Preparation of gold/titania core-shell nanocomposites with a tunable shell thickness.
Gold/titania nanocomposites with a core-shell structure were prepared by sol-gel reaction of titanium tetrabutoxide (TTBO) with gold nanoparticles, core-stabilized with cetyltrimethylammonium bromide (CTAB), using a ternary mixture of alcohol/acetonitrile/water as solvent. TEM characterization of the resulting constructs revealed spherical nanocomposites, each containing a single gold core. The mean diameter of the gold cores was 13 nm, while the thicknesses of titania shells were readily tuned in the range 4-30 nm by varying the alkyl chain length of the alcohol. In addition, the gold nanoparticles exhibited a deep red color, with an intense extinction peak at 527 nm, owing to their surface plasmon resonance (SPR) properties. When the Au nanoparticles were coated with a titania shell, their color changed to purple and the SPR peak shifted to a higher wavelength of 537 nm. Furthermore, the core-shell nanocomposites were found to display photocatalytic activity for the oxidation of 2-propanol under illumination by visible light (λ=500-560 nm).
Faculty of Science and Technology, Tokyo University of Science.
Takashi
T
Kanda
Kazuyoshi
K
Komata
Kanjiro
K
Torigoe
Takeshi
T
Endo
Kenichi
K
Sakai
Masahiko
M
Abe
Hideki
H
Sakai
D019840:2-Propanol / Q000737:chemistry; D000097:Acetonitriles; D000438:Alcohols; D000440:Butanols / Q000737:chemistry; D002384:Catalysis; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008027:Light; D008029:Lighting; D053768:Metal Nanoparticles; D053761:Nanocomposites; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D020349:Surface Plasmon Resonance; D014025:Titanium / Q000737:chemistry*; D014867:Water
D000097:Acetonitriles; D000438:Alcohols; D000440:Butanols; D002593:Cetrimonium Compounds; D009942:Organometallic Compounds; D014867:Water; C009495:titanium dioxide; C060171:tetrabutoxy titanium; D006046:Gold; D014025:Titanium; D019840:2-Propanol; C032159:acetonitrile; D000077286:Cetrimonium