Mechanistic insight into piezo-catalytic H2 evolution on BiOCl loaded with AuPt alloy cocatalysts

The use of piezo-catalysis for H ₂ production from water at ambient conditions has recently gained significant attention, yet the importance of cocatalyst engineering has been largely overlooked. In this study, AuPt alloy nanoparticles were used as cocatalysts on the piezoelectric material BiOCl for H ₂ evolution driven by sonication. The Au:Pt ratio of 3:1 significantly enhanced the reaction, resulting in a doubling of H ₂ production compared to Au alone and a tripling compared to Pt alone. Experiments and simulations showed that AuPt alloys promote H* adsorption and facilitate the separation of piezoelectric carriers. Additionally, the cocatalysts enhance the piezo-catalytic reaction by increasing the stress and deformation of the BiOCl microplates. Unlike the photocatalytic process, the piezo-catalytic H ₂ evolution on BiOCl succeeded due to the suppression of BiOCl reduction by the periodically accumulated piezo-electrons and holes. This research highlights the critical role of cocatalyst engineering in optimizing piezo-catalytic H ₂ production and presents a promising strategy for efficient H ₂ generation.