Abstract
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► A method has been developed to synthesize metal and metal oxide nanostructures in high yields on the surface of SiO2/Si substrate. The capability for growth of nanomaterials by simple manner makes the present method attractive for a creation of new nanostructures for various nanoscale device applications. ► Spherical gold nanoparticles with a size of 15
nm and nanowires with a diameter of 70
nm were synthesized. SnO
2 rough microwires, smooth nanowires, and nanoknives were synthesized by using Sn granules, SnO powder, and SnO
2 powder as source materials, respectively. ► Nanocomposite gas sensors on the base of noble metal (Au) and metal oxide were fabricated. The results demonstrated that gold doping improved the sensor response to NO
2 gas.
A method has been developed to synthesize metal and metal oxide nanostructures in high yields on the surface of SiO
2/Si substrate. In this method, starting materials in a covered alumina crucible are thermally evaporated under a high vacuum or a low pressure of ambient air. Spherical gold nanoparticles with a size of 15
nm and nanowires with a diameter of 70
nm were synthesized. SnO
2 rough microwires, smooth nanowires, and nanoknives were synthesized by using Sn granules, SnO powder, and SnO
2 powder as source materials, respectively. The microwires showed a quadrangular cross section and a length of several microns, while the nanowires showed a circular cross section and approximately the same length. The effects of source temperature and deposition time on nanostructure growth were studied. X-ray diffraction patterns suggested that the as-synthesized products consisted of crystalline nanostructure. Nanocomposite gas sensors on the base of noble metal and metal oxide were fabricated. These SnO
2 nanowire gas sensors showed a reversible response to dilute NO
2 gas at operating temperatures ranging between room temperature and 300
°C even at high concentrations. The results demonstrated that gold doping improved the sensor response.