The Rubus fruticosus Leaf Extract as an Eco-Friendly Copper Corrosion Inhibitor

Abstract

The behavior of copper in 0.5 mol/L NaCl containing different Rubus fruticosus leaf extract (RFLE) concentrations was studied. Electrochemical methods such as open circuit potential (OCP) measurement and cyclic voltammetry (CV) were performed. The weight loss measurements were performed at different immersion times to determine the time influence on copper corrosion in the solution without and with the addition of RFLE. UV–Vis spectrophotometry was used to examine whether the formation of a copper-extract complex occurs. The characterization of the copper surface after exposure to the solution with the addition of 15 g/L RFLE was performed using SEM-EDS analysis. The results show the examined extract acts as a good copper corrosion inhibitor in 0.5 mol/L NaCl. Both electrochemical methods indicate that blackberry leaf extract acts as a mixed type of inhibitor. Better CV results were achieved in the presence of higher extract concentrations. The gravimetric results show that corrosion rate values decrease with an increase in the RFLE concentration. The lowest value of the corrosion rate was obtained with the addition of 15 g/L RFLE, after 10 days, with an inhibition efficiency of 99.1%. The UV–Vis absorption spectrums confirmed the formation of a complex between copper and extract molecules. SEM-EDS analysis confirmed that RFLE molecules adsorb on the copper surface, acting as a corrosion inhibitor.