (MC) studies have received appreciable attention recently because of the unique talent to retain the catalytic performance in the dark condition. However, the MC activity is still low owing to the relatively limited electron storage capacity of the present materials. Here, a TiO2@Ag composite was synthesized by a “dark-deposition (DD)” method, which is based on the electron trap effect of TiO2. Unlike traditional photodeposition (PD), an exploration of the morphology and chemical compositions of as-prepared samples shows that DD can inhibit the growth of Ag nanoparticles and the formation of Ag2O, which greatly improve the electron storage capacity. We further demonstrated that the maximum electronic capacity was in the order of TiO2@Ag-DD (1 μmol/mg) > TiO2@Ag-PD (0.35 μmol/mg) > TiO2 (0.11 μmol/mg). Moreover, the enhanced MC activity was confirmed by various degradation experiments. Especially, the use of TiO2@Ag-DD as a round-the-clock catalyst for the degradation of multicomponent p...

Heterogeneous Fenton-like system has been proved to be an promising alternative to Fenton system due to its easy separation. However, it’s a challenge to design heterogeneous Fenton-like catalysts with high activity and great durability. Here, ternary solid solution Fe1-xZnxS were prepared via hydrothermal synthesis as heterogeneous Fenton-like catalysts. The Fe0.7Zn0.3S sample exhibited state of the art activity for yielding OH by H2O2 decomposition, and the ultrafast degradation of phenol was achieved in 4 min at initial acidic condition under room temperature. The phenol degradation rate constant of Fe0.7Zn0.3S was 99 and 70 times of ZnS and FeS, respectively. Further, we show that the unique structural configuration of iron atoms, the formation of FeS2-pyrite with (200) plane, are responsible for the excellent activity. The intermediate products were identified by LC–MS and a possible pathway was accordingly proposed to elucidate the mechanism of phenol degradation by OH. Overall, this work provides an idea for the rational design of the relevant heterogeneous Fenton-like catalysts.

Photoinduced electron transfer and separation from its home atom to form spatial isolated electron/hole pairs is the most crucial factor in artificial photocatalysis field. The scalable production of nanoscale g-C3N4 with remarkable electron separation efficiency in one-step, green, economic and “bottom-up” approach is of great challenge. Herein, one-dimensional porous architectural g-C3N4 nanorods have been facilely prepared by direct calcination of hydrous melamine nanofibers precipitated from aqueous solution of melamine. Porous morphologies with increased interfacial area enhance light capture capacity and accelerate catalysis reaction. It is noted that oxygen atoms were simultaneously doped into g-C3N4 matrix, which broke the symmetry of pristine g-C3N4, resulting in more effective separation of electron/hole pairs. Thus, the oxygen-doped g-C3N4 nanorods loaded with Pt presented excellent visible-light photocatalytic hydrogen evolution in the triethanolamine solution (732 μmol g−1 h−1) and in overall water splitting (29.6 μmol g−1 h−1), and 2,4-dinitrophenol degradation for O-doped g-C3N4 nanorod (removal efficiency of 100% within 75 min). Subsequently, the visible-light photocatalytic H2 evolution (96 μmol g−1 h−1) with simultaneous 2,4-dinitrophenol degradation were achieved for Pt@g-C3N4 nanorod. The proposed synthesis strategy overcomes long-standing, stubborn and serious stacking/agglomeration for g-C3N4 synthesis, and paves the pathway for industrial scale-up production of high-performance g-C3N4 and application in practical energy and environment area.

The development of new rechargeable safe battery with high energy density and low cost is one of the most desirable goals for personal electronics and grid storage. Aluminum based rechargeable ion batteries offer the possibilities for safe, high energy density and low cost. Here, we developed a novel aluminum based high-rate capability dual-ion battery with an aluminum anode and a 3D graphene cathode. The battery operated through the electrochemical deposition and dissolution of aluminum at the anode, and intercalation/de-intercalation of ClO 4 - anions in the graphene based cathode with a new Al(ClO 4 ) 3 /Propylene carbonate - Fluoroethylene carbonate electrolyte. The battery exhibited high discharge voltage plateaus (about 1 V), high-rate capacity (101 mA h g -1 at 2000 mA g -1 ) and long cycle life (more than 400 cycles). More importantly, the battery also showed superior electrochemical properties with fast charge and slow discharge (the battery could be fully charged in 13 min and discharged for more than 73 min). And the reaction mechanisms of the aluminum based dual-ion battery is also proposed and discussed in detail.

