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

Hydrogen peroxide (H 2 O 2 ) finds extensive applications in various industries, particularly in the environmental field. The photocatalytic production of H 2 O 2 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 H 2 O 2 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 H 2 O 2 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 H 2 O 2 . Finally, this review explores the potential environmental applications of photocatalytically produced H 2 O 2 . This review guides the design and optimization of photocatalysts, facilitating the continued advancement and application of photocatalysts in environmental contexts.