Nanoarchitectonic composites with direct z-scheme heterojunction of CsPbBr3 quantum dot/CuCo2O4 nanosheet for efficient photocatalytic CO2 reduction

Photocatalytic CO 2 reduction has attracted extensive attention because of its abilities to generate renewable clean fuels while immobilizing CO 2 . However, the widely used CO 2 reduction photocatalysts generally have the problems of inadequate light absorption performance and insufficient photocatalytic reaction yield. Here we report 0D/2D CsPbBr 3 quantum dot/CuCo 2 O 4 nanosheet composites (CsPbBr 3 QD/CuCo 2 O 4 NS composites) synthesized by mechanical mixing method, which are applied for photocatalytic CO 2 reduction. Thanks to the narrow bandgaps of CsPbBr 3 QD and CuCo 2 O 4 NS, CsPbBr 3 QD/CuCo 2 O 4 NS composites represent strong light absorption performance. The p-n heterojunction forms between CsPbBr 3 QD and CuCo 2 O 4 NS obviously boosts the charge separation, leading to the photocatalytic activity and stability of CsPbBr 3 QD/CuCo 2 O 4 NS composites significantly exceeding that of CsPbBr 3 QD and CuCo 2 O 4 NS. After 5 h of photocatalytic reaction, the generation rate for CH 4 of CsPbBr 3 QD/CuCo 2 O 4 NS composites is 285.93 μmolg −1 , which is about 3.2 times and 9.2 times higher than CsPbBr 3 QD (88.08 μmolg −1 ) and CuCo 2 O 4 NS (30.92 μmolg −1 ), respectively. This work provides a new insight to construct novel heterojunction photocatalysts based on lead halide perovskite QD, which shows the enhanced photocatalytic activity and light absorption performance.