Long-term corrosion resistance of superhydrophobic Ce-Co-Al LDH composite coatings prepared on the surface of Al alloy

Ce-Co-Al Layered double hydroxides (LDH) coatings with WO 4 2− intercalation and 1H, 1H, 2H, 2H-Perfluorodecyltrimethoxysilane (PFDTMS) film was successfully prepared through in situ growth, ion exchange and self-assembly method. In this work, we designed a novel anti-corrosion system composed of a LDH coating as an anionic nano-container, an anionic corrosion inhibitor between layers and a superhydrophobic film that plays a barrier role. The morphology, structure and composition of different samples were characterized using SEM, EDX, XRD, FT-IR, and XPS. The performance of the samples was evaluated through electrochemical, contact angle, and wear behavior testing. The results revealed that PFDTMS-WO 4 2− -LDH exhibited superhydrophobic properties and excellent anti-corrosion performance compared to Al alloy, with a corrosion current density from 1.248 × 10 −5 A·cm −2 to 1.606 × 10 −10 A·cm −2 and a static contact angle from 76.3° to 152.8° Covering the Al alloy with Ce-Co-Al LDH resulted in the friction coefficient decreased from 0.7 to 0.2, demonstrating the superior tribological performance of LDH. It was confirmed that the main reason for the significant improvement of the long-term corrosion resistance of PFDTMS-WO 4 2− -LDH was the barrier function of the PFDTMS film and the corrosion inhibition effect of the Ce 3+ and WO 4 2− . This work is of great significance for the preparation of corrosion-resistant LDH and engineering an anti-corrosion system with the surface of the material.