Kinetic Study of the Effect of Benzoic Acid Derivatives on Copper Electrodeposition

The effect of anodic oxygen bubbles on the rate of mass transfer in presence of benzoic acid, p-nitro, p-chloro and p-aminobenzoic acids were studied by measuring the limiting current of cathodic deposition of copper from acidified copper sulphate solution using lead anode. It is found that the rate of deposition decreases by adding organic substances. The rate of deposition depends on the type of inhibitor as well as its concentration. The ability of inhibitors to decrease the limiting current is as follows: p-nitrobenzoic > p-chlorobenzoic > benzoic > p-aminobenzoic acid. The thermodynamic parameters prove that the reaction is diffusion controlled.