Influence of niobium doping on the phase selection in plasma-synthesized TiO₂ nanoparticles

Abstract

High-concentration niobium (V)-doped TiO2 nanoparticles of the non-equilibrium chemical composition have been synthesized via Ar/O2 radio-frequency thermal plasma oxidation of mist precursor solutions, with various Nb5+ concentrations (Nb/(Ti+Nb)=0–0.25.0). The solubility as high as ~25.0 at.% has not been achieved before by wet-chemical techniques. The preferable anatase formation was attained in the plasma-synthesized powders, and was enhanced by the niobium doping. The transformation from anatase to rutile was effectively inhibited with increasing the Nb5+ content.