Bi5+ , Bi(3-x)+ , and Oxygen Vacancy Induced BiOClx I1-x Solid Solution toward Promoting Visible-Light Driven Photocatalytic Activity.
Bi5+ , Bi(3-x)+ , and Oxygen Vacancy Induced BiOClx I1-x Solid Solution toward Promoting Visible-Light Driven Photocatalytic Activity.
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DOI：
10.1002/chem.201706164
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发表时间：
2018-05
期刊：
影响因子：
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通讯作者：
Guoqiang Zhang;Lei Cai;Yanfeng Zhang;Yu Wei
中科院分区：
文献类型：
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作者：
Guoqiang Zhang;Lei Cai;Yanfeng Zhang;Yu Wei
通过化学沉淀法在室温下调整初始Cl与I摩尔比，合成了具有不同带隙的BiOClx I1-x固溶体。分别通过 XRD、XPS、Raman、SEM、TEM 和 UV/Vis 对样品的结构、形貌和光学性质进行了表征。光催化实验表明，BiOCl0.9 I0.1样品在可见光照射（λ>420 nm）下12分钟内完全分解大浓度的50 mg L-1罗丹明B（RhB）水溶液，比纯BiOI高11倍。此外，利用DFT（密度泛函理论）计算方法和电化学方法研究了BiOCl、BiOI和BiOClx I1-x的电子能带结构和态密度。结果发现BiOClx I1-x样品中存在多个Bi5+、Bi(3-x)+晶体缺陷和氧空位。 Mott-Schottky 图和价带 XPS 光谱结果表明 BiOCl0.9 I0.1 的导带 (CB) 位置上移，这有利于光催化剂的氧化还原能力。可以阐明，多晶体缺陷和独特能带结构的协同效应对于提高太阳能驱动的光催化活性至关重要。这项工作通过简单有效的方式调节晶体缺陷和能带结构，为构建高性能光催化剂提供了新的亮点。
BiOClx I1-x solid solutions with different band gaps were synthesized by adjusting the initial Cl to I molar ratios through a chemical precipitation method at room temperature. The structures, morphologies and optical properties of the samples were characterized by XRD, XPS, Raman, SEM, TEM and UV/Vis, respectively. The photocatalytic experiments showed that the BiOCl0.9 I0.1 sample totally decomposed a large concentration of 50 mg L-1 aqueous Rhodamine B (RhB) solution within 12 minutes under visible light irradiation (λ>420 nm), which is 11 times higher than that of pure BiOI. Furthermore, the electron band structure and density of states of BiOCl, BiOI and BiOClx I1-x have been investigated using the DFT (density functional theory) calculation method and electrochemical methods. It was found that there are multiple crystal defects of Bi5+ , Bi(3-x)+ , and oxygen vacancies in the BiOClx I1-x samples. The results for Mott-Schottky plots and valence-band XPS spectra showed the position of conduction band (CB) for BiOCl0.9 I0.1 was up-shifted, which is favourable to the redox capacity for the photocatalysts. It could be elucidated that the synergistic effects of multiple crystal defects and unique band structure are critical to improving solar driven photocatalytic activity. This work provides a new highlight toward the construction of high property photocatalysts by tuning the crystal defect and band structure in a simple and efficient way.