Fe-doped TiO_2 nanopowders by oxidative pyrolysis of organometallic precursors in induction thermal plasma: synthesis and structural characterization

摘要

Undoped and Fe-doped TiO_2 ultrafine powders with dopant concentration ranging from 0.05% up to 20% (Fe/Ti atomic ratio) have been readily fabricated by induction thermal plasma processing through the oxidative pyrolysis of organometallic precursors dissolved in ethanol in an attempt to obtain high-performance photocatalyst. Energy dispersive spectroscopy (EDS) investigation indicates that the Fe/Ti atomic ratios can be kept in the solution precursors. The synthesized powders consist of spherical particles with mean size of about 40 nm. No other phases but anatase and rutile are identified in the synthesized ultrafine powders. Iron doping remarkably prompts the preference of TiO_2 phase formation for rutile to anatase, suggesting that iron ions are prone to be doped in rutile structure. Upon iron doping, the absorption edge shifts to visible light region as indicated by diffuse reflectance UV-Vis spectra.