43Influence of niobium doping on phase composition and defect-mediated photoluminescence properties of Eu~(3+)-doped TiO_2 nanopowders synthesized in Ar/O_2 thermal plasma

摘要

Nb~(5+):Eu~(3+)-codoped TiO_2 nanopowders for chemical composition adjustment have been synthesized via Ar/O_2 radio-frequency thermal plasma. X-ray diffraction (XRD) results reveal that all the resultant powders exhibited mixture polymorphs of anatase (mean size: ~45 nm) as the major phase and rutile (mean size: ~71 nm). Rutile formation was promoted by the Eu~(3+) doping but suppressed by the Nb~(5+) addition. Combined observation using FE-SEM and TEM indicates that all the plasma-synthesized powders had a majority of facet-shaped particles (several nanometers) and a small proportion of nearly spherical crystals (~150 nm).