Influence of La~(3+) and Fe~(3+) co-doping to nano-TiO_2 prepared by graded calcination

摘要

The un-doping, single-doping and co-doping TiO_2 nanoparticles have been prepared through the graded calcination method with Ti(OC_4H_9)_4 as raw material and characterized by X-ray diffraction (XRD) and UV-vis reflection spectra. Their photocatalytic activities have been investigated by the photocatalytic oxidation of methyl orange. It is indicated that Fe~(3+)-doping makes the reflection profile narrow, improves photoutilization of TiO_2, and then generates more electron-hole pairs. La~(3+)-doping restrains the increase of grain size, leads to crystal expansion plus matrix distortion and retards the recombination of the photoexcited charge carriers. The photocatalytic activity of TiO_2 co-doped with La~(3+) and Fe~(3+) is notably improved due to the cooperative actions of the two dopants.