Effect of pH Value on Electroless Deposition of Copper Graphite Powders

Abstract

The effect of pH value on the electroless deposition of copper coated graphite powders (Cu@GPs) was investigated in this paper. The cathodic and anodic polarization curves were determined by linear sweep voltammetry in the plating at various pH value. pH value increasing can reduce the initial oxidation potential of formaldehyde, increase peak current density and accelerate electroless copper nuclei generated by the reduction reaction. With increasing pH value Cu+ disproportionation reaction was inhibited. Through the complexation competition and discharge competition among them, Na₂EDTA, –OH and TART affect the reduction of cupric ions. The increasing pH value promote the formation of copper nuclei on the surface of graphite powders. Uniform Cu@GPs were fabricated by optimizing the pH 12.5~13. The copper plating layer is tightly combined with graphite, and the coating is complete.