Synthesis of vanadium doped tantalum oxy-nitride for photocatalytic reduction of carbon dioxide under visible light

We successfully used V as dopant to enhance activity of TaON for visible light photocatalytic reduction of CO2 into valuable fuels. We investigated that the used V dopants existed in the TaON lattice and replaced several Ta elements in the lattice leading to decrease in the conduction band minimum and increase in the valence band maximum of the prepared V TaON. Hence, the band gap energy of the prepared V TaON was lower than that of prepared TaON or the prepared V TaON material could absorb significant amount of incident visible light for production of e− and h+ pairs, which participated in reactions with CO2 and H2O to generate CH4, CO, O2 and H2. We also investigated that the optimal V/Ta ratio (or optimal amount of V dopant) for maximum enhancing photocatalytic activity of TaON was 1.5 wt%. The prepared 1.5V TaON visible light photocatalytically converted CO2 with H2O to generate CH4, CO, O2 and H2 with generation rates of 673, 206, 1479 and 67 (µmol·g−1cat·h−1), respectively.