Cyclodextrin Modified Graphene Membrane for Highly Selective Adsorption of Organic Dyes and Copper (II) Ions

Mengmeng Cheng1

Chenxue Yao1

Yan Su1

Jinglei Liu1

Lijian Xu1

Jidong Bu1

Hua Wang2,*,Email

Shifeng Hou1,*,Email

1School of Chemistry and Chemical Engineering, National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, China

2School of Public Health, Jining Medical University, Jining, 272013, China

Abstract

Organic dyes and copper ions are the main industrial wastewater pollutants, which have potential threats to the environment and humans. Here, a novel β-cyclodextrin decorated reduced graphene oxide complex (rGO-β-CD) is synthesized by wet-chemical strategy. The characterization results confirm the successful synthesis of rGO-β-CD complex, which also exhibits high stability in polar solvent. In addition, the quantitative analysis reveals that rGO has excellent loading capacity for β-CD (up to 19 wt.%). Benefiting from the tightly stacked structure, the rejection rate of the rGO-β-CD membrane for rhodamine B (RhB), methyl orange (MO) and evans blue (EB) is nearly 100%. Furthermore, the membrane displays significantly lower copper ions permeation in mixed ion solutions, with a permeability of 0.05 mmol m-2 h-1. Importantly, the membrane exhibits specific adsorption for copper ions, resulting in a Zn2+/Cu2+ selectivity of 4.6. Based on the results, rGO-β-CD membrane was observed to be a promising material for wastewater treatment. This study provides a novel rGO-β-CD membrane to separate organic dyes and copper ions from wastewater.