Plasmonic Effect of Au Nanoparticles Deposited onto TiO<sub>2</sub>-Impact on the Photocatalytic Conversion of Acetaldehyde
A comparison of two synthesis methods for depositing Au nanoparticles onto TiO<sub>2</sub> was performed: (1) impregnation with HAuCl<sub>4</sub> followed by thermal treatment in argon, and (2) magnetron sputtering from a Au disc. The obtained materials were used for acetalde...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-07-01
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| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/30/15/3118 |
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| Summary: | A comparison of two synthesis methods for depositing Au nanoparticles onto TiO<sub>2</sub> was performed: (1) impregnation with HAuCl<sub>4</sub> followed by thermal treatment in argon, and (2) magnetron sputtering from a Au disc. The obtained materials were used for acetaldehyde decomposition in a high temperature reaction chamber and ch aracterised by UV-Vis/DR, XPS, XRD, SEM, and photoluminescence measurements. The process was carried out using an air/acetaldehyde gas flow under UV or UV-Vis LED irradiation. The mechanism of acetaldehyde decomposition and conversion was elaborated by in situ FTIR measurements of the photocatalyst surface during the reaction. Simultaneously, concentration of acetaldehyde in the outlet gas was monitored using gas chromatography. All the Au/TiO<sub>2</sub> samples showed absorption in the visible region, with a maximum around 550 nm. The plasmonic effect of Au nanoparticles was observed under UV-Vis light irradiation, especially at elevated temperatures such as 100 °C, for Au/TiO<sub>2</sub> prepared by the magnetron sputtering method. This resulted in a significant increase in the conversion of acetaldehyde at the beginning, followed by gradual decrease over time. The collected FTIR spectra indicated that, under UV-Vis light, acetaldehyde was strongly adsorbed onto Au/TiO<sub>2</sub> surface and formed crotonaldehyde or aldol. Under UV, acetaldehyde was mainly adsorbed in the form of acetate species. The plasmonic effect of Au nanoparticles increased the adsorption of acetaldehyde molecules onto TiO<sub>2</sub> surface, while reducing their decomposition rate. The increased temperature of the process enhanced the decomposition of the acetaldehyde. |
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| ISSN: | 1420-3049 |