Surface complexation of organic arsenic on nanocrystalline titanium oxide
Surface complexation of organic arsenic on nanocrystalline titanium oxide
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DOI：
10.1016/j.jcis.2005.04.019
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发表时间：
2005-10-01
影响因子：
9.9
通讯作者：
Korfiatis, GP
中科院分区：
文献类型：
--
作者：
Jing, CY;Meng, XG;Korfiatis, GP
采用x射线吸收光谱（XAS）、表面电荷和zeta电位测量、吸附边和表面络合模拟等方法研究了一甲基larsinic酸（MMA）和二甲基larsinic酸（DMA）在纳米晶氧化钛（TiO2）上的吸附机理。XAS数据表明，MMA和DMA分别与TiO2表面形成双齿和单齿内球配合物。TiO2的电荷和zeta电位行为随离子强度的变化表明，在pH值为5.8时，TiO2的零电荷点（PZC）和等电点（IEP）是相同的。MMA和DMA在TiO2上的吸附使IEP分别达到了pH 4.1和4.8，表明形成了带负电荷的表面配合物。在XAS证据约束下，具有三平面选项的电荷分布（CD）多位点络合（MUSIC）模型对实验数据提供了满意的解释。(c) 2005爱思唯尔公司版权所有。
The adsorption mechanisms of monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) on nanocrystalline titanium oxide (TiO2) were investigated with X-ray absorption spectroscopy (XAS), surface charge and zeta potential measurements, adsorption edge, and surface complexation modeling. XAS data demonstrated that MMA and DMA formed bidentate and monodentate inner sphere complexes with the TiO2 surface, respectively. The charge and zeta potential behaviors of TiO2 as a function of ionic strength suggested that the point of zero charge (PZC) and isoelectric point (IEP) of TiO2 were identical at pH 5.8. Adsorption of MMA and DMA on TiO2 shifted the IEP to pH 4.1 and 4.8, respectively, indicating the formation of negatively charged surface complexes. A satisfactory interpretation of the experimental data was provided by the charge distribution (CD) multi-site complexation (MUSIC) model with the triple plane option under the constraint of the XAS evidence. (c) 2005 Elsevier Inc. All rights reserved.