Corrosion inhibition performance of dwarf palm and<i>Cynara cardunculus</i>leaves extract for St37 steel in 15% H<sub>2</sub>SO<sub>4</sub>: a comparative study
Hana Lahbib, Samia Ben Hassen, Hüsnü Gerengi, Marziya Rizvi, Yasser Ben Amor
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.