My watch list  

Nanoparticles digging the world’s smallest tunnels


The world’s smallest tunnels have a width of a few nanometers only. Researchers from Karlsruhe Institute of Technology (KIT) and Rice University, USA, have dug such tunnels into graphite samples. This will allow structuring of the interior of materials through self-organization in the nanometer range and tailoring of nanoporous graphite for applications in medicine and battery technology. Results are now presented in Nature Communications.

The tunnels are manufactured applying nickel nanoparticles to graphite which then is heated in the presence of hydrogen gas. The surface of the metal particles, that measure a few nanometers only, serves as a catalyst removing the carbon atoms of the graphite and converting them by means of hydrogen into the gas methane. Through capillary forces, the nickel particle is drawn into the “hole” that forms and bores through the material. The size of the tunnels obtained in the experiments was in the range of 1 to 50 nanometers, which about corresponds to one thousandth of the diameter of a human hair.

To furnish proof of the real existence of these graphite tunnels, the researchers have made use of scanning electron and scanning tunneling microscopy. “Microscopes, in fact, image only the upper layers of the sample,” the principal authors of the study, Maya Lukas and Velimir Meded from KIT’s Institute of Nanotechnology, explain. “The tunnels below these upper layers, however, leave atomic structures on the surface whose courses can be traced and which can be assigned to the nanotunnels by means of the very detailed scanning tunneling microscopy images and based on computerized simulations.” In addition, the depth of the tunnels was determined precisely by means of a series of images taken by a scanning electron microscope from different perspectives.

Porous graphite is used, for example, in the electrodes of lithium ion batteries. The charge time could be reduced using materials with appropriate pore sizes. In medicine, porous graphite could serve as a carrier of drugs to be released over longer periods of time. Replacing graphite by nonconductive materials, e.g. boron nitride,  with atomic structures similar to that of graphite,  the tunnels could serve as basic structures for nanoelectronic components such as novel sensors or solar cells.

Facts, background information, dossiers
  • Rice University
  • Karlsruher Institut…
More about KIT
  • News

    Quantum computing with molecules for a quicker search of unsorted databases

    Scrapbooks or social networks are collections of mostly unsorted data. The search for single elements in very large data volumes, i.e. for the needle in the data haystack, is extremely complex for classical computers. Scientists of Karlsruhe Institute of Technology (KIT) have now quantum me ... more

    ZEISS Invests €30 Million in Innovation Hub at KIT

    ZEISS plans to build a new shared innovation hub on the north campus of the Karlsruhe Institute of Technology (KIT). Construction is scheduled to begin in early 2018; the €30 million hub will cover 12,000 square meters. With the ZEISS Innovation Hub, the global technology leader in optics a ... more

    Tiny lasers from a gallery of whispers

    Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a phenomenon similar to an effect observed in circular galleries, such as in some cathedrals or museums, where sound waves travel across t ... more

More about Rice University
  • News

    Touchy nanotubes work better when clean

    Carbon nanotubes bound for electronics need to be as clean as possible to maximize their utility in next-generation nanoscale devices, and scientists at Rice and Swansea universities have found a way to remove contaminants from the nanotubes. Rice chemist Andrew Barron, also a professor at ... more

    Nature's toughest substances decoded

    How a material breaks may be the most important property to consider when designing layered composites that mimic those found in nature. A method by Rice University engineers decodes the interactions between materials and the structures they form and can help maximize their strength, toughn ... more

    Borophene shines alone as 2-D plasmonic material

    An atom-thick film of boron could be the first pure two-dimensional material able to emit visible and near-infrared light by activating its plasmons, according to Rice University scientists. That would make the material known as borophene a candidate for plasmonic and photonic devices like ... more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE