Study of the products of melamine (C₃N₆H₆) treated at high pressure and high temperature

Abstract

Abstract A black‐brown powder was synthesized from melamine (C 3 N 6 H 6 ) at 850 °C and 4.5 GPa. There are two possibilities for the sample phase components based on the analyses of C/N/H elements and X‐ray diffraction patterns. One is that the powder is composed of 2H‐type g‐C 3 N 4 and some intermediate phases, while the other is that it consists of some undecomposed raw material, graphite and intermediate phases. The existence of the intermediate phase with long periodicity along one direction is confirmed through transmission electron microscopy observations. Scanning electron microscopy images show many block regions, in which a few holes exist. The atomic fraction of carbon and nitrogen was checked with energy dispersive X‐ray analysis, and the chemical bond states were investigated by Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy. Based on the general analysis of the experimental results, the second possibility is favoured. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)