Sorption of iodide on cuprite (Cu2O)
Sorption of iodide on cuprite (Cu2O)
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DOI：
10.1021/1a9908999
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发表时间：
2000-05-16
期刊：
影响因子：
3.9
通讯作者：
Bessière, J
中科院分区：
文献类型：
--
作者：
Lefèvre, G;Walcarius, A;Bessière, J
采用批量实验和表面分析相结合的方法，研究了碘离子与铜（Cu2O）表面的相互作用。研究了碘离子吸收随pH的变化规律。热力学计算和表面分析（x射线光电子能谱、扫描电子显微镜、拉曼光谱和电化学）表明，两种不同的ph依赖机制是导致Cu2O上碘化物积累的原因。在pH值低于6.5时，铜表面发生了CuI的沉淀，而在碱性较强的介质中，通过取代Cu2O的表面羟基来吸附碘化物。吸附过程不受氯离子过量1000倍的影响，但被限制在与Cu2O稳定域对应的电位范围内（即pH 8时-10 ~ +190 mV/ENH）；因此，在金属铜或CuO上都没有观察到积累。
The interactions of iodide ions with cuprite (Cu2O) surfaces were studied by combining batch experiments and surface analyses. The evolution of iodide uptake with pH was investigated. The thermodynamical calculations and surface analyses (X-ray photoelectron spectroscopy, scanning electron microscopy, Raman spectroscopy, and electrochemistry) were used to show that two different pH-dependent mechanisms are responsible fbr the accumulation of the iodide species on Cu2O. At pH values lower than 6.5, the precipitation of CuI occurs on the cuprite surface, while in more alkaline medium, the iodide adsorption takes place by substituting the surface hydroxyl groups of Cu2O. The sorption processes were not affected by a 1000-fold excess of chloride ions, but they were limited to the potential range corresponding to the stability domain of Cu2O (i.e., between -10 and +190 mV/ENH at pH 8); thus no accumulation was observed either on metallic copper or on CuO.