Corrosion Inhibition of Al–alloy in 3.5% NaCl Solution by a Natural Inhibitor: An Electrochemical and Surface Study

Abstract

Root extract of Copt is chinensis (CCR) was used and its inhibition efficiency on corrosion of Al alloy in 3.5 wt.% NaCl was investigated through surface morphology and electrochemical techniques. The Nyquist diagrams containing the extract with different concentrations showed increase in Rct values, thus increasing inhibition efficiency. Potentiodynamic curves suggested that the extract acted as mixed type in nature. The surface analysis through scanning electrochemical microscopy (SECM), UV - Visible Spectroscopy for Al alloy specimens also proved the results obtained by the electrochemical experiments. The adsorption of the studied inhibitor obeyed the Temkin’s adsorption isotherm.