ToF-SIMS depth profiling analysis of the uptake of Ba2+ and Co2+ ions by natural kaolinite clay

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:277

Article

Shahwan, T ; Erten, HN ; Black, L ; Allen, GC

关键词: Ba;    Co;    sorption;    kaolinite;    depth profiling;    ToF-SIMS;   

DOI  :  10.1016/j.jcis.2004.04.013

来源: Elsevier

【 摘 要 】

The sorption behavior of Ba2+ and Co2+ ions on a natural clay sample rich in kaolinite was studied using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling at 10-Angstrom steps was performed up to a 70-Angstrom matrix depth of the clay prior to and following sorption. The results showed that Co2+ is sorbed in slightly larger quantities than Ba2+, with significant numbers of ions fixed on the outermost surface of the clay. Depletion of the ions K+, Mg2+, and Ca2+ from the clay lattice was observed to accompany enrichment with Co2+ and Ba2+ ions. The data obtained using X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) indicated insignificant structural and morphological changes in the lattice of the clay upon sorption of both Ba2+ and Co2+ ions. Analysis using energy dispersive X-ray spectroscopy (EDS) showed that the average atomic percentage (+/-S.D.) of Ba and Co on kaolinite surface were 0.49+/-0.11 and 0.61+/-0.19, respectively, indicating a limited uptake capacity of natural kaolinite for both ions. (C) 2004 Elsevier Inc. All rights reserved.

【 授权许可】

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