Effects of V doping and calcination temperature on the phase evolution of Ti-V-O nanoparticles synthesized by coprecipitation method

Abstract

Ti-V-O nanoparticles were produced by coprecipitation process using TiCl₄ and VOCl₃ as starting materials. The precipitates were calcined into different phases of a mixture of Ti-V-O oxides. The effects of V content and calcination temperature (500∼700°C) on the phase transition of the mixture of crystalline Ti-V-O oxides were studied. Increasing V addition and calcination temperature promotes the transformation of Ti-V-O oxides from anatase to rutile phase. Based on TG/DTA analysis, the reduction from V⁵⁺ to V⁴⁺ was observed in the V-rich samples at 730°C. The V⁵⁺ may exist as the form of V₂O₅ homogeneously dispersed within crystalline of TiO₂, while V⁴⁺ is possible in the octahedral lattice of TiO₂. A significant portion of vanadium ions can be incorporated at 730°C into TiO₂ lattice resulting in rutile Ti_1−xV_xO₂ solid solution formation.