Expired Etoricoxib as a corrosion inhibitor for steel in acidic solution

• Published in: Journal of molecular liquids 2019-04, Vol.279, p.594-602
• Main Authors: Anaee, Rana Afif, Tomi, Ivan Hameed R., Abdulmajeed, Majid Hameed, Naser, Shaimaa Alaa, Kathem, Mustafa Mohammed
• Format: Article
• Language: English
• Subjects: AFM analysis; Carbon steel; DFT theory; Etoricoxib; Expired drugs; Green inhibitor
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2019.01.169

Expired Etoricoxib was investigated as a green corrosion inhibitor for carbon steel in 0.5 M H3PO4 solution using electrochemical methods at 30 and 60 °C. Etoricoxib was shown to be an efficient inhibitor of carbon steel corrosion with an efficiency of 80.627% at an inhibitor concentration of 225 ppm at 30 °C and 63.803% at 125 ppm and 60 °C. The adsorption of Etoricoxib on the carbon steel surface followed a Langmuir adsorption isotherm. The polarization plots revealed that Etoricoxib acts as an anodic type inhibitor and the parameters of the inhibition process were calculated and discussed. The surface morphology of the carbon steel was analyzed using scanning electron microscopy and energy-dispersive X-ray analysis. The antibacterial activity of the inhibitor was also tested. Fourier-transform infrared spectroscopy confirmed the inhibitive role of Etoricoxib and the quantum chemical parameters showed good correlation with the inhibition efficiency. The highest and lowest occupied molecular orbitals, separation energy (ΔE), and the dipole moment (μ) were calculated and explained well by the experimental data. [Display omitted] •Expired Etoricoxib is used as a green corrosion inhibitor for carbon steel.•Etoricoxib has an efficient inhibitor for carbon steel with the efficiency reached to 80.627%.•The theoretical calculation by DFT was done which was agreement with experimental tests.