Photocatalytic hydrogen peroxide synthesis: State-of-the-art design, performance, and challenges

Hydrogen peroxide (H2O2) is an eco-friendly oxidant and is extensively used in chemical synthesis, medical, and environmental fields. It is also emerging as a new energy carrier in fuel cell technology. In comparison with the traditional anthraquinone synthesis procedure, the photocatalytic route for the synthesis of H2O2 has gained significant research attention owing to its safety, sustainability, and low cost; however, the faster recombination of charge carriers, poor optical absorption, and low product selectivity has restricted its application on a commercial scale. Designing new photocatalytic systems for H2O2 synthesis is a promising approach to achieving highly efficient solar-to-chemical energy conversion. This review article focuses on the recently reported state-of-the-art photocatalytic systems prepared by different strategies on supports, including TiO2, C3N4, MOFs, COFs, and biomass-derived materials. Furthermore, the conclusion and perspectives are discussed to identify the issues and to develop and bridge the gap between current research and practical applications.