The Synthesis Process and Thermal Stability of V(2)C MXene

The effect of etching solution on the synthesis process of two-dimensional vanadium carbide (V(2)C MXene) was researched. Three etching solutions were used to etch ternary carbide V(2)AlC 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 V(2)C MXene. The existence of sodium (Na(+)) and chloridion (Cl(−)) in etching solution was essential for the synthesis. The thermal stability of the as-prepared V(2)C MXene in argon or air was studied. From thermogravimetry and differential thermal analysis, V(2)C MXene was found to be stable in argon atmosphere at a temperature of up to 375 °C. As the temperature increased, V(2)C MXene was gradually oxidized to form nanoparticles composed of vanadium trioxide (V(2)O(3)) and a part of V(2)C MXene was broken and transformed to vanadium carbide (V(8)C(7)) at 1000 °C. In air atmosphere, V(2)C MXene was stable at 150 °C. At 1000 °C, V(2)C MXene was oxidized to form vanadium pentoxide (V(2)O(5)).