Amino-Functionalized MXene Nanosheets Doped with Ce(III) as Potent Nanocontainers toward Self-Healing Epoxy Nanocomposite Coating for Corrosion Protection of Mild Steel

Abstract

MXene sheets, as new 2D nanomaterials, have been used in many advanced applications due to their superior thin-layered architecture, as well as their capability to be employed as novel nanocontainers for advanced applications. In this research, intercalated Ti₃C₂ MXene sheets were synthesized through an etching method, and then they were modified with 3-aminopropyltriethoxysilane (APTES). Cerium cations (Ce³⁺) as an eco-friendly corrosion inhibitor were encapsulated within Ti₃C₂ MXene sheets to fabricate novel self-healing epoxy nanocomposite coatings. The corrosion protection performance (CPP) of Ce³⁺-doped Ti₃C₂ MXene nanosheets (Ti₃C₂ MXene-Ce³⁺) in a 3.5 wt % sodium chloride (NaCl) solution was studied on bare mild steel substrates using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The self-healing CPP of epoxy coatings loaded with 1 wt % undoped and doped Ti₃C₂ MXene was evaluated using EIS, salt spray, and field emission scanning electron microscopy (FE-SEM) techniques. The introduction of Ti₃C₂ MXene-Ce³⁺ into the corrosive solution and artificially scribed epoxy coating enhanced the total impedance from 717 to 6596 Ω cm² and 8876 to 32092 Ω cm², respectively, after 24 h of immersion compared to the control samples.