Corrosion inhibition performance of dwarf palm and Cynara cardunculus leaves extract for St37 steel in 15% H₂SO₄: a comparative study

Abstract

The inhibition effect of extracts obtained from the commercially insignificant, perennial and overgrowing plants in Tunisia such as Dwarf palm (DP) and Cynara cardunculus (CC) plants leaves against St37 steel corrosion in 15% H₂SO₄ has been investigated with weight loss experiments (WL) and classical electrochemical methods. The investigations were conducted at the various concentrations of studied extracts, experiment temperature and time. The obtained results were compared with electrochemical impedance spectroscopy (EIS), dynamic electrochemical impedance spectroscopy (DEIS) and surface imaging method outcomes. The results showed that DP and CC extracts exhibit good corrosion inhibitor for St37 steel in 15% H₂SO₄ solution. From all applied methods, DP extracts approximately showed better inhibition efficiency than CC. The adsorption of the inhibitors was found to obey the Langmuir adsorption isotherm. Results of infrared spectroscopy (FTIR) and physical electronics spectrometry (XPS) analysis strengthen the authenticity of other experimental results by proving that the extract molecules have bonded with the surface of the St37 steel.

Keywords:

• Dwarf palm leaf extract
• Cynara cardunculus leaf extract
• weight loss
• EIS
• DEIS
• AFM

Acknowledgements

All the authors specially acknowledge Mesut Yildiz for his assistance in the DEIS analysis.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

For this work, the authors gratefully acknowledge the financial support provided by the Duzce University Research Fund [Project No: 2018.06.05.817]. One of the authors, Marziya Rizvi, thankfully acknowledges financial support provided by Turkiye Burslari [19IN001804] for this research.