Synthesis and visible catalytic applications of graphene–titania dioxide nanotube composites

A novel photocatalyst of graphene–titania dioxide nanotube (GN–TNT) composites was prepared using a simple hydrothermal reaction with ascorbic acid as a reducing agent. High resolution transmission electron microscope (HR-TEM), fourier transform infrared spectrometer (FT-IR), thermo gravimetric analyzer (TGA) and N2 adsorption/desorption analyzer (BET) methods were used to assess the morphologies and structures of as-synthesized materials. HR-TEM analysis further confirmed the presences of graphene and titanium (TiO2) nanotubes in the nanocomposite photocatalyst. The results exhibited that photocatalytic performance of a GN–TNT photocatalyst significantly improved under visible light. In addition, the existence of a competitive effect between As3+ and reactive black 5 (RBK5) molecules in the mixed solution was found. The photocatalytic process is also discussed in this paper.