Investigation of Corrosion Protection Properties of TiO 2 -CdO Nanocomposite Coating Prepared by Sol-Gel Method on Copper

Abstract

Sol–gel nanocomposite coatings have been investigated for copper metal as a potential replacement for the hazardous and banned hexavalent chromate conversion coatings. TiO 2 –CdO nanocomposite thin films were deposited on copper using the sol–gel method. The sol-gel coatings were prepared using a sol obtained by the hydrolysis and condensation of tetra-o-butyl titanate. They were doped with cadmium oxide inhibitor to provide active corrosion protection. The synthesized coatings were characterized by X-ray diffraction (XRD)and atomic force microscopy (AFM). The anticorrosion performances of TiO 2 -CdO nanocomposite coatings were investigated in 3.5% NaCl solution by the potentiodynamic polarization technique Tafle and electrochemical impedance spectroscopy (EIS). The potential corrosion increases from -210 mV versus Ag/AgCl (3M) for uncoated copper to -202 mV versus Ag/AgCl (3M) for TiO 2 -CdO nanocomposite-coated copper electrodes. The results of this study clearly ascertain that the TiO 2 -CdO nanocompositehas outstanding potential to protect the copper against corrosion in a chloride environment.