Improvement of Photocatalytic Activity of Bi2WO6 by Doping Ag and Y: A DFT Study

• Published in: Journal of electronic materials Vol. 50; no. 7; pp. 4027 - 4033
• Main Authors: Linh, Tran Phan Thuy, Phu, Nguyen Dang, Van Hai, Pham, Hoang, Luc Huy
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-07-2021; Springer Nature B.V
• Subjects: Bismuth compounds; Catalytic activity; Characterization and Evaluation of Materials; Chemistry and Materials Science; Density functional theory; Doping; Electronics and Microelectronics; Energy bands; Instrumentation; Materials Science; Optical and Electronic Materials; Optical properties; Original Research Article; Photocatalysis; Silver; Solid State Physics; Tungstates; Valence band; Ag-doped Bi; optical properties; Bi; photocatalytic semiconductor; electronic structure; effective mass; WO; Y-doped Bi2WO6
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-021-08935-3

Although much attention has been recently focused on Bi
2
WO
6
and doping materials as highly efficient visible-light photocatalysts, the selection of an appropriate element as dopant and our understanding of the photocatalytic mechanism from the electronic level still need to be further investigated. In the current work, electronic band structures, density of states, optical properties, and effective mass for Bi
2
WO
6
, Ag-doped Bi
2
WO
6
and Y-doped Bi
2
WO
6
semiconductors have been studied by density functional theory calculations. We find that, while both the doped systems show little change in the band gap from Bi
2
WO
6
, Ag-doped and Y-doped Bi
2
WO
6
produce more dispersive bands compared to the original Bi
2
WO
6
, implying that the doped systems can facilitate the spatial separation of photo-induced electron–hole pairs, and thus enhance the photocatalytic performance. In addition, for Ag-doped Bi
2
WO
6
, the presence of an Ag impurity energy band just above the valence band is expected to act as electron-trapping sites leading to a reduction of the recombination rate of photogenerated carriers. Our findings could provide an explanation for the experimental observations reported in the literature.