Research of two kinds of PANI@semiconductor based photocathodic coating corrosion protection effect and mechanism

Abstract

Purpose

This study aims to report the development and experimental evaluation of two kinds of PANI@semiconductor based photocathodic anti-corrosion coating, for application on stainless steel substrates.

Design/methodology/approach

PANI was in situ chemical polymerized on TiO₂ and BiVO₄ particles, and FT-IR and SEM/EDS were used to understand the characteristics and elemental distribution of the composite particles. Composite coatings, which consisted of epoxy, PANI@TiO₂ or PANI@BiVO₄ and graphene, were prepared on the 304L stainless steel. Photoelectrochemical response measurement, electrochemical tests and immersion tests were used to assess the anti-corrosion performance of the prepared coatings in 45°C 3.5 wt.% NaCl solution. And the corrosion protection mechanism was further explained by combining with surface observation.

Findings

The photoelectrochemical response tests revealed the good photocathodic effect of the coatings, and the reversible oxidation-reduction properties of PANI (pseudocapacitive effect) leading to the repeated usage of the coatings. Consequently, the anti-corrosion mechanism of the composite coating is attributed to the physical barrier effect of the coating, the anodic protection effect of PANI and the photocathodic and energy store effect.

Originality/value

These kind coatings could prevent corrosion from day to night for stainless steel, which has great engineering application prospects on stainless steel corrosion protection.

Citation

Jin, X., Xu, H., Zhao, Q., Zeng, H., Lin, B., Xiao, Y., Tang, J., Nie, Z., Yan, Y., Di, Z. and Zhou, R. (2024), "Research of two kinds of PANI@semiconductor based photocathodic coating corrosion protection effect and mechanism", Anti-Corrosion Methods and Materials, Vol. 71 No. 6, pp. 650-662. https://doi.org/10.1108/ACMM-02-2024-2961