Modification Strategies of Bismuth‐Based Halide Perovskites for Solar to Fuel Conversion by Photocatalytic CO 2 Reduction

Abstract In light of the increasingly pressing energy and environmental challenges, the use of photocatalysis to convert solar energy into chemical energy has emerged as a promising solution. Halide perovskites have recently attracted considerable interest as photocatalysts due to their outstanding properties. Early developments focused on Lead‐based perovskites, but their use has been severely restricted due to the toxicity of Lead. Consequently, researchers have introduced non‐toxic elements to replace Lead, with common substitutes being transition metals such as Tin (Sn), Bismuth (Bi), and Antimony (Sb). Among them, Bi‐based perovskites have demonstrated superior photocatalytic performance. Nevertheless, the inherent instability of perovskites and the severe recombination of charge carriers have necessitated the development of various modification strategies to enhance their performance. This Review discusses the modification strategies for Bi‐based halide perovskites and illustrates the impact of these strategies on the photocatalytic performance. Finally, future research directions and challenges of Bi‐based perovskites for photocatalysis are proposed.