Optical and structural properties of titanium dioxide nanoparticles fixed on graphene oxide due to heat treatment

In this paper, we study the decorated graphene oxide with titanium dioxide nanoparticles. In order to produce this nanomaterial, the titanium dioxide nanoparticles were produced and anchored simultaneously on graphene oxide sheets by arc current. The morphology of the prepared samples was studied by scanning and tunneling electron microscopy, showing that nanoparticles were stabilized on the graphene oxide sheets. Investigating the optical band gap by the Tauc plot of the UV-visible spectrum showed that the band gap energy of the nanomaterials was first reduced and then increased by raising the annealing temperature; the lowest band gap with a value of 2.2 eV was related to the samples annealed at 600 ° C. In addition, the X-ray diffraction patterns showed the crystalline structure of nanoparticles was a mixture of anatase and rutile phase, in which the ratio of two phase changed for different annealing temperatures. In addition, the crystallite size of the anatase phase was always smaller than the rutile one.