Recent Advances in Innovative Device Designs and Engineering Strategies of Hybrid Perovskite Halides for Efficient Photoelectrochemical and Photocatalytic Applications

Photoelectrochemical (PEC) hydrogen/oxygen generation, CO 2 reduction, and photocatalytic dye degradation offer promising pathways for sustainable energy production and environmental remediation by utilizing solar energy. Perovskite halides, with their exceptional optoelectronic properties, have garnered significant attention in these applications. This review comprehensively reviews recent developments in using perovskite halides for PEC hydrogen and oxygen evolution reactions, CO 2 reduction, and photocatalytic detoxification of water. State‐of‐the‐art achievements in enhancing these performances using various device design engineering and construction strategies for efficient charge transfer in aqueous environments are highlighted. The review continues with the exploration of dimensional/compositional engineering, nanocomposites/heterojunctions, core–shell nanostructures, and functionalization of protective layers to improve the efficiency and water stability of perovskite halides for PEC applications. Furthermore, organic–inorganic, all‐inorganic, Pb‐free hybrid halide perovskites, metal double halide perovskite, their multilayer nanocomposites, and the tandem configuration of PEC/Perovskite solar cell reported design strategies are reviewed and critically assessed in the context of device performance and durability. Finally, challenges such as material stability, scalability, and toxicological considerations are addressed, alongside future research directions to advance the practical implementation of hybrid perovskite nanomaterials in sustainable energy and environmental applications.