Nuclear Magnetic Resonance Study of Hydroxylated Detonation Nanodiamond

Abstract

We report on a detailed nuclear magnetic resonance (NMR) study of hydroxylated diamond nanoparticles. ¹³C and ¹H 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 ¹³C spin–lattice relaxation time compared with natural diamond and non-exponential behavior of the ¹³C magnetization recovery were observed similar to the findings on other detonation nanodiamond samples and attributed to the interaction of nuclear spins with paramagnetic defects.

Keywords:

• Nanodiamond
• NMR
• hydroxylation

Acknowledgments

The work in Israel was partially supported by the New Energy Development Organization of Japan (NEDO) grant #04IT4 and MOST-RFBR grant #3-5708. O. S. is thankful for the support from the Space and Naval Warfare Systems Centers (SSC) under grant N66001-04-1-8933. We thank A. I. Shames (BGU) for EPR measurements and S. Hens (ITC) for hydroxylated nanodiamond preparation.