Molecular engineering of carbon nitrides for overall photosynthesis of H2O2

Artificial photocatalysis offers a promising strategy to sustainably produce hydrogen peroxide (H2O2) that is one of the most valuable multifunctional chemicals. Among various photocatalysts, polymeric carbon nitride (pCN) has drawn continuous attention in non-sacrificial H2O2 production. However, the poor activity of half reactions, i.e., the oxygen reduction reaction (ORR) and water oxidation reaction (WOR), greatly restricts the efficiency of photocatalytic H2O2 production. In this highlight, we discuss the significant advances in molecular engineering of carbon nitrides for H2O2 photosynthesis and the importance of the deep understanding of the photocatalysis process for rational design and reaction pathways of organic conjugated polymers to address the growing H2O2 demand. Furthermore, we summarize the emerging applications of photocatalytic H2O2 productions beyond energy and environment.