| Flowerlike architectures constructed with SnO nanosheets, spherical flowerlike architectures assembled with SnO2submicron rods, SnO2nanospheres, SnO2pencil-like nanorods and Ag/SnO2composite microspheres were synthesized through direct reaction and hydrothermal routes. Morphologies and structures of these products were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction and IR spectrum. The processes of nucleation, growth, self-assemble of SnO and SnO2nanostructures with various geometrical morphologies were studied, and the possible growth mechanisms of SnO and SnO2nanostructures were proposed. The photoluminescence, photocatalytic behaviors, and gas-sensing properties of SnO and SnO2nanostructures with various morphologies were studied, and the relations between morphologies, size and properties were investigated. These research results would provide a base for further research on synthesises of SnO and SnO2nanostructures, the physical and chemical properties of SnO and SnO2nanostructures and their applications in photonic and electronic devices, lithium ion storage, gas sensor, solar cell and photocatalyst.(1) Flowerlike architectures constructed with SnO nanosheets were prepared via a direct reaction of SnO2·2H2O with NaOH at room temperature. The SnO flowerlike architectures with diameters of7to9μm are constructed from tetragonal SnO nanosheets with diameters of3to5μm and the thicknesses of200to500nm. The influence of different tin source on morphologies of the products was investigated, and a possible growth mechanism was proposed. The photoluminescence and photocatalytic activity of SnO nanosheet-based flowerlike architectures were studied at room temperature. The results indicate that the flowerlike architectures constructed with SnO nanosheets display a strong band edge emission at390nm and a very weak Sn vacancy related emission at482nm. The flowerlike architectures constructed with SnO nanosheets were effective photocatalyst for the degradation of malachite green. The photodegradation of malachite green catalyzed by the SnO nanosheet-based flowerlike architectures is a pseudo first-order reaction.(2) The spherical flowerlike architectures assembled with SnO2submicron rods were synthesized via a simple hydrothermal reaction of SnCl4-5H2O with NaOH and PVP at200℃for24h. The SnO2spherical flowerlike architectures with diameters of1.7to2.0μm are constructed from submicron rods with diameters of300to600nm. The role of PVP in the growth of spherical flowerlike architectures assembled with SnO2submicron rods was investigated, and a possible growth mechanism was also proposed. The influences of temperature and film thickness on the gas sensing properties of the SnO2spherical flowerlike architectures were investigated. The gas sensing properties of the SnO2spherical flowerlike architectures sensors toward ethanol and triethylamine with different concentration were tested. The sensor response of SnO2spherical flowerlike architectures toward105ppm ethanol and45ppm triethylamine at350℃is3.65and2.97, respectively. The response performance of the sensors based on the SnO2spherical flowerlike architectures toward ethanol and triethylamine is better than that of SnO2powders.(3) The SnO2nanospheres with the diameters of about230nm were synthesized via a simple hydrothermal reaction of SnCl2·2H2O with H2C2O4·2H2O and PVP at200℃for12h. The role of H2C2O4·2H2O and PVP in the growth of SnO2nanospheres was investigated, and a possible mechanism was also proposed. The gas sensing properties of the SnO2nanospheres sensors toward methanol, formaldehyde, triethylamine and acetone with different concentration were tested. The sensor response of SnO2nanospheres toward30ppm methanol,16ppm formaldehyde,9ppm triethylamine and85ppm acetone at350℃is1.49,1.47,1.62and1.5, respectively. The response performance of the sensors based on the SnO2nanospheres toward methanol, formaldehyde, triethylamine and acetone is better than that of SnO2spherical flowerlike architectures. The photocatalytic activity of the as-prepared SnO2nanospheres for the degradation of organic pollutants was studied, and the results indicate that the SnO2nanospheres were effective photocatalyst for the degradation of malachite green.(4) The SnO2pencil-like nanorods were synthesized via a simple hydrothermal reaction of SnCl4·5H2O, NaOH, Na3C6H5O7·2H2O and PVP at220℃for24h. The diameters and lengths of the SnO2pencil-like nanorods are320to550nm and2.1to2.9μm, respectively. The role of PVP and Na3C6H5O7·2H2O in the growth of SnO2pencil-like nanorods was investigated, and a possible mechanism was also proposed. The gas sensing properties of the SnO2pencil-like nanorods sensors toward methanol, triethylamine and ethanol with different concentration were tested. The sensor response of SnO2pencil-like nanorods toward30ppm methanol,9ppm triethylamine and21ppm ethanol at350℃is1.11,2.96and1.35, respectively. The response performance of the sensors based on the SnO2pencil-like nanorods toward methanol, triethylamine and ethanol is better than that of SnO2powders.(5) The Ag doped Ag/SnO2composite microspheres with diameters of550to850nm were synthesized via a simple hydrothermal reaction of SnCl4·5H2O with NaOH and AgNO3in the presence of PVP at200℃for24h. The influence of AgNO3with different quantity on the growth of the Ag/SnO2composite microspheres was investigated. The gas sensing properties of the Ag/SnO2composite microspheres sensors toward acetone, methanol, triethylamine and ethanol with different concentration were tested. The sensor response of the Ag/SnO2composite microspheres toward17ppm acetone,30ppm methanol,5ppm triethylamine and21ppm ethanol at350℃is2.04,1.92,2.74and2.04, respectively. The response performance of the sensors based on the Ag/SnO2composite microspheres toward acetone, methanol, triethylamine and ethanol is better than that of Ag-undoped SnO2microspheres. The photocatalytic activity of the as-prepared Ag/SnO2composite microspheres for the degradation of organic pollutants was studied, and the results indicate that the Ag/SnO2composite microspheres were effective photocatalyst for the degradation of malachite green. The photocatalytic ability of the Ag/SnO2composite microspheres is stronger than that of the Ag-undoped SnO2microspheres. |
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