Gold photocatalysis in sustainable hydrogen peroxide generation

Abstract

Hydrogen peroxide (H2O2) is a mild and green oxidant widely employed in organic syntheses, medical sector, disinfection, pulp bleaching, environmental remediation and biological processes. However, its production via the expensive, multistep and energy intensive anthraquinone process renders it less sustainable. Photocatalysis is a viable, sustainable and promising strategy to produce H2O2 from green sources: water and molecular O2. This article presents key developments of photocatalytic H2O2 generation using gold (Au) nanoparticles supported on semiconductor photocatalysts. Several photocatalytic systems containing Au nanoparticles and the roles of Au nanoparticles in enhancing photocatalytic H2O2 generation including increasing the visible light absorption, facilitating the charge carrier separation and transfer, and as catalytic active sites are discussed. Factors defining the photocatalytic activity such as the effects of Au particle size and loading, localised surface plasmon resonance, mixed-gold component, and the design of photocatalysts are reviewed. Finally, the challenges and prospects for further developments of Au photocatalysis in sustainable H2O2 synthesis as well as other related applications are highlighted.