The corrosion inhibition effect of 5-(2-Thienyl)pyrazole (5-TPZ) on steel in 1.0 M HCl was investigated by weight loss and electrochemical methods. The effect of concentration was studied. The results indicated that the compound are efficient, mixed type and fellow Langmuir adsorption isotherm and the calculated Gibbs free energy value confirms the physicochemical nature of the adsorption. EIS results show that the charge in the impedance parameters (Rct and Cdl) with concentrations of 5-TPZ is indicative. The adsorption of this molecule leads to the formation of a protective layer on carbon steel surface. The electrochemical results have also been supplemented by Monte Carlo simulation studies.
Keywords: Corrosion inhibition; 5-(2-Thienyl) pyrazole; Mild steel; EIS; Monte Carlo.