Epoxy resins serve as anticorrosive coatings due to their robust mechanical properties, chemical resistance, and adhesion. Enhancing these coatings with nanoparticles—particularly titanium dioxide (TiO₂)—has proven effective in improving both corrosion resistance and other functional properties. In this work, we synthesized a photoactive TiO₂-based ZnAl-layered double oxide (TiO₂-LDO; 1:10) nanocatalyst via a wet impregnation method and incorporated it into an epoxy matrix. The epoxy resin, formulated with 2 wt.% TiO₂-LDO, was applied to AA2024 substrates using a coating bar coater, yielding a cured film thickness of 20 ± 2 µm. The developed TiO₂-LDO nanocatalyst exhibited high selectivity in the NOx abatement and a minimum NO2 release (3-4%), achieving remarkably up to an 80% NO photoconversion efficiency under 20 W/m² of irradiation in a customized continuous-flow portable photoreactor, designed specifically for NOx studies. In comparison, while TiO₂ (anatase) achieved a similar NO conversion efficiency, it generated 20–25% NO₂ as a byproduct, which is even more toxic than NOx, whereas LDO alone produced minimal NO₂ but achieved a lower NO conversion efficiency of 25–30%.
Electrochemical impedance spectroscopy (EIS) over 28 days revealed that incorporating TiO₂-LDO into the epoxy coating provided a comparable corrosion resistance to the pure resin. However, the improvement was pronounced when the systems were exposed to UV irradiation (10 days of aging with fluorescent source with λmax = 365 nm, 20 W·m−2), which induces micropore formation in the pure epoxy film compared to epoxy with TiO2-LDO, and thus improved corrosion resistance for the epoxy composite on AA2024. The results underscore the dual functionality of TiO₂-LDO as both a photoactive nanocatalyst (air pollution) and an effective anticorrosion additive, offering a promising, environmentally friendly solution for UV-resistant corrosion protection.