Self-assembly preparation of lignin-graphene oxide composite nanospheres for highly efficient Cr(vi) removal

Zhenyu Yan; Ting Wu; Guigan Fang; Miao Ran; Kuizhong Shen; Guangfu Liao

doi:10.1039/d0ra09190a

Self-assembly preparation of lignin-graphene oxide composite nanospheres for highly efficient Cr(vi) removal

RSC Adv. 2021 Jan 25;11(8):4713-4722. doi: 10.1039/d0ra09190a. eCollection 2021 Jan 21.

Authors

Zhenyu Yan^{1

2}, Ting Wu¹, Guigan Fang^{1

2}, Miao Ran¹, Kuizhong Shen¹, Guangfu Liao³

Affiliations

¹ Institute of Chemical Industry of Forest Products, CAF, Jiangsu Key Lab. of Biomass Energy and Material Nanjing 210042 Jiangsu China ppfangguigan@163.com.
² College of Light Industry and Food Engineering, Nanjing Forestry University Nanjing 210042 Jiangsu China.
³ Electrochemical Energy and Interfaces Laboratory, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong Shatin, N.T. Hong Kong SAR China guangfuliao@cuhk.edu.hk.

Abstract

Recently, research interest in the application of lignin is growing, especially as adsorbent material. However, single lignin shows unsatisfactory adsorption performance, and thus, construction of lignin-based nanocomposites is worth considering. Herein, we introduced graphene oxide (GO) into lignin to form lignin/GO (LGNs) composite nanospheres by a self-assembly method. FTIR and ¹H NMR spectroscopy illustrated that lignin and GO are tightly connected by hydrogen bonds. The LGNs as an environmental friendly material, also exhibit excellent performance for Cr(vi) removal. The maximum sorption capacity of LGNs is 368.78 mg g^-1, and the sorption efficiency is 1.5 times than that of lignin nanospheres (LNs). The removal process of Cr(vi) via LGNs mainly relies on electrostatic interaction, and it also involves the reduction of Cr(vi) to Cr(iii). Moreover, LGNs still have high adsorption performance after repeating five times with the sorption capacity of 150.4 mg g^-1 in 200 mg g^-1 Cr(vi) solution. Therefore, the prepared lignin-GO composite nanospheres have enormous potential as a low-cost, high-absorbent and recyclable adsorbent, and can be used in wastewater treatment.