title: Magnetic semiconductor photocatalysts for the degradation of recalcitrant chemicals from flow back water.
abstract: In the present study treatability of persistent organic compounds from the flow back water after hydrauling fracturing was investigated. The combination of TiO2photocatalyst and magnetic oxide nanoparticles enhance the separation and recoverable property of nanosized TiO2photocatalyst. Fe3O4/TiO2and Fe3O4@SiO2/TiO2nanocomposites were prepared by heteroagglomeration. The photocatalysts' characteristics by X-ray diffractometry (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS) showed that sample with the mass ratio of Fe3O4to TiO2equal 1:4 and molar ratio of TEOS:Fe3O4= 8:1 and NH4OH:TEOS = 16:1 obtained by deposition TiO2P25 (Evonik) on magnetite core had about 124 m2g-1specific surface area and superparamagnetic properties. The prepared composites contained TiO2and Fe3O4crystal phases. The photocatalytic activity was estimated by measuring the decomposition rate of three model pollutants identified in the flow back water from one of the Baltic Shale Basin. Regarding flow back water treatment after shale gas exploration, the progress of photocatalytic degradation of organic compounds was measured by chemical oxygen demand (COD) concentration. The Fe3O4@SiO2/TiO2_P25 composite nanoparticles were recovered and re-used without significant reduction of efficiency.
authors.affiliation: Department of Chemical Technology, Chemical Faculty, Gdansk University of Technology (GUT), Narutowicza 11/12, 80-233 Gdansk, Poland. Electronic address: annjurek@pg.gda.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Zielińska-Jurek
authors.affiliation: Department of Chemical Technology, Chemical Faculty, Gdansk University of Technology (GUT), Narutowicza 11/12, 80-233 Gdansk, Poland.
authors.forename: Zuzanna
authors.initials: Z
authors.lastname: Bielan
authors.affiliation: Department of Chemical Technology, Chemical Faculty, Gdansk University of Technology (GUT), Narutowicza 11/12, 80-233 Gdansk, Poland.
authors.forename: Izabela
authors.initials: I
authors.lastname: Wysocka
authors.affiliation: Department of Solid State Physics, Faculty of Applied Physics and Mathematics, (GUT), Poland.
authors.forename: Judyta
authors.initials: J
authors.lastname: Strychalska
authors.affiliation: Department of Chemical Technology, Chemical Faculty, Gdansk University of Technology (GUT), Narutowicza 11/12, 80-233 Gdansk, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Janczarek
authors.affiliation: Department of Solid State Physics, Faculty of Applied Physics and Mathematics, (GUT), Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Klimczuk
mesh_terms: D002384:Catalysis; D053761:Nanocomposites / Q000737:chemistry; D012666:Semiconductors; D012822:Silicon Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D018508:Water Purification
chemical_list: D012822:Silicon Dioxide; D014025:Titanium
keywords: Fe(3)O(4)/TiO(2) nanocomposites; Flow back water; Heterogenous photocatalysis; Magnetic nanoparticles; Titanium (IV) oxide