Advantageous roles of phosphate decorated octahedral CeO2 {111}/g-C3N4 in boosting photocatalytic CO2 reduction: Charge transfer bridge and Lewis basic site

Abstract

For photocatalytic CO2 reduction, directional charge-transfer channel and abundant active sites are of significance. Herein, we designed and fabricated phosphate modified octahedral CeO2 {111} surface coupling with g-C3N4 (P-CeO2/g-C3N4) for photocatalytic CO2 reduction, which had superior activity than others, i.e., P-CeO2, g-C3N4, CeO2/g-C3N4. The characterization results revealed the coordination environment of P species, as well as, the presence of hydrogen bond between phosphate and amino. Through the PO43− bridge, the interfacial electrons donated from g-C3N4 to CeO2, leading to the Z-scheme formation and fast photo-generated charge transfer. Furthermore, PO43− modification increased more oxygen-containing functional groups on surface, which acted as Lewis basic sites for CO2 reactant adsorption and activation. Therefore, under the synergistic interaction of charge-transfer channel and abundant active sites, P-CeO2/g-C3N4 is a potential photocatalyst for CO2 reduction.