Experimental and theoretical optimization of Chelidonium Majus (Papaveraceae) extract as an environmentally friendly inhibitor for corrosion of a-brass in nitric acid solution

Abstract

The research paper discusses the study of the inhibition rates of Chelidonium Majus (Papaveraceae) plant extract (CME) on abrass in 1.0 M HNO3 solution. The study was carried out using chemical and electrochemical techniques, which showed results of up to 97% inhibition with 150 ppm at 250C. For the polarization results, CME is a mixed-type inhibitor. The increase in the charge transfer resistance and the decrease in the capacitance of the double layer with increasing concentration were observed by Nyquist diagrams and it was found that the inhibition process follows the Langmuir isotherm which proves the formation of a monolayer on the surface of the abrass. Quantum chemical calculations were performed using the DFT method to determine the active centres of the CME which responsible for adsorption, as well, to their possible interaction mechanism with the brass surface.