Abstract In this work, the oxygen defect strategy was conducted to promote photo-splitting H2S into hydrogen (H2) on the typical anatase TiO2 with active {0 0 1} facet for the first time. Density functional theory (DFT) calculation results illustrate that surface oxygen vacancy can efficiently facilitate the electron transition across the forbidden band and enhance the surface adsorption ability with more negative adsorption energies of −0.82 to −2.85 eV for H2S and its fragments than that of 0.24 to −0.90 eV on the perfect surface. Importantly, the energy barrier is reduced by 1.58 eV in maximum along the reaction paths on the defected surface, and the changes of rate-determining step lead to H2 as the final product. In addition, the time-resolved fluorescence tests, photocurrent measurements and electrochemical impedance spectroscopy demonstrate that the oxygen vacancies can effectively separate photo-generated electron-hole pairs. As a result, the photocatalytic activities of H2 evolution from H2S on TiO2 {0 0 1} doped with oxygen vacancies have been significantly enhanced from 21.44 μmol g−1 h−1 to 95.25 μmol g−1 h−1. This enhanced photoactivity is due to the low recombination of photo-generated carriers, the favorable surface adsorption and reaction activity induced by oxygen vacancies.

中文翻译：

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氧缺陷促进了硫化氢在锐钛矿 TiO2 活性 {001} 面上的光催化析氢

摘要 在这项工作中，首次采用氧缺陷策略促进具有活性{0 0 1} 面的典型锐钛矿型 TiO2 上的 H2S 光解为氢 (H2)。密度泛函理论（DFT）计算结果表明，表面氧空位可以有效地促进电子跨越禁带的跃迁并增强表面吸附能力，对 H2S 及其碎片的负吸附能为 -0.82 至 -2.85 eV，而不是 0.24在完美的表面上达到 -0.90 eV。重要的是，沿着缺陷表面的反应路径，能垒最大降低了 1.58 eV，并且决定速率步骤的变化导致 H2 作为最终产物。此外，时间分辨荧光测试，光电流测量和电化学阻抗谱表明氧空位可以有效地分离光生电子-空穴对。因此，H2S 对掺杂氧空位的 TiO2 {0 0 1} 的 H2 析出光催化活性从 21.44 μmol g-1 h-1 显着提高到 95.25 μmol g-1 h-1。这种增强的光活性是由于光生载流子的低复合、有利的表面吸附和氧空位引起的反应活性。