Preparation and photocatalytic property of phosphorus-doped TiO2 particles

Phosphorus-doped titania powders were prepared by a sol-gel method using titanium (IV) tetrabutoxide and sodium hypophosphite as starting materials. The as-prepared products were characterized by XRD, XPS, TEM and UV-vis spectroscopy. The TiO2 powders calcined at 400 degrees C for 5 h in an N2 atmosphere showed an anatase structure. The crystallinity of TiO2 was improved by calcination both in air and in N2 atmospheres. Furthermore, UV-vis spectroscopy analysis indicated that the absorption edge of the samples shifted to a longer wavelength after calcination. The XRD results suggested that phosphorus was doped into the crystal lattice of TiO2. The electronic states of phosphorus were determined by XPS, which indicated that the phosphorus in the prepared titania powders was in a lower oxidization state than the pentavalent oxidation state of phosphorus. Also, the photocatalytic activity was tested by observing the photodecomposition of methylene blue.