Chemistry

Metallurgy

Materials science

Organic chemistry

Thermogravimetry

Pentoxide

Carbide

Thermal stability

Nuclear chemistry

Lithium fluoride

Inorganic chemistry

Vanadium

Hydrofluoric acid

Hydrochloric acid

Materials

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).

The Synthesis Process and Thermal Stability of V2C MXene