Artificial Photosynthesis over Metal Halide Perovskites: Achievements, Challenges, and Prospects.

Over the last 5 years, metal halide perovskites (MHPs) have emerged as promising photocatalysts for CO2 reduction because of their extraodinary visible-light-harvesting capabilities and appropriate band structure. However, the CO2 photoreduction activity of pristine MHPs is still unsatisfactory because of the phase instability, serious radiative recombination, and insufficient surface-active sites. This Perspective summarizes the strategies employed in recent studies for enhancing the photocatalytic CO2 reduction performance of MHPs from the standpoint of structure engineering, which includes composition/dimension regulation, surface modification, and heterostructure construction. The relationship between the structure (composition, dimension, and shape) and photocatalytic performance is established, which is instructive for exploiting highly efficient perovskite-based photocatalysts in artificial photosynthesis applications. Further, some important challenges and future prospects of MHPs in this field are proposed and discussed.