A Review on Photocatalytic Hydrogen Peroxide Production from Oxygen: Material Design, Mechanisms, and Applications

Hydrogen peroxide (H2O2) finds extensive applications in various industries, particularly in the environmental field. The photocatalytic production of H2O2 through the oxygen reduction reaction (ORR) or the water oxidation reaction (WOR) offers a promising approach. However, several challenges hinder effective on-site production, such as the rapid electron–hole pair recombination, inefficient visible light utilization, and limited selectivity in H2O2 formation. Thus, developing efficient photocatalysts to overcome these challenges is crucial. This review comprehensively outlines the development of photocatalysts and their modification techniques. It also summarizes and compares the H2O2 yield and apparent quantum yield among various photocatalysts with and without the use of organic sacrificial reagents. Density functional theory (DFT) calculations propose the band structure of photocatalysts and the mechanisms underlying oxygen reduction to H2O2. Finally, this review explores the potential environmental applications of photocatalytically produced H2O2. This review guides the design and optimization of photocatalysts, facilitating the continued advancement and application of photocatalysts in environmental contexts.