Exceptional cerium(III) adsorption performance of poly(acrylic acid) brushes-decorated attapulgite with abundant and highly accessible binding sites

Abstract

Numerous adsorbents have been used for recovery of rare earth ions, but very few of them simultaneously possess the advantages of high adsorption capacity and fast adsorption kinetics. In the present work, a novel rod-like nanocomposite, poly(acrylic acid) brushes-decorated attapulgite (PAA@ATP), was synthesized by a simple, fast, and previously unreported surface-initiated polymerization, and its cerium ion (Ce3+) adsorption performance was systematically investigated. Due to the presence of abundant and highly accessible carboxyl groups in the PAA brushes, PAA@ATP nanocomposite demonstrated exceptional adsorption properties in terms of adsorption capacity and adsorption kinetics on recovery of Ce3+ ions. Under optimized conditions, the Ce3+ adsorption capacity of PAA@ATP reached 295.4mgg−1, which was significantly higher than the Ce3+ adsorption capacities for most reported adsorbents. Moreover, at an initial Ce3+ concentration of 50mgL−1, the time to reach equilibrium for Ce3+ adsorption was as short as 1min. Even at very high initial Ce3+ concentration (i.e., 200mgL−1), the adsorption reached saturation within 20min. Overall, this work not only provides a new insight into the fabrication of PAA brushes-decorated attapulgite nanocomposite but also demonstrates its adsorptive application for recovery of rare earth ions.