Characterization, uniformity and photo-catalytic properties of graphene/TiO₂ nanocomposites via Raman mapping

Three types of anatase TiO₂, graphene-TiO₂, TiO₂-graphene composites (G/TiO₂) were developed, synthesized via a combination of simple sol-gel self-assembly method and additional thermal annealing process. Their structures and properties are determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and Raman spectrum analysis. In addition, Raman spectra of TiO₂ and graphene, the band shift and intensity of G and 2D band were analyzed, in order to verify the mutual coupling between TiO₂ and graphene. Combined Raman mapping with AFM analysis, the agglomeration effect of TiO₂ nanoparticles was figured out by quantitative analysis. Finally, the photo-catalytic properties of three kinds of composites were experimentally studied via Raman mapping measurements. The results reveal that graphene with high electron mobility, as an acceptor through interfacial interactions, was certificated to enhance the photo-catalytic effect of TiO₂.