Formation of crystalline carbon nitride powder by a mild solvothermal method

Crystalline carbon nitride powder has been successfully prepared via the liquid-solid reaction between anhydrous C₃N₃Cl₃ and Li₃N in benzene at 355°C and 5-6 MPa for 12 h. X-Ray diffraction (XRD) indicated that the major part of our brown sample was composed mainly of α-C₃N₄ and β-C₃N₄ with lattice parameters of a = 6.49 Å, c = 4.70 Å for α-C₃N₄ and a = 6.43 Å, c = 2.43 Å for β-C₃N₄. X-Ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FTIR), electron energy-loss spectroscopy (EELS) and energy loss near edge structure (ELNES) strongly supported the existence of C-N covalent bonds. The relative N/C ratio is about 0.66. The temperature had an effect on the crystallization of carbon nitride powder. We have shown that the solvothermal technique might hold some promise for synthesizing pure crystalline α-C₃N₄ and β-C₃N₄.