A novel full spectrum light driven carbon quantum dots (CQDs)/Bi2WO6 (CBW) hybrid materials were synthesized via a facile hydrothermal method. Multiple techniques including XRD, TEM, XPS, BET, UV–vis, XPS, PL and TRPL, were employed to investigate the structures, morphology, optical and electronic properties and photocatalytic performance of as-prepared samples. The results indicated that CBW heterojunctions were assembly of CQDs on m-BWO and presented high separation efficiency of photo-generated carriers and full light spectrum absorption. The photocatalytic mechanism of CBW hybrid materials was revealed, suggesting that the excellent photocatalytic activity towards organic pollutants was ascribed to the up converted photoluminescence (PL) and electron reservoir properties of CQDs. Density functional theory calculations indicated that complementary conduction and valence band-edge hybridization between CQDs and m-BWO could apparently increase separation efficiency of electron-hole pairs of CBW hybrid materials. According to ESR measurement and quenching experiments, the O2 −, OH and h+ were the main active species during the photocatalytic process. This study could shed light on 0D/2D interface engineering of carbon quantum dots based heterojunctions with enhanced photoactivity for full spectrum light utilization in pollutant degradation and energy conversion.

A three-dimensional (3D) reduced graphene oxide–Mn3O4 nanosheet (Mn3O4@rGO) hybrid was achieved by simple electrodeposition technique. Small palladium nanoparticle were homogeneously anchored onto Mn3O4@rGO substrate through the reduction of palladium salt. The interpenetrating network architecture of Mn3O4@rGO greatly inhibited the aggregation of 2D sheets of Mn3O4 and rGO, and the open 3D orientation of the Mn3O4@rGO hybrid nanosheets on the electrode facilitated both mass transport and electron transfer as well as maximally exposed active sites. The introduction of Mn3O4 enhanced the structural and electrochemical stability of rGO. The as-synthesized Pd/Mn3O4@rGO hybrid was employed as an electrocatalyst for electrocatalytic hydrogen evolution reaction (HER). The electrocatalyst showed a low overpotential of 20 mV at 10 mA cm−2, a small Tafel slope of 48.2 mV dec−1, and a large exchange current density of 0.59 mA cm−2. Importantly, the catalyst possessed superior durability with 85.87% of catalytic activity after a long-time test (10 h). This work presents a simple and efficient stratagy to construct high-performance electrocatalysts for energy and environmental applications.

The ultrathin thickness and lateral morphology of a two dimensional (2D) MoS2 nanosheet contribute to its high surface-to-volume ratio and short diffusion path, rendering it a brilliant electrode material for lithium-ion batteries (LIBs). However, the low conductivity and easy restacking character of the pure MoS2 nanosheet during extended cycling result in severe capacity fading and poor cycling performance. In this work, we developed an attractive strategy by using a metal-doping method to engineer chemical, physical and electronic properties of MoS2, achieving an outstanding performance in LIBs. The computational results show that V–Mo–S has semimetallic properties. Semimetallic vanadium molybdenum sulfide nanoarrays (V–Mo–S NAs) were prepared to overcome the low conductivity of semiconducting MoS2 and thus further optimize its performance in LIBs. A reversible capacity as high as 1047 mA h g−1 was achieved at 1000 mA g−1. It also displayed an excellent stability even after 700 cycles. This fascinating study may pave a way for utilizing semimetallic material-based nanomaterials for batteries.

