Valorization of Cinnamon Essential Oil as Eco-Friendly Corrosion Inhibitor for Mild Steel in 1.0 M Hydrochloric Acid Solution

The aim of the present work was to evaluate the inhibition effect of cinnamon essential oil (CEO) on mild steel corrosion in 1.0 M HCl. Its antioxidant activity was also analyzed. The CEO characteristics were studied using a chromatography-flame ionization detector, gas chromatography-mass spectrometry analysis, potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, and weight loss measurements, the results achieved via different techniques were in excellent agreement. The inhibition efficiency of CEO exceeded 92% at 1.0 g/L at 298 K and increased with increasing the oil concentration but decreased slightly with an increase of temperature. The adsorption of the inhibitor on the surface of mild steel followed best the Langmuir isotherm model. The scanning electron microscopy and energy dispersive X-ray spectroscopy data confirmed the formation of a protective film on the surface of the mild steel.

Automated summary

The present study aimed to evaluate the inhibition effect of cinnamon essential oil on mild steel corrosion in 1.0 M HCl, with an inhibition efficiency exceeding 92% and the formation of a protective film on the mild steel surface confirmed by scanning electron microscopy and energy dispersive X-ray spectroscopy.