Design Principles and Strategies of Photocatalytic H2O2 Production from O2 Reduction

H2O2, as an important chemical and environmentally friendly oxidant, has been applied in various fields, such as chemical synthesis, pulp bleaching, disinfection, and environmental remediation. Nevertheless, the industrial anthraquinone process for production of H2O2 is energy-intensive only suitable for centralized production of H2O2. Photocatalytic H2O2 production from O2 reduction is a promising approach for on-site and decentralized H2O2 synthesis. Although various photocatalysts have been developed, the efficiency is still limited by the narrow light absorption range, rapid charge recombination, and slow surface reaction. In this perspective, we briefly introduce the basic mechanism of photocatalytic production of H2O2 from O2 reduction. Subsequently, we propose the design principles and discuss the universal strategies for enhancing the performance of photocatalytic H2O2 production, from the aspects of light absorption, charge separation, surface catalytic reaction, and reactor configurations. Finally, we present our prospects and suggestions for the development of photocatalytic H2O2 production in future. We hope that this perspective can provide useful guidance for the rational design of efficient and novel photocatalysts for H2O2 production and advance both the mechanism insights and practical applications of photocatalytic H2O2 production.