Inorganic Metal‐Oxide Photocatalyst for H2O2 Production

Abstract Hydrogen peroxide (H 2 O 2 ) is a mild but versatile oxidizing agent with extensive applications in bleaching, wastewater purification, medical treatment, and chemical synthesis. The state‐of‐art H 2 O 2 production via anthraquinone oxidation is hardly considered a cost‐efficient and environment‐friendly process because it requires high energy input and generates hazardous organic wastes. Photocatalytic H 2 O 2 production is a green, sustainable, and inexpensive process which only needs water and gaseous dioxygen as the raw materials and sunlight as the power source. Inorganic metal oxide semiconductors are good candidates for photocatalytic H 2 O 2 production due to their abundance in nature, biocompatibility, exceptional stability, and low cost. Progress has been made to enhance the photocatalytic activity toward H 2 O 2 production, however, H 2 O 2 photosynthesis is still in the laboratory research phase since the productivity is far from satisfaction. To inspire innovative ideas for boosting the H 2 O 2 yield in photocatalysis, the most well‐studied metal oxide photocatalysts are selected and the modification strategies to improve their activity are listed. The mechanisms for H 2 O 2 production over modified photocatalysts are discussed to highlight the facilitating role of the modification methods. Besides, methods for the quantification of H 2 O 2 and associated radical intermediates are provided to guide future studies in this field.