Enhancement of the electrical properties of MXene Ti3C2 nanosheets by post-treatments of alkalization and calcination

Two-dimensional (2D) MXene Ti3C2 nanosheets are prepared by liquid phase exfoliation of layered Ti3AlC2 in aqueous solution of HF, followed by alkalization and calcination. The electrical properties of the as-prepared Ti3C2 nanosheets are investigated as a function of calcining temperatures to find the optimum process condition. The microstructures and structural changes of the MXene Ti3C2 nanosheets are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is found that the post-treatment processes could effectively remove the functional groups on the surface of 2D nanosheets to enhance the electrical properties of MXene Ti3C2. As a result, the MXene Ti3C2 nanosheets after calcination at 600 °C exhibit a high conductivity of 2140 S/cm, nearly three times as high as that of the un-treated Ti3C2 samples.