A New Approach in Corrosion Study Using DFT and Monte Carlo Simulation to Investigate the Synergistic Effects Natural Green Inhibitor Citrus Sinensis and Synthetic Benzotriazole on Low Carbon Steel

This study investigates the corrosion inhibition of low carbon steel using a synergistic blend of Citrus sinensis extract and 1H-benzotriazole. The inhibition efficiency was evaluated using Density Functional Theory (DFT) with the B3LYP/6-31G(d) basis set and Monte Carlo simulations. Quantum chemical parameters such as EHOMO, ELUMO, ionization potential (IP), and electron transfer (ΔN) were calculated. The results indicate that the mixed inhibitor provides superior corrosion protection compared to individual inhibitors, with adsorption energies of-20511.53 kcal/mol for the combination, significantly higher than-175.09 kcal/mol for Citrus sinensis and-10359.80 kcal/mol for 1H-benzotriazole alone. The combined inhibitor demonstrated enhanced electron donation, reducing the energy gap (ΔE) and improving the stability of adsorption on the steel surface. This suggests that the synergistic interaction of the inhibitors leads to a more efficient, sustainable corrosion protection method, offering an environmentally friendly alternative for steel protection.