Influence of Fe~(3+) and Ho~(3+) co-doping on the photocatalytic activity of TiO_2

摘要

The un-doping, single-doping and co-doping TiO_2 nanoparticles have been prepared by sol-gel method with Ti(OC_4H_9)_4 as a raw material and characterized by X-ray diffraction (XRD) and UV-vis absorption spectra, and their photocatalytic activities have been investigated by photocatalytic oxidation of methyl orange. It is found that Fe~(3+)-doping broadens the absorption profile, improves photoutilization of TiO_2, and then generates more electron-hole pairs. Ho~(3+)-doping restrains the increase of grain size, leads to crystal expansion and matrix distortion and retards the recombination of the photoexcited charge carriers. The photocatalytic activity of TiO_2 co-doped with Fe~(3+) and Ho~(3+) ions is markedly improved due to the cooperative actions of the two dopants.