Effect of structure and composition of nanodiamond powders on thermal stability and oxidation kinetics

Publication date: Available online 1 March 2018
Source:Carbon
Author(s): Carlo Bradac, Sebastian Osswald
Oxidation has been suggested as an effective and scalable means for industrial purification of nanodiamond (ND) powders. However, conflicting accounts were reported with respect to oxidation behavior of commercial powders and the temperature range in which non-diamond phases can be removed efficiently. In this study, we investigate the effects of composition and structural characteristics of ND on the oxidation kinetics. The effect of crystal size was analyzed by directly measure the oxidation behavior of individual ND crystal in the size range 2–20 nm, probing the size-dependence of the oxidation kinetics at the lower end of the nanoscale. This study also leads to the first experimental data on the minimum size at which ND crystals become thermodynamically unstable and cease to exist as well as the minimum size of a luminescent ND still hosting an optically active nitrogen-vacancy (NV) center.

Graphical abstract

http://ift.tt/2GUrX6r