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

    3-D-printing of glass now possible

    Glass is one of mankind's oldest materials. It was used as far back as in ancient Egypt and ancient Rome and has found a place now also in manufacturing technology of the 21st century. An interdisciplinary team at the KIT led by mechanical engineer Dr. Bastian E. Rapp developed a process us ... more

    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

More about Rice University
  • News

    Zap! Graphene is bad news for bacteria

    Scientists at Rice University and Ben-Gurion University of the Negev (BGU) have discovered that laser-induced graphene (LIG) is a highly effective anti-fouling material and, when electrified, bacteria zapper. LIG is a spongy version of graphene, the single-atom layer of carbon atoms. The Ri ... more

    Graphene-nanotube hybrid boosts lithium metal batteries

    Rice University scientists have created a rechargeable lithium metal battery with three times the capacity of commercial lithium-ion batteries by resolving something that has long stumped researchers: the dendrite problem. The Rice battery stores lithium in a unique anode, a seamless hybrid ... more

    Gas gives laser-induced graphene super properties

    Rice University scientists who invented laser-induced graphene (LIG) for applications like supercapacitors have now figured out a way to make the spongy graphene either superhydrophobic or superhydrophilic. And it's a gas. Until recently, the Rice lab of James Tour made LIG only in open air ... more

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