Fagonia arabica extract as a safe‐environment green corrosion inhibitor for Cu in HNO3 solution

• Published in: Journal of the Chinese Chemical Society (Taipei) Vol. 68; no. 8; pp. 1445 - 1455
• Main Authors: Fouda, Abd El‐Aziz El‐Sayed, Ahmed, Abd El‐Moneim Mohamed, El‐Darier, Salama Mohamed, Badr, Sherif Elsayed
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley‐VCH Verlag GmbH & Co. KGaA 01.08.2021; Wiley Subscription Services, Inc
• Subjects: Adsorption; AFM; Atomic force microscopy; Copper; Corrosion; Corrosion effects; Corrosion environments; corrosion inhibition; Corrosion inhibitors; Corrosion rate; Electrochemical impedance spectroscopy; Fagonia arabica; Flory‐huggins isotherm; HNO3; Metal surfaces; Morphology; Nitric acid; Scanning electron microscopy; SEM; Surface chemistry
• ISSN: 0009-4536; 2192-6549
• DOI: 10.1002/jccs.202000571

The effect of Fagonia arabica as corrosion inhibitor for Cu in nitric acid solution was studied utilizing mass loss technique, potentiodynamic polarization measurement, electrochemical impedance spectroscopy method, and scanning electron microscopy (SEM); the inhibition efficiency was found to increase with increase in the concentration of inhibitor; the inhibitive effect of this inhibitor was explained based on adsorption metal surface, the adsorption effect follows Flory‐Huggins adsorption isotherm. The corrosion rate was calculated; the results revealed that F. arabica has good inhibition effect on Cu. The surface morphology of Cu metal was examined by employing various techniques such as atomic force microscopy (AFM) and SEM. The AFM results observed greater inhibition efficiency of F. arabica for Cu dissolution in the acid corrosive environment. The parameters for the corrosion procedure have also been determined and discussed. The Nyquist plots for copper dissolution in 2 M HNO3 with and without altered doses of Fagonia arabica at 25°C. This plot confirms the adsorption of Fagonia arabica extract on copper surface as indicated by increasing the diameters of the semicircles by increasing the doses of the extract. The diameter of these semicircles represents the charge transfer resistance which used to calculate the inhibition efficiency. So, by increasing the charge transfer resistance the inhibition efficiency will increase.