Graphene-like 2D Ti3C2Tx MXene/dodecyltrimethoxysilane coating for corrosion protection on aluminum alloy by designing multilayer structure

Corrosion of metals leads to great economic losses and safety hazards. To address the corrosion problem of Al alloy in aggressive medium, two-dimensional (2D) graphene-like MXene composite coatings are proposed to enhance the corrosion resistance. Despite great progress, it still faces challenge to design high-performance MXene-based composite coating via a facile strategy because of the complex surface functionalization, orientation control, and the conductivity of MXene. Herein, a multilayer Ti3C2Tx MXene/dodecyltrimethoxysilane (MXene/DTMS) coating is prepared by a layer-by-layer spraying method at ambient temperature to maximize the physical barrier of MXene nanosheets. As a result, the incorporation of MXene nanosheets can avoid the structural defects of silane coating after curing process, thereby improving the coating resistance and charge transfer resistance by ~11- and ~390-fold in comparison to Al counterpart, respectively. Beyond the traditionally complex surface functionalization and orientation control, the multilayer coating with complete coverage and strong physical barrier ability exhibits the high corrosion resistance with a impedance modulus of 3.74 × 107 Ω·cm2 in 3.5 wt% NaCl solution. The designed coating shows promising applications in surface protection on Al alloy used in transmission cable, shafts, gears, and blades for offshore wind turbines.