Carbon Nitride Compounds Synthesized by Thermal Annealing Amorphous Nanostructured Graphite under the Flow of NH₃ Gas

Graphitic-C₃N₄ (g-C₃N₄) and pseudocubic-C₃N₄ (p-C₃N₄) have been synthesized by thermally annealing high-energy ball milled amorphous nanostructured graphite powders under NH₃ atmosphere. The experimental results by x-ray, transmission electron microscopy, selected electron area diffraction and parallel electron energy loss spectroscopy indicated that g-C₃N₄ grew from the milled graphite powders in the presence of NH₃ gas at a temperature of 1050°C. After treatment at a temperature of 1350°C, the pseudocubic-C₃N₄ phase forms. It was believed that the high-energy ball milling generates nanosized amorphous graphite structures, under subsequent isothermal annealing in a flow of NH₃ gas, the carbon nitride compound can easily form through reaction of nanostructured carbon with nitrogen of NH₃.