Study on the pressure-induced phase transition of g-C3N4

Graphitic carbon nitride (g-C 3 N 4 ) is prepared by pyrolysis of melamine. At room temperature, the structure change of the g-C 3 N 4 is investigated by in situ high pressure angle-dispersive X-ray diffraction with a synchrotron radiation source, which is in a diamond-anvil cell. The results show that structural phase transition occurred in g-C 3 N 4 within 16.57GPa pressure range. The crystal structure changes from graphitic to triclinic structure at 6.6GPa. The isothermal equation of the state of C 3 N 4 is fitted using the Birch-Murnagha equation of state.