Efficient photocatalytic CO2 conversion over 2D/2D Ni-doped CsPbBr3/Bi3O4Br Z-scheme heterojunction: Critical role of Ni doping, boosted charge separation and mechanism study

Artificial photoreduction of CO2 is confined by low separation efficiency of photoinduced charge carriers and poor activation of CO2 over photocatalysts. Herein, a brilliant ultrathin 2D/2D Ni-doped CsPbBr3/Bi3O4Br Z-scheme heterostructure was rationally constructed, which showed superior CO yield of 387.57 μmol g−1 with 98.2% selectivity, 12.3 times higher than that of pristine CsPbBr3. Both experimental results and theoretical calculations confirmed that Ni doping in CsPbBr3 not only efficiently expand spectral response but also is beneficial for the adsorption and activation of CO2. Moreover, in-situ irradiated XPS validated the Z-scheme charge transfer path, forming an internal electric field (IEF) directing from Ni-doped CsPbBr3 to Bi3O4Br, which results in higher charge separation efficiency. Besides, in-situ DRIFTS and DFT studies reveal that the photocatalyst depressed the formation energy of COOH* and CO* . This work shows a new path for boosting photocatalytic CO2 reduction of photocatalysts by the synergistic effect between doping and heterostructure.