Photosynthesis of H2O2 under sunlight is a sustainable method; however, most developed photocatalysts utilize limited near-infrared light, which accounts for 52% of the solar spectrum. In typical near-infrared photocatalysts, excited electrons fall into low-energy sub-gap states, reducing the driving force for H2O2 generation. Here, a polydopamine-loaded porphyrin supramolecular photocatalyst efficiently utilizes near-infrared light for H2O2 production from H2O and O2, achieving an apparent quantum yield of 2.8% at 1020 nm. This substantial near-infrared utilization significantly boosts activity under full-spectrum irradiation, with an H2O2 generation rate of 3.37 mM/h and solar-to-chemical conversion efficiency of 2.2%. Persistent semiquinone radicals in polydopamine are demonstrated to enable ultrafast sub-gap electron transfer (ca. 79 fs) from porphyrin to polydopamine and facilitate near-infrared-driven •OOH radical generation, thereby accelerating H2O2 production. This study sheds light on the potential of near-infrared-responsive photocatalysts and offers insights into optimizing their performance for sustainable H2O2 synthesis. A porphyrin-polydopamine photocatalyst enables efficient near-infrared light use for hydrogen peroxide production from water and oxygen, achieving high quantum efficiency and solar conversion through ultrafast electron transfer mediated by persistent radicals.
Dou et al. (Mon,) studied this question.