Synthesis of Reduced Graphene Oxide Wrapped TiO2 Ball Composites for Enhanced Photodegradation of Methylene Blue

Reduced graphene oxide wrapped TiO2 ball composites (RGO-TiO2) were synthesized via two step hydrothermal process. SEM analysis indicated the formation of TiO2 balls with average size of 2.8 μm and the RGO sheets were wrapped on the surface. XRD characterization indicated the formation of anatase phased TiO2 after the annealing treatment while UV-vis and FTIR spectroscopy confirmed that the graphene oxide in the resulting material was in the reduced form. The photocatalytic activity of as-prepared RGO-TiO2 composites were determined by the photodegradation of methylene blue under UV illumination. More specifically, the RGO-TiO2 composites can completely degrade methylene blue solution within 50 min. The degradation rate constant of using RGO-TiO2 composites were twice higher than pure TiO2 balls. The main reason of enhanced photocatalytic property might be the increased adsorption capacity, and the strong electron transfer ability of RGO sheets in the composites as well as the retarded charge recombination rate of the energy level of the two components. In addition, the RGO-TiO2 composites also exhibited an excellent reusability. We believe that this TiO2 based composite material can be effectively used as a highly active and stable photocatalyst to remove various pollutants.