Z-Scheme 2D/2D Heterojunction of CsPbBr3/Bi2WO6for Improved Photocatalytic CO2Reduction

Heterojunction engineering, especially 2D/2D heterojunctions, is regarded as a quite promising strategy to manipulate the photocatalytic performance of semiconductor catalysts. In this manuscript, a direct Z-scheme 2D/2D heterojunction of CsPbBr3/Bi(2)WO(6)is designed and fabricated by a simple electrostatic self-assembly process. By using ultrathin nanosheets with several atomic layers as the building blocks, a close CsPbBr3/Bi(2)WO(6)heterointerface over large area with quite a short charge transport distance is obtained, which enables a valid Z-scheme interfacial charge transfer between Bi(2)WO(6)and CsPbBr(3)and thus boosts charge separation. The CsPbBr3/Bi(2)WO(6)heterojunction exhibits a superior photocatalytic performance toward CO(2)reduction. By incorporating Pt nanoparticles as the cocatalyst, a high photoelectron consumption rate of 324.0 mu mol g(-1)h(-1)under AM 1.5G irradiation (150 mW cm(-2)) is obtained, which is 12.2 fold higher than that of CsPbBr(3)nanosheets. Moreover, a stable product yield of up to 1582.0 mu mol g(-1)and electron consumption yield of 8603.0 mu mol g(-1)for photocatalytic CO(2)reduction to CO (11.4%) and CH4(84.3%) can be achieved after 30 h of continuous catalytic reaction. The accelerated photogenerated charge transfer and spatial charge separation are investigated in detail by ultrafast spectra, photoelectrochemical test, and Kelvin probe force microscopy.