Abstract
Etching of copper by anodically oxidized graphite suspension in sulfuric acid solution was investigated with special attention to the effects of anode material, amount of suspension, size of graphite particles, temperature and pH of the solution. The anodic current-potential curves for Pt, graphite and PbO2 (Pb) anodes depend only upon the amount of graphite in the solution as far as the potential is below the gas evolution potential. The quantity of electricity required to oxidize graphite particles per unit surface area of graphite particles increases with increasing temperature. As graphite particles are oxidized at the anode, the potential of the suspension approaches near the anode potential. The etching velocity of copper increases with increasing amount of graphite and with decreasing diameter of graphite. The velocity also increases with increasing temperature and lowering pH. The current efficiency for the dissolution of copper are over 100%. This is probably due to the reaction with dissolved oxygen. The dissolved copper is able to recover simultaneously as the deposit at the cathode.
