Direct and mediator-based Z-scheme heterojunctions involving bi₂moo₆ for abatement of dyes and pharmaceuticals

Dyes and pharmaceuticals are some major water pollutants that cause serious health-related problems to human beings. BiVO₄, BiOX, Bi₂O₃, Bi₂S₃, and Bi₂MoO₆ are bismuth-based photocatalysts that have received enormous attraction in photocatalysis due to their photostable, photoactive, chemically inert, and eco-friendly nature, along with their reduced band gaps, which enables them to utilize visible light. The Z-scheme-based photocatalysts offer improved separation of charges along with the retention of high redox ability, which makes them highly efficient for photocatalytic purposes. In this article, recent developments regarding Bi₂MoO₆-based Z-scheme heterojunctions and their use for the mitigation of dyes and pharmaceuticals have been revisited. We discuss the need for organic-pollutants removal from water and present a brief description of the relationship between morphological and crystal phase properties of Bi₂MoO₆ with photocatalytic activity. We also provide a brief description of the strategies that can be used to enhance the photocatalytic properties of Bi-based photocatalysts. We include a brief account of the advancement in heterojunctions development with different charge transfer mechanisms and their interconversion and discuss the most recent advances regarding the development of Z-scheme heterojunctions based on Bi₂MoO₆ for the photodegradation of dyes and pharmaceuticals. Lastly, we present some of the challenges and future directions regarding Z-scheme photocatalysis for further improvement in the field.