Tailoring the photocatalytic activity of WO3 by Nb-F codoping from first-principles calculations

• Published in: Chinese journal of physics (Taipei) Vol. 56; no. 5; pp. 2285 - 2290
• Main Authors: Xu, Ying, Zhou, Ying, Nie, Guo Zheng, Zou, Daifeng, Ao, Zhi Min
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2018
• ISSN: 0577-9073
• DOI: 10.1016/j.cjph.2018.07.003

•Nb-F codoping in WO3 can decrease the band gap significantly.•Both CBM and VBM move to higher energies, which is desirable for water splitting.•This anion-cation codoping is easy to realize in both O-rich and O-poor condition.•The visible light absorption can be significantly improved by Nb-F codoping in WO3.•Nb-F co-doped WO3 is a promising visible light photocatalyst for water spitting. In this letter, the electronic structure properties of Nb, F monodoping and Nb-F codoping are explored by first-principles calculations. Our results show that Nb-F codoping can reduce the band gap notably. The band edge analysis indicates that both conduction band maximum (CBM) and valence band minimum (VBM) move to higher energies, which is desirable for water splitting. The formation energy and pair binding energy calculation shows that this anion-cation codoping is easy to realize in both O-rich and O-poor conditions. The calculated optical absorption spectra indicate that the visible light absorption can be significantly improved by Nb-F codoping in WO3. Therefore, Nb-F co-doped WO3 is predicted to be a promising visible light photocatalyst for water splitting.