▎ 摘　　要

Due to the well dispersibility of graphene oxide (GO) in aqueous solution, it is very difficult to separate GO after adsorption. Therefore, various organic/inorganic molecules have been composited with GO to produce novel adsorbents with relatively lower dispersibility and better adsorption performance. The rational selection of these organic/inorganic molecules seems very important. In this work, three-dimensional (3D) (graphene oxide-N-benzyloxycarbonylglycine) GO-ZG composites were synthesized by an easy-to-operate, one-step hydrothermal method. The 3D GO-ZG composites were illustrated by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM), powder x-ray diffraction (PXRD), Raman spectroscopy and specific surface area (SSA) analysis. The effects of GO-to-ZG mass ratio (x: y), hydrothermal reaction time, and hydrothermal reaction temperature were investigated. The adsorption properties of 3D GO-ZG(x:y) composites toward rare earth elements (REEs) were studied. The results showed that the composite with a GO-to-ZG mass ratio of 2:1, reaction time of 6 h, and reaction temperature of 120 degrees C possessed the best adsorption performances. Further investigation of the adsorption conditions on 3D GO-ZG(2:1/6) (h/120) degrees(C) composites toward REEs including initial solution pH value, contact time, initial REE 3+ concentration, and contact temperature was carried out. The adsorption of REEs could reach equilibrium in 60 min at room temperature. The adsorption capacities of 3D GO-ZG(2:1/6) (h/120) degrees(C) composite for La3+, Yb3+, Nd3+, Er3+ and Y3+ were 44.56, 53.64, 45.96, 50.48 and 30.63 mg.g(-1), respectively. Ten adsorption/desorption cycles revealed that GO-ZG(2:1/6) (h/120) degrees(C) composite possessed good stability and recoverability. The adsorption mechanism of REEs by GO-ZG(2:1/6) (h/120) degrees(C) composite can be summarized as ion exchange, surface complexation, and electrostatic attraction. The as-prepared GO-ZG(2:1/6) (h/120) degrees(C) composite might be used as a renewable and structurally stable adsorbent in the adsorption.