Powder synthesis and characterization of amorphous carbon nitride

Carbon nitride powder has been prepared by solid-state reaction between cyanuric chloride or its fluoro analogue and lithium nitride. The determined, by elemental analysis, atomic N/C ratio (1.33) in the synthesized material is entirely consistent with the C3N4 stoichiometry. Combined material characterization data, obtained by Fourier transform infrared, Raman, UV-visible, (C-13) magic-angle spinning NMR, X-ray photoelectron spectroscopy, thermal gravimetric analysis/differential thermal analysis, and pyrolysis-electron ionization mass spectrometry methods, provide substantial evidence for graphite-like sp(2)-bonded structure composed of building blocks of s-triazine rings bridged by the 3-fold coordinated nitrogen atoms in the bulk carbon nitride. As indicated by X-ray and scanning electron microscopy analytical data, the material is amorphous and changes from turbostratic to more ordered layered graphitic morphology under high pressures. The availability of stoichiometric carbon nitride a-C3N4 in gram quantities, made possible by a developed low-cost synthetic method, facilitates the extensive studies of bulk processing and electromechanical properties, and high-pressure/high-temperature transformations of this material into superhard crystalline polymorphic phases.