Purpose The study aims to enhance the corrosion resistance of mild steel by developing advanced nanocomposite coatings based on poly(3,4-ethylenedioxythiophene) (PEDOT) reinforced with nanoscale fillers that improve both barrier and electroactive protective mechanisms. Design/methodology/approach α-Fe2O3 and γ-Al2O3 nanoparticles were synthesized via co-precipitation and characterized by X-ray powder diffraction, revealing crystallite sizes of 8.4 nm and 6.4 nm, respectively. PEDOT and its nanocomposites were electrodeposited onto steel substrates through electrochemical polymerization. Corrosion performance was systematically evaluated using open-circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy in 0.05 M H2SO4. Complementary analyses, including atomic absorption spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy, provided insights into morphology, elemental composition and passive film formation. Findings The incorporated nanoparticles enhanced the electropolymerization of EDOT and improved the protection efficiency (PE) of the resulting polymer coatings. Electrochemical measurements showed PE values of 56.9% and 77.2% for the PEDOT/ γ-Al2O3 and PEDOT/ α-Fe2O3 coatings, respectively. Atomic absorption spectroscopy analysis further confirmed that the PE increased upon aging in the solution, reaching 88.77%, 90.32% and 92.53% for the PEDOT, PEDOT/ α-Fe2O3 and PEDOT/ γ-Al2O3 coatings after six days, respectively. Thick, compact deposits of iron oxides and oxides of minor elements were observed to accumulate beneath the coating. Originality/value This study establishes PEDOT/metal oxide nanocomposites as eco-friendly, high-performance coatings that combine barrier reinforcement with redox-driven self-passivation. The synergistic role of α-Fe2O3 and γ-Al2O3 highlights a sustainable pathway for developing long-term corrosion protection strategies for steel in aggressive environments.
Ali et al. (Wed,) studied this question.