Optimization Methods of Tungsten Oxide-Based Nanostructures as Electrocatalysts for Water Splitting

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.

Fabrication of Ru/WO3-W2N/N-doped carbon sheets for hydrogen evolution reaction

Recent experimental analysis indicates WO₃-based nanostructures exhibit poor hydrogen evolution reactivity, particularly in alkaline medium, arising from the low electron transfer rate. It is imperative to tune the composition and structure of WO₃ to boost the cleavage of H-OH bond. Here, we construct Ru/WO₃-W₂N/N-doped carbon sheets (Ru/WO₃-W₂N/NC) using m-WO₃ nanosheets as precursors with the aid of RuCl₃, Tris (hydroxymethyl) aminomethane, and dopamine. Structural investigation reveals the formation of N-doped carbon sheets, Ru nanoparticles, and WO₃-W₂N. As a result, hydrogen evolution reactivity is greatly improved on Ru/WO₃-W₂N/N-doped carbon sheets with 64 mV at 10 mA/cm² in 1 mol/L (M) KOH, outperforming most of WO₃-based electrocatalysts in previous literatures. Meanwhile, it facilitates the generation of H₂ in 0.5 M H₂SO₄ with the excellent activity of 110 mV at 10 mA/cm². Our work provides an efficient strategy to tailor the electronic structure of WO₃ to catalyze acidic and alkaline hydrogen evolution reaction.