High-flux nanofiltration membranes prepared with β-cyclodextrin and graphene quantum dots

In this study, high flux β-CD/GQDs nanofiltration (NF) membranes were prepared by interfacial polymerization with β-cyclodextrin (β-CD) as the aqueous monomer, graphene quantum dots (GQDs) as the additive and trimesoyl chloride (TMC) as the organic monomer. The addition of GQDs not only modulated the membrane surface properties, but also led to the formation of a loose selective layer due to the nonspecific hydrogen bonding interactions between GQDs and β-CD. The pure water flux of the β-CD/GQDs NF membranes increased from 122.2 to 474.7 L/m2h (at the pressure of 0.1 MPa) when the concentration of GQDs increased from 0 to 0.5 wt%, almost 3.9 times higher than that of the pristine β-CD membrane. The dye rejection of Eriochrome Black T and Congo Red essentially remained above 93.0%. The β-CD/GQDs NF membranes with superior filtration performance and excellent chlorine resistance hold great promise in dye wastewater treatment.