An interesting and efficient green corrosion inhibitor for aluminium from extracts of <i>Moringa oleifera</i> in acidic solution

Abstract

The leaf extracts of Moringa oleifera has been studied as a possible source of green inhibitor for corrosion of aluminium alloy in 0.5M HCl using gravimetric and thermometric techniques at 30 and 60^oC. Results obtained showed that Moringa oleifera functioned as an excellent corrosion inhibitor for aluminium in the acidic environment. Inhibition efficiency increased with extract concentration but decreased with temperature. The adsorption of Moringa oleifera on Al surface is in accord with Langmuir adsorption isotherm. Both kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. Results show that Moringa oleifera which is biodegradable, environmentally benign, and are obtained from a renewable resource with minimal health and safety concerns has the potential to be a cost effective alternative to synthetic corrosion inhibitors. This present study provides new information on the inhibiting characteristics of Moringa oleifera extract under specified conditions. The environmentally friendly inhibitor could find possible applications in metal surface anodizing and surface coating in industries.

Keywords: Moringa oleifera, Aluminium, Hydrochloric acid, Langmuir isotherm, Plant extracts, Corrosion inhibition