Electrochemical behavior and anti-corrosion property of Ti3C2Tx MXene/LDH heterostructured coating on aluminum alloy

Two-dimensional (2D) materials show potential applications in anti-corrosion on metals in aggressive medium. However, it remains a challenge in uniform dispersion, complex functionalization, and structure control of 2D nanosheets in composite coatings. Herein, a Ti3C2Tx/layered double hydroxide (LDH) heterostructured coating for corrosion protection on Al alloy is proposed by in situ growth and dip coating process. Without complex functionalization, dispersion, and structure control, the heterostructured coating provides an enhanced corrosion resistance confirmed by electrochemical tests and microstructure characterization. As a result, the incorporation of Ti3C2Tx MXene can decrease the corrosion current density by ~40-fold and increase the coating resistance by 54-fold compared to bare Al alloy. Furthermore, the Ti3C2Tx/LDH coating still exhibits a self-healing ability after immersion in 3.5 wt% NaCl solution over 3 days, thereby providing long-term corrosion protection on Al alloy for 30 days. The protective behavior is attributed to the blocking effect and the feature of participating in electrochemical corrosion reaction and losing electrons of 2D MXene prior to the metal. This strategy provides a facile and effective approach to designing 2D materials-based anticorrosion coatings on Al alloy used in aggressive environments.