Electrochemical Investigation of Extracts of Musa Basjoo Leaves as Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Solution
Objective To investigate the inhibitive action of extracts of Musa basjoo leaves ( MBLE) on the corrosion of carbon steel in acidic medium. Methods MBLE was achieved by hot water extraction method, and its inhibition effect on the carbon steel corrosion in 1 mol/L HCl solution at different temperatures and extract concentrations was investigated by electrochemical methods.The surface morphology of the carbon steel was examined by scanning electron microscopy ( SEM) both in the absence of an inhibi-tor and in the presence of a MBLE-containing corrosive medium. Results The obtained results of polarization curves indicated that MBLE acted as a mixed-type inhibitor with a preferential effect on cathodic reaction for steel corrosion in 1 mol/L HCl solution. The inhibition efficiency was found to increase with increasing MBLE concentration and reached up to maximum 94. 7 % at the MBLE concentration of 160 mg/L at 25℃. The analysis of electrochemical impedance spectroscopy implied that the charge transfer resistance of surface corrosion reaction increased with increasing MBLE concentration, which could lead to more effective suppres-sion of the corrosion reaction. Changing-temperature measurements indicated that the inhibition of MBLE had a preferable thermal stability within the range of experiment temperature. When the temperature increased from 25 ℃ to 40 ℃, the variations of inhibi-tion efficiency obtained by the two electrochemical methods at MBLE concentration of 160 mg/L were less than 3%. The adsorption of MBLE molecules on the steel surface obeyed the Dhar-Flory-Huggins adsorption isotherm and was a spontaneous adsorption process including both physisorption and chemisorption. The SEM observations showed that MBLE could effectively inhibit steel corrosion. Conclusion MBLE is an effective and environmentally friendly inhibitor for carbon steel in HCl medium.
国家科技期刊平台
NSTL
万方数据
维普
