Main content area

High saturation magnetization superparamagnetic Fe/Ni core/shell microparticles for chromium removal

Lu, Zhaoqing, Xu, Yanling, Zhou, Shaomin
RSC advances 2017 v.7 no.67 pp. 42363-42369
X-ray diffraction, adsorption, chromium, crystal structure, electron transfer, hydrogen, hysteresis, iron, iron oxides, magnetism, microparticles, nickel, nickel oxide, remediation, transmission electron microscopy
In this paper, the Fe/Ni microparticles are synthesized by two reactions which directly utilize H₂ to reduce NiO and Fe₃O₄ microspheres. X-ray diffraction and transmission electron microscopy show that the as-synthesized Fe/Ni microparticles possess a body/face-centered cubic crystalline structure and core/shell morphology. The magnetic hysteresis loops show that the as-fabricated core/shell Fe/Ni microparticles have a high saturation magnetization (132.8 emu g⁻¹) at 305 K. The as-prepared Ni/Fe microparticles are used to remove Cr(vi) via a coupled adsorption/reduction process. The introduction of nickel not only controls the iron passivation but also advances efficient flow of electron transfer between iron and Cr(vi), thus efficient reduction of Cr(vi) to Cr(iii). The excellent products with both high saturation magnetization and Cr(vi) adsorption capacity can be used as candidates for environmental remediation materials.