http://repository.iitr.ac.in/handle/123456789/2824
Title: | Enhancing photocatalytic degradation of quinoline by ZnO:TiO2 mixed oxide: Optimization of operating parameters and mechanistic study |
Authors: | Gupta D. Chauhan R. Kumar N. Singh V. Srivastava, Vimal Chandra Mohanty, Paritosh Mandal, Tapas Kumar |
Published in: | Journal of Environmental Management |
Abstract: | This study focuses on the photocatalytic degradation of quinoline, a recalcitrant heterocyclic nitrogenous aromatic organic compound, using the mixed oxide ZnO–TiO2 photo-catalyst. Photo-catalysts were synthesized by the solid-state reaction method at different calcination temperatures of 400 °C, 600 °C, and 800 °C. Different analytical methods, including Field emission scanning electron microscope, Brunauer-Emmett-Teller surface area, X-ray diffraction, UV–vis diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy analysis were used for the catalyst characterization. The highest pore surface area of 57.9 m2g?1 was obtained for the photo-catalyst calcined at 400 °C. The effects of calcination temperature, solution pH, initial concentration, catalyst dose as well as irradiation time were studied. At the optimum condition, i.e., calcination temperature of 400 °C, pH ?8 and catalyst dose of 2.5 gL?1, maximum quinoline degradation and total organic carbon (TOC) removal efficiency of ?92% and ?78% were obtained after 240 min for initial quinoline amount of 50 mgL?1. The 1st, 2nd , and nth-order kinetic models were applied to analyze the quinoline degradation rate. The photocatalytic mechanism was studied by drawing energy level diagram with the help of the band-gap structures of the ZnO and TiO2, potential of the free radicals like [rad]OH and [rad]O2 and HOMO-LUMO energy gap of the quinoline molecule. The proposed pathways of quinoline mineralization were suggested on the basis of the identified intermediates by the gas chromatograph-mass spectrometer analysis and scavenger study. © 2019 Elsevier Ltd |
Citation: | Journal of Environmental Management (2020), 258(): - |
URI: | https://doi.org/10.1016/j.jenvman.2019.110032 http://repository.iitr.ac.in/handle/123456789/2824 |
Issue Date: | 2020 |
Publisher: | Academic Press |
Keywords: | Energy level Mineralization pathway Photo-catalysis Quinoline degradation ZnO:TiO2 mixed oxide |
ISSN: | 3014797 |
Author Scopus IDs: | 57212765054 57197047692 57203728717 57213256302 35565811700 55930648500 57200780613 |
Author Affiliations: | Gupta, D., Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Chauhan, R., Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Kumar, N., Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Singh, V., Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Srivastava, V.C., Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Mohanty, P., Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Mandal, T.K., Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India |
Corresponding Author: | Srivastava, V.C.; Department of Chemical Engineering, Indian Institute of Technology RoorkeeIndia; email: vimalcsr@yahoo.co.in |
Appears in Collections: | Journal Publications [CH] Journal Publications [CY] |
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