▎ 摘　　要

Graphene oxide-supported L-glutamic acid (L-Glu/GO) composite was synthesized by the nucleophilic substitution reaction. The composite was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The characterization indicates that L-Glu was successfully grafted onto the surface of GO nanosheets. The adsorption of methyl orange (MO) and Cr(VI) from aqueous solution on L-Glu/GO was investigated as a function of solution pH, adsorbent dosage and reaction time. The maximum adsorption capacities of MO and Cr(VI) on the L-Glu/GO composite at pH 2.0 and 25 degrees C were 123.9 and 38.9 mg/g, respectively. The Langmuir isotherm, Freundlich isotherm, and the pseudo-second-order kinetic model were used to explain the adsorption mechanism of the L-Glu/GO composite and it shows the adsorbent was inclined to multi-layer adsorption for MO and monolayer adsorption for Cr(VI). The adsorption was mainly a chemical process. The composite could be well regenerated using HCl solution. These results suggest that the L-Glu/GO composite can be applied as a promising adsorbent in water pollution cleanup.