Competitive ligand exchange on akagan茅ite surfaces enriches bulk chloride loadings

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• 作者：Xiaowei Song ; Jean-Franç ; ois Boily ; ^{jean-francois.boily@chem.umu.se}
• 关键词：尾-FeOOH ; Competitive adsorption ; Chloride occupancy ; FTIR
• 刊名：Journal of Colloid and Interface Science
• 出版年：2012
• 期刊代码：125_00219797
• 类别：ch
• 出版时间：15 June, 2012
• 卷：376
• 期：1
• 页码：331-333
• 文件大小：412 K

摘要

Akagan茅ite (尾-FeOOH) is a nanosized iron oxyhydroxide mineral with a hollandite structure containing chloride ions in 0.4 脳 0.4 nm wide channels. Proton and chloride co-sorption into these channels induces variations in bulk O-H stretching vibrations, crystallographic lattice size, and thermal stability, as a result of hydrogen bond formation with chloride ions. In this work, we show that chloride ions bound to akagan茅ite surfaces can be dislodged into aqueous solutions by competitive adsorption of foreign ions and then transferred alongside co-sorbed protons into the akagan茅ite bulk. Fourier transform infrared and X-ray photoelectron spectroscopic measurements show that HClO₄, H₂SO₄, and benzoic acid, and thereby, many other anions of various charge-to-size ratios can all effectively contribute to this phenomenon. This linked surface-bulk reactivity should be accounted for in mixed anion systems containing akagan茅ite-like materials.