An attempt to prepare carbon nitride by thermal plasma chemical vapor deposition from graphite and nitrogen

RF induction thermal plasma was applied to the chemical vapor deposition of carbon nitride from graphite powders and Ar–N₂ gas at about 1 atm. Low-density and fragile amorphous powder-like bulk deposits whose color is light yellow were obtained. Elementary analysis by a combustion method and x-ray photoelectron spectroscopy showed that the N/C ratio is higher than that of stoichiometric C₃N₄. Also, a large amount of hydrogen and oxygen are included, which seems to be due to the absorption of moisture and oxygen after exposure to air. Infrared absorption spectra suggest the presence of sp CN and sp² CN bonds, and nitrogen-containing polycondensed ring structures. Thermogravimetric analysis with mass spectroscopy shows that the deposits decompose almost completely at 800 °C, suggesting that the polycondensed rings are not large and not well cross-linked.