Corrosion Inhibition of Dialium guineense Leaf Extract on Mild Steel in 1M HCl Using Electrochemical and Theorietical Studies
Loveth N. Emembolu
*
Department of Chemical Engineering, Nnamd Azikiwe University, Awka, Nigeria.
Ikenna Nwokedi
Department of Chemical Engineering, Nnamd Azikiwe University, Awka, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Mild steel is highly susceptible to corrosion in acidic media, leading to significant material degradation in industrial applications. Plant-based extracts like Dialium guineense offer an eco-friendly and cost-effective alternative for corrosion inhibition. The current work employed electrochemical tests to assess how well Dialium guineense leaf extract (DGLE) prevented mild steel (MS) from corroding in a 1M HCl solution. Surface analysis was done using atomic force microscopy (AFM) and scanning electronic microscopy (SEM-EDX). The chemical makeup of DGLE extract was examined using FTIR. Density functional theory (DFT) and molecular dynamics (MD) simulation were used to computationally investigate the inhibitory efficiency of DGLE. Using the MD modeling approach, the adsorption energies of the DGLE components on the Fe (110) plan were determined, and a relationship between the adsorption energy and the energy gaps was found. The electrochemical measurements showed that corrosion inhibition rose with increasing inhibitor concentration, reaching a moderate inhibition efficiency of 95.08% at 500 mg/L. DGLE compounds behaved as mixed-type inhibitors, according to polarization curves and the adsorption process followed Temkin isotherm. The adsorption of the chemicals in the extract was verified by SEM-EDX and AFM analysis of the corroded steel surface. Chemical quantum calculations were used to identify the primary components of the electronic properties of the natural extract, which also explained adsorption modalities and interactions between inhibitors and metal surfaces.
Keywords: AFM, DFT, Dialium guineense leaf extract, EIS, Mild Steel, SEM-EDX