Synthesis of Flower-Like Co9S8/Reduced Graphene Oxide Nanocomposites and Their Photocatalytic Performance

The novel flower-like Co 9 S 8 /reduced graphene oxide (rGO) microsphere nanocomposites were synthesized using wet chemical method in combination with a spray drying technique. The structures and morphologies of as-synthesized Co 9 S 8 /rGO nanocomposites were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results reveal that Co 9 S 8 is homogeneously dispersed on the surface of rGO microspheres. The significantly enhanced photocatalytic activity of Co 9 S 8 /rGO nanocomposites in comparison with a pure Co 9 S 8 was investigated by the degradation of methylene blue (MB) using ultraviolet (UV) spectroscopy. The photodegradation ratios of MB using flower-like Co 9 S 8 /rGO nanocomposites with a Co 9 S 8 mass ratio of 67.3, 35.3 and 55.6 wt% are about 86.7, 92.0, and 98.7%, respectively, after irradiation for 80 min. By comparing the nanocomposites and pure flower-like Co 9 S 8 , the pure Co 9 S 8 showed less photocatalytic activity upon the degradation of MB than the nanocomposites. It can be attributed to the improved electron–hole pair separation and enhanced adsorption due to the presence of rGO microspheres.