Photocatalytic reduction behavior of hexavalent chromium on hydroxyl modified titanium dioxide
Photocatalytic reduction behavior of hexavalent chromium on hydroxyl modified titanium dioxide
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羟基修饰二氧化钛光催化还原六价铬行为
DOI：
10.1016/j.apcatb.2017.01.044
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发表时间：
2017-06-05
影响因子：
22.1
通讯作者：
Bian, Zhenfeng
中科院分区：
文献类型：
--
作者：
Li, Yali;Bian, Yingying;Bian, Zhenfeng
六价铬（Cr2 O 72-（Cr（VI）在光催化剂表面的选择性吸附和三价铬（Cr 3+（Cr（III）的脱附是决定Cr（VI）光催化还原活性的重要因素。在这里，通过在碱性溶液中的简单浸泡方法实现了羟基在TiO 2上的均匀锚定。X射线光电子能谱（XPS）和傅立叶变换红外光谱（FTIR）证实了表面羟基的增加。此外，zeta电位分析显示，带正电荷的TiO 2表面在酸体系中显示出显着的改善。表面正电荷对Cr（VI）有选择性吸附，对Cr（III）有选择性脱附。进一步的实验结果表明，这种选择性吸附过程在Cr（VI）的光催化还原过程中起着重要的作用。最后，提出了选择性吸附/脱附促进Cr（IV）光催化还原的过程。(C)2017爱思唯尔B. V.保留所有权利。
The selective adsorption of hexavalent chromium (Cr2O72-(Cr(VI))) and the desorption of trivalent chromium (Cr3+(Cr(III))) at the surface of photocatalysts are very important factors in determining the photocatalytic reduction activity of Cr(VI). Here, a homogeneous anchoring of hydroxyl groups on TiO2 was achieved via a simple soaking method in alkaline solution. The increase of surface hydroxyl groups was confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectra (FTIR). Moreover, the zeta potential analysis revealed the positive charged TiO2 surface in the acid system shown a significant improvement. The surface positive charges had the selective adsorption for Cr(VI) and desorption for Cr(III). Further experimental results revealed that such selective adsorption process played important roles in the photocatalytic reduction of Cr(VI). Finally, a process of selective adsorption/desorption promoted photocatalytic reduction of Cr(IV) was proposed in detail. (C) 2017 Elsevier B.V. All rights reserved.