title: Rapid photo-degradation of 2-chlorophenol under visible light irradiation using cobalt oxide-loaded TiO2/reduced graphene oxide nanocomposite from aqueous media.
abstract: The photocatalytic removal of 2-chlorophenol (2-CP) from water environment was investigated by TiO2-RGO-CoO. Cobalt oxide-loaded TiO2 (TiO2-CoO) supported with reduced graphene oxide (RGO) was synthesized using a sol-gel method and then annealed at 500 °C for 5 min. The material characteristics were analyzed by UV-Vis analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. Incorporation of cobalt oxide and RGO into the TiO2 system (TiO2-RGO-CoO) lowered the band gap energy to 2.83 eV, which greatly enhanced the visible light absorption. The TiO2-RGO-CoO photocatalyst showed complete removal of 20 mg/L 2-CP within 8 h with the addition of 0.01% H2O2 under 100 W visible light irradiation. The photo-degradation efficiency of 2-CP (10 mg/L) was 35.2, 48.9, 58.9 and 98.2% for TiO2, TiO2-RGO, TiO2-CoO and TiO2-RGO-CoO, respectively, in the presence of visible light irradiation at solution pH of 6.0. The TiO2-RGO-CoO photocatalyst retained its high removal efficiency even after five photocatalytic cycles.
authors.affiliation: Department of Civil and Environmental Engineering, University of Ulsan, Nam-gu, Daehak ro 93, Ulsan 680-749, Republic of Korea.
authors.forename: Ajit
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Department of Civil and Environmental Engineering, University of Ulsan, Nam-gu, Daehak ro 93, Ulsan 680-749, Republic of Korea. Electronic address: bklee@ulsan.ac.kr.
authors.forename: Byeong-Kyu
authors.initials: BK
authors.lastname: Lee
mesh_terms: D002384:Catalysis; D002733:Chlorophenols / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008027:Light; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D010777:Photochemistry / Q000379:methods*; D056951:Photoelectron Spectroscopy; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D002733:Chlorophenols; D010087:Oxides; D014874:Water Pollutants, Chemical; D014867:Water; C009495:titanium dioxide; D003035:Cobalt; D006108:Graphite; D006861:Hydrogen Peroxide; D014025:Titanium; C030683:2-chlorophenol; C060728:cobalt oxide
keywords: 2-Chlorophenol; Dopant; Kinetics; Photocatalysis; Regeneration