Electrochemical Synthesis and Corrosion Behaviour of Poly(o-anisidine)-TiO2 Nanocomposite on ZnNi-Plated Carbon Steel

Electrosynthesis of poly(o-anisidine) (POA) homopolymer and poly(o-anisidine)-TiO2 (POA-TiO2) nanocomposite were carried out on ZnNi plated carbon steel (CS/ZnNi). The synthesis was achieved cyclic voltammetry technique in 0.2 M sodium oxalate solution containing 0.1 M o-anisidine and o-anisidine + 0.2 gL(-1) TiO2 nanoparticles for POA and POA-TiO2, respectively. The POA and POA-TiO2 nanocomposite were characterized by scanning electron microscopy (SEM), energy dispersion x-ray analysis (EDX), electrochemical impedance spectroscopy, linear sweep voltammetry, open circuit potential-time and potentiodynamic polarization techniques. Electrochemical impedance spectroscopy, open circuit potential-time (E-ocp-t) and potentiodynamic polarization tests were done in 3.5% NaCl solution. Potentiodynamic polarization curves showed that a strong decrease of corrosion current for POA-TiO2 coated CS/ZnNi (CS/ZnNi/POA-TiO2) electrode when compared to the POA coated CS/ZnNi (CS/ZnNi/POA) and CS/ZnNi electrodes. Electrochemical impedance spectroscopy results indicated that polarization resistance (R-p) of the CS/ZnNi/POA-TiO2 electrode was higher than the other electrodes. These results revealed that TiO2 nanoparticles increased the anticorrosive property of the POA film.