General Strategy for High-Density Covalent Functionalization of Diamond Nanoparticles Using Fenton Chemistry

Diamond nanoparticles (npD) from detonation do not undergo covalent functionalization to a large extent, as assessed by conventional IR and NMR spectroscopy. This low level of surface modification is due to the low density of surface hydroxyl groups and the presence of soot matter covering npD. We have found that the Fenton reaction of npD remarkably increases the density of surface OH groups, decreases the undesirable amorphous soot matter, and makes possible the subsequent high-density covalent functionalization of these nanoparticles. In this way, the polarity and solubility of npD can be controlled and, besides by IR spectroscopy, we have shown that it is even possible to characterize the resulting diamond nanoparticles by conventional solution 1 H NMR spectroscopy in which the signals corresponding to the proton ligands can be monitored.