Tungsten sulfide sheets with tunable layered structures: Piezocatalysis via multi-channels to generate H₂O₂

Driven by the urgent need for eco-friendly, safe and facile production processes for hydrogen peroxide (H₂O₂), piezocatalysis shows significant potential due to its accessible energy supply and capacity for on-site H₂O₂ preparation. Owing to their tunable surface properties and unique electronic structures, transition metal dichalcogenides (TMDCs) are regarded as promising piezocatalysts. Nevertheless, the uneven distribution of active sites, poor stability, and restricted electron transport capabilities hinder the further improvement of their piezocatalytic performance. In this study, WS₂ thin sheets were prepared by liquid-phase stripping, which significantly increase the number of exposed active sites to provide an optimized interfacial environment for the adsorption of reactant molecules, and the resulting thin-layer structure greatly improves the charge transfer efficiency. More importantly, WS₂ thin sheets were utilized in piezocatalytic H₂O₂ evolution. Remarkably, under conditions of pure water and ambient air, these thin sheets exhibit outstanding piezocatalytic performance with an H₂O₂ evolution rate as high as 994.7 μmol g^-1 h^-1. And they retained 80.14 % of their activity after 10 h of cyclic operation, demonstrating excellent cycling stability. Furthermore, mechanistic investigations propose three potential pathways for H₂O₂ evolution, providing a novel perspective for elucidating the underlying mechanism of piezocatalysis in TMDCs.