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http://cimav.repositorioinstitucional.mx/jspui/handle/1004/1280| Enhanced Photocatalytic Hydrogen Production Under Visible Light over Ag Doped TiO2 | |
| VANESSA GUADALUPE GUZMAN VELDERRAIN ALEJANDRO LOPEZ ORTIZ VIRGINIA HIDALINA COLLINS MARTINEZ | |
| Acceso Abierto | |
| Sin Derechos Reservados | |
| TiO2 doped Ag | |
| TiO2 is the most widely used photocatalyst for water and air purification, and for hydrogen production, due to its good properties such as chemical and photo-corrosion resistance and low cost. One disadvantage of this material, resides in its bandgap energy (3.2eV), which lies in the UV spectrum. For this reason, studies have been conducted to modify TiO2 bandgap into the visible light range. Doping elements used for this purpose are noble metals such as Au, Pt and Ag. However, Au and Pt are expensive and scarce materials, leaving Ag as a preferred candidate. TiO2 and doped TiO2 were synthesized via sol-gel/hydrothermal (SGH) named TiO2-F and TiO2Ag-F, respectively, while under the sol-gel/hydrothermal/thermal (SGHT) technique was named as TiO2Ag-C, using titanium butoxide as a precursor and ethanol as solvent. XRD characterization resulted in the presence of the anatase phase in all three synthesized samples as well as the characteristic signals for metallic Ag in TiO2Ag-F. Samples crystal sizes were determined by the Scherrer equation, and were ~ 10 nm. Light absorption exhibited a shift in the Eg value from 3.05 eV for TiO2-F to 2.8 eV for TiO2Ag-F. BET surface area for the SGH and SGHT photocatalysts were of 140 and 95m2/g, respectively. SEM images presented particle agglomerates of irregular morphology. Photocatalytic evaluation for hydrogen production was performed using a 250 W mercury light lamp, filtering the UV spectrum. TiO2Ag-F was the only sample that showed activity, producing 180 μmol of H2/g catalyst over a 4h irradiation period. This activity can be mainly attributed to the ability of this material to be activated under the visible light spectrum and to the silver in a metallic state in TiO2, which inhibits the recombination of the electron-hole pair generated when the material is activated under light exposure. | |
| 2014 | |
| Memoria de congreso | |
| Inglés | |
| OTRAS | |
| Versión revisada | |
| submittedVersion - Versión revisada | |
| Aparece en las colecciones: | Artículos de Congresos |
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