Hydrothermal synthesis of graphene-ZnTiO3 nanocomposites with enhanced photocatalytic activities

Pure phase ZnTiO 3 was prepared through a sol–gel process, then graphene-ZnTiO 3 nanocomposites were synthesized by a hydrothermal method using the prepared ZnTiO 3 nanoparticles and graphene oxide as precursors. X-ray diffraction results revealed the production of pure cubic ZnTiO 3 at 600 °C. ZnTiO 3 was anchored on the graphene nanosheets, demonstrating a spherical morphology in transmission electron microscope images. The existence of chemical bond Ti–O–C in the nanocomposites was proved by Fourier-transforming infrared spectroscopy. UV–Vis diffusive reflection spectra indicated that the absorption edge of the nanocomposites shifted towards the visible region. The photocatalytic activity of the composites was tested through the photocatalytic degradation of methyl blue under simulated solar irradiation. The results showed that the photocatalytic activity of the nanocomposites was obviously increased in contrast to pure ZnTiO 3 , which was strongly affected by the crystalline structure of ZnTiO 3 and the concentration of graphene. The enhanced photocatalytic activity was mainly attributed to the conglomeration inhibition of ZnTiO 3 nanoparticles, the electron transfer between ZnTiO 3 and graphene and the extended absorption range. Furthermore, other contaminants such as tetracycline, Rhodamine B and methyl orange were tested under the same conditions to investigate the photocatalytic performance of the photocatalysts. The reusability tests indicated that the prepared composites exhibited good stability.