Electron-donating five-membered heterocyclic modulated electronic states boosting visible-light-driven H2O2 production

Abstract

Pyridyl-conjugated microporous polymers (CMPs) were synthesized and discovered that the catalyst with a five-membered heterocycle could facilitate O2 reduction and H2O oxidation into H2O2 under photo-irradiation. The electronic state structure of the CMPs was further modulated by incorporating aldehyde-based monomers containing five-membered heterocycles. It was observed that the introduction of an electron-donating thiophene ring (Th-CMP) or a furan ring (Fu-CMP) significantly increased the H2O2 production yield. Remarkably, the H2O2 yield from Th-CMP in pure water and O2, without the need for any sacrificial agents, achieved 855 μM h−1, which surpasses most of the reported organic polymer photocatalysts. Mechanism researchs indicated Thiophene groups not only expanded the range for visible light absorption, but also facilitates the separation and migration of charge carriers, thereby providing favorable conditions for H2O2 generation. This study presents a promising and innovative direction to designing cost-effective and efficient CMPs for the photocatalytic generation of H2O2.