Electrochemical Coating of PANI/Nanometal Oxide Composites on 304 L Stainless Steel Surface and Investigation of Corrosion Behavior

Abstract

In this study, cyclic voltammetry method was used in 0.5 M oxalic acid and 0.2 M aniline solutions with and without different amounts (0.1, 0.3, 0.5 g) of NiO, WO₃, Sb₂O₃, inorganic nano metal oxide. PANI and PANI/nanometal oxide coating was applied to the 304 L steel electrode surface. The corrosion behavior of coated 304 L steel in 2.0 M NaCl solution was investigated using Tafel polarization and impedance spectroscopy methods. The structure characterizations of the polymeric composites coated on the 304 L steel surface were determined by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and their thermal behaviors were determined by differential scanning calorimetry DSC analyses. The time dependence of the coating was examined by SEM images by keeping the coated steel plates in NaCl solution for 7 days. Accordingly, it has been determined that PANI/nanometal oxide (NiO, WO₃, Sb₂O₃) is more effective than pure PANI in preventing the corrosion of 304 L steel, which is preferred in the industry. As the amount of nano metal oxide used in PANI/nanometal oxide composites increased, the corrosion inhibition effectiveness of the metal increased. This increase was maximum (92–98%) in composites containing 0.5 g nanometal oxide.