Solvothermal Synthesis of Hierarchical Colloidal Nanocrystal Assemblies of ZnFe₂O₄ and Their Application in Water Treatment

Peizhi Guo; Meng Lv; Guangting Han; Changna Wen; Qianbin Wang; Hongliang Li; Xiusong Zhao

doi:10.3390/ma9100806

Solvothermal Synthesis of Hierarchical Colloidal Nanocrystal Assemblies of ZnFe₂O₄ and Their Application in Water Treatment

Materials (Basel). 2016 Sep 29;9(10):806. doi: 10.3390/ma9100806.

Authors

Peizhi Guo¹, Meng Lv², Guangting Han³, Changna Wen⁴, Qianbin Wang⁵, Hongliang Li⁶, Xiusong Zhao⁷

Affiliations

¹ Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. pzguo@qdu.edu.cn.
² Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. lm199133@126.com.
³ Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. kychgt@163.com.
⁴ Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. qsdwcn256@163.com.
⁵ Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. material_wqb@163.com.
⁶ Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. lhl@qdu.edu.cn.
⁷ Institute of Materials for Energy and Environment, State Key Laboratory Breeding Based of New Fiber Materials and Modern Textile, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China. chezxs@qdu.edu.cn.

Abstract

Hierarchical colloidal nanocrystal assemblies (CNAs) of ZnFe₂O₄ have been synthesized controllably by a solvothermal method. Hollow ZnFe₂O₄ spheres can be formed with the volume ratios of ethylene glycol to ethanol of 1:4 in the starting systems, while solid ZnFe₂O₄ CNAs are obtained by adjusting the volume proportion of ethylene glycol to ethanol from 1:2 to 2:1. Magnetometric measurement data showed that the ZnFe₂O₄ CNAs obtained with the volume ratios of 1:2 and 1:1 exhibited weak ferromagnetic behavior with high saturation magnetization values of 60.4 and 60.3 emu·g^-1, respectively. However, hollow spheres showed a saturation magnetization value of 52.0 emu·g^-1, but the highest coercivity among all the samples. It was found that hollow spheres displayed the best ability to adsorb Congo red dye among all the CNAs. The formation mechanisms of ZnFe₂O₄ CNAs, as well as the relationship between their structure, crystallite size, and properties were discussed based on the experimental results.

Keywords: magnetism; nanocrystal assembly; solvothermal synthesis.