Characterization of ZnO-TiO2-coated tapered fibres synthesized by a low-temperature hydrothermal method

We characterize ZnO-nanorod fibres doped with different concentrations of TiO2 powder which is introduced on the final stage of synthesis of ZnO nanorods, using a low-temperature hydrothermal method. Their surface morphology, size of particles, behaviour of crystallites and optical properties are investigated using techniques of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and an optical spectrometer. A presence of ZnO nanorods and a globular structure of TiO2 are confirmed by the SEM analysis. The EDS spectra and chemical-element mapping reveals a presence of Ti incorporated into a globular surface, along with Zn. The XRD analysis testifies that ZnO doped with TiO2 has a primary crystallite phase of ZnO. ZnO doped with 10 and 15 mM of TiO2 shows a stronger and more expressed peak corresponding to (002) and (011) planes, which implies improved crystallinity of ZnO-TiO2 system. Optical properties of ZnO-TiO2 are studied by measuring the intensity of halogen-source light transmitted through the fibres. The ZnO & 15 mM TiO2 fibre sample shows the lowest intensity of the transmitted light due to higher refractive index of a cladding layer coated under condition of high TiO2 concentration. The increased light leakage in such a fibre can improve sensitivity of a relevant sensor, especially a gas one.

Automated summary

In this study, ZnO nanorod fibers doped with different concentrations of TiO2 powder were synthesized using a low-temperature hydrothermal method. The surface morphology, crystallite behavior, and optical properties of the fibers were investigated. The results showed that the TiO2 doping improved the crystallinity of the ZnO nanorods and resulted in higher refractive index.