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

Abstract

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 84wt%, while it is 71% for pure TiO2. rGO plays a key role in the charge recombination to enhance the electron hole separation.