Charge redistribution of a spatially differentiated ferroelectric Bi<sub>4</sub>Ti<sub>3</sub>O<sub>12</sub> single crystal for photocatalytic overall water splitting.

Jia, Guangri; Sun, Fusai; Zhou, Tao; Wang, Ying; Cui, Xiaoqiang; Guo, Zhengxiao; Fan, Fengtao; Yu, Jimmy C · Nat Commun · 2024

basic_science · Level V

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Abstract

Artificial photosynthesis is a promising approach to produce clean fuels via renewable solar energy. However, it is practically constrained by two issues of slow photogenerated carrier migration and rapid electron/hole recombination. It is also a challenge to achieve a 2:1 ratio of H<sub>2</sub> and O<sub>2</sub> for overall water splitting. Here we report a rational design of spatially differentiated two-dimensional Bi<sub>4</sub>Ti<sub>3</sub>O<sub>12</sub> nanosheets to enhance overall water splitting. Such a spatially differentiated structure overcomes the limitation of charge transfer across different crystal planes in a single crystal semiconductor. The experimental results show a redistribution of charge within a crystal plane. The resulting photocatalyst produces 40.3 μmol h<sup>-1</sup> of hydrogen and 20.1 μmol h<sup>-1</sup> of oxygen at a near stoichiometric ratio of 2:1 and a solar-to-hydrogen efficiency of 0.1% under simulated solar light.