Corrosion inhibitory action of Commiphora caudata extract on the mild steel corrosion in 1 M H₂SO₄ acid medium

Abstract

Corrosion inhibitory action of Commiphora caudata extract on the mild steel corrosion in 1 M H₂SO₄ acid medium is investigated by weight loss and electrochemical studies. The weight loss method shows that the inhibition efficiency increases with the increase of inhibitor concentration, time, and temperature. The polarization studies reveal that the extract acts as a mixed type inhibitor. In electrochemical impedance measurement, the semicircle curves indicated that the charge transfer process controlled the corrosion of mild steel. Thermodynamic parameter such as free energy value was negative, that indicates spontaneous adsorption of inhibitor on mild steel surface. In the presence of inhibitor decreases the activation energy value which shows the chemical adsorption. The Commiphora caudata extract is found to obey Langmuir adsorption isotherm. Scanning electron microscopy, FTIR, and Quantum chemical studies confirmed that the mild steel protect from the corrosion by adsorption of the inhibitor molecules on surface of metal.

Keywords:

• Commiphora caudata
• mild steel
• Langmuir adsorption
• polarization studies
• FTIR

Acknowledgments

The authors acknowledge Dr. Rameshkumar, Principal, Asian College of Engineering and Technology, Coimbatore for providing the Lab facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.