The effect of etching solution on the synthesis process of two-dimensional vanadium carbide (V₂C MXene) was researched. Three etching solutions were used to etch ternary carbide V₂AlC at 90 °C. The three solutions were: lithium fluoride + hydrochloric acid (LiF + HCl), sodium fluoride + hydrochloric acid (LiF + HCl), and potassium fluoride + hydrochloric acid (KF + HCl). It was found that only NaF + HCl solution was effective for synthesizing highly pure V₂C MXene. The existence of sodium (Na⁺) and chloridion (Cl⁻) in etching solution was essential for the synthesis. The thermal stability of the as-prepared V₂C MXene in argon or air was studied. From thermogravimetry and differential thermal analysis, V₂C MXene was found to be stable in argon atmosphere at a temperature of up to 375 °C. As the temperature increased, V₂C MXene was gradually oxidized to form nanoparticles composed of vanadium trioxide (V₂O₃) and a part of V₂C MXene was broken and transformed to vanadium carbide (V₈C₇) at 1000 °C. In air atmosphere, V₂C MXene was stable at 150 °C. At 1000 °C, V₂C MXene was oxidized to form vanadium pentoxide (V₂O₅).

MXene is a new type of two-dimensional layered material. Herein, a GO/Ti₃C₂T_x nanocomposite was prepared by a simple liquid phase method, and the obtained GO/Ti₃C₂T_x was transformed into RGO/Ti₃C₂T_x under high temperature with Ar/H_2. The prepared samples were characterized using X-ray diffraction (XRD), Raman measurement, scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). As an electrode material in lithium-ion batteries, the RGO/Ti₃C₂T_x nanocomposite exhibited an excellent electrochemical performance and an excellent rate performance. Compared to pure Ti₃C₂T_x, the nanocomposite had a better reversible capacity at different current densities and had no attenuation after 200 cycles, which is one time higher than pure Ti₃C₂T_x. The improvement in the specific capacity was due to the excellent electrical conductivity and the unique structure of RGO, in which a charge transfer bridge was built among the Ti₃C₂T_x flakes. Such a bridge shortened the transmission distance of the electrons and ions and effectively controlled the restacking of the laminated materials.