In Situ Synthesis of V4+ and Ce3+ Self-Doped BiVO4/CeO2 Heterostructured Nanocomposites with High Surface Areas and Enhanced Visible-Light Photocatalytic Activity

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• 作者：Long Chen ; Dawei Meng ; Xiuling Wu ; Anqi Wang ; Junxia Wang ; Yongqian Wang ; Meihua Yu
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：August 25, 2016
• 年：2016
• 卷：120
• 期：33
• 页码：18548-18559
• 全文大小：682K
• 年卷期：0
• ISSN：1932-7455

文摘

In order to achieve high performance in visible-light photocatalysis, V⁴⁺ and Ce³⁺ self-doped BiVO₄/CeO₂ heterostructured nanocomposites with high surface areas were prepared using the templating approach employing mesoporous silica MCM-41 as the hard template. X-ray photoelectron spectroscopy (XPS) spectra have demonstrated the presence of plentiful V⁴⁺ and Ce³⁺ species in the nanocomposites accompanied by the formation of oxygen vacancies. The presence of V⁴⁺ species is further identified by the electron spin resonance (ESR) spectrum. Furthermore, the BiVO₄ and CeO₂ could be affecting each other by arousing the structural changes in the formed nanocomposites. The V⁴⁺ and Ce³⁺ self-doped 0.4BiVO₄/0.6CeO₂ nanocomposite with the surface area as large as 78.35 m²/g exhibits the highest photocatalytic activity for the rhodamine B (RhB) and methyl orange (MO) degradation and photoelectrochemical performances. The enhanced photocatalytic mechanism is systematically studied via UV–vis diffuse reflectance spectra (DRS), photoluminescence (PL) spectra, transient photocurrent responses, and electrochemical impedance spectroscopy (EIS) spectra. The remarkable enhanced photocatalytic activity could be mainly attributed to the formed heterojunction nanostructures, the presence of defect states induced by oxygen vacancies, and self-doped V⁴⁺ and Ce³⁺ centers, as well as high surface areas. A possible photocatalytic mechanism over the V⁴⁺ and Ce³⁺ self-doped BiVO₄/CeO₂ nanocomposites is proposed based on the active species trapping experiments and calculated energy band structures.