Abstract

To remove pollutants from industrial waste, magnetic separation by use of magnetic reduced graphene oxide (rGO) is a possible route, due to the high specific surface area of rGO. Reduced graphene oxide decorated with nickel, cobalt and cobalt ferrite nanoparticles was synthesized by means of modified coprecipitation methods. Nitrogen-doped reduced graphene was prepared by a thermal doping method. The resulting composites were characterized with scanning electron microscope, transmission electron microscope (TEM), powder X-ray diffraction (XRD), thermal analysis and Raman spectroscopy. Samples were magnetically characterized using vibrating sample magnetometer to determine the magnetic properties. All the prepared sampled were found to have weak ferromagnetic properties. The particle size distribution of the nanoparticles was determined using the TEM images and Image J software. The average particle size for the Co-rGO was 1.89 nm, 35.12 nm for Ni–rGO and 32.15 nm for CoFe–rGO. The Co–rGO was used as proof of principle to remove Cr(VI) ions from solution. The Co–rGO was recycled five times before it was deemed unusable.

Graphic abstract

中文翻译：

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Ni，Co和FeCo纳米粒子在还原氧化石墨烯上去除Cr（VI）的合成，表征和磁性能

摘要

为了除去工业废料中的污染物，由于rGO的高比表面积，使用磁性还原氧化石墨烯（rGO）进行磁选是一种可行的方法。通过修饰共沉淀法合成了以镍，钴和钴铁氧体纳米粒子修饰的还原型氧化石墨烯。通过热掺杂方法制备氮掺杂的还原石墨烯。通过扫描电子显微镜，透射电子显微镜（TEM），粉末X射线衍射（XRD），热分析和拉曼光谱对所得复合材料进行表征。使用振动样品磁力计对样品进行磁性表征，以确定磁性。发现所有制备的样品具有弱的铁磁性能。使用TEM图像和Image J软件确定纳米颗粒的粒度分布。Co-rGO的平均粒径为1.89 nm，Ni–rGO的平均粒径为35.12 nm，CoFe–rGO的平均粒径为32.15 nm。Co-rGO用作从溶液中去除Cr（VI）离子的原理证明。Co-rGO在被认为不可用之前被回收了五次。

图形摘要