Measurement of steady-state diffusion by the use of confocal X-ray microscopy

An interesting application of confocal micro-X-ray fluorescence has been reported by Dr. Tianxi Sun (Beijing Normal University, China) and his colleagues. The technique employs a polycapillary focusing X-ray lens and a polycapillary parallel X-ray lens, as well as the laboratory X-ray source (Mo tube). In the present research, the scan of the confocal point can give the Cu²⁺ ion distribution near the surface of the electrode in a steady-state diffusion in an electrolytic tank. The research group studied the effects of the concentration of the electrolyte and the bath voltage on the shape of the layer on the nonuniform distribution of the Cu²⁺ ions. For more information, see the paper, "Spatially Resolved In Situ Measurements of the Ion Distribution Near the Surface of Electrode in a Steady-State Diffusion in an Electrolytic Tank with Confocal Micro X-ray Fluorescence", S. Peng et al., Anal. Chem., 86, 362 (2014).