Photoelectrochemical water oxidation for on-site production of hydrogen peroxide

Photoelectrochemical (PEC) two -electron water -oxidation reaction is a promising route for renewable and on -site generation of H 2 O 2 as an alternative to the traditional anthraquinone process. However, large overpotential, low product selectivity, and poor stability limit its practical applications of PEC producing H 2 O 2 . This review discusses the fundamental aspects of two -electron water oxidation toward H 2 O 2 in a simple PEC device. It also presents the research background and all prevailing and recent breakthrough in the mechanisms of anodic H 2 O 2 generation. Afterward, it comprehensively reviews the progress made so far in enhancing the Faradaic efficiency of H 2 O 2 synthesis by tuning the thermodynamic energy barriers and reaction kinetics, facilitating the mass transfer of reactants and products, and stabilizing the products and catalytic surfaces. Finally, the critical challenges and opportunities for future development in this field are discussed. We believe that this review would stimulate further efforts to achieve highly efficient on -site H 2 O 2 production and high -power -density fuel cells with H 2 O 2 chemical utilization.