Structure, Morphology, and Band Gap of Ti-V-O Mixed Oxides Processed by Coprecipitation and Calcination

Mixed oxides of Ti-V-O were co-precipitated by wet process using TiCl4 and VOCl3 as starting materials. As-precipitated gels were calcinated at 800 ◦C for 4 hours in oxygen atmosphere. Effects of vanadium content on the structural evolution, morphology, and band gap of Ti-V-O oxides were investigated. Calcination has produced mixtures of TiO2/VO2/V2O5 oxides and has allowed formation of Ti1−xVxO2. Lattice parameters of rutile TiO2 were precisely measured to investigate vanadium substitution into single rutile phase of Ti1−xVxO2 with varying vanadium content. As vanadium addition was increased, particles were coarsening rapidly during calcination. Band gap of the Ti-V-O oxides was measured using ultraviolet visible light spectrometer. A decrease of band gap down to 1.7 eV with the addition of maximum of 10 at.% of vanadium was measured, which is due to the formation of single phase of Ti1−xVxO2 as well as the formation of metallic VO2 or V2O5 particles.