Growth and characterization of ceria thin films and Ce-doped γ - Al 2 O 3 nanowires using sol-gel techniques
Date
2010Author
Gravani, S.Polychronopoulou, K.
Stolojan, V.
Cui, Q.
Gibson, P. N.
Hinder, S. J.
Gu, Z.
Doumanidis, C. C.
Baker, M. A.
Rebholz, Claus
Source
NanotechnologyVolume
21Google Scholar check
Metadata
Show full item recordAbstract
γ - Al 2 O 3 is a well known catalyst support. The addition of Ce to γ - Al 2 O 3 is known to beneficially retard the phase transformation of γ - Al 2 O 3 to α - Al 2 O 3 and stabilize the γ-pore structure. In this work, Ce-doped γ - Al 2 O 3 nanowires have been prepared by a novel method employing an anodic aluminium oxide (AAO) template in a 0.01 M cerium nitrate solution, assisted by urea hydrolysis. Calcination at 500 °C for 6 h resulted in the crystallization of the Ce-doped AlOOH gel to form Ce-doped γ - Al 2 O 3 nanowires. Ce 3 + ions within the nanowires were present at a concentration of < 1 at.%. On the template surface, a nanocrystalline CeO 2 thin film was deposited with a cubic fluorite structure and a crystallite size of 6–7 nm. Characterization of the nanowires and thin films was performed using scanning electron microscopy, transmission electron microscopy, electron energy loss spectroscopy, x-ray photoelectron spectroscopy and x-ray diffraction. The nanowire formation mechanism and urea hydrolysis kinetics are discussed in terms of the pH evolution during the reaction. The Ce-doped γ - Al 2 O 3 nanowires are likely to find useful applications in catalysis and this novel method can be exploited further for doping alumina nanowires with other rare earth elements.