The advanced photocatalytic performance of V doped CuWO4 for water splitting to produce hydrogen

Abstract In the study, we successfully conducted vanadium doping to improve photocatalytic performance of the CuWO 4 for water splitting to produce hydrogen. The doping mechanism, optimal doping ratio and material stability were investigated by various characterization methods and water splitting experiments. We found that the V substituted several W elements of the CuWO 4 crystal. In the V–CuWO 4 , V dopant existed in form of the V 5+ , which created new energy level between the conduction band (CB) and the valence band (VB) of the CuWO 4 to improve charge transfer as well as to prevent the e − and h + recombination of the material. The substitution of W by V dopant also led the formation of Cu + and W 5+ in the CuWO 4 crystal. The formation of Cu + and W 5+ in the CuWO 4 crystal not only narrowed the energy band gap but also increased the CB potential of the material. Therefore, the V–CuWO 4 generated significant amount of e − under visible light and the generated e − was strong enough to react with H + to produce H 2 . The optimal V/W ratio for maximum improving photocatalytic performance of the CuWO 4 was 6 wt%. Finally, we investigated that our prepared V–CuWO 4 showed high stability during long-term water splitting process.