The topotactic transformation from magnetite to maghemite sub-microparticles was demonstrated by a variety of techniques that include X-ray diffraction, Raman spectroscopy, electron microscopy, Mössbauer spectroscopy, magnetic measurements, and vis-NIR diffuse reflectance. The physical, chemical, and morphological properties of the particles were correlated with their adsorptive properties in water with respect to arsenic (V). The adsorptive properties of the iron oxide are increased by changing the crystal phases involved, specifically, the transformation of magnetite to maghemite. Maghemite sub-microparticles are capable of efficiently decreasing the arsenic content in water from 100 ppb to below the World Health Organization (WHO) guideline of 10 ppb.
Bibliographical noteFunding Information:
This work was supported by the “Programa de Atracción e Inserción de Capital Humano Avanzado” MEC #80150069 and Proyecto Anillo ACT1204. The authors wish to thank the Archaeometry Lab (Universidad Nacional Mayor de San Marcos) for the Mössbauer measurements, and to the Magnetism Lab (Geology Department of UCN). DLP wishes to acknowledge support by the U.S. Department of Energy under Contract No. DE-ACO3-76SF00098 . MEM acknowledges Cinvestav, for supporting a research stay in Saltillo.
© 2017 Elsevier B.V.
- Diffuse reflectance
- First-order reversal curve (FORC) diagrams
- Mossbauer spectroscopy
- Sorption properties