Investigation on corrosion inhibition and adsorption mechanism of triazine-thiourea derivatives at mild steel / HCl solution interface: Electrochemical, XPS, DFT and Monte Carlo simulation approach

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 877; p. 114599
• Main Authors: Paul, Priya Kumari, Yadav, Mahendra
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2020; Elsevier Science Ltd
• Subjects: Adsorption; AFM; Corrosion; Corrosion inhibition; Corrosion inhibitors; Corrosion mechanisms; Corrosion prevention; Corrosion tests; DFT; EIS; Electrochemical corrosion; Gravimetry; Low carbon steels; Monte Carlo simulation; Surface chemistry; Thiourea derivatives; X ray photoelectron spectroscopy; XPS; AFM; XPS; DFT; Corrosion inhibition; EIS; Monte Carlo simulation
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2020.114599

The corrosion inhibition behavior of synthesized triazine-thiourea compounds, namely, 1,3-bis(5,6-diphenyl-1,2,4-triazin-3-yl)thiourea (BTT) and 1,3-bis(5H-[1,2,4]triazino[5,6-b]indol-3-yl)thiourea (BTI) on mild steel in 15% HCl solution was investigated by using gravimetric and electrochemical corrosion testing methods at different experimental conditions. BTT was found more efficient corrosion inhibitor than BTI. It was observed from experimental outcomes that at optimum concentration (200 ppm) and 303 K temperature, BTT was 98.5% efficient towards the corrosion protection of mild steel in 15% HCl solution. The surface morphological study of uninhibited and inhibited samples was performed by FESEM and AFM analysis. Adsorption of both inhibitor molecules on the surface of mild steel obeyed Langmuir adsorption isotherm. XPS analysis was performed to determine the binding energy and elemental composition of adsorbed inhibitor molecules on the surface of mild steel. DFT and Monte Carlo simulation (MCS) was performed to get more insight into the protection mechanism adopted by inhibitor molecules.
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•Studied corrosion inhibitors, BTT and BTI act as efficient corrosion inhibitor.•BTT and BTI act as mixed inhibitors.•SEM, EDX, AFM and XPS studies suggested adsorption of inhibitor molecules on mild steel surface.•DFT and MDS parameters were consistent with experimental results.