Copper electrodeposition into ion-exchange materials

Electrodeposition of copper into spherical granules of ion-exchange materials KU-23 and KU-2 out of acid sulfate solutions is studied by a method of cyclic voltammetry. It is discovered that the discharge of copper ions in an ion-exchange matrix is characterized by a cathodic overvoltage that is higher than the overvoltage of the same process on a graphite substrate by 0.08 V, which is most probably connected with a limited mobility of ions localized at fixed groups RSO ₃ ^? ]. The cyclic voltammogram exhibits an additional cathodic peak in the potential region corresponding to the reduction of single-charged copper ions that form as a result of their accumulation inside pores of the ion-exchange matrix during anodic dissolution of metal deposited previously. It is fixed microscopically that the process of deposition begins at the graphite substrate/ion-exchanger interface and passes into bulk upon the formation of an electron-conducting layer saturated with copper. Preliminary saturation of the ion-exchanger by copper deposited chemically facilitates uniform electrodeposition of copper over the entire volume of pores of the ion-exchange matrix.