Flaky graphene makes reliable chemical sensors
The researchers created the one-atom-thick carbon lattice flakes by placing bulk graphite in a solution and bombarding it with ultrasonic waves that broke off thin sheets.
The researchers then filtered the solution to produce a graphene film, composed of a haphazard arrangement of stacked flakes, that they used as the top layer of a chemical sensor. When the graphene was exposed to test chemicals that altered the surface chemistry of the film, the subsequent movement of electrons through the film produced an electrical signal that flagged the presence of the chemical.
The researchers experimented by adjusting the volume of the filtered solution to make thicker or thinner films. They found that thin films of randomly stacked graphene could more reliably detect trace amounts of test chemicals than previously designed sensors made from carbon nanotubes or graphene crystals.
The results are accepted for publication in the AIP's journal Applied Physics Letters.
The researchers theorize that the improved sensitivity is due to the fact that defects in the carbon-lattice structure near the edge of the graphene flakes allow electrons to easily “hop” through the film.
Article: “Chemical Sensors Based On Randomly Stacked Graphene Flakes” is accepted for publication in Applied Physics Letters.
Authors: Amin Salehi-Khojin (1, 7), David Estrada (2, 3), Kevin Y. Lin (1), Ke Ran (4, 5), Richard T. Haasch (5), Jian-Min Zuo (4, 5), Eric Pop (2, 3, 6), and Richard I. Masel (7).
(1) Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign
(2) Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign
(3) Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign
(4) Department of Material Science and Engineering, University of Illinois at Urbana-Champaign
(5) Materials Research Laboratory, University of Illinois at Urbana-Champaign
(6) Beckman Institute, University of Illinois at Urbana-Champaign
(7) Dioxide Materials, Champaign, Ill.
Alle Nachrichten aus der Kategorie: Physics and Astronomy
This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.
innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.
Surplus sugar helps whiteflies detoxify plant defenses
This pest insect uses sugar from its food to prevent the activation of the mustard oil bomb in cruciferous plants. Worldwide dreaded crop pest of hundreds of plant species Whiteflies…
Discovery of large family of two-dimensional ferroelectric metals
It is usually believed that ferroelectricity can appear in insulating or semiconducting materials rather than in metals, because conducting electrons of metals always screen out the internal static electric field…