A metal-free photocatalyst for highly efficient hydrogen peroxide photoproduction in real seawater.

Wu, Qingyao; Cao, Jingjing; Wang, Xiao; Liu, Yan; Zhao, Yajie; Wang, Hui; Liu, Yang; Huang, Hui et al. · Nat Commun · 2021

basic_science · Level V

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Abstract

Artificial photosynthesis of H<sub>2</sub>O<sub>2</sub> from H<sub>2</sub>O and O<sub>2</sub>, as a spotless method, has aroused widespread interest. Up to date, most photocatalysts still suffer from serious salt-deactivated effects with huge consumption of photogenerated charges, which severely limit their wide application. Herein, by using a phenolic condensation approach, carbon dots, organic dye molecule procyanidins and 4-methoxybenzaldehyde are composed into a metal-free photocatalyst for the photosynthetic production of H<sub>2</sub>O<sub>2</sub> in seawater. This catalyst exhibits high photocatalytic ability to produce H<sub>2</sub>O<sub>2</sub> with the yield of 1776 μmol g<sup>-1</sup>h<sup>-1</sup> (λ ≥ 420 nm; 34.8 mW cm<sup>-2</sup>) in real seawater, about 4.8 times higher than the pure polymer. Combining with in-situ photoelectrochemical and transient photovoltage analysis, the active site and the catalytic mechanism of this composite catalyst in seawater are also clearly clarified. This work opens up an avenue for a highly efficient and practical, available catalyst for H<sub>2</sub>O<sub>2</sub> photoproduction in real seawater.