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Zinc‐ion batteries (ZIBs) have attracted considerable attention and global interest due to their high gravimetric and high volumetric capacities (820 mAh g−1 and 5855 mAh cm−3). However, the Zn protrusions/dendrites during the plating/stripping process of Zn (Zn2+) severely affect the performance of Zn anode, causing a low Coulombic efficiency, rapid degradation of capacity, and even failure of Zn‐anode‐based batteries. In order to reduce the dendritic deposition of Zn, the key is to adjust the initial uniform nucleation, which determines the subsequent uniform deposition of Zn. Herein, a cathode material (MnO2) ultrathin film is first modified on the surface of the carbon cloth as active sites for the in situ nucleation and directed epitaxial growth of metal Zn. As a result, the CC@MnO2‐UTF@Zn anode can be cycled in aqueous electrolyte and maintain stable cycling performance during repeated Zn deposition/stripping processes. Subsequently, the CC@MnO2‐UTF@Zn anode and CC@MnO2 cathode are assembled into full cells, which deliver a superior electrochemical performance. Moreover, the flexible solid‐state ZIBs with the CC@MnO2‐UTF@Zn anode show excellent capacities and high energy/power densities, which is superior to the most reported results so far. This work provides a new strategy to design an advanced flexibility Zn anode toward future high‐performance wearable electronic ZIBs. [ABSTRACT FROM AUTHOR]

To achieve highly efficient photoelectrochemical (PEC) water splitting, great efforts have been dedicated to develop various photoelectrode materials in pure water electrolytes. Recently, some studies are turning to hydrogen production from seawater or wastewater, to save valuable freshwater resources and make waste profitable. Here, we fabricate one-dimensional SnO2@BiVO4 core–shell nanorod arrays decorated with cobalt-phosphate cocatalyst (1D SnO2@BiVO4/Co-Pi NRAs), which show efficient charge separation and transport properties due to the rational design of conducting core-layer and introduction of the cocatalyst. The as-obtained SnO2@BiVO4/Co-Pi photoanodes exhibit largely enhanced PEC water oxidation performance: the maximum photocurrent density of 2.63 mA cm−2 at 1.23 V vs. RHE is 6.58 times higher than that of pristine BiVO4 films (∼0.40 mA cm−2). Moreover, the ternary photoanode exhibits promising PEC performance for urea oxidation, giving rise to a current density of 3.44 mA cm−2 at 1.23 V vs. RHE in a neutral urea electrolyte. This work presents a sunlight-driven, eco-friendly and sustainable method to produce hydrogen and simultaneously treat urea-rich wastewater. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is an efficient and clean strategy to produce sustainable energy productions (especially hydrogen) from earth-abundant water. Recently, layered double hydroxide (LDH)-based materials have gained increasing attentions as promising electrocatalysts for water splitting. Designing LDHs into hierarchical architectures (e.g., core-shell nanoarrays) is one of the most promising strategies to improve their electrocatalytic performances, owing to the abundant exposure of active sites. This review mainly focuses on recent progress on the synthesis of hierarchical LDH-based core-shell nanoarrays as high performance electrocatalysts for electrochemical water splitting. By classifying different nanostructured materials combined with LDHs, a number of LDH-based core-shell nanoarrays have been developed and their synthesis strategies, structural characters and electrochemical performances are rationally described. Moreover, further developments and challenges in developing promising electrocatalysts based on hierarchical nanostructured LDHs are covered from the viewpoint of fundamental research and practical applications. [ABSTRACT FROM AUTHOR]

The development of bifunctional electrocatalysts towards both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is promising for highly efficient overall water splitting to meet sustainable energy demands. In this work, a bifunctional electrocatalyst based on ultrathin transition metal selenide nanosheet arrays (NSAs) for both the OER and HER has been designed and synthesized. The as-obtained (Ni,Co)0.85Se NSAs give excellent electrochemical activity and high long-term stability under alkaline conditions, with a low overpotential of 169 mV at a current density of 10 mA cm−2 for the HER and an overpotential of 287 mV at a current density of 20 mA cm−2 for the OER. Furthermore, (Ni,Co)0.85Se NSAs exhibit superior performance and durability toward overall water splitting with a cell voltage as low as 1.65 V at a current density of 10 mA cm−2 and a long-term stability of 50 h, which makes (Ni,Co)0.85Se NSAs a promising alternative for electrochemical hydrogen generation. [ABSTRACT FROM AUTHOR]

A highly-matched semiconductor/cocatalyst is crucial to enhance the bulk charge separation and surface reaction kinetics of the photoelectrode in the solar water splitting system. In this work, well-aligned, hierarchical zinc-iron layered double hydroxide (LDH) is in situ synthesized on the surface of TiO 2 by a facile and effective photo-assisted electrodeposition (PED) method. An experimental-computational combination study reveals that the photogenerated holes of TiO 2 tend to travel to ZnFe-LDH which enhances the bulk charge separation; while ZnFe-LDH acts as a cocatalyst which accelerates the surface water oxidation reaction. The resulting TiO 2 /ZnFe-LDH-PE photoanode exhibits a largely enhanced PEC performance: the photocurrent density at 1.0 V vs. RHE is 2.29 and 1.31 times higher than that of the pristine TiO 2 and TiO 2 /ZnFe-LDH-E (prepared by a conventional electrosynthesis method) photoanode, with 150 mV and 50 mV of negative shift for onset potential. This can be ascribed to the enhanced interface interaction and highly-matched band structure between ZnFe-LDH and TiO 2 . It is expected that this strategy can be extended to other heterostructures for advanced performance in the fields of energy conversion and storage. [ABSTRACT FROM AUTHOR]

Arsenic contaminated water and soil is seriously threatening the ecosystems safety and human health. Specially, the As(III) has higher toxicity, mobility and lower affinity to typical adsorbents, thus posing substantial obstacles for remediation. Herein, we report a zinc-iron layered double hydroxide (ZnFe-LDH) that exhibits high removal capacity of 134.5 mg/g toward As(III) with the aid of photo-oxidation at the initial concentration of 200 mg/L with pH of 8.4, and can efficiently reduce the total concentration of As from 20 mg/L to 8.2 μg/L within 240 min, lower than the 10 μg/L upper limit for As in drinking water. Detailed investigations suggested that the active oxidative species of photogenerated holes, superoxide and hydroxyl radicals take part in the transformation of As(III) to As(V), which enhances the adsorption capacity. For As(III)-pollutant soil remediation, the bioavailability of As in soil dramatically decreased by 87.7% and 78.1% under visible and nature light in 3 days after introduction of ZnFe-LDH as in-situ immobilization amendment. Moreover, the plant cultivation experiment demonstrated that the bioaccumulation of As in Brassica chinensis effectively reduced to safety range after remediation of the As(III)-contaminated soil with ZnFe-LDH. We envision that the strategy of photocatalytic oxidation will open a new door to address the problem of As(III)-contaminated water and soil. • Photogenerated active oxidative species play great effect on the removal of As(III). • The capture capacity of ZnFe-LDH to As(III) reach to 134.5 mg/g. • The bioavailability of As in soil obviously decreased with ZnFe-LDH as stabilizer. • ZnFe-LDH can effectively reduce the As accumulation in vegetables. [ABSTRACT FROM AUTHOR]