Nuclear Magnetic Resonance Study of Hydroxylated Detonation Nanodiamond

We report on a detailed nuclear magnetic resonance (NMR) study of hydroxylated diamond nanoparticles. C-13 and H-1 NMR reveal signals originated from diamond core, hydroxyl, hydrocarbon groups and moisture on the diamond surface. In order to distinguish between the contributions of moisture and other hydrogen-containing groups to the NMR spectra and spin-lattice relaxation, as-prepared and exhausted down to 10(-5) Torr samples have been studied. This approach is shown to be useful for correct analysis of the NMR data. Significant reduction in the C-13 spin-lattice relaxation time compared with natural diamond and non-exponential behavior of the C-13 magnetization recovery were observed similar to the findings on other detonation nanodiamond samples and attributed to the interaction of nuclear spins with paramagnetic defects.