| Autor: |
El Mragui A; Research team 'Materials and Applied Catalysis: MCA', 'CBAE' Laboratory, Moulay Ismail University, Faculty of Sciences, BP. 11201 Zitoune, Meknès, Morocco.; CIQ(UP) - Research Center in Chemistry, DGAOT, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007, Porto, Portugal., Zegaoui O; Research team 'Materials and Applied Catalysis: MCA', 'CBAE' Laboratory, Moulay Ismail University, Faculty of Sciences, BP. 11201 Zitoune, Meknès, Morocco. o.zegaoui@fs.umi.ac.ma., Daou I; Research team 'Materials and Applied Catalysis: MCA', 'CBAE' Laboratory, Moulay Ismail University, Faculty of Sciences, BP. 11201 Zitoune, Meknès, Morocco., Esteves da Silva JCG; CIQ(UP) - Research Center in Chemistry, DGAOT, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007, Porto, Portugal. |
| Abstrakt: |
In this work, TiO 2 -based nanomaterials have been successfully synthesized by doping TiO 2 with Co, Mn, and Ni and by co-doping it with (P,Mo) or (P,W). The structural, optical, and morphological properties of the synthesized nanomaterials have been investigated using various techniques such as XRD, FTIR spectroscopy, UV-vis diffuse reflectance spectroscopy, XPS, and SEM-EDS. The obtained results showed that the crystalline structure of the doped TiO 2 -based nanomaterials depends strongly on the nature of the doping ions. The obtained band gap energy of TiO 2 co-doped with (P,Mo) changes to a level below the band gap energy of TiO 2 anatase indicating a high ability to absorb visible light. The obtained photocatalytic activity results of methyl orange degradation showed that, under visible light, the mono-doping of TiO 2 with Co and its co-doping with (P,Mo) or (P,W) improve significantly the photocatalytic activity of TiO 2 in comparison with undoped TiO 2 . The activity order obtained under UV-A irradiation for the used photocatalysts is TiO 2 > > 1%Ni-TiO 2 > 1%Co-TiO 2 > 30%(P,Mo)-TiO 2 ≈ 30%(P,W)TiO 2 > 1%Mn-TiO 2 while under visible light, it is 1%Co-TiO 2 > 30%(P,Mo)-TiO 2 > 30%(P,W)TiO 2 ≈ TiO 2 > 1%Ni-TiO 2 > 1%Mn-TiO 2 . The high photocatalytic activity observed for these samples could be the result of a synergetic effect of the high visible light absorption capacity and the low recombination rate of photoexcited electrons and holes. |
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