Enhancing the photocatalytic degradation of selected chlorophenols using Ag/zno nanocomposites
- PDF / 1,297,678 Bytes
- 8 Pages / 432 x 648 pts Page_size
- 20 Downloads / 217 Views
MRS Advances © 2018 Materials Research Society DOI: 10.1557/adv.2018.170
Enhancing the photocatalytic degradation of selected chlorophenols using Ag/zno nanocomposites Kate Kotlhao1, Fanyana M. Mtunzi1, Vusumzi Pakade1, Neelan Laloo2, Ikechukwu P. Ejidike1, Sekomeng J. Modise3, Richard. M. Moutloali4, Michael J. Klink1,2* 1 Department of Chemistry, Vaal University of Technology, Andries Potgieter Boulevard, Vanderbijlpark, 1911, South Africa 2 Department of Biotechnology, Vaal University of Technology, Andries Potgieter Boulevard, Vanderbijlpark, 1911, South Africa 3 Institute of Chemical and Biotechnology, Vaal University of Technology, Andries Potgieter Boulevard, Vanderbijlpark, 1911, South Africa 4 Department of Applied Chemistry, Faculty of Science, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg 2028, South Africa
Chlorophenols are among the priority listed water contaminants due to their estrogenic, mutagenic or carcinogenic health effects. The Ag/ZnO nanocomposites (NCs) were synthesized, characterized and tested for photacatalytic degradation of chlorophenols in water. The synthesis was done using zinc nitrate hexahydrate (ZnNO 3. 6H2O) precursor and sodium hydroxide (NaOH). Silver nitrate (AgNO3) was added to ZnO and reduced with sodium brohydride to produce the silver nanoparticles (NPs) within the ZnO structure. The silver content was varied from 1, 3 and 5wt% for optimisation. The nanocomposites were characterised using ultraviolet - visible spectroscopy (UV-Vis), photolumniscence (PL), x-ray diffraction (XRD), and scanning transmission electron microscopy (STEM). The nanocomposites were tested for their photocatalytic properties on 2- chlorophenol (CP), 2chlorophenol (CP) and 2,4- dichlorophenol (DCP) in water. The UV-Vis results showed that, as the amount of silver was increased a gradual slight red shift was observed. The XRD patterns for Ag/ZnO exhibited peaks that were characteristic of the hexagonal wurzite structure and peaks characteristic for Ag appeared at 38.24o, 44.37o, 64.67o and 77.58o corresponding to (111), (200), (220) and (311) reflection planes. STEM results showed the presence of Ag in ZnO with ZnO appearing as rods shapes. The EDX elemental analysis confirmed the presence of Ag in the Ag/ZnO nanocomposites with no contaminants peaks. On testing the nanocomposites for phohotocatalytic degradation of chlorophenols, addition of Ag to ZnO improved degradation of the chlorophenols compared to the pristine ZnO.
Downloaded from https://www.cambridge.org/core. Access paid by the UCSB Libraries, on 25 Mar 2018 at 07:40:15, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/adv.2018.170
Introduction ZnO nanosized semiconductor has attracted attention as an alternative to TiO 2 in degradation of organic pollutants. ZnO is relativley cheaper, and it has a comparable photocatalytic properties to TiO2. However, its photocatalytic activity is limited due to the fast recombination of the photo excited e
Data Loading...
