Designing Stable Nanoarchitectonics of Metal Halide Perovskite‐Based Materials for Aqueous Electrocatalysis

The development of water-stable metal halide perovskites (MHPs) presents a significant challenge for advanced materials and their application in electrochemical energy conversion and storage. Understanding the electronic structure of MHPs, considering electrocatalysis under an aqueous electrolyte, is essential for its widespread applications. Also, considerable efforts have been devoted to enhancing water stability through ligand passivation, compositional engineering, and surface encapsulation strategies. However, the long-term stability and charge transport properties of these materials may still fall short of expectations. Therefore, synthesizing intrinsically stable MHPs is crucial for their use in energy conversion and storage applications. Numerous comprehensive reviews have addressed the optical properties, regulation of electronic properties, and stability of MHPs. This review aims to provide an in-depth analysis of electronic structure and properties, followed by theoretical and experimental evidence of degradation mechanisms in aqueous media of various organic and inorganic MHPs. Subsequently, we also highlight the perspectives and progress in MHPs designing strategies and the synthesis of intrinsically water-stable perovskites to overcome stability challenges. By connecting the degradation dynamics with synthesis approaches for water-stable MHPs, this report paves the way for their application in electrocatalysis and energy storage devices.