Controllable synthesis of Bi 2 MoO 6 nanosheets and their facet-dependent visible-light-driven photocatalytic activity
Controllable synthesis of Bi 2 MoO 6 nanosheets and their facet-dependent visible-light-driven photocatalytic activity
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DOI：
10.1016/j.apsusc.2017.08.072
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发表时间：
2018-02
影响因子：
6.7
通讯作者：
Zixin Yang;Min Shen;Ke Dai;Xuehao Zhang;Hao Chen
中科院分区：
文献类型：
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作者：
Zixin Yang;Min Shen;Ke Dai;Xuehao Zhang;Hao Chen
以十六烷基三甲基溴化铵（CTAB）为模板剂，通过调节pH值，采用水热法选择性合成了{010}晶面暴露的Bi 2 MoO 6纳米片。采用X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、紫外-可见漫反射光谱（DRS）、傅里叶变换红外光谱（FTIR）、拉曼光谱（Raman）和Brunauer-Emmett-Teller比表面积分析等手段，研究了CTAB含量和水热条件对产物形貌和晶相的影响。结果表明，在碱性水热条件下，可以得到尺寸较大（片长0.5 ~ 3 μm）、沿着{010}面各向异性生长的Bi 2 MoO 6纳米片.通过调节水热溶液的pH值，可以在2.30 ~ 2.57 eV范围内对Bi 2 MoO 6的禁带宽度进行微调。pH值对水热前驱体的组成有显著影响，导致Bi 2 MoO 6纳米片具有不同的{010}面比例，特别是水热处理初期Bi 2 O3的形成是{010}面暴露的关键因素。以罗丹明B、土霉素和四环素为降解物，研究了不同{010}晶面暴露率的Bi 2 MoO 6光催化活性.在pH值为10.0时合成的{010}晶面暴露率最高的Bi 2 MoO 6纳米片具有高效的可见光催化降解污染物的活性，这主要归因于片状结构、结晶度以及最重要的是，{010}晶面暴露产生高浓度的dotO 2 −自由基。
Bi2MoO6nanosheets with exposed {010} facets were selectively synthesized through hydrothermal method by adjusting the pH value in the presence of cetyltrimethyl ammonium bromide (CTAB) as the templates. The effects of CTAB content and hydrothermal conditions on the morphologies and crystal phases of the products were determined by using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectrometry, and Brunauer-Emmett-Teller surface area analyses. It is found that Bi2MoO6nanosheets with relatively large particle sizes (plate length 0.5–3 μm) and special anisotropic growth along the {010} plane can be obtained from an alkaline hydrothermal environment. The band gap of Bi2MoO6can be fine-tuned from 2.30 to 2.57 eV by adjusting the pH value of hydrothermal solution. The pH value has a significant effect on the composition of hydrothermal precursors, which results in Bi2MoO6nanosheets with different ratio of {010} faces, especially the formation of Bi2O3in the primary stage of the hydrothermal treatment is a key factor for the exposure of {010} facets. The visible-light-driven photocatalytic activities of the Bi2MoO6products with different ratio of {010} facets exposed are investigated through the degradation of Rhodamine B, oxytetracycline, and tetracycline. Bi2MoO6nanosheets synthesized at pH 10.0 with highest {010} facet exposed ratio exhibited highly efficient visible light photocatalytic activity for pollutant decomposition, which can be mainly attributed to the flake structures, the crystallinity and most importantly, the exposed {010} facet which generate high concentration of radical dotO2−.