THIOL-DERIVATIZED NANOCRYSTALLINE ARRAYS OF GOLD, SILVER, AND PLATINUM

A simple procedure has been developed to prepare thiol-derivatized nan oparticles of metals, The procedure involves the transfer of well-char acterized metal hydrosols to a hydrocarbon medium containing the thiol . Thiol-derivatized nanoparticles Au, Ag, and Pt of near spherical sha pe forming nanocrystalline arrays have been characterized by X-ray dif fraction, transmission electron microscopy (TEM), and other techniques , Thiol-derivatized Au particles Au mean diameters of 1.0, 2.1, and 4. 2 nm from nanocrystalline arrays show characteristic X-ray diffraction patterns. The nanoparticles exhibit Moire fringes when deposited on a flake of MoSe2, showing that each particle is in itself crystalline. Besides spherical nanoparticles, thiol-derivatized particles of other shapes have been prepared, hexagonal Pt nanoparticles being particular ly hovel. Scanning tunneling microscopy images not only confirm the si ze and shape of nanoparticles revealed by TEM, but also show evidence for thiol molecules on the surface.