Solenostemon monostachyus Leaf Extract as Eco-friendly Inhibitor of Aluminium Corrosion in Acidic Medium

The inhibitory effect of Solenostemon monostachyus leaf extract on aluminium corrosion in hydrochloric acid solution was studied using weight loss, thermometric and hydrogen evolution methods. The results obtained reveal that Solenostemon monostachyus leaf extract functioned as a good inhibitor of aluminium corrosion in HCl solution. Inhibition efficiency was found to increase with increase in extract concentration and temperature. Chemical adsorption mechanism has been proposed for the adsorption of the leaf extract onto aluminium surface. Thermodynamic parameters revealed that the adsorption of the extract onto the metal surface was endothermic and spontaneous. The adsorption of Solenostemon monostachyus leaf extract on aluminium surface obeyed the Freundlich adsorption isotherm.