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

Graphitic carbon nitride(g-C3N4) is prepared by pyrolysis of melamine.At room temperature,the structure change of the g-C3N4 is investigdted 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-C3N4 within 16.57 GPa pressure range.The crystal structure changes from graphitic to triclinic structure at 6.6 GPa.The isothermal equation of the state of C3N4 is fitted using the Birch-Murnagha equation of state.