▎ 摘　　要

In this study, a facile covalent conjugation method was utilized to prepare N, N-bis(2-hydroxyethyl)glycine (Bicine) modified graphene oxide (GO), which was employed for the adsorption and separation of phenols, organic dyes and REE3+(Y3+, Nd3+, Eu3+) from aqueous solution. Various characterizations including scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and BrunauerEmmett-Teller were carried out. The adsorption capacities of GO-Bicine composite for REE3+, phenols and dyes were also investigated. GO-Bicine composite showed some differences in adsorption capacities for various contaminants. The adsorption capacity for Y3+ was 4.8 times and 6.8 times higher than that for Nd3+ and Eu3+. While the adsorption capacity for p-nitrophenol was 1.4, 5.7, 2.4, 1.3, 1.7 times higher than those for 1-naphthol, hydroquinone, p-aminophenol, 3-nitrophenol, tert-butyl hydroquinone. For the adsorption of organic dyes, GO-Bicine composite showed high adsorption capacity for methylene blue, which was 4 times higher than that for alizarin yellow R. Complexation, electrostatic interactions and Lewis acid-base interactions were involved in the adsorption of REE3+, while electrostatic interactions, pi-pi stacking interactions, and hydrogen bonding interactions were considered as the main adsorption mechanisms for phenols and dyes. The adsorption of p-nitrophenol on GO-Bicine composite fitted well with the Langmuir isothermal model. The adsorption thermodynamics demonstrated that the adsorption of p-nitrophenol by GO-Bicine composite was endothermic and spontaneous. The adsorption selectivity of GO-Bicine composite will make it be a potential adsorbent for removal or separation of different pollutants from aqueous solutions.