Synergistic reinforcement coating with anti-corrosion and UV aging resistance by filling modified CeO2 nanoflakes

Abstract Organic coatings are widely used to protect metals from corrosion. However, they still have several disadvantages; for example, they are single function, age, and have a complex preparation strategy and limited application possibilities. Here, we incorporated modified CeO2 nanoflakes (VTEO-CeO2) into an epoxy matrix and thus developed a simultaneous anti-corrosion and ultraviolet (UV) aging resistant composite coating. The corrosion resistance was investigated using electrochemical impedance spectroscopy and salt spray tests. The results demonstrated that incorporating VTEO-CeO2 nanoflakes improved the anticorrosive properties of the coatings. The composite coating with 1 wt% VTEO-CeO2 had the largest system resistance (Rt) value (2.96 ×10^5 ohm·cm2) and the highest impedance modulus (|Z|0.01 Hz) after 240 h 3.5 wt% NaCl solution exposure; this was attributed to the inhibitory effect of the Ce-rich passive layer and the barrier effect of nanoflakes. Analysis of the effectiveness of the CeO2 nanoflakes as UV absorbing agents was conducted using Fourier transform infrared spectroscopy and fluorescence emission spectra. After 240 h of UV aging, 1 wt% CeO2/epoxy and VTEO-CeO2/epoxy coatings have less change in the structural indices (IC˭O), and this indicates better UV aging resistance. This work could facilitate the development of epoxy coatings that provide long-term protection and extend the application of rare earth elements in functional composite coatings.