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. © 2018, © 2018 Taylor & Francis Group, LLC.