Constructing an all zero-dimensional CsPbBr 3 /CdSe heterojunction for highly efficient photocatalytic CO 2 reduction

Metal halide perovskite quantum dots (QDs) are regarded as one of the promising photocatalysts for CO 2 reduction because of their unique optoelectronic properties. However, severe charge recombination and insufficient CO 2 absorption/activation have limited photocatalytic CO 2 reduction. Herein, we report an efficient 0D/0D CsPbBr 3 /CdSe heterojunction consisting of CdSe QDs in situ grown on CsPbBr 3 QDs for high-performance photocatalytic CO 2 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 CsPbBr 3 facilitates fast electron transfer. Moreover, the specific abundant edge- and corner-sites of CdSe accelerate the CO generation by forming a Cd–C 2 O 4 − adduct, enabling superior CO 2 activation capacity and efficient CO 2 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 CsPbBr 3 . This study is expected to provide a new way to fabricate high-performance perovskite-based catalysts in the field of photocatalysis.