Electrochemical adsorption studies of urea on copper surface in alkaline medium

The inhibitive action of urea on the corrosion behavior of copper was investigated in borate buffer pH (8.4) by means of cyclic voltammetry and electrochemical impedance spectroscopy (EIS). A consistent trend of increase in inhibition efficiency was observed as a function of concentration of urea. The adsorption of urea on copper surface was found to obey the Langmuir adsorption isotherm with ΔG = −35.2 kJ/mole and adsorption constant K = 2.7 × 10⁴ dm³/mole. Impedance spectroscopic measurements confirmed that charge transfer resistance increases in presence of urea upon increasing its concentration.