A series of Bi₂MoO₆ (BMO) nanoplates with a heterogeneous Bi₂MoO_6-x@Bi₂MoO₆ core/shell structure were successfully obtained by reduction with CaH₂ at 140 °C and subsequent reoxidation in air under low temperatures (≤250 °C). It is found that the oxygen vacancies mainly exist in the core, while the shell is formed by surface disorder layer with few oxygen vacancies, which is almost stoichiometric. The controllable growth of the surface disorder layer can be realized by the reduction and/or reoxidation temperatures. The reoxidized BMO with the surface disorder layer exhibits about five times higher visible-light photocatalytic activity toward phenol degradation and an order of magnitude higher activity toward methylene blue (MB) degradation than those of the unmodified sample. The visible-light absorption is mainly dominated by the oxygen vacancies through the modulation of the band gap structure, which promote the solar light utilization and photogenerated charge carriers. Density functional theory calculation shows that BMO is a direct band gap semiconductor. It is suggested that the surface disorder layer could suppress the direct recombination of photogenerated carriers and improve surface reactivity, and results in the enhancement of the photocatalytic activity. In addition, the existence of the stoichiometric surface disorder can promote the catalyst stability. It is demonstrated that the reduction- reoxidation method applied here is simple, easily control, and beneficial for the design and realization of heterogeneous core-shell nanostructured photocatalysts to improve visible and infrared optical absorption by engineering the surface disorder and the oxygen vacancies inside core of Bi₂MoO₆ nanoplates and the related nanostructured photocatalysts.

通过用CaH ₂还原成功获得了一系列具有异质Bi ₂ MoO _6-x @Bi ₂ MoO ₆核/壳结构的Bi ₂ MoO ₆（BMO）纳米板。在140°C的温度下，随后在低温（≤250°C）的空气中再氧化。发现氧空位主要存在于核中，而壳由几乎无化学空位的氧空位的表面无序层形成。表面无序层的可控生长可以通过降低和/或再氧化温度来实现。与未改性样品相比，具有表面无序层的再氧化BMO表现出的对苯酚降解的可见光光催化活性高约5倍，并且对亚甲基蓝（MB）降解的活性高约一个数量级。可见光的吸收主要是通过带隙结构的调节来控制氧空位，从而促进了太阳光的利用和光生载流子的产生。密度泛函理论计算表明，BMO是直接带隙半导体。提示表面无序层可以抑制光生载流子的直接复合并提高表面反应性，并导致光催化活性的增强。另外，化学计量表面无序的存在可以促进催化剂的稳定性。结果表明，本文所采用的还原-再氧化方法简单，易控制，有利于设计和实现核壳纳米结构光催化剂，通过工程化核的表面无序和核内氧空位来提高可见光和红外光吸收率。双 提示表面无序层可以抑制光生载流子的直接复合并提高表面反应性，并导致光催化活性的增强。另外，化学计量表面无序的存在可以促进催化剂的稳定性。结果表明，本文所采用的还原-再氧化方法简单，易控制，有利于设计和实现核壳纳米结构光催化剂，通过工程化核的表面无序和核内氧空位来提高可见光和红外光吸收率。双 提示表面无序层可以抑制光生载流子的直接复合并提高表面反应性，并导致光催化活性的增强。另外，化学计量表面无序的存在可以促进催化剂的稳定性。结果表明，本文所采用的还原-再氧化方法简单，易控制，有利于设计和实现核壳纳米结构光催化剂，通过工程化核的表面无序和核内氧空位来提高可见光和红外光吸收率。双 化学计量表面无序的存在可以促进催化剂的稳定性。结果表明，本文所采用的还原-再氧化方法简单，易控制，有利于设计和实现核壳纳米结构光催化剂，通过工程化核的表面无序和核内氧空位来提高可见光和红外光吸收率。双 化学计量表面无序的存在可以促进催化剂的稳定性。结果表明，本文所采用的还原-再氧化方法简单，易控制，有利于设计和实现核壳纳米结构光催化剂，通过工程化核的表面无序和核内氧空位来提高可见光和红外光吸收率。双₂ MoO ₆纳米板和相关的纳米结构光催化剂。