Immersed Halide Perovskite‐Based Electrochemical Cells for Stable Solar Water Splitting: Achievements, Opportunities, and Prospects

Recently, halide perovskite materials have attracted significant research interest in photoelectrochemical cells as promising photoabsorbers due to their superior optoelectronic properties. However, their instability under environmental conditions remains a major obstacle to the development of stable water-splitting devices. This review thoroughly examines the growing array of encapsulation strategies that have accelerated the integration of perovskite materials into water-splitting systems. In addition, various approaches to extending device lifetime while maintaining high performance are discussed in detail. Recent advances that render perovskite-based water-splitting systems a viable source of low-cost green hydrogen are also highlighted. Finally, current scientific challenges, emerging concepts, and future research directions aimed at enhancing both the performance and operational stability of perovskite-based electrochemical cells are introduced.