Synthesis process, thermal and electrical behaviors of Ti3C2Tx MXene; [Syntheseprozess, thermisches und elektrisches Verhalten von Ti3C2Tx MXene]

Synthesis of two-dimensional (2D) titanium carbide (Ti3C2Tx), with the name of MXene, by etching Ti3AlC2 (MAX) for different times 20 (v/v) % hydrofluoric acid (HF) at 40 °C was carried out. The influences of time, temperature and source of MAX on the synthesis of MXene were researched. The MXenes produced were characterized by fourier-transform ınfrared (FT-IR) spectroscopy technique, energy dispersive x-ray spectroscopy (EDX), scanning electron microscopy (SEM), x-ray diffraction (XRD) and thermogravimetry (TG) instruments. Above 390 °C, MXene layers were considerably oxidizing and forming anatase and rutile phases of TiO2 under air atmosphere. The resistance of MAX and MXene was 3.6 Ω and 116 Ω, respectively. However, the resistance of the residual part of MXene heated to 620 °C considerably increased to 17850 Ω. This behavior is another important piece of evidence showing that the MXene crystal structure has changed significantly and transformed into a new chemical structure containing anatase and rutil titanium oxide (TiO2). The dielectric loss (ϵ’’) and alternating conductivity (δac) of the MAX and MXenes were determined from their impedance measurements. The ϵ’’ and δac values of MXene were compared with those of MAX. Direct curent conductivities of MAX and MXene produced for 24 h were found to be 0.016 S/cm and 0.0023 S/cm, respectively.