title: [Low-temperature preparation of TiO2/PS/Fe3O4, and its photocatalytic activity and magnetic recovery].
abstract: This study reports the fabrication of magnetically responsive titania catalyst, which consisted of a magnetic core surrounded by a titania shell. The magnetic core (oleic acid-modified Fe3O4 nanoparticles) was modified with polystyrene as inert isolating layer. The magnetic photocatalyst was prepared at low temperature (90 degrees C) and a neutral pH (about 7). The phase composition, morphology, surface properties and magnetic properties of the composite particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier infrared photometer (FT-IR) and vibrating sample magnetometer (VSM). The photocatalytic activity of the samples were determined by degradation of phenol and their recovery characteristics were determined by a self-regulating magnetic recycling equipment. The results illustrated that the mean diameter of anatase titanium dioxide synthesized at low temperature was 2-5 nm, the catalyst TiO2/PS/Fe3O4 [the molar ratio of the magnetic photocatalyst was n(TiO2): n(St): n(Fe3O4) = 60:2.5:1] had the structural integrity of shell/shell/core, and titanium dioxide was loaded firmly on the PS/FeO4 surface. The photocatalytic degradation of phenol followed first-order reaction kinetics and the reaction rate constant K of the TiO2/PS/Fe3O4 [n(TiO2): n(St): n (Fe3O4) = 60:2.5:1] was 0.0258, which was close to that of pure TiO2 (K = 0.0262). After 5 times recycling, the K value reduced only by 0.0034. The catalyst had a strong magnetic induction, and the average recovery rate reached 92%. The magnetic TiO2 photocatalyst prepared by this low-temperature hydrolysis method has a good application prospect.
authors.affiliation: Engineering Research Center for Cold and Arid Regions Water Resource Comperehensive Utilization of the Ministry of Education, School of Environmental & Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China. xiaopihaixuejiao@163.com
authors.forename: Xue-jiao
authors.initials: XJ
authors.lastname: Wang
authors.forename: Xue-chang
authors.initials: XC
authors.lastname: Ren
authors.forename: Juan-ni
authors.initials: JN
authors.lastname: Nian
authors.forename: Ju-qian
authors.initials: JQ
authors.lastname: Xiao
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Chang
mesh_terms: D002384:Catalysis; D003080:Cold Temperature; D003198:Computer Simulation; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D008027:Light; D059346:Magnets; D053768:Metal Nanoparticles / Q000737:chemistry*; D019800:Phenol / Q000302:isolation & purification; D055668:Photochemical Processes; D011137:Polystyrenes / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D011137:Polystyrenes; C009495:titanium dioxide; D019800:Phenol; D014025:Titanium; D052203:Ferrosoferric Oxide