Non thermal plasma synthesis of ZnO nanoparticles and their corrosion inhibition activity on XC70 mild steel pipeline in 1 M HCl acidic medium

Abstract

This paper investigates the inhibitory efficiency of zinc oxide nanoparticles (ZnO Nps) as an eco-friendly inhibitor against the corrosion of XC70 mild steel pipelines in a 1 M HCl acidic medium. The ZnO Nps were synthesized using non thermal plasma, in particular the gliding arc discharge-assisted (GAD) method, a chemical solvent free and safe approach that utilizes humid air as the vector gas and distilled water as the solvent. Characterization techniques such as DLS, EDX, SEM, and XRD confirmed the positive zeta potential, hexagonal wurtzite structure, spheroidal shape, and median particle size of 65.6 nm for the synthesized ZnO Nps, respectively. To evaluate the corrosion inhibition efficiency, investigations were conducted utilizing electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques at varying temperature range (298–333K). Results showed that increasing the concentration of ZnO Nps improved their ability to inhibit corrosion, with an optimum concentration of 70 mg/L achieving a high effectiveness of 90.71 % at ambient temperature. SEM analysis confirmed the formation of a protective barrier film on the inhibited substrate, effectively hindering the diffusion of corrosive ions. Furthermore, the DFT method was employed to examine the corrosion mitigation mechanism. These results demonstrate the significant inhibiting properties of ZnO Nps in preventing corrosion of XC70 mild steel in a 1 M hydrochloric acid environment.