title: Photocatalytic activity of Ho-doped anatase titanium dioxide coated magnetite.
abstract: A composite photocatalyst (Ho/TiO(2)/Fe(3)O(4)) with Ho-doped anatase titanium dioxide (Ho/TiO(2)) shell and a magnetite core was prepared by coating photoactive Ho/TiO(2) onto a magnetic Fe(3)O(4) core through the hydrolysis of tetrabutyltitanate (Ti(OBu)(4), TBT) in water/oil (w/o) microemulsion with precursors of Ho(NO(3))(3) and TBT in the presence of Fe(3)O(4) nanoparticles. The morphological, structural and optical properties of the prepared samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis diffusive reflectance spectroscopy (UV-Vis DRS). The effect of Ho ion content on the photocatalytic activity was studied. The photodegradation behavior of the prepared photocatalyst under UV and visible light was investigated in aqueous solution using methyl orange (MO) as target pollutant. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photo-oxidation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, Ho/TiO(2) was tightly bound to Fe(3)O(4) and could be easily recovered from the medium by a simple magnetic process. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.
authors.affiliation: School of Applied Chemistry, Shenyang University of Chemical Technology, Shenyang, China.
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Shi
authors.forename: Yongfang
authors.initials: Y
authors.lastname: Xiang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Shuhua
authors.initials: S
authors.lastname: Yao
mesh_terms: D001391:Azo Compounds / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis / Q000528:radiation effects*; D052203:Ferrosoferric Oxide / Q000737:chemistry / Q000378:metabolism*; D006695:Holmium / Q000737:chemistry*; D006868:Hydrolysis / Q000528:radiation effects; D008027:Light; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction / Q000528:radiation effects; D055668:Photochemical Processes / Q000528:radiation effects; D010782:Photolysis / Q000528:radiation effects*; D013057:Spectrum Analysis; D014025:Titanium / Q000737:chemistry; D014877:Water Pollution, Chemical / Q000517:prevention & control; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D001391:Azo Compounds; C009495:titanium dioxide; C100258:methyl orange; D014025:Titanium; D006695:Holmium; D052203:Ferrosoferric Oxide