Corrosion inhibition activity of carbon steel in 1.0 M hydrochloric acid medium using Hammada scoparia extract: gravimetric and electrochemical study

摘要

The interest for the environment is becoming more demanding with regard to the use of toxic and non-biodegradable substances and their impacts on different environments. Therefore, the need to develop 'green inhibitor' to preserve the nature from pollution is urgent. In this context, an investigation of medicinal plant (Hammada scoparia; HSP) as a corrosion inhibitor on C-steel in 1.0 M HCl solution has been implemented. To accomplish this work, several methods were used as weight loss, electrochemical measurements and surface analysis. Polarization curves show that HSP extract acts as mixed inhibitor type with cathodic predominance. The efficiency of C-steel protection increases with increasing the HSP extract concentration but decreases with the temperature in the range of 303-333 K. The effect of the temperature on the inhibition efficiency, as well determination of the different kinetic and activation parameters, make it possible to deduce a physisorption mechanism of HSP extract on the surface of C-steel. The theoretical fitting of different isotherms was also investigated. It was found the results obeyed the Langmuir isotherm. Surface analysis using FT-IR, UV-visible, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) allowed the clarification of the inhibition mechanism and the relative inhibition efficiency.