Real-time Cr(VI) monitoring and remediation using Fe3O4 nanoparticles: Insights into Fe-Cr Spinels
An analytical approach for the rapid and remote determination of Cr(VI) in water samples is demonstrated using Fe3O4 nanoparticles and a cost-effective portable AC magnetometer. Cr(VI) reduction by surface Fe²⁺ leads to Fe/Cr precipitate formation, which alters the nanoparticles’ magnetic properties...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/126510 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/126510 |
| Access Level: | acceso abierto |
| Palabra clave: | 538.9 544 Drinking water monitoring Pollutant sensors Hexavalent chromium Magnetite nanoparticles Magnetic anisotropy AC magnetometry DFT calculations XPS analysis Física de materiales Agua Física (Química) 2210 Química Física |
| Sumario: | An analytical approach for the rapid and remote determination of Cr(VI) in water samples is demonstrated using Fe3O4 nanoparticles and a cost-effective portable AC magnetometer. Cr(VI) reduction by surface Fe²⁺ leads to Fe/Cr precipitate formation, which alters the nanoparticles’ magnetic properties. Validation in natural water spiked with Cr(VI) showed a linear correlation between magnetic remanence and Cr(VI) concentrations from 0 to 10 mg/L, with a R2 value of 0.99. Limitations of the method emerged at loadings above 10 mg/g, where extensive chromite (CrxFe3-xO4) coverage reduced the magnetic hysteresis area. Advanced characterization and DFT calculations revealed changes in spin-dependent properties, including magnetization reversal, electrical conductivity and magnetoresistance. This robust correlation between collective magnetic properties and Cr(VI) exposure enables, for the first time, milligram-per-liter detection via ultra-fast AC magnetometry, paving the way for real-time insight into redox processes in liquid environments and novel strategies for environmental remediation. |
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