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

• Published in: International journal of hydrogen energy Vol. 45; no. 36; pp. 18186 - 18194
• Main Authors: Le Minh Tri, Nguyen, Trung, Do Quang, Van Thuan, Doan, Dieu Cam, Nguyen Thi, Al Tahtamouni, Talal, Pham, Thanh-Dong, Duc, Dao Sy, Thanh Tung, Mai Hung, Van Ha, Hoang, Anh Thu, Ngo Hong, Trang, Hoang Thu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 17.07.2020
• Subjects: CuWO4; Doping mechanism; Hydrogen; Stability; Vanadium doping; Doping mechanism; Stability; CuWO4; Hydrogen; Vanadium doping
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.06.132

In the study, we successfully conducted vanadium doping to improve photocatalytic performance of the CuWO4 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 CuWO4 crystal. In the V–CuWO4, V dopant existed in form of the V5+, which created new energy level between the conduction band (CB) and the valence band (VB) of the CuWO4 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 W5+ in the CuWO4 crystal. The formation of Cu+ and W5+ in the CuWO4 crystal not only narrowed the energy band gap but also increased the CB potential of the material. Therefore, the V–CuWO4 generated significant amount of e− under visible light and the generated e− was strong enough to react with H+ to produce H2. The optimal V/W ratio for maximum improving photocatalytic performance of the CuWO4 was 6 wt%. Finally, we investigated that our prepared V–CuWO4 showed high stability during long-term water splitting process. [Display omitted] •Successfully doped V into CuWO4 crystal to enhance its photocatalytic performance.•V dopant prevented recombination of photo-excited e− and h+ of the CuWO4.•V doping narrowed the band gap energy and increased the CB potential of the CuWO4.•The V–CuWO4 exhibited excellent photocatalytic water splitting for hydrogen production.•The optimal mole ratio of V/W in the V–CuWO4 for water splitting was 6%.