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

    Metal-organic frameworks used as looms

    Researchers of Karlsruhe Institute of Technology (KIT) have made major progress in the production of two-dimensional polymer-based materials. To produce cloths from monomolecular threads, the scientists used SURMOFs, i.e. surface-mounted metal-organic frameworks, developed by KIT. They inse ... more

    Cloud Formation: How Feldspar Acts as Ice Nucleus

    In the atmosphere, feldspar particles act as ice nuclei that make ice crystals grow in clouds and enable precipitation. The reason was found by researchers of Karlsruhe Institute of Technology (KIT) and University College London (UCL) with the help of electron microscopy observations and mo ... more

    Light to design precision polymers

    Chemists of Karlsruhe Institute of Technology (KIT) have succeeded in specifically controlling the setup of precision polymers by light-induced chemical reactions. The new method allows for the precise, planned arrangement of the chain links, i.e. monomers, along polymer chains of standard ... more

More about Rice University
  • News

    Proton-nuclei smashups yield clues about ‘quark gluon plasma’

    Findings from Rice University physicists working at Europe’s Large Hadron Collider (LHC) are providing new insight about an exotic state of matter called the “quark-gluon plasma” that occurs when protons and neutrons melt. As the most powerful particle accelerator on Earth, the LHC is able ... more

    'Fuzzy' fibers can take rockets' heat

    To stand up to the heat and pressure of next-generation rocket engines, the composite fibers used to make them should be fuzzy. The Rice University laboratory of materials scientist Pulickel Ajayan, in collaboration with NASA, has developed "fuzzy fibers" of silicon carbide that act like Ve ... more

    Pulverizing electronic waste is green, clean - and cold

    Researchers at Rice University and the Indian Institute of Science have an idea to simplify electronic waste recycling: Crush it into nanodust. Specifically, they want to make the particles so small that separating different components is relatively simple compared with processes used to re ... more

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