Studies on the removal of As(III) by Fe-based materials have been carried out for decades, but the time-consuming process and low removal capacity are obstacles for large-scale practical applications. Here, a rapid and efficient technique was proposed for the removal of As(III) using Cu-doped Fe@Fe2O3 core–shell nanoparticles (CFF) synthesized by a facile two-step reduction method and aging process, which realized a thorough removal of As(III) from smelting wastewater at neutral pH within 30 min. The copper doped in CFF not only provided two extra oxygen reduction pathways to enhance the molecular oxygen activation, but also improved the electron transfer ability and removal efficiency of As(III). The existence of copper contributed to the rapid oxidization and adsorption of As(III), and the removal rate increased nearly 10-times in the aerobic system. Meanwhile, the proposed Cu-doped Fe@Fe2O3 core–shell nanoparticles and shifted oxygen reduction pathway could be easily scaled up for other transition metals, such as Ni. Molecular dynamics (MD) simulations based on the large-scale atomic/molecular massively parallel simulator (LAMMPS) were also employed to investigate the formation process of CFF. Furthermore, the removal efficiency of arsenic in smelting wastewater remained to be 90% after 6 times of cycling. Therefore, the distinctive oxidation activities of CFF hold great promise for applications in arsenic removal.

It is highly demanded to steer the charge flow in photocatalysts for efficient photocatalytic hydrogen reactions (PHRs). In this study, we developed a smart strategy to position MoS2 quantum dots (QDs) at the S vacancies on a Zn facet in monolayered ZnIn2S4 (Vs-M-ZnIn2S4) to craft a two-dimensional (2D) atomic-level heterostructure (MoS2QDs@Vs-M-ZnIn2S4). The electronic structure calculations indicated that the positive charge density of the Zn atom around the sulfur vacancy (Vs) was more intensive than other Zn atoms. The Vs confined in monolayered ZnIn2S4 established an important link between the electronic manipulation and activities of ZnIn2S4. The Vs acted as electron traps, prevented vertical transmission of electrons, and enriched electrons onto the Zn facet. The Vs-induced atomic-level heterostructure sewed up vacancy structures of Vs-M-ZnIn2S4, resulting in a highly efficient interface with low edge contact resistance. Photogenerated electrons could quickly migrate to MoS2QDs through the intimate...

It is attractive to photocatalytically purify wastewater and simultaneously convert solar energy into clean hydrogen energy. However, it is still a challenge owing to the relatively low photocatalytic efficiency of photocatalysts. In this study, we synthesized a molybdenum disulfide (MoS 2 ) quantum dot-decorated 3D nanoarchitecture (MoS 2 QDs) of indium zinc sulfide (ZnIn 2 S 4 ) and reduced grapheme oxide (MoS 2 QDs@ZnIn 2 S 4 @RGO) photocatalyst using a simple solvothermal method. The RGO promotes the electron transfer, and the highly dispersed MoS 2 QDs provides numerous catalytic sites. The photocatalytic purification of rhodamine B (RhB), eosin Y (EY), fulvic acid (FA), methylene blue (MB) and p -nitrophenol (PNP) in simulated wastewaters were further tested. The degradation efficiencies and TOC removal were 91% and 75% for PNP, 92.2% and 72% for FA, 98.5% and 80% for MB, 98.6% and 84% for EY, and 98.8% and 88% for RhB, respectively (C organics = 20 mg/L, C catalyst = 1.25 g/L, t = 12 h, I light = 3.36 × 10 −5 E L −1 s −1 ). Among these tests, the highest hydrogen production was achieved (45 μmol) during RhB degradation. Both experimental and calculational results prove that lower LUMO (lowest unoccupied molecular orbit) level of organic molecules was available for transferring electrons to catalysts, resulting in more efficient hydrogen production. Significantly, the removal efficiencies of natural organic substances in actual river water reached 76.3–98.4%, and COD reduced from 32 to 16 mg/L with 13.8 μmol H 2 production after 12 h.

Molybdenum disulfide (MoS 2 ) is a promising non-precious-metal cocatalyst to replace scarcity and cost Pt, but still suffers from less active sites and poor electrical transport due to the unoptimized geometrical configuration of MoS 2 on the semiconductor surface. Here, two different morphological and structural CdS/MoS 2 heterostructures were successfully prepared by a simple hydrothermal reaction with glucose-assisted or not. With the help of glucose, the MoS 2 nanosheets can nearly vertical stand on the CdS nanowires, which do not have the characteristic stacked layer structure of MoS 2 . This unique configuration leads to a high exposure of the active edge sites and increases charges separation and transfer rate. As expected, the 1D/2D nearly vertical CdS/MoS 2 heterostructures exhibited excellent photocatalytic activity and good durability even after being reused five times. Simultaneously, an apparent quantum yield can be reached to 60.3% at 420 nm, which was the advanced performance among all CdS/MoS 2 composites. This work will provide an intriguing and effective approach on design of low-cost and efficient photocatalysts for enhanced HER performance.

The development of efficient visible light photocatalysts for refractory organic pollutant degradation has gained considerable attention in wastewater treatment. Here, close-connected AgI/Bi 5 O 7 I (AI/BOI) heterojunctions were successfully synthesized by a facile deposition–precipitation approach. Multiple antibiotics, including tetracycline, deoxytetracycline, oxytetracycline, and ciprofloxacin, were employed as target pollutants to evaluate the visible light photoactivity of the prepared samples. The obtained AI/BOI-5 exhibited optimal photocatalytic activity and photoelectric property, which was 8.62 times (tetracycline degradation rate) and 12.44-fold (photocurrent intensity) than those of bare BOI, respectively. The strengthened visible light absorption and effective separation and transfer of the photoinduced electrons and holes should be responsible for the improvement of photocatalytic performance. The mineralization ability comparison was explored by total organic carbon and three-dimensional excitation–emission matrix fluorescence spectra measurements. The AI/BOI-5 also revealed good adaptability to higher initial contaminant concentrations and desired photodegradation stability in practical applications. By the studies of reactive species trapping, electron spin resonance and nitroblue tetrazolium agent of O 2 − transformation experiments verified that O 2 − , h + , and OH were all produced in AI/BOI photocatalytic systems, while only O 2 − and h + worked during BOI photolysis. A possible Z-scheme heterojunction mechanism can be ascribed to the enhanced photocatalytic degradation of multiple antibiotics induced by AI/BOI. This work gives deep insight into heterostructured photocatalysis and provides a novel way to construct and design highly efficient photocatalysts for water purification.

We first report a novel cobalt-phosphide (Co-P) hybrid with flake-like structure by a facile one-step electrodeposition combined with in-situ potentiostatic activation technique. Exotic microstructure transformation of Co-P hybrid from microspheres to nanosheets has been noted during the activation process. The Co-P catalyst exhibits striking kinetic metrics with an overpotential of 85 mV (at 10 mA cm–2) and Tafel slope of 37 mV dec–1, performing among the best of all the HER catalysts in strong alkaline media (at pH 14). This study offers a new in-situ approach to optimize catalytic materials for high-performance electrocatalysts towards energy-related applications.

Although photocatalytic degradation is an ideal strategy for cleaning environmental pollution, it remains challenging to construct a highly efficient photocatalytic system by steering the charge flow in a precise manner. In this study, a novel atomic scale g-C3N4/Bi2WO6 heterojunction (UTCB) constructed by ultrathin g-C3N4 nanosheets (ug-CN) and monolayer Bi2WO6 nanosheets (m-BWO) was successfully prepared by hydrothermal reaction. The UTCB heterojunctions were characterized by various techniques including XRD, TEM, AFM, BET measurements, UV–vis spectrometry, and XPS. The results indicated that UTCB heterojunctions were assembly of m-BWO on ug-CN and presented high separation efficiency of photogenerated carriers. Under visible light irradiation, the optimum molar ratio of ug-CN/m-BWO (1:4, UTCB-25) reached almost 96.1% removal efficiency of IBF within 1 h, which was about 2.7 times as that of pure m-BWO. The photocatalytic mechanisms of UTCB-25 were revealed, suggesting that the synergistic effect of UTCB-25 heterojunction with strong interfacial interaction promoted the photoinduced charge separation. According to the LC–MS/MS, five photodegradation pathways of IBF under visible light irradiation were proposed. This study could open new opportunities for the rational design and a better understanding of atomic scale two dimensions/two dimensions (2D/2D) heterojunctions in environmental or other applications.

