REACTIVE DEPOSITION OF COBALT ELECTRODES .1. EXPERIMENTAL

Reactive deposition is a novel method for producing highly porous, high-surface-area metal structures. The process involves the electrodeposition of metal in the presence of bubbling oxygen and Cl− ions in solution. The cobalt electrodes produced by the reactive deposition technique have grain and pore size of less than one micron. In this paper, the processes of reactive deposition of Co electrodes were investigated by using both galvanostatic and potentiostatic techniques. In the presence of bubbling oxygen, the deposition processes of Co metal are the results of competition of direct electrodeposition of Co2+ ions and the reduction of cobalt oxides/hydroxides. It has been found that the reduction of cobalt oxides, particularly CoOOH at the electrode surface, is the predominant process. The presence of Cl− ions in the solution also plays an important role, possibly by activating and increasing the dissolution processes of freshly formed cobalt/cobalt oxides. © 1990, The Electrochemical Society, Inc. All rights reserved.