Anticorrosion performance of biopolymer pectin on 6061 aluminium alloy: Electrochemical, spectral and theoretical approach

Pectin (PECT), a carbohydrate polymer, is presented as an active, environmentally benign inhibitor to attenuate the 6061 aluminium alloy acid corrosion. The study was performed by adopting electrochemical and spectroscopic procedures. Surface studies were performed by scanning electron microscopy (SEM), energy dispersion X-ray studies (EDX), and atomic force microscopic (AFM) technique. Mode of adsorption of PECT on the surface of the alloy was arrived at by applying appropriate adsorption isotherm, which is further confirmed spectral studies like FT-IR and UV–visible spectroscopy. Adsorption of PECT was reiterated by quantum chemical calculations using density functional theory (DFT). Pectin emerged as a potent green inhibitor with an inhibition efficiency of around 80% for the addition of 800 ppm of it. DFT calculations contributed a deeper insight in systematic understanding of the mechanism of the corrosion inhibition process.