Kinetics of electrodeposition of Zn-Co alloy using mild steel rotating disc electrode

The rotating disc electrode technique was used to investigate the electrodeposition of Zn-Co alloys onto mild steel from both acid and alkaline solutions. Measurements made under controlled hydrodynamic conditions show that zinc-cobalt alloy deposition from alkaline electrolytes is charge transfer controlled over a range of rotation speeds. This was true up to a limiting current at which the deposition became mass transport controlled. Deposition from the acid electrolyte was verified to be charge transfer controlled at very low overpotential. Scanning electron microscopy and energy dispersive spectroscopy were used to reveal the influence of the electrode rotation speed on the morphology and chemical composition of the deposit.