Molecular-Scale Study of Salicylate Adsorption and Competition with Catechol at Goethite/Aqueous Solution Interface
Molecular-Scale Study of Salicylate Adsorption and Competition with Catechol at Goethite/Aqueous Solution Interface
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DOI：
10.1021/jp4027578
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发表时间：
2013-05
影响因子：
3.7
通讯作者：
Yanli Yang;J. Duan;C. Jing
中科院分区：
文献类型：
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作者：
Yanli Yang;J. Duan;C. Jing
深入研究水杨酸盐在针铁矿上的吸附机制，特别是其与邻苯二酚的竞争吸附机制，有助于我们进一步了解天然有机物类似物在环境中的归宿和迁移规律。吸附过程进行了研究，使用多种互补的技术，包括批量吸附实验，流动池ATR-FTIR测量，和DFT计算。宏观结果表明，由于静电相互作用，增加pH值和离子强度对水杨酸盐的吸附产生不利影响。在pH 5-9范围内，水杨酸盐与羧酸盐形成单核单齿内球配合物，羧酸盐与针铁矿表面的铁原子结合。在高水杨酸浓度和低离子强度下，可以观察到静电外层复合物。在水杨酸盐和邻苯二酚的竞争吸附过程中，它们各自的界面复合物共存并相互竞争。邻苯二酚可取代表面水杨酸酯。
Insights into the adsorption mechanisms of salicylate on goethite, especially its competition with catechol, can further our understanding of the fate and transport of natural organic matter analogues in the environment. The adsorption process was investigated using multiple complementary techniques including batch adsorption experiments, flow-cell ATR-FTIR measurement, and DFT calculations. The macroscopic results show that increasing pH and ionic strength had an adverse effect on salicylate adsorption because of electrostatic interactions. Salicylate formed an inner-sphere complex in a mononuclear monodentate configuration with carboxylate bound to the iron atom on goethite surface within pH 5–9. The electrostatic outer-sphere complex could be observed under high salicylate concentrations and low ionic strength. In the competitive adsorption of salicylate and catechol, their individual interfacial complexes coexisted and competed with each other. The surface salicylate could be replaced by catechol duri...