Abstract

Ceria (CeO2) nanoparticles were synthesized and characterized using scanning electron microscopy (SEM), powder x-ray diffraction (XRD), attenuated total reflectance infrared (ATR-IR) spectroscopy and thermogravimetric analysis (TGA) techniques. The effect of addition of the synthesized CeO2 on the corrosion inhibition effect of pectin for X60 steel in 0.5 M HCl solution was evaluated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss techniques at 25 and 60 C. Water contact angle measurements, scanning electron microscopy and ATR-IR techniques were employed for surface morphology characterization. Results obtained show that both CeO2 and pectin acts as moderate corrosion inhibitors for X60 steel in the acid environment. Inhibition efficiency increased with increase in the additives concentration. Inhibition efficiency of pectin was enhanced on addition of CeO2 due to synergistic effect especially at ambient temperature and higher concentration of CeO2. Temperature was found to have profound effect on the corrosion inhibition performance of pectin without and with addition of CeO2. The potentiodynamic polarization studies revealed that Pectin, CeO2 and Pectin-CeO2 mixtures functions as a mixed-type inhibitor. Results from all the surface analyses confirm the formation of protective film on the X60 steel surface.