Ultrathin Two-Dimensional Bi-Based photocatalysts: Synthetic strategies, surface defects, and reaction mechanisms

Photocatalysis is one of the most flexible methodologies for environmental remediation and sustainable energy demand. Bismuth (Bi)-based materials have been developed as typical photocatalysts, but the carriers tend to be recombined, and thus they have insufficient photocatalytic activity. The atomically ultrathin strategy demonstrates significant advantages in improving the photocatalytic capability of Bi-based materials. In this review, the recent progress in ultrathin two-dimensional (2D) Bi-based photocatalyst is summarized. The synthetic methods and defect engineering strategies, including anion/cation vacancies, vacancy associates, pits, and dislocations, are discussed and reviewed. The effects of ultrathin structure on reactive oxygen species (ROS) generation and reaction pathways during photocatalysis are also summarized. Finally, this review concerning ultrathin 2D Bi-based materials ends with future chances and challenges in the energizing and developing area for photocatalytic applications.