Solvothermal synthesis of novel hierarchical Bi₄O₅I₂ nanoflakes with highly visible light photocatalytic performance for the degradation of 4-tert-butylphenol

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• 作者：Xin Xiao ; Chunlan Xing ; Guangping He ; Xiaoxi Zuo ; Junmin Nan ; Lishi Wang
• 关键词：Bi4O5I2 nanoflakes ; Solvothermal synthesis ; Visible light photocatalysis ; 4-Tert-butylphenol ; Photocatalytic mechanism
• 刊名：Applied Catalysis B: Environmental
• 出版年：27 April, 2014
• 年：2014
• 卷：148-149
• 期：Complete
• 页码：154-163
• 全文大小：4495 K

文摘

A facile solvothermal route is successfully developed to synthesize Bi₄O₅I₂, a novel I-poor bismuth oxyiodide, with hierarchical nanoflake structure. The composition, structure, morphology, formation mechanism, photoabsorption, energy band, and photocatalytic properties of this material are systematically investigated. The results reveal that highly pure Bi₄O₅I₂ can be easily obtained by reacting Bi³⁺, I^{鈭?/sup>, and OH鈭?/sup> at pH values of 6 to 10 under solvothermal conditions, and the formation of such hierarchical structure can be explained by a dissolution-recrystallization mechanism. The as-synthesized Bi₄O₅I₂ nanoflakes show a favorable energy band structure (bandgap energy 2.17 eV, conduction band edge potential is more negative than the reduction potential of superoxide radicals), a high specific surface area (38.6 m2 g鈭?), and a hierarchical micro/nano structures. Thus, they exhibit superior photocatalytic and mineralization efficiency for the degradation of 4-tert-butylphenol (PTBP, a representative alkylphenol) under visible light irradiation, with a reaction rate is 6.8 and 57 times faster than that of BiOI microspheres and N-doped TiO₂, respectively. The photogenerated reactive species and degradation intermediates are identified, and possible photocatalytic mechanism is proposed. What's more, the as-synthesized Bi₄O₅I₂ nanoflakes remain stable during the photocatalytic reaction and can be used repeatedly, revealing their promising applications in the treatment of organic wastewaters.}