Synthesis of highly dispersed and versatile anatase TiO2 nanocrystals on graphene sheets with enhanced photocatalytic performance for dye degradation

A highly dispersed and versatile anatase TiO2 nanocrystal on graphene sheets (TiO2-G) was synthesized by a simple solvent thermal method. The structural and optical properties of the as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-Vis absorption spectroscopy and Raman spectra. The results show that the anatase TiO2 nanocrystals with approximately 20-30 nm size are well distributed on the graphene sheets, and the introduction of graphene increases the light absorption intensity in visible light region. Noticeably, the TiO2-G exhibits excellent photocatalytic activity and reusability, and can be applied to the degradation of various organic dyes, such as methyl orange (MO), methyl blue (MB) and rhodamine-B (RhB). This unique TiO2-G composite photocatalyst proved to have great potentials for organic contaminants degradation in wastewater.