Influence of O/F ratio on oxygen defect and photochemical properties of BixOyFz

Publication date: 5 October 2017
Source:Materials & Design, Volume 131
Author(s): Ming Ren, Fei Teng, Yang Yang, Yifei Zhai, Wenhao Gu, Zailun Liu, Zhe Liu, Yiran Teng
The BixOyFz samples with different O/F molar ratios are prepared by a simple hydrothermal method through controlling reaction medium composition. The effect of O/F molar ratio on the oxygen defect and photochemical property are mainly investigated. It is found that BiO0.51F1.98, BiO0.67F1.66, Bi7O5F11 and BiF3 can form in acetic acid/water (AA/W) medium; whereas in tetrahydrofuran/water (THF/W) medium, BiF3 and BiOF can only form. Moreover, with decreasing O/F ratio, the energy band of BixOyFz down shifts and the band gap becomes wider; but the amount of oxygen defect decreases with decreasing O/F ratio, namely, Bi7O5F11 (O/F=0.4545, g=307mT)>BiO0.67F1.66 (O/F=0.4036, g=260mT)>BiO0.51F1.98 (O/F=0.2576, g=130mT). This work suggests that BiO0.51F1.98 and BiO0.67F1.66 can be developed as the new photocatalysts.

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