Enhanced Hydrogen Peroxide Photosynthesis Using X-Packed Cocrystal Catalysts.

Wang, Lingsong; Deng, Jingheng; Li, Shuyu; Liu, Huapeng; Liu, Kexin; Lv, Xiaocai; Zhang, Yufan; Li, Jikun et al. · Adv Mater · 2026

basic_science · Level V

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Abstract

Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) is an essential chemical and potent energy carrier. Its production through solar energy and metal-free photocatalysts is desirable. Organic semiconductors, as a new generation of semiconductors, can form suitable transition state intermediates showing great ability in enhancing the efficiency and selectivity of photocatalytic H<sub>2</sub>O<sub>2</sub> generation, offering a metal-free, green, and more economical solution. However, the smaller Frenkel exciton radius and larger exciton Coulomb binding energy lead to a constrained capacity for exciton dissociation, blocking the way of photocatalysts based on organic semiconductors. Here, we overcome the bottleneck by cocrystal engineering. A kind of cocrystal photocatalysts with X-packing are designed and synthesized, which permit all excited states to be optically allowed due to reduced energy splitting, enhancing the exciton participation in photosynthesis of H<sub>2</sub>O<sub>2</sub> giving much more efficient singlet exciton dissociation and exciton utilization. Indeed, the X-packed cocrystals show photosynthesis of H<sub>2</sub>O<sub>2</sub> from O<sub>2</sub> and H<sub>2</sub>O at a rate of 2.65 mmol h<sup>-1</sup> g<sup>-1</sup> and a solar-chemical energy conversion efficiency of 0.42%, which can be further improved to 13.3 mmol h<sup>-1</sup> g<sup>-1</sup> with a hole sacrificial agent. This work seems to open a new door for high solar exciton utilization with organic semiconductors by cocrystal engineering.