One-step synthesis of an environment-friendly cyclodextrin-based nanosponge and its applications for the removal of dyestuff from aqueous solutions

Cyclodextrin-based nanosponges (CDNS) are a novel kind of polymers belonged to cross-linked derivatives of cyclodextrins, and they are safe, biodegradable materials with appreciable toxicity to the environment. In this work, CDNS were fabricated in one-step solvothermal method by β-cyclodextrin (β-CD) and diphenyl carbonate (DPC), for the removal of dyestuffs from wastewater using two of the familiar dyes as the model contaminant. It was systematically investigated by the influence of the amount of adsorbent, the molar ratio of β-CD and DPC, pH, time, and initial concentration. Experimental results showed the maximum adsorption capacities of Basic red 46 and Rhodamine B were 101.43 mg/g and 52.33 mg/g, the adsorption behavior of two contaminants followed pseudo-second-order model and the Langmuir monolayer adsorption models. The differences in adsorption capacities on two model contaminants might due to the influence of dye structure. In conclusion, cyclodextrin-based nanosponges are a promising kind of environment-friendly materials in water treatment.