▎ 摘　　要

In this work, cotton-like Fe2O3-reduced graphene oxide (rGO) composites were synthesized by a one-step microwave-assisted hydrothermal method, using ferrous sulfate (FeSO4) precursor in graphene oxide (GO) solution. The as-obtained products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared (FT-IR) spectra. The results indicated that the cotton-like Fe2O3 was successfully anchored on graphene sheets with a homogeneous distribution. To demonstrate the potential applications, the sensor was fabricated by using the cotton-like Fe2O3-rGO composites for detection of NO2 at room temperature. The testing results demonstrate that the sensor exhibited an excellent selectivity and a significant response to NO2 with a concentration lower to 1 ppm. The present study may serve as a facile and green approach for preparing graphene materials modified with metal oxides to improve their sensing performances.