X-ray induced photocurrents at the metal/solution interface

A technique is herein described for the acquisition of X-ray absorption spe ctra of electrodes fully immersed in an electrolyte solution by monitoring the energy dependence of X-ray induced photocurrents. This novel strategy m ade it possible to obtain in situ Au L-III-edge X-ray absorption spectra of solid Au electrodes displaying virtually identical features to those recor ded simultaneously via X-ray fluorescence. The dependence of the X-ray indu ced photocurrents on chopping frequency and electrode potential was found t o be consistent with a temperature modulation of the rate of the interfacia l electron transfer (faradaic heating currents), rather than electron photo emission, as the primary source of the observed effects.