Formation of Carbon Nanostructures in Cobalt- and Nickel-Doped Carbon Aerogels

Journal Article · Tue Nov 09 00:00:00 EST 2004 · Langmuir

OSTI ID:15020092

Fu, R; Baumann, T F; Cronin, S; Dresselhaus, G; Dresselhaus, M

We have prepared carbon aerogels (CAs) doped with cobalt or nickel through sol-gel polymerization of formaldehyde with the potassium salt of 2,4-dihydroxybenzoic acid, followed by ion-exchange with M(NO{sub 3}){sub 2} (where M = Co{sup 2+} or Ni{sup 2+}), supercritical drying with liquid CO{sub 2} and carbonization at temperatures between 400 C and 1050 C under an N{sub 2} atmosphere. The nanostructures of these metal-doped carbon aerogels were characterized by elemental analysis, nitrogen adsorption, high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Metallic nickel and cobalt nanoparticles are generated during the carbonization process at about 400 C and 450 C, respectively, forming nanoparticles that are {approx}4 nm in diameter. The sizes and size dispersion of the metal particles increase with increasing carbonization temperatures for both materials. The carbon frameworks of the Ni- and Co-doped aerogels carbonized below 600 C mainly consist of interconnected carbon particles with a size of 15 to 30 nm. When the samples are pyrolyzed at 1050 C, the growth of graphitic nanoribbons with different curvatures is observed in the Ni and Co-doped carbon aerogel materials. The distance of graphite layers in the nanoribbons is about 0.38 nm. These metal-doped CAs retain the overall open cell structure of metal-free CAs, exhibiting high surface areas and pore diameters in the micro and mesoporic region.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15020092
• Report Number(s): UCRL-JRNL-207910; LANGD5; TRN: US200519%%176
• Journal Information: Langmuir, Vol. 21; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ADSORPTION
CARBON
CARBONIZATION
COBALT
DRYING
FORMALDEHYDE
GRAPHITE
ION EXCHANGE
NANOSTRUCTURES
NICKEL
NITROGEN
POLYMERIZATION
POTASSIUM
RESOLUTION
SURFACE AREA
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY