Synthesis and Characterization of Nanostructured Materials Based on Metal Oxides for Sensor Applications

This paper describes the methodology of synthesis and characterization in nanostructured samples based on alumina and tin oxide for potential applications as gas sensors. In the process 99.95% purity aluminum sheets were used, in which an anodizing process was applied to form the nanoporous templates of alumina. Subsequently, the samples with the alumina formed are used to introduce tin material by electrodeposition, which were sintered at 400, 450, 500 and 550 °C, in order to analyze the formation of stannic oxide. The characterization of the samples was carried out through scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and capacitive tests. The SEM images analyzed by Image J present a homogenous distribution of pores with a resulting porosity level of 18.6%. The morphological parameters obtained from these images indicate a pore size of average diameter at 24.0 nm, and a nanoporous film thickness of 12.0 μm. The resulting value of the pore density in the samples was 4.46x10^10 pores/cm2. The analysis of the X-ray diffraction patterns indicates the formation of the nanocrystalline rutile phase structure, mainly for samples sintered at 550 °C. The presented results show that the methodologies used in the synthesis of tin oxide nanowires produce good quality nanostructures with potential applications as gas sensors.