TEMPLATE SYNTHESIS OF NEAR-MONODISPERSE MICROSCALE NANOFIBERS AND NANOTUBULES OF MOS2

Near-monodisperse microscopic nanostructures of MoS2 were prepared by thermal decomposition of two different ammonium thiomolybdate molecula r precursors, (NH4)(2)MoS4 and (NH4)(2)Mo3S13, within the confined voi ds af a porous aluminum oxide membrane template. Our low-temperature ( 450 degrees C) synthetic route yielded large quantities of hollow tubu les of MoS2 of uniform size and shape that were similar to 30 mu m lon g with diameter of 50 nm and wall thicknesses of about 10 nm. More irr egularly shaped, mainly solid fibers of MoS2 with diameters of about 2 00 nm were synthesized by changing the template to one with larger por es. The morphology of the fibers or tubules was studied with respect t o the choice of precursor. the characteristics of the precursor soluti ons, the incorporation methods, the template characteristics, and the heat treatment during firing. The MoS2 structures were characterized b y scanning and transmission electron microscopies, energy dispersive s pectroscopy, electron and X-ray diffraction,and optical absorption spe ctroscopy. This template-assisted growth process yielded large quantit ies of MoS2 tubules or fibers that could be isolated from the template . However, under the growth conditions studied, the formation of HxMoS 2 ''bronzes'' could not be discounted.