Hydrophobic-polymer-grafted graphene oxide nanosheets as an easily separable adsorbent for the removal of tetrabromobisphenol A.

Hydrophobic polymer brushes have been grafted from graphene oxide nanosheets (GO) via the facile surface-initiated redox radical polymerization of tert-butyl acrylate (tBA) from the GO with cerium ammonium nitrate (CAN) as an oxidant. After the hydrophobic surface modification, the poly(tert-butyl acrylate) (PtBA)-grafted graphene oxide nanosheets (GO-PtBA) could still be dispersed in water because of the remaining oxygen-containing groups but deposited within 40 min. The feature makes it an easily separable adsorbent for environmental pollutants. For example, tetrabromobisphenol A (TBBPA) could be removed from aqueous solution via hydrogen bonds (between hydroxyl groups of TBBPA and hydroxyl and carboxyl groups of GO) and π-π interactions (between the benzene ring of TBBPA and GO), with an adsorption capacity of 22.2 mg g(-1) at pH 7.0. The TBBPA-adsorbed GO-PtBA could be deposited completely within 30 min, and the adsorbed TBBPA could be easily desorbed with ethanol, demonstrating its good recyclability.