Novel Ag-ZnO-La2O2CO3 photocatalysts derived from the Layered Double Hydroxide structure with excellent photocatalytic performance for the degradation of pharmaceutical compounds

The experimental results show that the highest photocatalytic activity was obtained from the Ag (5) doped Zn-0.75Al-0.25La-CO3 photocatalysts calcined at 500 0C with a degradation efficiency of 99,4 after 40 min of irradiation only. This study could provide a new route for the fabrication of high performance photocatalysts and facilitate their application in the environmental remediation issues.
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Novel Ag-ZnO-La2O2CO3 photocatalysts derived from the Layered Double Hydroxide structure with excellent photocatalytic performance for the degradation of pharmaceutical compounds Journal of Science: Advanced Materials and Devices 4 (2019) 34e46 Contents lists available at ScienceDirect Journal of Science: Advanced Materials and Devices journal homepage: www.elsevier.com/locate/jsamdOriginal ArticleNovel Ag-ZnO-La2O2CO3 photocatalysts derived from the LayeredDouble Hydroxide structure with excellent photocatalyticperformance for the degradation of pharmaceutical compoundsA. Elhalil a, *, R. Elmoubarki a, M. Farnane a, A. Machrouhi a, F.Z. Mahjoubi b, M. Sadiq a,S. Qourzal c, M. Abdennouri a, N. Barka aa Laboratoire des Sciences des Mat eriaux, des Milieux et de la Mod elisation, Universit e Sultan Moulay Slimane, F.P. Khouribga, B.P. 145, 25000, Khouribga,Moroccob Universit e Sultan Moulay Slimane, Faculte des Sciences et Techniques, B eni Mellal, Laboratoire de Spectro-chimie Appliquee et Environnement (LSCAE),B.P: 523, B eni - Mellal, Moroccoc Equipe de Catalyse et Environnement, D epartement de Chimie, Faculte des Sciences, Universit e Ibn Zohr, B.P.8106 Cit e Dakhla, Agadir, Moroccoa r t i c l e i n f o a b s t r a c tArticle history: In this work, we have prepared the Ag-ZnO-La2O2CO3 nanomaterials as promising photocatalysts for theReceived 11 September 2018 photocatalytic degradation of pharmaceutical pollutants. Firstly, a series of ZnAl1-xLax(CO3) (0 x 0.5)Received in revised form layered double hydroxides (LDHs) were synthesized by the co-precipitation method at the component20 December 2018 molar ratio of Zn/(Al þ La ¼ 3, where La/Al ¼ 0, 0.25 and 0.5). Photocatalysts were prepared by theAccepted 4 January 2019Available online 6 January 2019 calcination of the LDH precursors at different temperatures of 300, 400, 500, 600, 800 and 1000 C. The effects of the La/Al molar ratio and the calcination temperature on the photocatalytic activity of the cat- alysts were evaluated by the degradation of caffeine as a model pharmaceutical pollutant in aqueousKeywords:Layered double hydroxides solutions under the UV irradiation. Thereafter, in order to increase the photocatalytic activity, the catalystsPhotocatalyst obtained at the optimal La/Al molar ratio and calcination temperature were doped with the Ag noble metalDoping at various concentrations (i.e. 1, 3 and 5 wt%) using the ceramic preparation process to obtain the desiredPhotocatalytic degradation Ag-ZnO-La2O2CO3 catalysts. The synthesized photocatalysts were characterized by X-ray diffraction (XRD),Caffeine Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX) and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). Detailed photocatalytic experiments based on the effects of the irradiation time, the dopant amount, the catalyst dose, the initial solution pH and reuseability were performed and discussed in this study. The Ag doped material showed significantly a higher photocatalytic activity compared to the undoped, pure ZnO and P- 25 catalysts. The experimental results show that the highest photocatalytic activity was obtained from the Ag (5%) doped Zn-0.75Al-0.25La-CO3 photocatalysts calcined at 500 C with a degradation efficiency of 99,4% after 40 min of irradiation only. This study could provide a new route for the fabrication of high performance photocatalysts and facilitate their application in the environmental remediation issues. © 2019 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).1. Introduction urine and feces discharged by human or animals onto the water bodies. These pollutants at low concentrations produce negative ...