Temperature-dependent morphological and phase evolution at the MXene/SiOC interface

Abstract Understanding the thermal stability of MXene/SiOC interface is critical for their use in high-temperature applications. In this work, we present a comprehensive in-situ transmission electron microscopy (TEM) study, coupled with thermogravimetric analysis (TGA), and X-ray diffraction (XRD), to investigate the morphological and chemical evolution of Ti₃C₂Tₓ MXene on polymer-derived SiOC ceramic, which was pre-pyrolyzed at 750 °C under argon and surface-treated with plasma. From room temperature (RT) to 1000 °C, the MXene layers near the SiOC interface began to collapse at ~ 700 °C, while the top layers persisted up to 800 °C. Loss of –F and –O terminations and diffusion of Ti, C, Si, and O atomic species toward the interface region occurred above 700 °C. TGA revealed an initial mass loss of about 5–6 wt% below 300 °C, followed by continued high-temperature degradation associated with surface termination loss and interfacial phase transformation. Intense rutile TiO₂ peaks emerge after 1000 °C with a transition from layered structures to aggregated bulk particles. These findings provide crucial insights into designing thermally stable MXene/SiOC interfaces.