Synthesis and study of the SnO2 nanowires growth

In this study, tin dioxide (SnO2) nanowires were synthesized on a silicon substrate (1 1 1) using a direct gas reaction route on a large scale at 800 °C. These SnO2 nanowires were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman-scattering spectroscopy. XRD, SEM and TEM indicated that the products were tetragonal SnO2 nanowires with lattice parameters of a = 4.73 Å and c = 3.17 Å. Three vibration modes were observed at 478, 634, and 776 cm−1 in the Raman spectra of the samples. Complex impedance analysis of SnO2 nanowires well fitted with a simple RC electrical model. According to the current–voltage (I–V) measurements, it was found that the SnO2 nanowires were a good sensing for detecting carbon monoxide. The response to 500 ppm CO of the SnO2 nanowires reached 60%.