Adsorption and Inhibition Action of a Novel Green Inhibitor on Aluminium and 6063 Aluminium Alloy in 1.0 M H3PO4 Solution

The corrosion inhibition characteristics of Garcinia indica extract (GIE) on the corrosion of aluminium and 6063 aluminium alloy in 1.0 M phosphoric acid solution were studied by using potentiodynamic polarization using Tafel extrapolation technique and electrochemical impedance spectroscopy (EIS) techniques at different temperatures and at different concentrations of inhibitor. Kinetic parameters and thermodynamic parameters were evaluated and discussed in detail. Inhibition efficiency increased with extract concentration and increased with temperature. The adsorption of GIE on metal surface obeyed Langmuir adsorption isotherm. GIE acted as mixed inhibitor in phosphoric acid solution and followed chemisorption on the surface of both material. Results obtained from Tafel extrapolation technique and by A.C electrochemical impedance spectroscopy (EIS) technique were in good agreement with one another. This study highlights the utility of GIE extract as a potential green inhibitor for corrosion control of Al and 6063 Al alloy in 1.0 M phosphoric acid environment.