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Electrocatalytic water splitting, as a sustainable, pollution-free and convenient method of hydrogen production, has attracted the attention of researchers. However, due to the high reaction barrier and slow four-electron transfer process, it is necessary to develop and design efficient electrocatalysts to promote electron transfer and improve reaction kinetics. Tungsten oxide-based nanomaterials have received extensive attention due to their great potential in energy-related and environmental catalysis. To maximize the catalytic efficiency of catalysts in practical applications, it is essential to further understand the structure–property relationship of tungsten oxide-based nanomaterials by controlling the surface/interface structure. In this review, recent methods to enhance the catalytic activities of tungsten oxide-based nanomaterials are reviewed, which are classified into four strategies: morphology regulation, phase control, defect engineering, and heterostructure construction. The structure–property relationship of tungsten oxide-based nanomaterials affected by various strategies is discussed with examples. Finally, the development prospects and challenges in tungsten oxide-based nanomaterials are discussed in the conclusion. We believe that this review provides guidance for researchers to develop more promising electrocatalysts for water splitting. [ABSTRACT FROM AUTHOR]

Constructing a heterogeneous interface using different components is one of the effective measures to achieve the bifunctionality of nanocatalysts, while synergistic interactions between multiple interfaces can further optimize the performance of single-interface nanocatalysts. The non-precious metal nanocatalysts MoS2/NiSe2/reduced graphene oxide (rGO) bilayer sandwich-like nanostructure with multiple well-defined interfaces is prepared by a simple hydrothermal method. MoS2 and rGO are layered nanostructures with clear boundaries, and the NiSe2 nanoparticles with uniform size are sandwiched between both layered nanostructures. This multiple-interfaced sandwich-like nanostructure is prominent in catalytic water splitting with low overpotential for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) and almost no degradation in performance after a 20 h long-term reaction. In order to simulate the actual overall water splitting process, the prepared nanostructures are assembled into MoS2/NiSe2/rGO||MoS2/NiSe2/rGO modified two-electrode system, whose overpotential is only 1.52 mV, even exceeded that of noble metal nanocatalyst (Pt/C||RuO2~1.63 mV). This work provides a feasible idea for constructing multi-interface bifunctional electrocatalysts using nanoparticle-doped bilayer-like nanostructures. [ABSTRACT FROM AUTHOR]

Li et al. [[3]] fabricated a CoFe SB 2 sb O SB 4 sb /g-C SB 3 sb N SB 4 sb composite catalyst with CoFe SB 2 sb O SB 4 sb particles supported on the flaky g-C SB 3 sb N SB 4 sb using a scalable facile method. However, currently, Li-S batteries suffer from low volumetric energy density and poor cycling stability due to the intrinsic low conductivity of sulfur and its discharge product, lithium polysulfide shuttle effect, and so on. Developing efficient and low-cost energy conversion and storage devices and technologies is all-important issue in order to achieve a low-carbon society, whose performance essentially depends on the properties of materials. Zhao et al. [[8]] designed a single-atom catalyst Au/WSSe by filling the single Au atom at the S vacancy site in the Janus WSSe monolayer. [Extracted from the article]

As a typical two-dimensional (2D) MXene, Ti3C2O2 has been considered as a potential material for high-performance hydrogen evolution reaction (HER) catalyst, due to its anticorrosion and hydrophilic surface. However, it is still a challenge to improve the Ti3C2O2 surficial HER catalytic activity. In this work, we investigated the HER activity of Ti3C2O2 after the surface was doped with S, Se, and Te by the first principles method. The results indicated that the HER activity of Ti3C2O2 is improved after being doped with S, Se, Te because the Gibbs free energy of hydrogen adsorption (ΔGH) is increased from −2.19 eV to 0.08 eV. Furthermore, we also found that the ΔGH of Ti3C2O2 increased from 0.182 eV to 0.08 eV with the doping concentration varied from 5.5% to 16.7%. The HER catalytic activity improvement of Ti3C2O2 is attributed to the local crystal structure distortion in catalytic active sites and Fermi level shift leads to the p-d orbital hybridization. Our results pave a new avenue for preparing a low-cost and high performance HER catalyst. [ABSTRACT FROM AUTHOR]

Transition metal sulfides have attracted a lot of attention as potential oxygen evolution reaction (OER) catalysts. Bimetallic sulfide possesses superior physicochemical properties due to the synergistic effect between bimetallic cations. By introducing a metal-semiconductor interface, the physicochemical properties of transition metal sulfide can be further improved. Using the solvothermal method, Au@NiCo2S4 core-shell heterostructure nanoparticles (NPs) and bare NiCo2S4 NPs were prepared. The measurement of the OER catalytic performance showed that the catalytic activity of Au@NiCo2S4 core-shell heterostructure was enhanced compared to bare NiCo2S4 NPs. At the current density of 10 mA cm−2, the overpotential of Au@NiCo2S4 (299 mV) is lower than that of bare NiCo2S4 (312 mV). The Tafel slope of Au@NiCo2S4 (44.5 mV dec−1) was reduced compared to that of bare NiCo2S4 (49.1 mV dec−1), indicating its faster reaction kinetics. Detailed analysis of its electronic structure, chemical state, and electrochemical impedance indicates that the enhanced OER catalytic performances of bare Au@NiCo2S4 core-shell NPs were a result of its increased proportion of high-valance Ni/Co cations, and its increased electronic conductivity. This work provides a feasible method to improve OER catalytic performance by constructing a metal-semiconductor core-shell heterostructure. [ABSTRACT FROM AUTHOR]