▎ 摘　　要

In the present study, a novel nanocomposite based on CuCo2O4 and N-doped graphene quantum dots (N-GQDs) as an iron-free heterogeneous Fenton-like catalyst was prepared by a two-step solvothermal method. The surface morphology, chemical structure, crystal phase, surface area and pore size distribution of the synthesized nanocomposite were characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Fourier Transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high resolution transmittance electron microscopy (HRTEM) and N-2 adsorption-desorption analysis. The results showed that the N-GQDs play a significant role in the enhancement of the catalytic degradation of methylene blue (MB) as a model contaminant. The CuCo2O4/N-GQD nanocomposite exhibited a higher degradation rate of about 47 times higher than that of pristine CuCo2O4. This promotion can be attributed to the higher surface area of the CuCo2O4/N-GQD nanocomposite compared to pristine CuCo2O4 as well as the synergistic effects between the N-GQDs and CuCo2O4. The effects of pH, catalyst mass and the initial concentration of H2O2 on the catalytic degradation of MB were investigated using Box-Behnken design. Finally, the dominant reactive oxygen species generated in the degradation process were identified and the possible mechanism of the catalytic degradation of MB was proposed.