Electrosynthesis of polyaniline-molybdate coating on steel and its corrosion protection performance

Electrosynthesis of polyaniline-molybdate (PANI-MoO42-) on mild steel was achieved in oxalic acid medium using cyclic voltammetry technique. Adherent and homogeneous PANI-MoO42- coating was obtained. The corrosion behavior of steel with PANI-MoO42- coatings in 1% NaCl solutions was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The coating was characterized by SEM, XPS, EDAX and FTIR. The self-healing ability of PANI-MoO42- coating was confirmed by SVET technique. It has been found that the PANI-MoO42- coating is able to offer higher corrosion protection in comparison to that of pure PANI coating due to inhibitive nature of molybdate ions. (C) 2010 Elsevier Ltd. All rights reserved.