FTIR studies on the spectral changes of the surface functional groups of ultradispersed diamond powder synthesized by explosive detonation after treatment in hydrogen, nitrogen, methane and air at different temperatures

Abstract

Ultradispersed diamond (UDD) powder prepared by explosive detonation and modified by hydrogen, plasma-ionized hydrogen, nitrogen, methane and air, as well as in vacuo, under different temperatures is investigated by Fourier-transform infrared spectroscopy (FTIR) and temperature programmed desorption (TPD) methods. After treatment in reductive media the contents of surface C—H groups are increased, when UDD is treated by plasma-ionized hydrogen the enhancement of intensity of ν_C–H is significant. The resemblance of the spectra of UDD treated in hydrogen, nitrogen and in vacuo at high temperature suggests that decomposition, decarbonylation and/or decarboxylation are the main reactions upon treatment with these gases and in vacuo at high temperature.