Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation
The ZnO-based visible-LED photocatalytic degradation and mineralization of two typical cyanotoxins, microcystin-LR (MC-LR), and anatoxin-A were examined. Al-doped ZnO nanoparticle photocatalysts, in Al:Zn ratios between 0 and 5 at.%, were prepared via sol-gel method and exhaustively characterized by...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-01-01
|
| Series: | Toxins |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-6651/13/1/66 |
| _version_ | 1797410549551595520 |
|---|---|
| author | Majdi Benamara Elvira Gómez Ramzi Dhahri Albert Serrà |
| author_facet | Majdi Benamara Elvira Gómez Ramzi Dhahri Albert Serrà |
| author_sort | Majdi Benamara |
| collection | DOAJ |
| description | The ZnO-based visible-LED photocatalytic degradation and mineralization of two typical cyanotoxins, microcystin-LR (MC-LR), and anatoxin-A were examined. Al-doped ZnO nanoparticle photocatalysts, in Al:Zn ratios between 0 and 5 at.%, were prepared via sol-gel method and exhaustively characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and nitrogen adsorption-desorption isotherms. With both cyanotoxins, increasing the Al content enhances the degradation kinetics, hence the use of nanoparticles with 5 at.% Al content (A5ZO). The dosage affected both cyanotoxins similarly, and the photocatalytic degradation kinetics improved with photocatalyst concentrations between 0.5 and 1.0 g L<sup>−1</sup>. Nevertheless, the pH study revealed that the chemical state of a species decisively facilitates the mutual interaction of cyanotoxin and photocatalysts. A5ZO nanoparticles achieved better outcomes than other photocatalysts to date, and after 180 min, the mineralization of anatoxin-A was virtually complete in weak alkaline medium, whereas only 45% of MC-LR was in neutral conditions. Moreover, photocatalyst reusability is clear for anatoxin-A, but it is adversely affected for MC-LR. |
| first_indexed | 2024-03-09T04:31:39Z |
| format | Article |
| id | doaj.art-4212f5bedcbe4b6d8240b34ed5ee1cf3 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-09T04:31:39Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-4212f5bedcbe4b6d8240b34ed5ee1cf32023-12-03T13:34:30ZengMDPI AGToxins2072-66512021-01-011316610.3390/toxins13010066Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED IrradiationMajdi Benamara0Elvira Gómez1Ramzi Dhahri2Albert Serrà3Laboratory of Physics of Materials and Nanomaterials Applied at Environment (LaPhyMNE), Faculty of Sciences, University of Gabes, Erriadh Manara Zrig, 6072 Gabes, TunisiaThin Films and Nanostructures Electrodeposition Group (GE-CPN), Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1, E-08028 Barcelona, SpainDepartment of Engineering, University of Messina, 98166 Messina, ItalyThin Films and Nanostructures Electrodeposition Group (GE-CPN), Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1, E-08028 Barcelona, SpainThe ZnO-based visible-LED photocatalytic degradation and mineralization of two typical cyanotoxins, microcystin-LR (MC-LR), and anatoxin-A were examined. Al-doped ZnO nanoparticle photocatalysts, in Al:Zn ratios between 0 and 5 at.%, were prepared via sol-gel method and exhaustively characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and nitrogen adsorption-desorption isotherms. With both cyanotoxins, increasing the Al content enhances the degradation kinetics, hence the use of nanoparticles with 5 at.% Al content (A5ZO). The dosage affected both cyanotoxins similarly, and the photocatalytic degradation kinetics improved with photocatalyst concentrations between 0.5 and 1.0 g L<sup>−1</sup>. Nevertheless, the pH study revealed that the chemical state of a species decisively facilitates the mutual interaction of cyanotoxin and photocatalysts. A5ZO nanoparticles achieved better outcomes than other photocatalysts to date, and after 180 min, the mineralization of anatoxin-A was virtually complete in weak alkaline medium, whereas only 45% of MC-LR was in neutral conditions. Moreover, photocatalyst reusability is clear for anatoxin-A, but it is adversely affected for MC-LR.https://www.mdpi.com/2072-6651/13/1/66cyanotoxinsmicrocystin-LRanatoxin-(a)photocatalysisZnO-doped nanoparticlesvisible light |
| spellingShingle | Majdi Benamara Elvira Gómez Ramzi Dhahri Albert Serrà Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation Toxins cyanotoxins microcystin-LR anatoxin-(a) photocatalysis ZnO-doped nanoparticles visible light |
| title | Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation |
| title_full | Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation |
| title_fullStr | Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation |
| title_full_unstemmed | Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation |
| title_short | Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation |
| title_sort | enhanced photocatalytic removal of cyanotoxins by al doped zno nanoparticles with visible led irradiation |
| topic | cyanotoxins microcystin-LR anatoxin-(a) photocatalysis ZnO-doped nanoparticles visible light |
| url | https://www.mdpi.com/2072-6651/13/1/66 |
| work_keys_str_mv | AT majdibenamara enhancedphotocatalyticremovalofcyanotoxinsbyaldopedznonanoparticleswithvisibleledirradiation AT elviragomez enhancedphotocatalyticremovalofcyanotoxinsbyaldopedznonanoparticleswithvisibleledirradiation AT ramzidhahri enhancedphotocatalyticremovalofcyanotoxinsbyaldopedznonanoparticleswithvisibleledirradiation AT albertserra enhancedphotocatalyticremovalofcyanotoxinsbyaldopedznonanoparticleswithvisibleledirradiation |