Ti1 - xVxO2 (x = 0.0-0.10) nanopowders were successfully synthesized by a microwave-assisted sol-gel technique and their crystal structure and electronic structure were investigated. The products were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and UV-Vis spectroscopy. The results revealed that TiO2 powders maintained the anatase phase for calcination temperature below 600 °C, but gradually changed to the rutile phase above 800 °C. The formation of the rutile phase was completed at 1000 °C. For Ti 1 - xVxO2 (x = 0.05) powders, the phase transformation appeared at 600 °C. The absorption edge of Ti 1 - xVxO2 (x > 0) powders broadened to the visible region with increasing V concentration and a strong visible light absorption was obtained with 10% V doping. V doping and subsequent coexistence of both anatase and rutile phases in our Ti1 - xVxO 2 nanoparticles are considered to be responsible for the enhanced absorption of visible light up to 800 nm.
Bibliographical noteFunding Information:
The authors would like to thank the key project QGTD. 10.29 of Vietnam National University , Ha noi; Vietnam's National Foundation for Science and Technology Development (NAFOSTED), grant 103.02.2010.04 and the National Research Foundation of Korea Grant 2009-0063320 for the financial support.
- Microwave-assisted synthesis
- TiVO nanopowders