Enhanced photocatalytic reduction of CO2 into alcohols on Z-scheme Ag/Ag3PO4/CeO2 driven by visible light

A unique three dimensional Ag/Ag3PO4/CeO2 with Z-scheme structure was constructed and applied in photocatalytic reduction of CO2 under visible light, demonstrating superior performance in yielding CH3OH (42.5 μmol gcat−1) and C2H5OH (31.5 μmol gcat−1). During the photocatalysis, CeO2 microspheres provide abundant pores for loading Ag/Ag3PO4 nanoparticles, ensuring the stability of the light sensitizers. Furthermore, there is an inner electric field formed between Ag3PO4 and CeO2 with Ag working as e−-h+ quenching bridge. Benefited from the high conductivity of Ag, the combination between holes in CeO2 VB and electrons in Ag3PO4 CB can be promoted, enabling the formation of Z-scheme structure and leaving plenty of electrons in CeO2 host for CO2 reduction. Moreover, CeO2 as a basic metal oxide can transform inert linear CO2 to b-HCO3− and b-CO32− species to decline reductive potential of CO2.