Adsorptive, kinetic and thermodynamic investigations of Sarcocephalus latifolius leaves extract as corrosion inhibitor on alloy steel in 0.6M HCl solution

Abstract

One of the materials that have many uses in the manufacturing, automotive, and construction industries is the alloy steel. When exposed to harsh environments this material is susceptible to deterioration and corrosion. Because of this reason, it is necessary to safeguard this valuable material. There have been many different methods used, but inhibition using particularly plant extract has reportedly been effective and acceptable to the environment. In this study, the behavior of alloy steel in 0.6M HCl at various concentrations of Sarcocephalus latifolius extract was assessed using weight loss and surface characterization methods of analysis. The plant extract's ability to inhibit corrosion increased during the weight loss experiment from 25.56% to 61.18% as concentration of the plant extract increased with a decrease in temperature from 323K to 303K respectively. Thermodynamic parameters of the inhibitory process were discovered to classify the process as feasible and spontaneous, obeying the Freundlich adsorption isotherm model's description of physical adsorption. The kinetic analysis of the inhibitory process demonstrates that it follows the first order model, with activation energy and half-life values rising with the concentration of the plant extract. In conclusion, Sarcocephalus latifolius extract is effective in inhibiting the corrosion of alloy steel in 0.6M HCl at low temperatures and higher plant extract concentrations through surface adsorption.