Doping strategy has demonstrated to be one effective approach to modify the band structure of oxide semiconductors, which usually introduce the discrete mid-gap states to extend the light absorption range. However, the localized mid-gap states have limited benefit to photocatalytic activity. In the present work, the density functional theory (DFT) calculations indicate that indium (In) doping in bismuth oxyhalides (BiOXs, X = F, Cl, Br and I) could overcome this issues through increasing the light absorption and improving the potential for water reduction. Substitutional In (SubIn) doping in BiOXs (X = F, Br and I) leads to band gap narrowing through shifting the conduction band edge to lower energies, which can improve the light absorption without creating the mid-gap states. Specifically, the SubIn-doped BiOCl increases band gap due to the increased energy levels of the In 5s states. Although SubIn-doped BiOCl cannot extend the light absorption of the photocatalyst into the visible light spectrum, it indeed improved the necessary redox potentials for splitting water and preventing from trapping charge carrier. We believe that the DFT calculation results on SubIn-doping BiOXs will guide the further development of highly efficient semiconductor photocatalysts.

掺杂策略已被证明是修改氧化物半导体的能带结构的一种有效方法，该方法通常引入离散的中间能隙状态以扩展光吸收范围。但是，局部的中间能隙状态对光催化活性的益处有限。在目前的工作中，密度泛函理论（DFT）计算表明，掺杂卤氧化铋（BiOXs，X = F，Cl，Br和I）中的铟（In）可以通过增加光吸收和提高潜在的吸收性来克服此问题。减少水。BiOX（X = F，Br和I）中的取代In（SubIn）掺杂通过将导带边缘移至较低能量而导致带隙变窄，这可以改善光吸收，而不会产生中间带隙状态。具体来说，由于In 5s态的能级增加，SubIn掺杂的BiOCl增大了带隙。尽管SubIn掺杂的BiOCl无法将光催化剂的光吸收范围扩展到可见光谱，但确实提高了必要的氧化还原电势，以使水分解并防止捕获电荷载流子。我们相信，SubIn掺杂BiOX的DFT计算结果将指导高效半导体光催化剂的进一步发展。