Investigation of superior electro-optical properties of SnO2/SiO2 nanocomposite over its individual counterpart SnO2 nanoparticles

A comparative investigation of SnO2/SiO2 nanocomposite with SnO2 nanoparticles has been conducted in the present study with the intent of learning the probable enhancement of the properties of the nanocomposite over those of the bare nanoparticles which has not been widely reported before. SnO2 nanoparticles and SnO2/SiO2 nanocomposite have been synthesized via the facile and versatile sol-gel method. The samples were characterized with X-Ray Diffraction (XRD), High Resolution Scanning Electron Microscopy (HRSEM), Brunauer Emmett Teller (BET) studies, Fourier Transform Infra-Red spectroscopy (FT-IR), UV-Visible (UV-Vis) spectroscopy and Field-dependent photo conductivity technique for the evaluation of their crystallite size, structure & morphology, surface, chemical, optical and electrical properties respectively. Scherrer's equation was used to determine the crystallite size of the as-synthesized samples from the XRD data. The particle size of SnO2/SiO2 nanocomposite as observed through HRSEM was found to be reduced when compared with the bare SnO2 nanoparticles suggesting a possible increase in the optical band gap of the former which has been further confirmed in the optical studies. The surface area of SnO2/SiO2 nanocomposite revealed a remarkable enrichment by approximately 5 folds in comparison with that of SnO2 nanoparticles which suggests an enhancement in its corresponding optical and electrical properties. The SnO2/SiO2 nanocomposite recorded appreciated values of field-dependent photo and dark currents with several folds of augmentation thereby qualifying as an efficient photoconducting material. Attributed with an improved surface area and increased photoconducting nature, the SnO2/SiO2 nanocomposite could be presented as an excellent photoanode material for nanomaterials based Dye Sensitized Solar Cells (DSSCs).