Submillimeter-Long WS(2) Nanotubes: The Pathway to Inorganic Buckypaper

[Image: see text] WS(2) nanotubes present many new technologies under development, including reinforced biocompatible polymers, membranes, photovoltaic-based memories, ferroelectric devices, etc. These technologies depend on the aspect ratio (length/diameter) of the nanotubes, which was limited to 100 or so. A new synthetic technique is presented, resulting in WS(2) nanotubes a few hundred micrometers long and diameters below 50 nm (aspect ratios of 2000–5000) in high yields. Preliminary investigation into the mechanistic aspects of the two-step synthesis reveals that W(5)O(14) nanowhisker intermediates are formed in the first step of the reaction instead of the ubiquitous W(18)O(49) nanowhiskers used in the previous syntheses. The electrical and photoluminescence properties of the long nanotubes were studied. WS(2) nanotube-based paper-like material was prepared via a wet-laying process, which could not be realized with the 10 μm long WS(2) nanotubes. Ultrafiltration of gold nanoparticles using the nanotube-paper membrane was demonstrated.