Emerging layered BiO2−x for photocatalysis: status, challenges, and outlook

Abstract

It is highly desired to develop new kinds of semiconductor photocatalysts for environmental remediation and energy production. Recently, BiO_2−x, a new bismuth-based oxide has attracted considerable interest due to its narrow band gap, high number of defect sites, and its unique layered structure, which will play a significant role in photocatalysis in the future. By synthesizing BiO_2−x-based nanocomposites with a thin layer structure, doped with various elements, or coupled with other semiconductors, it was demonstrated that they showed good photoactivity for H₂ production, organic pollutant degradation, O₂ activation, and so on. In this perspective, recently published works about bare BiO_2−x, doped BiO_2−x, and BiO_2−x-based heterogeneous nanocomposites were summarized, including discussion about current issues, such as preparation method, non-defined structure, and poor charge separation. Finally, potential applications of BiO_2−x photocatalysts were proposed in renewable energy production and environmental remediation.