Recent advances in synthesis of water-stable metal halide perovskites and photocatalytic applications

Solar-driven photocatalytic reactions have attracted wide interest as a viable method to generate green energy and alleviate environmental challenges posed by fossil fuels. Although, various classes of photocatalysts have been explored during the past decades, the pursuit towards even more efficient ones is still ongoing. Metal halide perovskites (MHPs) have been recently proposed as novel photocatalysts owing to their wide light absorption range and excellent optoelectronic properties. However, the instability of MHPs in water is the main obstacle that impedes their applications in practice and prompts stabilization strategies to be developed. This review focuses on the recent approaches for stabilizing MHPs in water, including surface engineering, common-ion effect, and intrinsic water stability. The photocatalytic applications of water-stable MHPs are summarized and an outlook with perspectives over the current challenges are provided.