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

Photocatalytic CO2 reduction has attracted extensive attention because of its abilities to generate renewable clean fuels while immobilizing CO2. However, the widely used CO2 reduction photocatalysts generally have the problems of inadequate light absorption performance and insufficient photocatalytic reaction yield. Here we report 0D/2D CsPbBr3 quantum dot/CuCo2O4 nanosheet composites (CsPbBr3 QD/CuCo2O4 NS composites) synthesized by mechanical mixing method, which are applied for photocatalytic CO2 reduction. Thanks to the narrow bandgaps of CsPbBr3 QD and CuCo2O4 NS, CsPbBr3 QD/CuCo2O4 NS composites represent strong light absorption performance. The p-n heterojunction forms between CsPbBr3 QD and CuCo2O4 NS obviously boosts the charge separation, leading to the photocatalytic activity and stability of CsPbBr3 QD/CuCo2O4 NS composites significantly exceeding that of CsPbBr3 QD and CuCo2O4 NS. After 5 h of photocatalytic reaction, the generation rate for CH4 of CsPbBr3 QD/CuCo2O4 NS composites is 285.93 μmolg−1, which is about 3.2 times and 9.2 times higher than CsPbBr3 QD (88.08 μmolg−1) and CuCo2O4 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.