Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles
The photocatalytic mechanism of TiO2 (P25) nanoparticles coated with SiO2 (SiO2:TiO2) by atomic layer deposition was investigated. The deposition of SiO2 on TiO2 not only gives a photocatalytic improvement for the degradation of both Rhodamine B (3.6–fold) and Acid Blue 9 (3–fold). SiO2 deposition a...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-05-01
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| Series: | Chemical Engineering Journal Advances |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666821122000497 |
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| author | Dominik Benz Hao Van Bui Hubertus T. Hintzen Michiel T. Kreutzer J. Ruud van Ommen |
| author_facet | Dominik Benz Hao Van Bui Hubertus T. Hintzen Michiel T. Kreutzer J. Ruud van Ommen |
| author_sort | Dominik Benz |
| collection | DOAJ |
| description | The photocatalytic mechanism of TiO2 (P25) nanoparticles coated with SiO2 (SiO2:TiO2) by atomic layer deposition was investigated. The deposition of SiO2 on TiO2 not only gives a photocatalytic improvement for the degradation of both Rhodamine B (3.6–fold) and Acid Blue 9 (3–fold). SiO2 deposition also changes the mechanism from direct oxidation of the pollutant at the surface of TiO2 to a predominantly OH⁎ radical based degradation of the pollutants originating from SiO2:TiO2. Low SiO2 loadings on TiO2, where the coating is incomplete, improve the OH⁎ radicals generation due to the higher number of acidic Si–OH groups combined with the facilitated charge separation at the TiO2–SiO2 interface. As a consequence of incomplete coverage, the TiO2 surface remains accessible, which allows both the oxidation and reduction reactions at the SiO2:TiO2 surface. On the other hand, high loading of SiO2 (>3 wt.% Si) results in photocatalytic suppression due to the coverage of TiO2 surface by SiO2. The degradation of differently charged dyes on the SiO2:TiO2 surface demonstrates the independence of the adsorption properties on the photocatalytic improvement. Simultaneous degradation of two dyes demonstrated the advantage of SiO2:TiO2 being less selective and, therefore, better suited for general water purification. |
| first_indexed | 2024-12-10T10:53:22Z |
| format | Article |
| id | doaj.art-1d5f4e960f4f4dcba04ab62106b58f49 |
| institution | Directory Open Access Journal |
| issn | 2666-8211 |
| language | English |
| last_indexed | 2024-12-10T10:53:22Z |
| publishDate | 2022-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Chemical Engineering Journal Advances |
| spelling | doaj.art-1d5f4e960f4f4dcba04ab62106b58f492022-12-22T01:51:56ZengElsevierChemical Engineering Journal Advances2666-82112022-05-0110100288Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticlesDominik Benz0Hao Van Bui1Hubertus T. Hintzen2Michiel T. Kreutzer3J. Ruud van Ommen4Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, NetherlandsFaculty of Materials Science and Engineering, Phenikaa University, Yen Nghia Ward, Ha-Dong District, Hanoi, 12116, VietnamFundamental Aspects of Materials and Energy, Delft University of Technology, Mekelweg 15, 2629 JB Delft, NetherlandsFaculty of Architecture, Delft University of Technology, Julianalaan 134, 2628 BL Delft, NetherlandsDepartment of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands; Corresponding author.The photocatalytic mechanism of TiO2 (P25) nanoparticles coated with SiO2 (SiO2:TiO2) by atomic layer deposition was investigated. The deposition of SiO2 on TiO2 not only gives a photocatalytic improvement for the degradation of both Rhodamine B (3.6–fold) and Acid Blue 9 (3–fold). SiO2 deposition also changes the mechanism from direct oxidation of the pollutant at the surface of TiO2 to a predominantly OH⁎ radical based degradation of the pollutants originating from SiO2:TiO2. Low SiO2 loadings on TiO2, where the coating is incomplete, improve the OH⁎ radicals generation due to the higher number of acidic Si–OH groups combined with the facilitated charge separation at the TiO2–SiO2 interface. As a consequence of incomplete coverage, the TiO2 surface remains accessible, which allows both the oxidation and reduction reactions at the SiO2:TiO2 surface. On the other hand, high loading of SiO2 (>3 wt.% Si) results in photocatalytic suppression due to the coverage of TiO2 surface by SiO2. The degradation of differently charged dyes on the SiO2:TiO2 surface demonstrates the independence of the adsorption properties on the photocatalytic improvement. Simultaneous degradation of two dyes demonstrated the advantage of SiO2:TiO2 being less selective and, therefore, better suited for general water purification.http://www.sciencedirect.com/science/article/pii/S2666821122000497PhotocatalysisAtomic layer depositionDye degradationMechanismSiO2 on TiO2 |
| spellingShingle | Dominik Benz Hao Van Bui Hubertus T. Hintzen Michiel T. Kreutzer J. Ruud van Ommen Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles Chemical Engineering Journal Advances Photocatalysis Atomic layer deposition Dye degradation Mechanism SiO2 on TiO2 |
| title | Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles |
| title_full | Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles |
| title_fullStr | Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles |
| title_full_unstemmed | Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles |
| title_short | Mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of SiO2 on TiO2 (P25) nanoparticles |
| title_sort | mechanistic insight into the improved photocatalytic degradation of dyes for an ultrathin coating of sio2 on tio2 p25 nanoparticles |
| topic | Photocatalysis Atomic layer deposition Dye degradation Mechanism SiO2 on TiO2 |
| url | http://www.sciencedirect.com/science/article/pii/S2666821122000497 |
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