Electrosynthesis of Zr-loaded copolymer coatings on Al for defluoridation of water and its corrosion protection ability

Aluminium and its alloys are widely used in almost all fields because of low cost. However, their surfaces are easily corroded by chemical reaction. We report here a simple method to fabricate zirconium-loaded copolymer coating on Al by electropolymerization and electrodeposition techniques. The fabricated coatings have been characterized by ATR-IR, XRD, FE-SEM, and EDX. This zirconium-loaded copolymer coated Al plate was used as a novel adsorbent for fluoride removal without any filtration. The defluoridation experiments were carried out for various influencing parameters like contact time, pH, and competitor anions for optimization. The adsorption capacity was found to be 4950 mg F−/kg at pH 7. The adsorption isotherm data were well described by Freundlich isotherm model. The values of thermodynamic parameters indicate that the nature of fluoride removal is spontaneous and endothermic. The corrosion behaviour of the coating in the 3.5% NaCl solution was investigated by EIS and potentiodynamic polarization. Based on corrosion parameters data, it was found that the zirconium loaded copolymer coating provided excellent corrosion resistance to aluminium and also this plate used as adsorbent, which has been successfully applied to remove fluoride from groundwater.