X-Ray Absorption and Electron Paramagnetic Resonance Studies of Cu(II) Sorbed to Silica: Surface-Induced Precipitation at Low Surface Coverages
✍ Scribed by Kang Xia; Ahmed Mehadi; Robert W. Taylor; William F. Bleam
- Book ID
- 102578447
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 107 KB
- Volume
- 185
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
they are not easily displaced by the background electrolyte Both EPR and XAFS spectroscopy were used to characterize ions (2). As a general rule, outer-sphere surface complexes, the sorption of Cu(II) on silica surfaces at extremely low surface which involve electrostatic bonding, are less stable than incoverage (0.8 and 9.9% monolayer). The binding structure of ner-sphere surfaces complexes.
Cu(II) on silica surfaces revealed by XAFS experiment was com-
In the past decade or so, a growing number of scientists pared to that predicted by EPR spectra. Our XAFS results show have come to realize that macroscopic approaches cannot that Cu(II) hydroxide clusters form on silica surfaces even at surprovide information on the composition and structure of face coverage as low as 0.8% of a monolayer. However, we observed sorption complexes at the microscopic level. Microscopic low EPR intensity and line-broadening which has been assigned to dipole-dipole interactions between isolated Cu(II) ions. The re-information on sorption complexes is essential to undersults of our XAFS studies indicate that the loss of EPR intensity standing sorption mechanisms at mineral-water interfaces. and line-broadening can be traced to Cu(OH) 2 clusters on silica Fortunately, various newly developed spectroscopic techsurfaces.