Since the discovery of carbon nanotubes in the early 1990s, nanotubes and nanowires have been the focus of much scientific attention. Aside from carbon, nanotubes have since been made from various other materials.
Possible applications for these nanostructures range across many fields, including microelectronic circuits, sensors, and special light conductors and light-emitting nanotubes for displays. A research team headed by Wolfgang Tremel at the University of Mainz has now developed a new process for the production of tin sulfide nanotubes. As reported in the journal Angewandte Chemie, the researchers let the SnS2 tubes “grow” out of a drop of metal.
Metal sulfides with a lamellar structure that form inorganic nanotubes are not a new concept. They are currently in use in medical technology, for fibers with ultrahigh tensile strength, in hydrogen storage, for rechargeable batteries, in catalysis, and in nanotechnology. One fundamental problem with the fabrication of sulfidic nanotubes is the need for high temperatures to make the planar layers bend and fuse into tubes. In addition, they must be trapped as unstable intermediates. In the case of tin disulfide, this is nearly impossible, however, because the compound decomposes at a significantly lower temperature.
The Mainz researchers thus implemented a different process for the production of tin disulfide nanotubes: they first used a vapor–liquid–solid (VLS) process, a method normally used in the production of semiconducting nanowires. Bismuth metal powder is mixed with tin sulfide nanoflakes and heated in a tube furnace under an argon stream. The reaction product is deposited at the cooler end of the tube.
Nanodroplets of bismuth are formed inside the oven; these act as local points of contact for the tin. In this way, the reaction partners become concentrated within the metal droplet, which then serves as the nucleus for growth of the nanotubes. “In this process, the metal drop is obtained as a sphere at the end of the tube, and the nanotubes grow out of the sphere like a hair out of a follicle,” explains Tremel. “Catalysis by the metal droplet makes growth possible at low temperatures.”
The new method allowed the scientists to produce nanotubes made of several SnS2 layers with few defects, diameters between 30 and 40 nm, and lengths between 100 and 500 nm.
Author: Wolfgang Tremel, Universität Mainz (Germany), http://www.ak-tremel.chemie.uni-mainz.de/
Title: Bismuth-Catalyzed Growth of SnS2 Nanotubes and Their Stability
Angewandte Chemie International Edition, doi: 10.1002/anie.200900546
Further reports about: > Angewandte Chemie > LED Drops > Metal sulfides > SnS2 > Tremel > hydrogen storage > microelectronic circuits > rechargeable batteries > semiconducting nanowires > special light conductors > sulfide nanotubes > tubes > ultrahigh tensile strength > vapor–liquid–solid (VLS) process
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences