JIF (Jurnal Ilmu Fisika) (Dec 2022)
A Corrosion Inhibition through the Adsorption of Cacao Peels Extract (Theobroma cacao) on Steel Surfaces: Experimental and DFT Methods
Abstract
A steel surface coating has been carried out using the immersion method in an inhibitor of cacao peel extract (Theobroma cacao) for 24, 72, 120, and 168 hours. The corrosion was treated using HCl with variations of immersion for 48, 96, and 144 hours given after the inhibitor coating process. The corrosion testing using the weight loss method gave the best results with the lowest corrosion rate of 0.2972 mg.cm2/hour and inhibition efficiency of 74.7128% for steel samples with the longest and the shortest variations of immersion time in inhibitor in HCl. The results of optical microscopy and SEM tests indicated that when the immersion time in the inhibitor is getting longer, the surface morphology of the steel is getting better with fewer holes and cracks. The XRD results also indicated that there were four sharp peaks which meant that the samples with the lowest corrosion rate produced crystalline Fe and C phases due to the reaction between the steel surface and the inhibitor. The quantum chemical analysis using the DFT (Density Functional Theory) method also produced a fairly high inhibition efficiency and was close to the experimental result of 80.2098%.
