Porous Copper Electrodes Formed by the Constant and the Periodically Changing Regimes of Electrolysis

Abstract

In this chapter, the formation of open and porous electrodes by the constant and periodically changing regimes of electrolysis are discussed. The formation of these electrodes in both potentiostatic and galvanostatic electrodeposition is presented. Three dimensional foam or honeycomb-like copper electrodes are formed by electrochemical deposition at high current densities and overpotentials where parallel to copper electrodeposition, hydrogen evolution occurs. Hydrogen evolution enabling the formation of these electrodes is vigorous enough to cause such stirring of the copper solution which leads to the decrease of the cathode diffusion layer thickness and to the increase in the limiting diffusion current density and hence to the change of the hydrodynamic conditions in the nearelectrode layer. The phenomenology of the formation of the honeycomb- like structures by potentiostatic electrodeposition, as well as parameters affecting number, size, and distribution holes in the honeycomb-like structures, is analyzed.