title: Comparison study on photocatalytic oxidation of pharmaceuticals by TiO2-Fe and TiO2-reduced graphene oxide nanocomposites immobilized on optical fibers.
abstract: Incorporating reduced graphene oxide (rGO) or Fe3+ions in TiO2photocatalyst could enhance photocatalytic degradation of organic contaminants in aqueous solutions. This study characterized the photocatalytic activities of TiO2-Fe and TiO2-rGO nanocomposites immobilized on optical fibers synthesized by polymer assisted hydrothermal deposition method. The photocatalysts presented a mixture phase of anatase and rutile in the TiO2-rGO and TiO2-Fe nanocomposites. Doping Fe into TiO2particles (2.40eV) could reduce more band gap energy than incorporating rGO (2.85eV), thereby enhancing utilization efficiency of visible light. Incorporating Fe and rGO in TiO2decreased significantly the intensity of TiO2photoluminescence signals and enhanced the separation rate of photo-induced charge carriers. Photocatalytic performance of the synthesized nanocomposites was measured by the degradation of three pharmaceuticals under UV and visible light irradiation, including carbamazepine, ibuprofen, and sulfamethoxazole. TiO2-rGO exhibited higher photocatalytic activity for the degradation of pharmaceuticals under UV irradiation, while TiO2-Fe demonstrated more suitable for visible light oxidation. The results suggested that the enhanced photocatalytic performance of TiO2-rGO could be attributed to reduced recombination rate of photoexcited electrons-hole pairs, but for TiO2-Fe nanocomposite, narrower band gap would contribute to increased photocatalytic activity.
authors.affiliation: Department of Civil Engineering, New Mexico State University, 3035 S Espina Street, Las Cruces, NM 88003, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Civil Engineering, New Mexico State University, 3035 S Espina Street, Las Cruces, NM 88003, USA. Electronic address: huiyao@nmsu.edu.
authors.forename: Huiyao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Civil Engineering, New Mexico State University, 3035 S Espina Street, Las Cruces, NM 88003, USA.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Department of Civil Engineering, New Mexico State University, 3035 S Espina Street, Las Cruces, NM 88003, USA.
authors.forename: Ahmed Radhi
authors.initials: AR
authors.lastname: Mkaouar
authors.affiliation: Department of Civil Engineering, New Mexico State University, 3035 S Espina Street, Las Cruces, NM 88003, USA. Electronic address: pxu@nmsu.edu.
authors.forename: Pei
authors.initials: P
authors.lastname: Xu
mesh_terms: D002220:Carbamazepine / Q000737:chemistry; D002384:Catalysis; D006108:Graphite / Q000737:chemistry*; D007052:Ibuprofen / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D008027:Light; D053761:Nanocomposites / Q000737:chemistry*; D055100:Optical Fibers; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D010782:Photolysis; D013420:Sulfamethoxazole / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D010087:Oxides; D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002220:Carbamazepine; D006108:Graphite; D014025:Titanium; D007501:Iron; D013420:Sulfamethoxazole; D007052:Ibuprofen
keywords: Pharmaceuticals; Photocatalyst; Photocatalytic oxidation; TiO(2)-Fe; TiO(2)-reduced graphene oxide