Synthesis of Au nanoclusters supported upon a TiO 2 nanotube array
- PDF / 998,988 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 35 Downloads / 173 Views
Andrei Kolmakov Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-5080
Sung-Hyeon Baeck Department of Chemical Engineering, Inha University, Incheon, Korea 402-751
Martin Moskovits and Galen D. Stucky Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-5080
Eric W. McFarlanda) Department of Chemical Engineering, University of California, Santa Barbara, California 93106-5080 (Received 5 January 2005; accepted 18 February 2005)
Gold nanoclusters were successfully deposited in the interior of TiO2 nanotubes fabricated as ordered arrays. This approach is a useful fabrication platform for miniature planar fuel cells, gas sensors, and heterogeneous catalysts. A pressure impregnation process was used to inject the titania and Au precursors into mesoporous alumina. After thermal treatment, Au nanoclusters were well-dispersed on the interior walls of nanotubular TiO2. The TiO2 nanotubes were shown by x-ray diffraction to be entirely anatase. Transmission electron microscopy imaging confirmed that 80% of the Au particles were 4.1 nm ± 2.0 nm in diameter. This material exhibited catalytic CO oxidation activity at low temperatures.
Because of titania’s biocompatibility, low cost, and its ability to photochemically catalyze a large variety of redox reactions with ultraviolet (UV) light and even sunlight, this wide-bandgap semiconductor has been extensively used on an industrial scale for water and air purification, mineralizing organic compounds to CO2, destroying viruses and bacteria, and isolating toxic metal ions from waste lines.1,2 In the last three decades, a large number of methods (including sol-gel, Ti metal oxidation, and chemical vapor deposition) have been used to synthesize titania with morphologies specific to particular technological needs.3–5 For many applications including catalysis, chemi- (bio-) sensing, fuel cells, chemi(bio-) filtering, and dye-sensitized solar cells, titania must have a high surface area and be highly permeable to both reactants and/or photons. To address the need for creating a heterogeneous catalyst, we report a facile approach toward fabricating high surface area, nanotubular TiO2 films impregnated with metal nanoparticles.
a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/JMR.2005.0170 J. Mater. Res., Vol. 20, No. 5, May 2005
Several methods have been developed to introduce nanoclusters inside a nanoporous matrix. Dag et al. utilized chemical vapor deposition (CVD) to prepare photoluminescent Si clusters within the hexagonal channels of a mesoporous silica film.6 Overbury et al. synthesized Au nanoparticles within mesoporous silica and mesoporous titania, utilizing a co-assembly approach for the former and deposition-precipitation (DP) in the case of the latter.7 Fan et al. synthesized a three-dimensional (3D) array of Au nanoparticles within mesoporous silica in a one-step process directed by the self-assembly of water soluble nanocrysta
Data Loading...
