Vacancy-Induced Symmetry Breaking in Titanium Dioxide Boosts the Photocatalytic Hydrogen Production from Methanol Aqueous Solution.

Liu, Limin; Sun, Yingjie; Ma, Zhentao; Liu, Qichen; Zhang, Rongao; Wu, Lihui; Pan, Haibin; Wang, Qingyu et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

The key to optimizing photocatalysts lies in the efficient separation and oriented migration of the photogenerated carriers. Herein, we report that breaking continuous TiO<sub>6</sub> tetragonal (<i>D</i><sub>4<i>h</i></sub>) symmetry in titanium dioxide material by oxygen vacancy engineering could induce a dipole field within the bulk phase and thus facilitate the separation and transfer of photogenerated electron-hole pairs. After further loading of Cu single-atom co-catalysts, the obtained catalyst attained a hydrogen (H<sub>2</sub>) yield rate of 15.84 mmol g<sup>-1</sup> h<sup>-1</sup> and a remarkable apparent quantum yield of 12.67% at 385 nm from methanol aqueous solution. This catalyst also demonstrated impressive stability for at least 24 h during the photocatalytic tests. The innovative concept of producing dipole fields in semiconductors by breaking the crystal symmetry offers a new perspective for designing photocatalysts.