Experimental and computational approach of an expired antibiotic drug Kynurenic acid as an efficient corrosion inhibitor for mild steel in HNO3 medium

• Published in: Journal of the Iranian Chemical Society 2022-06, Vol.19 (6), p.2311-2329
• Main Authors: Ganapathi Sundaram, R., Vengatesh, G., Thamaraiselvi, M., Prabakaran, R., Thailan, V., Muthuvel, I., Niraimathi, S.
• Format: Article
• Language: English
• Subjects: Acids; Adsorption; Analytical Chemistry; Antibiotics; Atomic force microscopy; Biochemistry; Chemistry; Chemistry and Materials Science; Corrosion; Corrosion inhibitors; Corrosion prevention; Density functional theory; Fourier transforms; Infrared spectroscopy; Inorganic Chemistry; Linear polarization; Low carbon steels; Microscopy; Molecular dynamics; Nitric acid; Organic Chemistry; Original Paper; Physical Chemistry; Spectroscopic analysis; Spectrum analysis; Surface chemistry; Weight loss measurement
• ISSN: 1735-207X; 1735-2428
• DOI: 10.1007/s13738-021-02446-y

An expired antibiotic drug Kynurenic acid (KYNA) was investigated for its adsorption and corrosion inhibition performance on mild steel (MS) in 1.0 M HNO 3 solution. Chemical methods like weight loss measurement, electrochemical methods like impedance spectroscopy, potentiodynamic polarization and linear polarization measurements were used to identify the adsorption behavior of KYNA in HNO 3 solution. The inhibition efficiency improved with an increase in KYNA concentration in nitric acid medium. The adsorption process of KYNA was spontaneous and favored Langmuir adsorption isotherm. Potentiodynamic polarization measurements indicate that the evaluated inhibitor acts as mixed type. The values of thermodynamic and activation parameters ( R 2 and Δ G ads 0 ) were calculated and discussed. The surface morphology of MS was characterized by using scanning electron microscopy, atomic force microscopy, Fourier transforms infrared spectroscopy and theoretical study. From both the experimental and theoretical studies, the investigated inhibitor molecule exhibited surface active properties and performed as a good inhibitor for corrosion control of MS in nitric acid medium. The experimental results corroborated with results obtained from theoretical molecular dynamics simulation with density functional theory studies.