Photocatalytic H2O2 production over photocatalysts prepared by phosphine-protected Au101 nanoparticles on WO3

Abstract

Photocatalytic H₂O₂ synthesis is an appealing and feasible strategy to replace the energy-intensive, tedious, and waste-generating anthraquinone process. This work investigated photocatalytic H₂O₂ production using monodisperse gold nanoclusters Au₁₀₁(PPh₃)₂₁Cl₅ supported on WO₃. Both uncalcined and calcined Au₁₀₁/WO₃ photocatalysts produce over 75 mM g⁻¹ h⁻¹ of H₂O₂ under UV light irradiation while pure WO₃ is inactive. At early times (up to 30 min), the production rate of H₂O₂ from calcined Au₁₀₁/WO₃ reaches 173 mM g⁻¹ h⁻¹ and is almost double the rate of the uncalcined catalyst (93 mM g⁻¹ h⁻¹). The roles of Au₁₀₁ have been identified to reduce the charge carrier recombination and provide the active sites for O₂ reduction which significantly enhances the photoactivity. The higher photoactivity of calcined versus uncalcined Au₁₀₁/WO₃ can be attributed to the strong metal–support interaction and aggregated Au₁₀₁. This work highlights a simple preparation of highly active photocatalysts derived from Au₁₀₁ clusters and WO₃ to produce H₂O₂.