High-temperature stability in air of TiCT MXene-based composite with extracted bentonite.

Although TiCT MXene is a promising material for many applications such as catalysis, energy storage, electromagnetic interference shielding due to its metallic conductivity and high processability, it's poor resistance to oxidation at high temperatures makes its application under harsh environments challenging. Here, we report an air-stable TiCT based composite with extracted bentonite (EB) nanosheets. In this case, oxygen molecules are shown to be preferentially adsorbed on EB. The saturated adsorption of oxygen on EB further inhibits more oxygen molecules to be adsorbed on the surface of TiCT due to the weakened p-d orbital hybridization between adsorbed O and TiCT, which is induced by the TiCT/EB interface coupling. As a result, the composite is capable of tolerating high annealing temperatures (above 400 °C for several hours) both in air or humid environment, indicating highly improved antioxidation properties in harsh condition. The above finding is shown to be independent on the termination ratio of TiCT obtained through different synthesis routes. Utilized as terahertz shielding materials, the composite retains its shielding ability after high-temperature treatment even up to 600 °C, while pristine TiCT is completely oxidized with no terahertz shielding ability. Joule heating and thermal cycling performance are also demonstrated.