Study On Gas-sensing And Photocatalytic Properties Of Metallic Oxides Low-dimensional Nanomaterials Based On Special Morphologies

The recent developments in nanotechnology opened new perspectives for many applications both for industry and society, which therefore lead to their increased use in commercial products. Semiconductor metallic oxide (SMO) nanomaterials played important roles in catalytic, environmental hygiene, sensors, luminous materials, magnetic materials, electrode materials, biomedical detection owing to their unique chemical and physical properties. Nowadays, researches on semiconductor metal oxide are focused on nanoparticles, nanofibers and nanobelts. In order to study their properties, it is necessary to prepare metal oxide nanomaterials with special morphologies. Electrospinning is the best choice to prepare one-dimensional nanomaterials due to its convenient operation, few synthesis steps and controllable morphology and size. Hence, it is an imperative and meaningful subject of study to prepare metallicoxides semiconductor nanomaterials with special morphology via electrospinning and to investigate their properties.A series of semiconductor metallic oxides with special morphologies were prepared through improvement of spun device in this dissertation, such as, SnO2/TiO2bistrand aligned nanobundles, ZnO//CeO2bistrand aligned nanobundles and ZnO/CeO2composite nanofibers, SnO2/NiO/ZnO tristrand aligned nanobundles and SnO2/NiO/ZnO composite nanofibers, SnO2//NiO//Fe2O3tristrand aligned nanobundles and SnO2/NiO/Fe2O3composite nanofibers, ZnO/CeO2/CdO tristrand aligned nanobundles and ZnO/CeO2/CdO composite nanofibers, ZnTiO3/SnO2/ZnTiO3tristrand aligned nanobundles. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS) and BET specific surface area analyzer were utilized to characterize the as-synthesized samples. The results showed that the width of bistrand aligned nanobundles was150-250nm, the width of tristrand aligned nanobundles was500nm-1μm, and obvious contact interface between the single fibers of the nanobundles can be seen.The photocatalytic activities of the prepared samples were studied by taking methyl orange, rhodamine B (RB) as degradation agents. The results demonstrated that, under UV light irradiation for90min, the degradation efficiency of methyl orange was98.0%for SnO2/TiO2bistrand aligned nanobundles. The degradation efficiency of RB was ca.97.1%for ZnO//CeO2bistrand aligned nanobundles, which exhibited higher photocatalytic activity than ZnO/CeO2composite nanofibers. The degradation efficiency of RB was about97.4%for SnO2//NiO//ZnO tristrand aligned nanobundles, which also demonstrated higher photocatalytic activity than SnO2/NiO/ZnO composite nanofibers. The sensor performance of SnO2/TiO2bistrand aligned nanobundles to ethanol, acetone and other gases were also studied, the results indicated that SnO2/TiO2bistrand aligned nanobundles has excellent selectivity and fast response recovery time to ethanol.