Oxidized carbon materials cooperative construct ionic imprinted cellulose nanocrystals films for efficient adsorption of Dy(III)

Abstract

Selectively extracting high-value rare earth elements from scrap rare earth products is a measure that combines economic and environmental benefits. In this paper, TEMPO-mediated oxidation of cellulose nanocrystals (CNCs) acted as film units, oxidized carbon materials were involved in the cooperative construction of high-performance CNC composite films, and applied them for selective adsorption of Dy(III). The carboxyl groups on multi-walled carbon nanotube and graphene oxide provide additional binding sites with Dy(III), thereby achieving improvement on mechanical properties and adsorption performance. Based on the surface ion-imprinted polymers, stable imprinted structure sites were distributed on the surface of films, which could effectively improve adsorption capacity and selectivity. When pH was 4.0, saturated adsorption capacities of CNC films were in the range of 22.57–34.03 mg g−1. Further, in selective experiments, materials exhibited preferential adsorption for Dy(III) with a partition coefficient of 872.266 mL g−1. Reusability tests revealed film materials have a strong regeneration performance. Overall, the green, highly efficient and non-toxic CNC composite films are expected to provide a novel method for recycling REEs.