Bi₂MoO₆ has emerged as a powerful visible-light-active oxidation photocatalyst with decent photocatalytic activity although further modifications are still essential to overcome its inherent high charge recombination efficiency. Among them, the strategy of constructing Bi₂MoO₆-based heterojunction has been demonstrated to be effective. In this work, a novel two-dimensional (2D) Bi₂MoO₆/Bi₂S₃ heterostructure was in situ fabricated via an anion exchange process, wherein [MoO₆]²⁻ layers were substituted by S²⁻ ions. With simply tuning the concentration of S source (thiourea), the content of Bi₂S₃ can be easily controlled. The formed heterogeneous materials with appropriate Bi₂S₃ amount were found to substantially boost the yield of evolved oxygen under visible light irradiation, whereas excessive Bi₂S₃ is detrimental to the photoactivity. Comprehensive analysis disclosed a complementary band alignment between the two materials, whereby a step-scheme heterojunction was formed. The charge transfer mechanism was carefully proposed based on diverse characterization. Photogenerated electrons on Bi₂MoO₆ recombined with the holes on Bi₂S₃, while maintaining the strong oxidative capability of Bi₂MoO₆ and reductive capability of Bi₂S₃. The enhanced activity was attributed to the suppressed electron-hole recombination on the single catalyst, and the promoted charge transfer across the junction interface was demonstrated to be beneficial for better performance. Additionally, high concentration of Bi₂S₃ can inevitably cover the oxidation-active component, Bi₂MoO₆, which in turn decreased the photocatalytic performance.

Bi ₂ MoO ₆已经成为具有强大光催化活性的强大的可见光活性氧化光催化剂，尽管进一步的修饰对于克服其固有的高电荷复合效率仍然是必不可少的。其中，已经证明构建基于Bi ₂ MoO ₆的异质结的策略是有效的。在这项工作中，一种新颖的二维（2D）Bi ₂ MoO ₆ / Bi ₂ S ₃异质结构是通过阴离子交换过程原位制备的，其中[MoO ₆ ] ^2-层被S ^2-取代。离子。通过简单地调节S源（硫脲）的浓度，可以容易地控制Bi ₂ S ₃的含量。发现形成的具有适当的Bi ₂ S ₃量的异质材料在可见光照射下显着提高了析出的氧气的产率，而过量的Bi ₂ S ₃不利于光活性。综合分析揭示了两种材料之间的互补能带排列，从而形成了阶梯式异质结。电荷转移机制是根据不同的特性精心提出的。Bi ₂ MoO ₆上的光生电子与Bi上的空穴重新结合₂ S ₃，同时保持Bi ₂ MoO ₆的强氧化能力和Bi ₂ S _3的还原能力。活性的提高归因于单一催化剂上电子-空穴复合的抑制，并且已证明跨结界面的电荷转移促进了更好的性能。另外，高浓度的Bi ₂ S ₃不可避免地会覆盖氧化活性成分Bi ₂ MoO ₆，从而降低了光催化性能。