Hydrogen-induced Ostwald ripening of cobalt nanoparticles on carbon nanotubes
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Nanoparticles on carbon nanotubes can be used as a high surface area catalyst or as a means to produce well-defined particles. In this study, cobalt nanoparticles were formed on xxsingle-walled carbon nanotubes during hydrogen exposure at an elevated temperature. The average particle size increased as a function of reaction time ranging from 1.5 to 40 nm, indicating hydrogen-induced Ostwald ripening which is remarkable for a nonhydrogen-absorbing material. Mass abundances and cobalt shells were observed which possibly contained hydrogen. The combination of large surface area, high atomic mobility, and hydrogen-induced Ostwald ripening resulted in a novel method to prepare various cobalt nanoparticle shapes and sizes.
KeywordsCobalt Nanoparticle Hydrogen Carbon nanotube, magic number Ostwald ripening Nanocomposites
The authors thank the National Science Foundation (NSF CBET-0828771) and AFOSR MURI (FA9550-08-1-0309) for financial support. Electron microscopy on the T20 was accomplished at the Electron Microscopy Center for Materials Research at Argonne National Laboratory, the U.S. Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357 by UChicago Argonne, LLC. TEM assistance by R. E. Cook is appreciated by the authors.
- Aceto S, Chang CY, Vook RW (1992) Hillock growth on aluminum and aluminum alloy films. Thin Solid Films 219(80):86Google Scholar
- Cbaiken J, Casey M, Villarica M (1992) Laser chemistry of organometallics as a general synthetic route to metal clusters. J Phys Chem 96:3185Google Scholar
- Jorio A, Fantini C, de Souza M, Saito R, Samsonidze GG, Dresselhaus G, Dresselhaus MS, Pimenta MA (2004) Raman on carbon nanotubes using a tunable laser and comparison with photoluminescence. In: Kuzmany H, Fink J, Mehring M, Roth S (eds) Electronic Properties of synthetic nanoparticle structures, American Institute of Physics conference proceeding, pp 157–162Google Scholar
- Natl. Bur. Stand. (US) (1960) Circulation 539:9–28 Google Scholar
- Ostwald W (1900) On the assumed isomerism of red and yellow mercury oxide and the surface-tension of solid bodies. Z Phys Chem (Leipzig) 34:495–503Google Scholar
- Palasantzas G, Koch SA, Vystavel T, De Hosson JTM (2005) Nano-sized cobalt cluster films: structure and functionality. Adv Eng Mater 7:21–25Google Scholar
- Pan GZ, Tu KN, Prussin A (1996) Size-distribution and annealing behavior of end-of-range dislocation loops in silicon-implanted silicon. J Appl Phys 81:1Google Scholar
- Patterson AL (1939) The Scherrer formula for x-ray particle size determination. Phys Rev Lett 56:978–982Google Scholar
- Schober T, Bechthold PS (1994) Hydrogen blisters on beta-NbD after laser pulse heating. J Appl Phys 76:2093–2096Google Scholar
- Smigelskas AD, Kirkendall EO (1947) Zinc diffusion in alpha-brass. Trans AIME 171:130–142Google Scholar