Electrochemical and Photoelectrochemical Water Oxidation for Hydrogen Peroxide Production

Hydrogen peroxide (H₂ O₂ ), as a green fuel and oxidant, has drawn increasing attention in the energy and environmental research. Compared with the traditional anthraquinone process, the electrochemical (EC) and photoelectrochemical (PEC) syntheses of H₂ O₂ are cost-effective and environmentally friendly. In order to construct membraneless EC/PEC devices for the full H₂ O₂ synthesis, anodic H₂ O₂ production by water oxidation, which is less developed than cathodic H₂ O₂ generation, is highly desirable. Here, we review recent developments for the EC/PEC H₂ O₂ production by water oxidation, including fundamental aspects, benchmarking activity evaluation, material/catalyst selection, and strategies for increasing selectivity, efficiency, and accumulation. Furthermore, we discuss the challenges and outlook of water oxidation for H₂ O₂ production, especially device-level development, accumulation and stability, and industrial applications. Our review is intended to stimulate studies further improving EC/PEC H₂ O₂ production.