Probing Electrochemical Interfaces with X-ray Standing Waves

The utility of the X-ray standing wave technique for the study of electrochemical interfaces is demonstrated. A platinum/carbon LSM (layered synthetic microstructure) with a d spacing of 56 A and with platinum as the outermost layer was used as a substrate. A layer of iodide was adsorbed, followed by the electrodeposition of a layer of copper. Simultaneously monitoring of the reflectivity as well as the fluorescence intensity arising from the iodide and copper layers showed that the copper layer is deposited on top of the platinum, consistent with previously reported LEED studies of Hubbard and co-workeis.