Halide Perovskites for Photo(electro)catalytic Sustainable Energy: Recent Advances and Challenges.

The development of highly efficient and stable photocatalysts for the direct conversion of solar energy into chemical energy stands out as a critical frontier in mitigating global energy and environmental crises. Owing to their exceptional photoelectric properties, halide perovskites have emerged as highly promising candidates for photocatalysis. Here, we systematically review the structure, properties, and synthesis methods of halide perovskites, and summarize recent advances in their photocatalytic and photoelectrocatalytic applications. Specifically, we focus on photocatalytic hydrogen production, carbon dioxide reduction, organic pollutant degradation, and photoelectrochemical systems. Notably, key challenges continue to hinder their practical application, particularly inherent instability in aqueous environments, lead toxicity, and charge recombination losses. To this end, we critically evaluate emerging strategies designed to circumvent these bottlenecks, including composition engineering, heterostructure construction, and protective encapsulation. Furthermore, we highlight lead-free alternatives and integrated systems that balance catalytic activity, operational stability, and environmental compatibility. Collectively, we outline future research directions to realize sustainable solar-to-chemical energy conversion through the rational design of next-generation halide perovskite photocatalysts.