Bovine Serum Albumin-Coated Graphene Oxide for Effective Adsorption of Uranium(VI) from Aqueous Solutions
journal contributionposted on 2017-03-10, 00:00 authored by Peipei Yang, Qi Liu, Jingyuan Liu, Hongsen Zhang, Zhanshuang Li, Rumin Li, Lianhe Liu, Jun Wang
Graphene oxide (GO) was modified by a carbodiimide-induced covalent cross-linking with bovine serum albumin (BSA), enriched with numerous amino and carboxyl functional groups, for radioactive uranium (UVI) removal. The adsorbent was confirmed through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). We investigated the effect of factors such as the pH, contact time, and initial concentration on the adsorption of UVI. In this work, the adsorption process closely fitted the Langmuir isotherm model, and pseudo-second-order indicates that chemical adsorption dominates the adsorption process of UVI onto GO–BSA composites. These results show that the optimal adsorption amount of UVI of GO–BSA composites was 389 mg g–1 at 298.15 K, pH = 6, C0 = 200 mg L–1, and t = 80 min. According to kinetics and the thermodynamic model as well as XPS analysis of pre- and postadsorption of UVI, we propose that the adsorption behavior of UVI onto GO–BSA adsorbent is divided into two stages: (1) chelation of the organic functional groups onto the surface of GO–BSA with UVI; (2) movement of UVI into the interior of the material after adsorption onto the surface. Moreover, the composites exhibit good adsorption efficiency in simulated seawater, indicating the potential of GO–BSA composites for UVI removal from seawater.