UV–Visible spectroscopy and dielectric studies of ZnO/TiO2 composite

Pure metal oxides ZnO and TiO2 and their composite ZnO:TiO2 (1:1 weight ratio) were prepared by using conventional solid-state reaction technique. X-ray diffraction (XRD) measurement reveals the hexagonal phase for ZnO, whereas anatase phase has been identified for TiO2 sample. Rietveld refinements have been performed using FULLPROF code to verify the structural phase purity for all three samples. No clear evidence of other mixed phase can be realized for ZnO:TiO2 composite. Field emission scanning electron microscopy and particle size analyzer measurements provide modifications in the grain size and particle size for pure metal oxides and their composite sample. Optical behaviours of all samples have been investigated using UV–visible absorption spectroscopy, where it is evident that UV absorption gets improved for ZnO:TiO2 composite that can be advantageous application to reduce UV light hazards. Bandgap value for the composite is found to be higher than both the pure oxides, which verifies the surface modification approach in the lattice of the composite. Room temperature dielectric permittivity gets reduced in accordance with frequency, indicating a disability of dipoles to follow a higher electric field. It is also observed that the dielectric constant of the composite is found to be lower than both the pure ZnO and TiO2 samples. Investigations on dielectric loss indicate its lower values experienced by composite sample.