▎ 摘　　要

Magnetic graphene oxide (MGO) was synthesized by co-precipitation and used as an adsorbent for the removal of methylene blue (MB) from aqueous solution in batch mode. Characterizations of the materials before and after modification were performed using several techniques such as scanning electron microscopy, Fourier transform infrared spectroscopy, vibrating-sample magnetometry, Raman spectra, X-ray photoelectron spectroscopy (XPS), etc. The effects of adsorbent dose, solution pH, common salt concentrations, MB concentration, and contacting time were systematically investigated. Results showed that the adsorption capacity at 313 K could reach up to 62.7 mg.g(-1). The optimal pH was 9 and the salinity was disadvantageous of MB adsorption. Equilibrium adsorption data were best fitted by Koble-Corrigan model, indicating that the adsorption process may be based on multi-layer heterogeneous adsorption and controlled by chemical adsorption process. The Elovich kinetic model can be used to describe the process of MB adsorption, indicating that the adsorption process may be the diffusion process of non-homogeneous phase. Thermodynamic analyses showed that the adsorption process was spontaneous, endothermic and entropic increase. In addition, the possible adsorption mechanism was also proposed based on the experimental results and XPS analysis. It is concluded that the mechanism of MB adsorption be mainly pi-pi bond and electrostatic force. Furthermore, MB-loaded MGO can be reused in a secondary adsorption for removal of congo red with the adsorption capacity of 319 mg.g(-1). Based on the results, it was inferred that MGO could be used as a promising adsorbent for dye removal.