Modification of Nanodiamonds with Gold Nanoparticles

摘要

Sodium borohydride reduction of the diazonium tetrachloroaurate(III) salt C8F17-4-C6H4N equivalent to NAuCl4 in the presence of nanodiamonds resulted in nanohybrid formation. X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), and energy dispersive spectroscopy (EDS) measurements testified the presence and connectivity of the gold and organic shell to the nanodiamonds. The two peaks at 1151 and 1209 cm(-1) in the FT-IR measurements assigned to C-F stretching bands support the presence of the perfluorinated shell C8F17-4-C6H4- and the two medium intensity peaks at 2849 and 2921 cm(-1) assigned to C-H stretching bands, which appear in the pristine and gold modified NDs, support the presence of NDs in the nanohybrid. The detected gold signal at 84 eV using XPS indicates that the terminating surface contains exposed gold and lies within the detection depth. TEM images showed the presence of 35 nm-sized gold nanoparticles and XRD pattern showed gold in zero-valence. The new approach is different than other nanodiamonds modifications in the in situ reduction of the diazonium tetrachloroaurate(III) salts and the utilization of the robust covalently functionalized gold nanoparticles. This work highlights the efficiency of aryl diazonium salts to construct multicomponent nano-objects provided that the counterion for the diazonium salt is appropriately chosen. By selecting tetrachloroaurate(III) as anion, we demonstrate that it is simple to design unusual, core/shell nanodiamonds/gold nanohybrids.