Acid corrosion inhibition of copper by mangrove tannin

Purpose - The purpose of this paper is to evaluate the corrosion inhibition potential of mangrove (Rhizopora apiculata) tannin in hydrochloric acid medium on copper with the view of developing a natural corrosion inhibitor. Design/methodology/approach - The mangrove tannin was extracted from the mangrove bark and its anticorrosion potential was studied by weight loss, electrochemical and scanning electron microscopy (SEM) analysis. Findings - It has been found that the mangrove tannin effectively inhibits the corrosion on copper metal in hydrochloric acid solution. The results of the electrochemical and weight loss methods showed that the inhibition efficiency of mangrove tannin increases with increasing its concentration. Inhibition is achieved through the adsorption of tannin molecules onto the copper surface and the adsorption follows the Langmuir adsorption isotherm model. SEM study also supports the adsorption of the inhibitor molecules onto the copper surface. Originality/value - In this paper, mangrove tannin has been studied for the first time as a potential copper corrosion inhibitor in hydrochloric acid medium. The anticorrosion effect of tannin has been proven by standard methods. This natural inhibitor could find use in industries where copper is used as a fabrication metal.