Au-nanoparticle-supported ZnO as highly efficient photocatalyst for H2O2 production

In this study, Au-nanoparticle-supported crystalline ZnO (Au/ZnO) is found to be a simple and efficient photocatalyst for direct H2O2 synthesis in an aerated aqueous solution. Compared with widely studied Au-nanoparticle-supported anatase TiO2 photocatalyst, Au/ZnO shows almost one order of magnitude higher activity in H2O2 production. The site-specific deposition of smaller Au nanococatalyst on ZnO delivers best photocatalytic performance and the H2O2 production is relatively stable with a rate more than 1.5 mmol L-1 h(-1). The electron spin resonance studies reveal that the H2O2 is produced through direct 2e(-) oxygen reduction over the optimized Au/ZnO photocatalyst.