Synthesis and characterization of nanostructured materials (SnO2 and Al2O3) for potential applications as gas sensors

Abstract

This paper describes the synthesis, morphological and structural characterization of nanoporous aluminum oxide templates (Al2O3) and tin oxide nanowires (SnOx). The templates of Al2O3 with tin deposition were treated thermally at 400, 450, 500 and 550 °C to obtain tin oxide (SnOx). The different samples were characterized by Scanning Electron Microscopy (SEM), Dispersive Energy Spectroscopy (EDS) and X-ray Diffraction (XRD). SEM images present a homogeneous pore distribution over the templates of Al2O3 with an estimated porosity value of 19.7%. The morphological parameters obtained from these images show pores size with an average diameter of 24.4 nm, and a nanoporous template thickness of 12.0 µm. Pore density was estimated in samples of approximately 4.27 x107 pores/cm2. The XRD patterns of the prepared samples evidence the formation of the nanocrystalline structure phase rutile, SnO2, for the sintered samples at 550 °C. The properties of nanostructured materials from SnO2 are responsible for many technological applications that are interesting in the field of material science. The results presented demonstrate that the methodologies used in the synthesis of nanowires from SnO2 produce a good quality nanostructure for potential applications such as gas sensors.