Sodium ion batteries (SIBs) have attracted extensive attention in recent years. However, the large volume change of cathode materials during the charge and discharge processes impedes the progress and application of SIBs. In this paper, three-dimensional (3D) tetsubo-like Beta-iron oxy-hydroxide (β-FeOOH) nano-cuboids on carbon nanotubes (CNTs) are synthesized by a simple solution method and used as cathode for SIBs. The β-FeOOH exhibits a (2×2) tunnel-type configuration, which can provide huge space for reversible sodium. The radial distribution of β-FeOOH nano-cuboids on the CNTs provides plenty cushion space and sufficient contact area with electrolyte during charge and discharge processes. Furthermore, the CNTs can enhance the electric conductivity and prevent the nanocomposite from agglomeration. Benefiting from the unique structure, the hybridization nanocomposite delivers a high initial discharge capacity (271 mA h g−1 at 10 mA g−1), long cycle life (120 mA h g−1 after 150 cycles with ~0.1% capacity decay per cycle at 120 mA g−1) and high rate performance (118 mA h g−1 at a current density of 240 mA g−1). These results indicate that the β-FeOOH@CNTs nanocomposite electrode may be a promising candidate for SIBs. Our work may provide a new way to construct and design high-performance cathode electrode materials for SIBs and related systems.

The serious photocorrosion of silver phosphate (Ag 3 PO 4 ) has limited its practical applications. In this work, we propose a strategy to suppress its photocorrosion by the construction of a Z-Scheme photocatalytic system, which composed of reduced graphene oxide-enwrapped Ag 3 PO 4 (Ag 3 PO 4 @RGO) and La,Cr-codoped SrTiO 3 (La,Cr:SrTiO 3 ). Dramatically, this system shows superior anti-photocorrosion and photocatalytic performances in degradation of both RhB and 2,4-DNP. Especially for RhB, it can be completely degraded after only 5 min under intense sunlight irradiation. The improved photoactivity and anti-photocorrosion of Ag 3 PO 4 @RGO@La,Cr:SrTiO 3 can be attributed to the following: (i) The sufficient interfacial contact between Ag 3 PO 4 and RGO is favorable to transfer the carriers and lengthen the lifetime of it; (ii) the package of Ag 3 PO 4 with RGO could work as a sheltering layer to protect Ag 3 PO 4 from photocorrosion. (iii) The aggregation of photogenerated holes in the VB of Ag 3 PO 4 makes it a rich-hole region due to Z-Scheme electrons transport mechanism, which can protect Ag 3 PO 4 from the photo-reduction. This strategy provides a new thought of protecting photosensitive semiconductor from photocorrosion and could regard as an efficient application method for environmental cleaning under natural sunlight irradiation. Furthermore, it even could be extended to outdoor or indoor air cleaning in the future.

In this paper, novel popcorn balls-like ZnFe 2 O 4 -ZrO 2 composite microspheres were successfully fabricated by a simple hydrothermal method. The morphology, structure and optical property of the microspheres were characterized. The microspheres were used as the photocatalysts to degrade 2,4-dinitrophenol, and exhibited superior photocatalytic performance. Under simulated solar visible light irradiation, the degradation rate of ZnFe 2 O 4 -ZrO 2 photocatalyst (mass ratio of ZnFe 2 O 4 /ZrO 2 = 2:1) was almost 7.4 and 2.4 times higher than those of pure ZnFe 2 O 4 and ZrO 2 . The enhancement could attribute to stronger light absorption, lower carrier recombination and multi-porous structure of the microspheres. Moreover, the popcorn balls-like photocatalysts can be easily separated, because of the magnetism of the samples. After five times runs, the photocatalyst still showed 90% of its photocatalytic degradation efficiency. This work demonstrated a good prospect for removing organic pollutants in water.

The metallic 1T-MoS2 has attracted considerable attention as an effective catalyst for hydrogen evolution reactions (HERs). However, the fundamental mechanism about the catalytic activity of 1T-MoS2 and the associated phase evolution remain elusive and controversial. Herein, we prepared the most stable 1T-MoS2 by hydrothermal exfoliation of MoS2 nanosheets vertically rooted into rigid one-dimensional TiO2 nanofibers. The 1T-MoS2 can keep highly stable over one year, presenting an ideal model system for investigating the HER catalytic activities as a function of the phase evolution. Both experimental studies and theoretical calculations suggest that 1T phase can be irreversibly transformed into a more active 1T′ phase as true active sites in photocatalytic HERs, resulting in a "catalytic site self-optimization". Hydrogen atom adsorption is the major driving force for this phase transition.

