title: Efficient photocatalytic degradation of organic pollutants by magnetically recoverable nitrogen-doped TiO2 nanocomposite photocatalysts under visible light irradiation.
abstract: Preparation of novel nanocomposite particles (NCPs) with high visible-light-driven photocatalytic activity and possessing recovery potential after advanced oxidation process (AOP) is much desired. In this study, pure anatase phase titania (TiO2) nanoparticles (NPs) as well as three types of NCPs including nitrogen-doped titania (TiO2-N), titania-coated magnetic silica (Fe3O4 cluster@SiO2@TiO2 (FST)), and a novel magnetically recoverable TiO2 nanocomposite photocatalyst containing nitrogen element (Fe3O4 cluster@SiO2@TiO2-N (FST-N)) were successfully synthesized via a sol-gel process. The photocatalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM) with an energy-dispersive X-ray (EDX) spectroscopy analysis, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). The photocatalytic activity of as-prepared samples was further investigated and compared with each other by degradation of phenol, as a model for the organic pollutants, in deionized (DI) water under visible light irradiation. The TiO2-N (55 ± 1.5%) and FST-N (46 ± 1.5%) samples exhibited efficient photocatalytic activity in terms of phenol degradation under visible light irradiation, while undoped samples were almost inactive under same operating conditions. Moreover, the effects of key operational parameters, the optimum sample calcination temperature, and reusability of FST-N NCPs were evaluated. Under optimum conditions (calcination temperature of 400 °C and near-neutral reaction medium), the obtained results revealed efficient degradation of phenol for FST-N NCPs under visible light irradiation (46 ± 1.5%), high yield magnetic separation and efficient reusability of FST-N NCPs (88.88% of its initial value) over 10 times reuse.
authors.affiliation: School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran, P.O. Box: 11365-4563.
authors.forename: Sahar
authors.initials: S
authors.lastname: Hamzezadeh-Nakhjavani
authors.affiliation: School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran, P.O. Box: 11365-4563. otavakoli@ut.ac.ir.
authors.forename: Omid
authors.initials: O
authors.lastname: Tavakoli
authors.affiliation: School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran, P.O. Box: 11365-4563.
authors.forename: Seyed Parham
authors.initials: SP
authors.lastname: Akhlaghi
authors.affiliation: School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran, P.O. Box: 11365-4563.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Salehi
authors.affiliation: Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, P.O. Box: 14965-161, Tehran, Iran.
authors.forename: Parvaneh
authors.initials: P
authors.lastname: Esmailnejad-Ahranjani
authors.affiliation: Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, P.O. Box: 14965-161, Tehran, Iran. arpanaei@yahoo.com.
authors.forename: Ayyoob
authors.initials: A
authors.lastname: Arpanaei
mesh_terms: D002384:Catalysis; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D008027:Light; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D009584:Nitrogen / Q000737:chemistry*; D019800:Phenol / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: C507641:TiO2-SiO2; D014874:Water Pollutants, Chemical; D014867:Water; C009495:titanium dioxide; D019800:Phenol; D012822:Silicon Dioxide; D014025:Titanium; D009584:Nitrogen; D052203:Ferrosoferric Oxide
keywords: Core/shell nanocomposite particles; Magnetic separation; Nitrogen-doping; Organic pollutants; Photocatalytic degradation; Titania; Visible light