Time-lapse observation of electrolysis of copper sulfate with a full-field X-ray fluorescence imaging microscope

The time-lapse observation of the electrodeposition of copper in copper sulfate solution was performed by imaging X-ray fluorescence from the copper deposition. The X-ray fluorescence was directly imaged with a full-field Wolter mirror microscope, which was constructed at the Photon Factory. Controlling the electric current in the solution from 0 to 71.7 μA, the deposition of copper on a Pt cathode was directly observed by imaging its X-ray fluorescence. One exposure time for obtaining an X-ray fluorescence image was 80s. Then, it was 17 min later from the beginning of the electrolysis when the Xray fluorescence image of the electrodeposition is observed for the first time. At this exposure time, the detection limit of the mass of copper was estimated to be 0.60pg/image, which was calculated using test samples of 1.00× 10 ^-31.00mol/l copper sulfate solutions.