New Crystal Structures of WS2: Microtubes, Ribbons, and Ropes

Abstract

WS2 microtubes, ribbons, and ropes are some of the unusual forms of inorganic crystals – grown by a chemical transport reaction – for which evidence is presented here. The Figure shows a WS2 rope composed of four nanotubes with one nanotube periodically wound around the widest tube. A further example, of two nanotubes wound around each other, can be found on the front cover.

Metallic Sub‐Nanometer MoS2–xIy Nanotubes

“…The near-equilibrium growth conditions that persist enable the synthesis of chiral nanotubes with a low density of structural defects. They grow to several millimeters in length, [10,11] with diameters ranging from several micrometers in multiwalled nanotubes to less than ten nanometers. The addition of a few atomic percent of gold or silver leads to the growth of alloyed MoS 2 and WS 2 nanotubes with suppressed chirality and typical crater±cone tube extremities.…”

Inorganic Nanotubes and Fullerene-Like Materials

“…This hypothesis is supported by the two‐step growth process, in which the oxide nanowhisker phase is obtained in the first step, and is subsequently converted to WS 2 nanotubes phase in an H 2 S atmosphere 14. Uniform WS 2 nanotubes were also obtained by the chemical vapor transport (CVT) technique,15 in which the WS 2 powder is transported from the hot to the colder zones of a quartz ampoule by means of a transporting agent, for example, iodine. Extremely uniform and very long single‐wall MoS 2 nanotubes with diameter of less than 1 nm have also been synthesized 16.…”

Polygonal Single‐Crystal Aluminum Borate Microtubes

“…In addition, the interior hollow structure has a great potential for many applications, including sensors, drug delivery, microfluidic processes in microelectromechanical systems (MEMS), optical resonance cavities, and waveguides. The successful synthesis of micro‐ and nanotubes in a number of materials, such as SiO 2 , TiO 2 , InGaSa/GaAs, WS 2 , MoS 2 , NbS 2 , NaV 3 O 7 , V 2 O 5 , VO x , BN, SiC, Si 3 N 4 , AlN, mullite, and sialon has been reported 2–20 …”