title: Integrated ternary nanocomposite of TiO2/NiO/reduced graphene oxide as a visible light photocatalyst for efficient degradation of o-chlorophenol.
abstract: This study investigated a novel approach for the synthesis of an integrated ternary nanocomposite which could act as a good photo-catalyst under visible light irradiation for the removal of organic pollutants from aqueous environments. The photo-catalyst included nickel oxide (NiO) as a dopant, and reduced graphene oxide (RGO) as a good carbon basal support for enhancement of the photo-catalytic activity of TiO2. Under irradiation with visible light, the ternary nanocomposite (TiO2/NiO-RGO) system generates e(-)/h(+) pairs, and then reacts with H2O and O2(-) molecules to produce oxy-radicals which can be used for the mineralization of o-chlorophenol from aqueous solution. The characteristic of all photo-catalysts were investigated by UV-Vis analysis, with surface area and pore size measurements by Brunauer-Emmett-Teller (BET), crystallinity by X-ray diffraction (XRD), elemental composition by X-ray photoelectron spectroscopy (XPS), and morphology by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). The functional groups were measured by Fourier transform infrared (FT-IR) spectroscopy before and after o-chlorophenol degradation. TiO2/NiO-RGO was capable of achieving 88.4% photo-degradation of 100 mg/L o-chlorophenol (100 mL) within 8 h with addition of 0.01% H2O2 under visible light irradiation at pH 6.5. The photo-degradation followed a pseudo-first-order reaction. The TiO2/NiO-RGO nanocomposite retained its high removal efficiency, even after four photo-catalytic 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*; D006108:Graphite / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008027:Light; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D002733:Chlorophenols; D010087:Oxides; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D006108:Graphite; D009532:Nickel; D006861:Hydrogen Peroxide; C028007:nickel monoxide; D014025:Titanium; C030683:2-chlorophenol
keywords: Efficiency; Photo-degradation; Regeneration; Visible light; o-chlorophenol