The Thermal Stability of Nanodiamond Surface Groups and Onset of Nanodiamond Graphitization

The results of study of the surface chemistry of nanodiamonds treated by a mixture of HClO4 and H2SO2 acids are presented. Changes of the composition of surface diamond groups brought up by thermal annealing were monitored by Fourier transformed infrared spectroscopy and temperature‐programmed desorption. The decomposition of oxygen‐containing groups is observed at 300–900°C; CHx groups decompose at 700–1150°C. The process of the annealing of ND was investigated by the X‐ray photoelectron spectroscopy. The clear onset of ND graphitization was observed at temperature of 950°C that is supported by the appearance of sp 2 component in the C1s spectrum. The presence of the N1s peak in spectra of ND is observed in initial and partially graphitized ND annealed up to 1100°C.