Persistent semiquinone radicals enable efficient near-infrared-driven H<sub>2</sub>O<sub>2</sub> photosynthesis.

Dou, Shuai; Zhang, Yaning; Xu, Jing; Zhang, Ying; Lou, Yang; Zhang, Jiawei; Dong, Yuming; Zhu, Yongfa et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Photosynthesis of H<sub>2</sub>O<sub>2</sub> 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 H<sub>2</sub>O<sub>2</sub> generation. Here, a polydopamine-loaded porphyrin supramolecular photocatalyst efficiently utilizes near-infrared light for H<sub>2</sub>O<sub>2</sub> production from H<sub>2</sub>O and O<sub>2</sub>, 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 H<sub>2</sub>O<sub>2</sub> 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 H<sub>2</sub>O<sub>2</sub> production. This study sheds light on the potential of near-infrared-responsive photocatalysts and offers insights into optimizing their performance for sustainable H<sub>2</sub>O<sub>2</sub> synthesis.