The Influence of the Ammonolysis Temperature on the Photocatalytic Activity of β-TaON

Phase-pure tantalum oxynitride (β-TaON) powders were synthesized by thermal ammonolysis of Ta2O5 powders. X-ray diffraction revealed an enlargement of the unit cell and an increase of the crystallite size with increasing ammonolysis temperature. Scanning electron microscopy showed reduced particle s...

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Bibliographic Details
Main Authors: Songhak Yoon, Alexandra E. Maegli, Santhosh Kumar Matam, Matthias Trottmann, Takashi Hisatomi, Céline Marie Leroy, Michael Grätzel, Simone Pokrant, Anke Weidenkaff
Format: Article
Language:English
Published: Wiley 2013-01-01
Series:International Journal of Photoenergy
Online Access:http://dx.doi.org/10.1155/2013/507194
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Summary:Phase-pure tantalum oxynitride (β-TaON) powders were synthesized by thermal ammonolysis of Ta2O5 powders. X-ray diffraction revealed an enlargement of the unit cell and an increase of the crystallite size with increasing ammonolysis temperature. Scanning electron microscopy showed reduced particle sizes for β-TaON synthesized at 800 and compared to the precursor oxide. With increasing nitridation temperature the Brunauer-Emmett-Teller surface area was reduced and the nitrogen content increased. UV-Vis spectroscopy showed a bandgap energy of 2.6–2.4 eV. The highest oxygen evolution rate of 220 μmol·g−1·h−1 was achieved for β-TaON synthesized at . The factors determining the photocatalytic activity of β-TaON powders were found to be the specific surface area and defects in the β-TaON.
ISSN:1110-662X
1687-529X