Photocatalytic reduction of CO2 by halide perovskites: recent advances and future perspectives

Photocatalytic CO2 reduction to generate energy-rich fuels through solar energy provides an attractive route to alleviate the global energy crisis and environmental concerns. Searching for various photocatalysts with high catalytic activity and selectivity for the transformation of CO2 is the key strategy to accomplish this goal. Halide perovskite nanomaterials, with the advancements of facile synthesis, excellent light-harvesting, efficient exciton generation, long carrier diffusion length, and abundant surface sites, have great potential in solar energy conversion. In this review, the fundamental photocatalytic mechanism for CO2 reduction is firstly highlighted and the impact of the structural properties of halide perovskites is presented. Then, recent advancements of the reaction medium, halide perovskites (e.g., ABX(3) structure and A(2)B ' B '' X-6 structure), and their composites (e.g., oxide, sulfide, carbide, metal-organic framework, noble metal, and carbon derivative) as photocatalysts are described and analyzed. Finally, potential research approaches and future perspectives for the improvement of halide perovskite-based photocatalysts toward efficient CO2 reduction are briefly discussed. This review sheds light on the upcoming innovative photocatalysts for CO2 reduction into high value-added products.