Electrochemical measurements for the corrosion inhibition of mild steel in 1Â M hydrochloric acid by using an aromatic hydrazide derivative

The influence of an aromatic hydrazide derivative, 2-(3,4,5-trimethoxybenzylidene) hydrazinecarbothioamide (TMBHC) as corrosion inhibitor on mild steel in 1 M hydrochloric acid was studied by Tafel polarization and electrochemical impedance spectroscopy (EIS) technique. The results showed that the inhibition efficiency (% IE) of TMBHC increased with increasing inhibitor concentrations and also with increase in temperatures. TMBHC acted as a mixed type of inhibitor and its adsorption on mild steel surface was found to follow Langmuir's adsorption isotherm. The evaluation of thermodynamic and activation parameters indicated that the adsorption of TMBHC takes place through chemisorption. The formation of protective film was further confirmed by scanning electron microscopy (SEM).