Reduced graphene oxide facilitates charge transfer over a dibenzothiophene-S,S-dioxide-based linear conjugated polymer for efficient photosynthesis of hydrogen peroxide

Linear conjugated polymers have emerged as a versatile class of visible light photocatalysts, attracting increasing interest due to their tunable optoelectronic properties. However, their linear backbones often result in insufficient electron transfer, a limitation that can be mitigated by coupling them with a conductive π-conjugated system such as reduced graphene oxide (rGO). Here, we report the electrostatic self-assembly of a dibenzothiophene-S,S-dioxide-based conjugated polymer (PSOBN2) with rGO, forming a PSOBN2-rGO heterostructure. The two-dimensional conjugated structure of rGO facilitates π-electron transfers over PSOBN2 through interfacial coupling, thereby overcoming the inherent charge carrier transport limitation of linear conjugated polymers for enhanced charge separation and accelerated interfacial electron transfer. An optimized heterostructure, PSOBN2-rGO1, exhibits a better H₂O₂ production rate of 9972 μmol h^–1 g^–1 in an air atmosphere under visible light irradiation, which is 1.42 times that of pristine PSOBN2. Notably, under natural sunlight irradiation, PSOBN2-rGO1 demonstrates an exceptional H₂O₂ production rate of 9267 μmol h^–1 g^–1 within the initial hour. Mechanistic studies confirm the crucial role of rGO-facilitated electron transfer in promoting the reduction of O₂ and oxidation of H₂O dual pathways for the photosynthesis of H₂O₂. This work offers a strategy for overcoming the inherent limitations of linear conjugated polymers toward efficient artificial photosynthesis of H₂O₂.