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 Fe<inf>3</inf>O<inf>4</inf> nanoparticles and a cost-effective portable AC magnetometer. Cr(VI) reduction by surface Fe²⁺ leads to Fe/Cr precipitate formation, which...
| Autores: | , , , , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/403375 |
| Acesso em linha: | http://hdl.handle.net/10261/403375 https://api.elsevier.com/content/abstract/scopus_id/105013676115 |
| Access Level: | acceso abierto |
| Palavra-chave: | AC magnetometry DFT calculations Drinking water monitoring Hexavalent chromium Magnetic anisotropy Magnetite nanoparticles Pollutant sensors XPS analysis |
| Resumo: | An analytical approach for the rapid and remote determination of Cr(VI) in water samples is demonstrated using Fe<inf>3</inf>O<inf>4</inf> 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 R<sup>2</sup> value of 0.99. Limitations of the method emerged at loadings above 10 mg/g, where extensive chromite (Cr<inf>x</inf>Fe<inf>3-x</inf>O<inf>4</inf>) 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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