Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED
Graphene oxide (GO) is used to enhance the photocatalytic activity of ZnO nanoparticles for the degradation of vanillic acid (VA) under simulated solar light and visible-LED (<i>λ</i> > 430 nm). ZnO-GO composites are prepared by a mixing and sonication process with different GO loadin...
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MDPI AG
2021-06-01
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| author | Neda Mirikaram Álvaro Pérez-Molina Sergio Morales-Torres Amir Salemi Francisco J. Maldonado-Hódar Luisa M. Pastrana-Martínez |
| author_facet | Neda Mirikaram Álvaro Pérez-Molina Sergio Morales-Torres Amir Salemi Francisco J. Maldonado-Hódar Luisa M. Pastrana-Martínez |
| author_sort | Neda Mirikaram |
| collection | DOAJ |
| description | Graphene oxide (GO) is used to enhance the photocatalytic activity of ZnO nanoparticles for the degradation of vanillic acid (VA) under simulated solar light and visible-LED (<i>λ</i> > 430 nm). ZnO-GO composites are prepared by a mixing and sonication process with different GO loadings (i.e., from 1.8 to 6.5 wt.%). The materials are extensively characterized by thermogravimetric analysis (TGA), physisorption of N<sub>2</sub>, X-ray diffraction (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM), point of zero charge (pH<sub>PZC</sub>), and UV-Vis diffuse reflectance spectroscopy (DRUV). The presence of GO increases the photocatalytic activity of all the prepared composites in comparison with the pristine ZnO. The highest photocatalytic activity is found for the composite containing 5.5 wt.% of GO (i.e., ZnO-GO5.5), reaching a VA degradation of 99% and 35% under solar light and visible-LED, respectively. Higher TOC removal/VA degradation ratios are obtained from the experiments carried out under visible-LED, indicating a more effective process for the mineralization of VA than those observed under simulated solar light. The influence of hole, radical, and non-radical scavengers is studied in order to assess the occurrence of the reactive oxygen species (ROS) involved in the photocatalytic mechanism. The study of the photo-stability during three reuse experiments indicates that the presence of GO in the composites reduces the photocorrosion in comparison with pristine ZnO. |
| first_indexed | 2024-03-10T10:22:49Z |
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| last_indexed | 2024-03-10T10:22:49Z |
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| series | Nanomaterials |
| spelling | doaj.art-ca31b4a68f1140b68d32eca5405ed0542023-11-22T00:15:54ZengMDPI AGNanomaterials2079-49912021-06-01116157610.3390/nano11061576Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LEDNeda Mirikaram0Álvaro Pérez-Molina1Sergio Morales-Torres2Amir Salemi3Francisco J. Maldonado-Hódar4Luisa M. Pastrana-Martínez5Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, ES-18071 Granada, SpainDepartment of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, ES-18071 Granada, SpainDepartment of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, ES-18071 Granada, SpainEnvironmental Sciences Research Institute, Shahid Beheshti University, Tehran 19839-63113, IranDepartment of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, ES-18071 Granada, SpainDepartment of Inorganic Chemistry, Faculty of Sciences, University of Granada, Avda. Fuente Nueva s/n, ES-18071 Granada, SpainGraphene oxide (GO) is used to enhance the photocatalytic activity of ZnO nanoparticles for the degradation of vanillic acid (VA) under simulated solar light and visible-LED (<i>λ</i> > 430 nm). ZnO-GO composites are prepared by a mixing and sonication process with different GO loadings (i.e., from 1.8 to 6.5 wt.%). The materials are extensively characterized by thermogravimetric analysis (TGA), physisorption of N<sub>2</sub>, X-ray diffraction (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM), point of zero charge (pH<sub>PZC</sub>), and UV-Vis diffuse reflectance spectroscopy (DRUV). The presence of GO increases the photocatalytic activity of all the prepared composites in comparison with the pristine ZnO. The highest photocatalytic activity is found for the composite containing 5.5 wt.% of GO (i.e., ZnO-GO5.5), reaching a VA degradation of 99% and 35% under solar light and visible-LED, respectively. Higher TOC removal/VA degradation ratios are obtained from the experiments carried out under visible-LED, indicating a more effective process for the mineralization of VA than those observed under simulated solar light. The influence of hole, radical, and non-radical scavengers is studied in order to assess the occurrence of the reactive oxygen species (ROS) involved in the photocatalytic mechanism. The study of the photo-stability during three reuse experiments indicates that the presence of GO in the composites reduces the photocorrosion in comparison with pristine ZnO.https://www.mdpi.com/2079-4991/11/6/1576graphene oxideZnOvanillic acidwater treatmentscavengers |
| spellingShingle | Neda Mirikaram Álvaro Pérez-Molina Sergio Morales-Torres Amir Salemi Francisco J. Maldonado-Hódar Luisa M. Pastrana-Martínez Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED Nanomaterials graphene oxide ZnO vanillic acid water treatment scavengers |
| title | Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED |
| title_full | Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED |
| title_fullStr | Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED |
| title_full_unstemmed | Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED |
| title_short | Photocatalytic Perfomance of ZnO-Graphene Oxide Composites towards the Degradation of Vanillic Acid under Solar Radiation and Visible-LED |
| title_sort | photocatalytic perfomance of zno graphene oxide composites towards the degradation of vanillic acid under solar radiation and visible led |
| topic | graphene oxide ZnO vanillic acid water treatment scavengers |
| url | https://www.mdpi.com/2079-4991/11/6/1576 |
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