Photocatalytic production of H₂O₂ and its in-situ environmental applications

Hydrogen peroxide (H₂O₂) is a mild, environmentally friendly, and versatile oxidizer. The current main production process, the anthraquinone method, has high energy consumption and pollution. However, the photocatalytic production of H₂O₂ is considered to be a green and sustainable process. In this paper, the research progress of photocatalytic production of H₂O₂ was reviewed. Firstly, the basic principle of photocatalytic production of H₂O₂ and the three production pathways, namely, oxygen reduction, water oxidation, and dual-channel were introduced. Then, advanced photocatalysts for H₂O₂ production were introduced with emphasis. From the reactants and products, several new reaction systems and improvement strategies were introduced, including the construction of a spontaneous system without a sacrifice agent, a gas–liquid–solid three-phase system, and inhibition of H₂O₂ decomposition. The in-situ applications of photocatalytic H₂O₂ production in the environmental field, including in-situ disinfection and in-situ degradation of pollutants are discussed. Finally, the research progress and future research directions in this field are summarized and prospected.