Beyond graphene and boron nitride: why MXene can be used in composite for corrosion protection on metals?

Corrosion of metals leads to huge economic loss and safety hazard in daily life and industrial production. Integration between two-dimensional (2D) MXene and polymer composite coating opens up great opportunities for multifunctional applications of MXene-based coatings, especially in corrosion protection. Similar to other 2D materials (graphene and boron nitride), the appealing features in physical structure and chemical properties endow the MXene with great potential for anti-corrosion. However, the oxidation and poor stability of MXene limit the application. Meanwhile, the differences from graphene and boron nitride are not clear. Therefore, the question why MXene can be used for surface protection and the differences from graphene and boron nitride are confusing for researchers. Unfortunately, there lacks a comprehensive review of this topic. In this review, the intrinsic surface protection ability of MXene is presented. Meanwhile, the characteristics of MXene beyond graphene and boron nitride, as well as the advantages of MXene for application in corrosion protection are analyzed. Furthermore, the recent progress of experimental results and theoretical calculations are summarized to explore the roles of MXene in corrosion protection. Finally, the challenges and perspectives of MXene-based anti-corrosion coatings are put forward. This review aims to provide guidance for designing and expanding the application of high-performance MXene-based anti-corrosion coatings.