The scrupulous design of hierarchical structure and highly active crystal facets exposure is essential for the creation of photocatalytic system. However, it is still a big challenge for scrupulous design of TiO2 architectures. In this paper, bird’s nest-like anatase TiO2 microstructure with exposed highly active (001) surface has been successfully synthesized by a facile one-step solvothermal method. Methylene blue (MB) is chosen as a model pollutant to evaluate photocatalytic activity of as-obtained TiO2 samples. The results show that the photocatalytic activity of the bird’s nest-like sample is more excellent than P25 in the degradation of MB due to high specific surface area and highly active (001) crystal facets exposure when tested under simulated solar light. Besides, it can be readily separated from the photocatalytic system by sedimentation after photocatalytic reaction, which is a significant advantage against conventional powder photocatalyst. The bird’s nest-like microspheres with novel structure may have potential application in photocatalysis and other fields.

Molybdenum disulfide (MoS2) is a promising non-precious-metal catalyst, but its performance is limited by its density of active sites and poor electrical transport. Here, we report the design and preparation of cracked monolayer 1T MoS2 with a porous structure through the ultrasonication enhanced lithium intercalation of hydrothermally synthesized MoS2 nanosheets. The unique resulting catalyst can have more active sites introduced via the formation of porosity within the monolayer nanosheet, and the electrical transport ability can be increased through the change in electronic states from semiconducting in the 2H phase to metallic in the 1T phase. As is expected, the cracked monolayer 1T MoS2 exhibited good durability and an excellent hydrogen evolution reaction performance with a low overpotential (at 10 mA cm−2) of 156 mV (V vs. RHE) in acid media and a small Tafel slope of 42.7 mV dec−1. This work will provide an intriguing and effective approach to designing electrocatalysts based on MoS2 or other layered materials with enhanced HER performance.

Potassium‐ion batteries (KIBs) are one of the most appealing alternatives to lithium‐ion batteries, particularly attractive in large‐scale energy storage devices considering the more sufficient and lower cost supply of potassium resources in comparison with lithium. To achieve more competitive KIBs, it is necessary to search for anode materials with a high performance. Herein, the bimetallic oxide Sb2MoO6, with the presence of reduced graphene oxide, is reported as a high‐performance anode material for KIBs in this study, achieving discharge capacities as high as 402 mAh g−1 at 100 mA g−1 and 381 mAh g−1 at 200 mA g−1, and reserving a capacity of 247 mAh g−1 after 100 cycles at a current density of 500 mA g−1. Meanwhile, the potassiation/depotassiation mechanism of this material is probed in‐depth through the electrochemical characterization, operando X‐ray diffraction, transmission electron microscope, and density functional theory calculation, successfully unraveling the nature of the high‐performance anode and the functions of Sb and Mo in Sb2MoO6. More importantly, the phase development and bond breaking sequence of Sb2MoO6 are successfully identified, which is meaningful for the fundamental study of metal‐oxide based electrode materials for KIBs.

Herein, Ag3PO4/mixed-valence MIL-88A(Fe) [AMM] Z-scheme heterojunctions with an in-situ-generated photo–Fenton process were successfully constructed. The optimized AMM-20 heterojunctions show the maximum rate of photocatalytic TC degradation, which is 2.5 and 6.6 times of pristine Ag3PO4 and MIL-88A(Fe). The electronic and band structures of Ag3PO4, MIL-88A(Fe), m-MIL-88A(Fe) and AMM heterojunctions were deeply investigated by both experimental and theoretical simulation. The Z-scheme transfer pathway greatly accelerates the transfer rate of charge carriers and effectively inhibits the photocorrosion, leading to the improvement of photocatalytic activity and photostability. Moreover, the adjustment of the FeII/FeIII ratio of mixed-valence MIL-88A(Fe) further enhances the photocatalytic activity of the hybrid photocatalysts, benefiting from the promotion of the efficiency of the in-situ-generated photo-Fenton process. The Z-scheme transfer route coupling with an in-situ-generated photo–Fenton process was verified by the free radical trapping experiment, in-situ XPS measurement, in-situ ESR measurement, and coumarin fluorescence analysis. The degradation pathways of TC were determined through LC-MS analysis and theoretical calculation. Furthermore, the toxicity of intermediates was evaluated by QSAR prediction.

