Bandgap tuning by lattice distortion in V and Ga doped TiO₂

Abstract

Pure and V/Ga doped TiO₂ nanoparticles are prepared by the modified sol-gel process and are investigated using TEM, XRD, Raman spectroscopy and DRS techniques. Crystallites size decreased in doped samples compared to pure TiO₂. Due to the difference in ionic radius and valence states of V and Ga, crystal structure changes locally. This structural change creates defect states which modify the bandgap. In V doped sample bandgap reduced and Urbach energy increased. Opposite behavior is observed in Ga doped sample. Hence, lower bandgap V doped TiO₂ can be used as good photocatalyst by visible light irradiation.

KEYWORDS:

• Sol-gel; TiO₂; bandgap; lattice distortion

Acknowledgments and funding

The authors are thankful to Indian Institute of Technology Indore for providing financial support and all research related facilities.