Synthesis of well-dispersed TiO₂@reduced graphene oxide (rGO) nanocomposites and their photocatalytic properties

In this work, graphene oxide (GO) nanosheets were prepared using a modified Hummers technique and as-obtained GO nanosheets were converted into particles by a spray drying method. Titanium dioxide (TiO₂) nanoparticles were grown on the surface of GO particles to get TiO₂@reduced graphene oxide (rGO) nanocomposites. Morphologies and structures of as-prepared pure TiO₂ nanoparticles, rGO particles and their composites were characterized by scanning electron microscope, transmission electron microscope and X-ray diffractometer. The photocatalytic activities of TiO₂@rGO nanocomposites were evaluated using UV-vis spectroscopy for the degradation of methylene blue. All the composites show better photocatalytic activities upon degradation of methylene blue than pure TiO₂. The degradation rate of methylene blue is 92% for TiO₂@rGO nanocomposites with TiO₂ mass ratio of 84 wt%, while it is 71% for pure TiO₂. rGO plays a key role in the charge recombination to enhance the electron hole separation.