Z-scheme SnS2/CsPbBr3 Heterojunctions for Photoreduction CO2 Reaction and Related Photoinduced Carrier Behaviors

CsPbBr 3 perovskite exhibits potential application in photocatalytic CO 2 reduction into valuable chemical fuels; however, enhancing carrier separation capability of the CsPbBr 3 and fully understanding the CO 2 reduction reaction process are still imperative. Herein, a new series of x SnS 2 /CsPbBr 3 nanocrystals (NCs)- y heterostructures are developed, which exhibit better catalytic activity in comparison with pure CsPbBr 3 NCs. Interface and surface carrier dynamic investigation reveals that this heterojunction structure can effectively improve carrier separation efficiency. Based on the interfacial electric field direction of CsPbBr 3 to SnS 2 , it is suggested that SnS 2 /CsPbBr 3 NC heterostructure satisfies Z-scheme transfer dynamics. Meanwhile, by the aid of in situ surface photovoltage, it is experimentally confirmed there is dynamic carrier interaction between CO 2 molecules and the SnS 2 /CsPbBr 3 NCs photocatalyst under irradiation, and a photocatalytic CO 2 reduction mechanism is thus proposed. This work expands the awareness of the interaction between CO 2 and the photocatalyst, which can be strongly influenced by carrier separation efficiency at the photocatalyst heterojunction.