Alkali-Induced in Situ Fabrication of Bi2O4-Decorated BiOBr Nanosheets with Excellent Photocatalytic Performance

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• 作者：Dan Wu ; Liqun Ye ; Songtao Yue ; Bo Wang ; Wei Wang ; Ho Yin Yip ; Po Keung Wong
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 14, 2016
• 年：2016
• 卷：120
• 期：14
• 页码：7715-7727
• 全文大小：867K
• 年卷期：0
• ISSN：1932-7455

文摘

A simple alkali (NaOH) post-treatment approach assisted with light irradiation to in situ obtain Bi₂O₄ nanoparticle-decorated BiOBr nanosheets, brown BiOBr-0.01, is presented for the first time. Bi₂O₄ nanoparticles are formed due to a combined action of NaOH-induced dehalogenation and light triggered photogenerated hole (h⁺) oxidation processes on the surface of BiOBr nanosheets. Importantly, by varying the NaOH concertation in the post-treatment, the content of Bi₂O₄ phase in the hybrid structures can be easily tuned, and predominantly exposed highly reactive {001}-facet of BiOBr nanosheet can be well preserved. Significantly, without any foreign elements, the light absorption of as-prepared BiOBr-0.01 is extended to the near-infrared (NIR) region. In comparison with normal BiOBr, brown BiOBr-0.01 nanosheet shows superior photocatalytic activity for the dye degradation and microbial disinfection. Particularly, it exhibit excellent capability to photocatalytically reduce CO₂ into CO and CH₄, whereas the normal BiOBr is completely incapable for CO₂ conversion under simulated sunlight irradiation. The exceptional enhancement is due to the Bi₂O₄ extended light absorption, efficient photogenerated e^–/h⁺ pair separation, and the increased surface-adsorbed ability to reactants. This facile post-treatment method is promising for different bismuth-based systems and hence offers a path to a large variety of materials.