Lead-free halide perovskite hollow nanospheres to boost photocatalytic activity for CO2 reduction

Strong photoresponse, efficient charge separation, and high surface activity are three important requirements for an ideal photocatalyst, while few photocatalysts can fully meet these requirements. Herein, we report such a photocatalyst based on lead-free halide perovskite hollow nanospheres (H-Cs3Sb2Br9) by a facile antisolvent-assisted method. The hollow structure of H-Cs3Sb2Br9 improves the light-harvesting performance; The formation of surface shallow trap states contributes to promoting the excited-carrier separation; The ligand-free termination surface of H-Cs3Sb2Br9 facilitates the exposure of Br vacancies and active sites, thus strengthens the CO2 adsorption and accelerates surface reactivity dynamics. As a result, with a dinuclear Co(II) complex as the co-catalyst, H-Cs3Sb2Br9 exhibits a record-high photocatalytic activity for CO2 reduction, with a CO yield of 15,010.4 ± 550.4 μmol g−1 after 8 h of illumination under simulated solar light (100 mW cm−2). This research presents a new way to develop cost-effective photocatalysts for CO2 reduction.