Redirecting the electron flow to coordinate oxidation and reduction reactions for efficient photocatalytic H2O2 production

Energy -efficient photocatalytic production of H 2 O 2 from water holds the potential to replace the anthraquinone process. However, the impracticality of oxygen bubbling in such processes necessitates addressing the H 2 O 2 production in oxygen -deficient environments. Here, we demonstrated the generation of singlet oxygen ( 1 O 2 ) as a highly active water oxidation derivative that redirects the electron flow for H 2 O 2 production in oxygen -deficient environments. Ground -state oxygen was in -situ generated on photocatalysts and undergoes transition to 1 O 2 , surpassing other competitive electron -consuming reactions. Self -generated 1 O 2 undergoes preferential photoreduction to H 2 O 2 , benefiting from a small activation energy (0.2 eV), facilitated electron trapping rate, adjacent oxidation/reduction sites and suppressed competitive energy transfer from excited -states to air 3 O 2 . A remarkable solar -to -chemical conversion (SCC) efficiency of 0.25 % was obtained for H 2 O 2 generation in oxygendeficient conditions. This work unveils a novel concept of redirecting electron flow towards H 2 O 2 production, taking advantage of highly active in -situ generated 1 O 2 .