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More recent APS results: |
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Probing the Electrochemical Double Layer with XSW |
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The electrochemical double layer (EDL) can be probed directly using X-ray standing waves (XSW). Diagram (right) the x-ray standing wave field (in red) formed from the superposition of the incident and reflected x-ray beams, and the fluorescent signal (blue arrow) from the double-layer ions (blue dots, whose distribution is shown schematically in the inset above). We have recently demonstrated the capability to probe the EDL structure by measuring the distribution of Sr2+ and Rb+ ions at the rutile-water interface using the XSW technique (Fenter et al., J. Coll. Int. Sci. 225, 154-165). |
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Proposed structure of Sr2+ ions adsorbed at the rutile-water interface in the condensed layer. The ion height was determined directly using XSW, while the local coordination structure is inferred from surface x-ray absorption spectroscopy measurements (Fenter et al., J. Coll. Int. Sci. 225, 154-165). |
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A schematic of the experimental system [at sector 12-ID-D (BESSRC-CAT), Advanced Photon Source] to probe the EDL using X-ray standing waves |
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