A novel robust adsorbent for efficient oil/water separation: Magnetic carbon nanospheres/graphene composite aerogel

Weiwei Kang; Yan Cui; Lei Qin; Yongzhen Yang; Zongbin Zhao; Xuzhen Wang; Xuguang Liu

doi:10.1016/j.jhazmat.2020.122499

A novel robust adsorbent for efficient oil/water separation: Magnetic carbon nanospheres/graphene composite aerogel

J Hazard Mater. 2020 Jun 15:392:122499. doi: 10.1016/j.jhazmat.2020.122499. Epub 2020 Mar 9.

Authors

Weiwei Kang¹, Yan Cui², Lei Qin¹, Yongzhen Yang³, Zongbin Zhao⁴, Xuzhen Wang⁴, Xuguang Liu⁵

Affiliations

¹ Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China.
² College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
³ Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China. Electronic address: yyztyut@126.com.
⁴ State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
⁵ Institute of New Carbon Materials, Taiyuan University of Technology, Taiyuan 030024, China. Electronic address: liuxuguang@tyut.edu.cn.

PMID: 32208315
DOI: 10.1016/j.jhazmat.2020.122499

Abstract

Recently, graphene aerogels (GAs) have attracted considerable research attention in oil/water separation owing to their remarkable properties. However, the serious stacking of graphene oxide nanosheets (GO) would lead to low adsorption capacity and poor recyclability. For the first time, with alkaline ammonium citrate as reducing agent and nitrogen source, the point-to-face contact between magnetic carbon nanospheres (MCNS) and graphene sheets was adopted to effectively inhibit the aggregation of graphene sheets. Nitrogen-doped magnetic carbon nanospheres/graphene composite aerogels (MCNS/NGA) were fabricated under weakly alkaline conditions by one-step hydrothermal in-situ electrostatic self-assembling strategy. The aerogels have low density, super-elasticity (up to 95 % compression), high specific surface area (787.92 m² g^-1) and good magnetic properties. Therefore, they exhibit adsorption capacity in the range of 187-537 g g^-1 towards various organic solvents and oils, superior to most reported materials to date. In addition, thanks to their good mechanical properties, excellent thermal stability and flame retardancy, they can be regenerated by squeezing, distillation and combustion. More importantly, magnetic control technology can be adopted to realize oriented adsorption and facilitate recycling of organic solvents and oils in extreme environments.

Keywords: Adsorption; Ammonium citrate; Compressibility; Graphene composite aerogel; Magnetic carbon nanosphere.