Selective-syntheses, characterizations and photocatalytic activities of nanocrystalline ZnTa2O6 photocatalysts

Nanocrystalline ZnTa2O6 photocatalysts with different crystal structures were prepared via a simple and facile sot-gel method in a temperature range of 650-950 degrees C. The absorption edges and particle sizes of the samples were located at about 285 nm (corresponding a band gap of 4.35 eV) and ranged from 25 to 150 nm, respectively. The photocatalytic activities of the samples were tested by the degradation of methyl orange under UV light irradiation. The results indicated that the crystal structure of ZnTa2O6 was a main factor for the different photocatalytic activities of the ZnTa2O6 samples. Moreover, the effects of crystallinities and surface areas of the obtained samples on the catalytic activities were also discussed. (C) 2011 Elsevier B.V. All rights reserved.