Carbon nitride prepared by solvothermal method

A solvothermal method has been successfully applied to prepare crystalline carbon nitride powder from 1,3,5-trichlorotriazine (C₃N₃Cl₃) and lithium nitride (Li₃N) in benzene at 300-400 °C and 5-7 MPa. The sample was brown and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The results show that the powder mainly consists of α-C₃N₄, β-C₃N₄. The experimental lattice constants of α-C₃N₄ (a = 6.48 Å, c = 4.72 Å) and β-C₃N₄ (a = 6.43 Å, c = 2.47 Å) match the latest ab initio calculations (a = 6.47 Å, c = 4.72 Å for α-C₃N₄, a = 6.40 Å, c = 2.40 Å for β-C₃N₄) quite well. The relative nitrogen-to-carbon composition ratio is 0.76. Only C-N and C = N bonds were demonstrated by XPS and FTIR.