Enhancing corrosion resistance of carbon steel and stainless steel through pothocathodic protection using TiO2-polyvinyl butyral electrophoretic deposition coating

Abstract

Photocathodic protection (PCP) is a promising eco-friend method to reduce the corrosion of metals. Considering industrial applicability, it is imperative to adopt cost-effective materials for implementing PCP on corrosion-vulnerable carbon steel (CS). This study examined the potential of photocatalytic TiO2-polyvinyl butyral (PVB) materials for PCP of CS and stainless steel (STS) using commercially available P-25 photocatalyst particles. The TiO2-PVB-electrophoretic deposition (EPD) film exhibited the improved cathodic protection time of STS owing to PVB addition. When the film was applied to various substrates, it achieved a PCP of −0.6 to −0.7 VSCE due to the photogenerated electrons under UV irradiation. For the CS, the PCP potential was maintained for more than 1.5 hours, even after light irradiation. We have found that PCP was achieved by Ecorr > EPCP of CS in an acidic environment, while in a neutral and basic environment, the corrosion of CS and photocathodic electronation contributed simultaneously to Ecorr ≈ EPCP. One findings is that the application of PCP effectively reduces the corrosion rate of CS in a 3.5% NaCl solution, regardless of the pH of the corrosive environment. This highlights the capability of PCP as a viable method for mitigating corrosion on CS.