Abstract
Electronic structure and surface character are two important factors of materials for photocatalytic CO2 reduction. Herein, the simultaneous regulation of electronic structure and surface basicity of pyrovanadate A2V2O7 (A = Co, Ni, Cu, Zn) were realized by changing the A-site element. The density functional theory (DFT) results suggested that Ni2V2O7 had the strongest crystal field and the greatest splitting of V 3d, resulting in the largest mobility of photogenerated electrons. Moreover, the Tanabe hypothesis predicted that the A-site cation was a basic surface site, and the CO2-TPD results revealed that Ni~(2+) had the strongest surface basicity. Ni2V2O7 exhibited much higher CO yield of 33.1 μmol/g, compared to Co2V2O7 (16.7 μmol/g) and Zn2V2O7 (12.9 μmol/g). Cu2V2O7 was not suitable for CO2 reduction due to its positive conduction band position caused by splitting the Cu 3d orbital. Altogether, this study could contribute to deeply understanding metal vanadates for photocatalytic CO2 reduction.
NSTL