Hydrothermal synthesis, structure and photocatalytic activity of PF-co-doped TiO2
Faculty of Sciences. Chemistry
Materials science in semiconductor processing. - Oxford
, p. 442-450
University of Antwerp
A series of PF-co-doped titanium dioxide (PF-TiO2) samples with various PF contents were synthesized hydrothermally at 250 degrees C and systematically investigated by means of X-ray diffraction, X-ray photoelectron spectroscopy and electron microscopy. For the PF-codoping of TiO2, hexafluorophosphoric acid (HPF6) was used. Increasing HPF6 concentration did not decrease the crystallinity of the synthesized samples, but the dopant concentration strongly influenced the size and morphology of the PF-TiO2 nanoparticles. The undoped TiO2 consisted of polymorphic and polydisperse nanoparticles, whereas smaller, predominantly spherical particles were observed for the PF-TiO2 samples. Diffuse reflectance UV-vis spectroscopy revealed that PF-TiO2 exhibited a slightly higher band gap energy than that of undoped TiO2. Despite this blue-shift in absorption edge, the photocatalytic activity of PF-TiO2 was higher than that of undoped TiO2 even under visible light irradiation. The effects of the dopant concentration on the structure and photocatalytic activity are discussed in detail. (C) 2014 Elsevier Ltd. All rights reserved.