Molybdenum disulfide (MoS2) is considered as one of the most effective materials which can supersede the high cost and scarcity of metal platinum (Pt) for the hydrogen evolution reaction (HER). One road block lying in access to high catalytic performance of MoS2 emanates from the inert basal plane. To enable inert basal plane of flexible MoS2, we demonstrate an effective synthesis strategy via the progressive transformation of MoS2 to MoS2-xOx with O atomically dispersed under actual photo-catalytic hydrogen evolution condition. The rate of hydrogen production of new reconstructed MoS2-xOx nanosheets is improved to be much higher than that of the initial MoS2. Our theoretical calculation results indicate that the appropriate O substitution and strain could modulate the surface electronic state and optimize the Gibbs free energy (ΔGH) of MoS2, thus dramatically accelerating the catalytic efficiency. This work showcases a promising route to achieve tunable photochemical reconstruction by optimizing the electronic structure for low-cost and robust MoS2-based HER catalysts.

The optimized geometrical configuration of muitiple active materials into hierarchical nanoarchitecture is essential for the creation of photocatalytic degradation system that can mimic natural photosynthesis. A bamboo-like architecture, CuO nanosheets and Ag nanoparticles co-decorated TiO2 nanotube arrays (Ag/CuO/TiO2), was fabricated by using simple solution-immersion and electrodeposition process. Under simulated solar light irradiation, the 2,4-dinitrophenol (2,4-DNP) photocatalytic degradation rate over Ag/CuO/TiO2 was about 2.0, 1.5 and 1.2 times that over TiO2 nanotubes, CuO/TiO2 and Ag/TiO2, respectively. The enhanced photocatalytic activity of ternary Ag/CuO/TiO2 photocatalyst was ascribed to improved light absorption, reduced carrier recombination and more exposed active sites. Moreover, the excellent stability and reliability of the Ag/CuO/TiO2 photocatalyst demonstrated a promising application for organic pollutant removal from water.

A new hierarchical nanoarchitecture with integration of multiple active materials has been developed for highly efficient hydrogen evolution reaction (HER), by decorating a perpendicular hybrid of MoS2 and N-doped graphene nanosheets with CdS nanoparticles. The unique architecture promoted light trapping and absorption for highly efficient light harvesting and photocarrier generation, and offered an unblocked electron transport pathway for rapid charge separation/transport to suppress charge recombination. Its high surface area and high density of active sites result in highly efficient utilization of photogenerated carriers for productive HER. Significantly, without using noble metals as co-catalysts, the photocatalysts demonstrated rapid HER rates as high as 5.01 mmol h−1 g−1 under visible-light irradiation, which was approximately 25 times that of pure CdS. The hydrogen production remained stable after a continued test for 30 h, showing an exceedingly high performance and superior stability.

The scrupulous design and integration of multiple active materials into hierarchical nanoarchitectures is essential for the creation of photocatalytic hydrogen evolution reaction (HER) system that can mimic natural photosynthesis. Here we report the design and preparation of a “cauline leaf”-like structure for highly efficient HER, by decorating TiO2 nanofibers with vertical arrays of atomically-thin MoS2 nanosheets and CdS nanocrystals. The unique integrated “cauline leaf” design can promote light trapping and absorption for highly efficient light harvesting and photocarrier generation, and offer unblocked electron transport pathway for rapid charge separation/transport to suppress charge recombination, as well as high surface area and high density of active sites for highly efficient utilization of photo-generated carriers for productive HER. Structural characterizations by transmission electron microscopy show well-integrated nanoarchitectures. Significantly, photocatalytic studies demonstrate rapid HER rates as high as 12.3 or 6.2 mmol h−1 g−1 under simulated solar light or visible light irradiation, with apparent quantum efficiencies of 70.5% at 365 nm or 57.6% at 420 nm, and excellent long term stability, representing one of the best reported MoS2 hybrid HER photocatalysts. The study could open new opportunities for the rational design of nanoscale architectures for HER or other application.