| Autor: |
Hoque MA; Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States., Barrios Cossio J; Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States., Guzman MI; Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States. |
| Jazyk: |
angličtina |
| Zdroj: |
The journal of physical chemistry. C, Nanomaterials and interfaces [J Phys Chem C Nanomater Interfaces] 2024 Oct 03; Vol. 128 (41), pp. 17470-17482. Date of Electronic Publication: 2024 Oct 03 (Print Publication: 2024). |
| DOI: |
10.1021/acs.jpcc.4c05777 |
| Abstrakt: |
Semiconductor photocatalysis with commercial TiO 2 (Degussa P25) has shown significant potential in water treatment of organic pollutants. However, the photoinduced reactions of adsorbed catechol, a phenolic air pollutant from biomass burning and combustion emissions, at the air-solid interface of TiO 2 remain unexplored. Herein we examine the photocatalytic decay of catechol in the presence of water vapor, which acts as an electron acceptor. Experiments under variable cut-off wavelengths of irradiation (λ cut-off ≥ 320, 400, and 515 nm) distinguish the mechanistic contribution of a ligand-to-metal charge-transfer (LMCT) complex of surface chemisorbed catechol on TiO 2 . The LMCT complex injects electrons into the conduction band of TiO 2 from the highest occupied molecular orbital of catechol by visible light (≥2.11 eV) excitation. The deconvolution of diffuse reflectance UV-visible spectral bands from LMCT complexes of TiO 2 with catechol, o -semiquinone radical, and quinone and the quantification of the evolving gaseous products follow a consecutive kinetic model. CO 2 (g) and CO(g) final oxidation products are monitored by gas chromatography and Fourier-transform infrared spectroscopy. The apparent quantum efficiency at variable λ cut-off are determined for reactant loss (Φ - TiO 2 /catechol = 0.79 ± 0.19) and product growth Φ CO 2 = 0.76 ± 0.08). Spectroscopic and electrochemical measurements reveal the energy band diagram for the LMCT of TiO 2 /catechol. Two photocatalytic mechanisms are analyzed based on chemical transformations and environmental relevance.
Competing Interests: The authors declare no competing financial interest.
(© 2024 American Chemical Society.) |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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