Enhanced Visible Light Photocatalysis of Bi2O3 upon Fluorination

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• 作者：Hai-Ying Jiang ; Jingjing Liu ; Kun Cheng ; Wenbin Sun ; Jun Lin
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：October 3, 2013
• 年：2013
• 卷：117
• 期：39
• 页码：20029-20036
• 全文大小：434K
• 年卷期：v.117,no.39(October 3, 2013)
• ISSN：1932-7455

文摘

For the better utilization of solar light and complete oxidation of environmental organic pollutants, it is desired to develop small band gap semiconductors with a deep valence band as efficient visible light photocatalysts. In this work, we prepared the fluorinated Bi₂O₃ catalysts using a precipitation method, followed by a solvothermal process in the presence of NH₄F. The fluorinated Bi₂O₃ catalysts, especially with the atomic ratio of F to Bi (R_F) at 0.2, exhibit much higher photocatalytic activities than the pure Bi₂O₃ for the degradation of methyl orange (MO) under the visible light irradiation. The effects of the fluorination on the phase structure, special surface areas, morphologies, optical properties, surface-adsorbed species, and electronic band structure of the Bi₂O₃ were investigated in detail. It was revealed that both the surface-adsorbed and lattice-substituted fluorine, induced by the fluorination to Bi₂O₃, play critical roles in the enhanced photocatalytic performance of the fluorinated Bi₂O₃. The two types of fluorine species effectively inhibit the recombination of the photoexcited electron鈥揾ole pairs by withdrawing the photoexcited electrons and increase the oxidation power of the photoexcited hole by lowering the valence band edge, respectively.