The role of oxygen vacancies (V_O) in semiconductors' photocatalytic hydrogen evolution reaction (PHER) activities is challenging. In this study, BiCeOS with different V_O abundances and n(Ce³⁺/Ce⁴⁺) amounts prepared by adjusting the hydrazine amount was evaluated. The theoretical and experimental results indicated that V_O converts tetravalent cerium into trivalent cerium to maintain electrical neutrality by creating an electron donor level in the band gap of BiCeOS. Thus, BiCeOS with rich V_O and higher n(Ce³⁺/Ce⁴⁺) amounts exhibits higher visible light–excited photocurrent and easier photoinduced charge separation than those of BiCeOS with poor V_O and lower n(Ce³⁺/Ce⁴⁺) amounts. DFT calculations indicate that BiCeOS with rich V_O strongly interacts with water at a high adsorption energy of −0.968 eV to form a distorted water molecule. Therefore, the introduction of V_O on the surfaces with subsequently partial Ce⁴⁺-to-Ce³⁺ conversion remarkably yields BiCeOS catalysts with excellent visible light PHER activities.

中文翻译：

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通过调整价带构型引发具有富氧空位的高效 (Bi,Ce)2(O,S)3−x 氧硫化物催化剂用于析氢

氧空位 (V _O ) 在半导体的光催化析氢反应 (PHER) 活动中的作用具有挑战性。在这项研究中，评估了通过调整肼用量制备的具有不同 V _O丰度和 n(Ce ³⁺ /Ce ^{4+ ) 量的 BiCeOS。}理论和实验结果表明，VO将四价铈转化为三价铈，通过在 BiCeOS 的带隙中产生电子供体能级来保持电中性_。因此，具有丰富 V _O和更高n (Ce ³⁺ /Ce ⁴⁺) 的量表现出更高的可见光激发光电流和更容易的光诱导电荷分离比 BiCeOS 具有较差的 V _O和较低的n (Ce ³⁺ /Ce ⁴⁺ ) 量。DFT 计算表明，富含 V2O_的BiCeOS 以 -0.968 eV 的高吸附能与水发生强烈相互作用，形成扭曲的水分子。因此，在表面引入 V _O并随后将部分 Ce ⁴⁺转化为 Ce ³⁺显着产生具有优异可见光 PHER 活性的 BiCeOS 催化剂。