Adsorption and Inhibitive Properties of Leaf Extract of Newbouldia leavis as a Green Inhibitor for Aluminium Alloy in H 2 SO 4

Abstract

The corrosion inhibition of Al and its alloys is the subject of tremendous technological importance due to the increased industrial applications of these materials. This study reports the corrosion inhibition of AA8011 aluminium alloy in acidic solutions using Newbouldia leavis leaf extract by way of gravimetric measurements. It was shown that the presence of Newbouldia leavis leaf extract inhibited the corrosion of aluminium in the test solutions and the inhibition efficiency de- pended on the concentration of the plant extract as well as on the time of exposure of the aluminium samples in H2SO4 so- lutions containing the extract. The experimental data complied to the Langmuir adsorption isotherm and the value and sign of the Gibb's free energy of adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the aluminium surface through a physical adsorption mechanism.