A Comparative Investigation on the Structural,Optical and Electrical Properties of SiO2-Fe3O4 Core-Shell Nanostructures with Their Single Components

The SiO-FeOcore-shell nanostructures were synthesized by sol-gel chemistry.The morphological features of the nanostructures were examined by field emission scanning electron microscopy which revealed the core-shell nature of the nanoparticles.X-ray diffraction studies evidenced the formation of SiO-FeOcore-shell nanostructures with high degree of homogeneity.The elemental composition of the SiO-FeOcore-shell nanostructures was determined by energy-dispersive X-ray spectroscopy analysis.Fourier transform infrared spectroscopy showed the Si-O-Fe stretching vibrations.On analysis of the optical properties with UV-Vis spectra and Tauc’s plot,it was found that the band gap of SiO-FeOcore-shell nanostructures diminished to 1.5 eV.Investigation of the electrical properties of the core-shell nanostructures using field-dependent conductivity measurements presented a significant increase in photoconductivity as compared to those of its single components,thereby rendering them as promising candidates for application as photoelectrodes in dye-sensitized solar cells.