Green approach to corrosion inhibition of 304 stainless steel in hydrochloric acid solution by the extract of Salvia officinalis leaves

The extract of Salvia officinalis (S. officinalis) leaves has been evaluated as a corrosion inhibitor for 304 stainless steel in 1 M HCl solution by means of weight loss measurements, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS). Tafel polarization study revealed that extract of S. officinails acts as a mixed type inhibitor. Adsorption of the inhibitor on the steel surface followed Langmuir adsorption isotherm. Quantum chemical calculations using the density functional theory (DFT) and semi-empirical method (AM1) were performed to illustrate the process of adsorption of some specific components of the extract. (C) 2012 Published by Elsevier Ltd.