Rapid Charge Transfer Endowed by Hollow-structured Z-Scheme Heterojunction for Coupling Benzylamine Oxidation With CO2 Reduction

In the field of photocatalysis, ultrafast electron transfer at the interface is the key factor affecting photocatalytic activity. Herein, ultrafast carrier transport is achieved through constructing a Z-scheme heterojunction of CoSe@Zn0.5Cd0.5S (CoSe@ZCS), which is prepared by in situ growth of ZCS on the ZIF-67-derived hollow CoSe. The ultrafast charge transfer at the Z-scheme heterojunction interface is verified by advanced fs-transient absorption, which provides vital evidence for the specific mechanism of photocatalytic charge transfer. In addition, the presence of key intermediates (*COOH and C & boxH;N) is detected by in-situ FTIR spectroscopy, which further clarified the mechanism of coupling benzylamine oxidation with CO2 photoconversion. DFT calculations also confirm that the Z-scheme heterojunction effectively reduces the energy barrier of the rate-limiting step of *COOH formation, facilitating the photocatalytic CO2 reduction process of ZCS. Benefiting from the ultrafast electron transfer at the interface of the Z-scheme heterojunction, CoSe@ZCS exhibits excellent bifunctional photocatalytic performance. This work lays the foundation for further exploration of the charge transfer mode at the heterojunction interface to facilitate solar-driven energy conversion.