Photocatalytic NOx removal in bismuth-oxyhalide (BiOX, X = I, Cl) cement-based materials exposed to outdoor conditions
Cement-based materials modified with 3D BiOX (X = I, Cl) microspheres at different percentages (1, 5 and 10% by weight of the cement binder) were prepared to investigate the durability of the photocatalytic NO removal under outdoor conditions. Weathering—corresponding to a period of 13 months outdoo...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/296488 |
| Acceso en línea: | http://hdl.handle.net/10261/296488 http://doi.org/10.3390/catal12090982 |
| Access Level: | acceso abierto |
| Palabra clave: | Biox Photocatalysis Mortar Nox Outdoor Exposure Self-Deactivation |
| Sumario: | Cement-based materials modified with 3D BiOX (X = I, Cl) microspheres at different percentages (1, 5 and 10% by weight of the cement binder) were prepared to investigate the durability of the photocatalytic NO removal under outdoor conditions. Weathering—corresponding to a period of 13 months outdoors—was studied in terms of NO removal efficiency under visible and UVA light irradiation for BiOI and BiOCl mortars, respectively. Following this period, the samples were protected from the environment for four years, and NO removal and selectivity to nitrates were assessed. BiOI and BiOCl mortar samples were initially photocatalytically active; NO removal performance increased as BiOX content increased. There was good photocatalyst dispersion, and compressive strength was not significantly impacted. The BiOI mortars had nearly completely lost their activity after 5 years from casting, whereas mortars containing 10% BiOCl had maintained about 7% of initial performance. The results suggest that mortar deactivation is due to surface dirt and nitrates accumulation from NO oxidation on the surface rather than carbonation. An internal self-deactivation mechanism that affects BiOI in mortar matrix has also been postulated. |
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