Porous dopamine–W/Mo functionalized sandwich-like h-BN/Ti-MXene nanohybrids for multifunctional epoxy composite coatings

A multifunctional epoxy-based priming composite coating was developed using covalently engineered h-BN/Ti-MXene nanohybrids, further decorated with a novel porous dopamine–tungsten–molybdenum (W–Mo) nanocomplex, and loaded with a zinc-based corrosion inhibitor (ZMWD-MXene-BN). This coating exhibits outstanding physical barrier properties against corrosive agents, along with active self-healing capability. The developed nanohybrids were characterized through various tests, including field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) theory. The inhibition efficiency toward corrosion of the ZMWD-MXene-BN nanohybrid in saltwater (NaCl media) was examined through electrochemical impedance spectroscopy (EIS). The results demonstrated a remarkable corrosion protection efficiency of 85.69% after 72 h of immersion. The epoxy coating containing the ZMWD-MXene-BN nanohybrid demonstrated exceptional protective performance. It exhibited superior barrier properties, maintaining an impedance value of 17.79 GΩ.cm² after an immersion duration of 70 days in a simulated seawater solution. Additionally, the coating showed active self-healing behavior, with about a 33% increase in total resistance after 48 h of exposure to saltwater. Its adhesion strength was also significantly enhanced, with improvements of about 65.8% in the wet pull-off strength and 71.46% in the cathodic delamination test.