1, 4-Bis (2-nitrobenzylidene) thiosemicarbazide as Effective Corrosion Inhibitor for Mild Steel

The inhibition efficiency of 1, 4-bis (2-nitrobenzylidene) thiosemicarbazide (BBTS) on the corrosion of mild steel in 1 mol/L HCl was investigated by potentiodynamic polarization and electrochemical impedance methods. Inhibition efficiency (IE), corrosion rate and surface coverage were evaluated at different concentrations of BBTS. The results of the investigation showed that this compound had good inhibiting properties for mild steel corrosion in hydrochloric acid and BBTS was a mixed-type inhibitor. BBTS chemisorbed at the electrode surface obeyed Langmuir adsorption isotherm and formed a stable surface complex on the mild steel surface. The synergistic effect of halide ion in acid solution suggested a co-adsorption of BBTS inhibitor by the adsorbed iodide ion.