Constructing an all zero-dimensional CsPbBr3/CdSe heterojunction for highly efficient photocatalytic CO2 reduction

Abstract

Metal halide perovskite quantum dots (QDs) are regarded as one of the promising photocatalysts for CO₂ reduction because of their unique optoelectronic properties. However, severe charge recombination and insufficient CO₂ absorption/activation have limited photocatalytic CO₂ reduction. Herein, we report an efficient 0D/0D CsPbBr₃/CdSe heterojunction consisting of CdSe QDs in situ grown on CsPbBr₃ QDs for high-performance photocatalytic CO₂ reduction using water as the electron donor in organic solution. The type-II 0D/0D heterojunction with the strong electronic coupling of Pb–Se and Br–Cd bonds between CdSe and CsPbBr₃ facilitates fast electron transfer. Moreover, the specific abundant edge- and corner-sites of CdSe accelerate the CO generation by forming a Cd–C₂O_4⁻ adduct, enabling superior CO₂ activation capacity and efficient CO₂ conversion into CO. Consequently, assisted by water to provide electrons and protons, the yield of main product CO reaches 115.26 μmol g⁻¹, which is 4.6-fold higher than that of pristine CsPbBr₃. This study is expected to provide a new way to fabricate high-performance perovskite-based catalysts in the field of photocatalysis.