| WO3and MoO3have very stable physical and chemical properties, which became one focus of current research in materials science due to the excellent characteristics in many areas, such as optical, catalytic, electrical, gas sensing application, as well as in other fields. WO3and MoO3nanomaterials were prepared by hydrothermal method in this paper. Then, the morphology and microstructure of the as-obtained products were studied using the technology of X-ray Diffraction, Scanning Electron Microscope, Raman Spectra, Transmission Electron Microscope, Fourier-Transform Infrared Spectrography, X-ray Photoelectron Spectroscopy, Energy Dispersive Spectra, Brunauer-Emmett-Teller. Moreover, the effect of growth conditions on WO3and MoO3nano structures were expatiated, their growth mechanisms were discussed, and their properties and applications were investigated. The main contents are as follows:1. The white WO3powders were prepared using sodium tungstate and sodium hydrogen sulfate as raw materials under180℃for24hours with hydrothermal method. The as-synthesized products were characterized by Scanning Electron Microscope, Transmission Electron Microscope, Energy Dispersive Spectra, X-ray Diffraction, X-ray Photoelectron Spectroscopy, Raman Spectra, Fourier-Transform Infrared Spectrography, Brunauer-Emmett-Teller. It is shown that the obtained product was a hexagonal WO3with the morphology of nanotube bundles. While other conditions remain unchanged, other inorganic acids such as potassium bisulfate and ammonium hydrogen sulfate were used instead of sodium bisulfate in the reaction system. As a result, the WO3nanotube bundles with good crystalline were not obtained. The results indicate that the sodium bisulfate can affect the morphology of the products. What’s more, the obtained WO3nanotube bundles also were studied in water treatment.2. The blue WO3powders were synthesized utilizing sodium tungstate, sodium hydrogen sulfate, ethylene glycol as raw materials under180℃for24hours with hydrothermal method. The suitable ratio of ethylene glycol and water is1:1through investigation. It is found that the reaction time has a greateimpact on the morphology of the products. Based on the reaction time and the alcohol-water ratio, the reaction mechanism was proposed. Finally, the obtained WO3nanotube bundles also were studied in gas sensing area.3. The fairly monodisperse smaller silver nanoparticles were fabricated through the reaction of silver ions with EG by using tungstates (such as potassium tungstate, sodium tungstate) as catalysts at room temperature. Particularly, in this method, tungstates as catalysts can dramatically speed up the reduction of silver ions, and EG acts as both a solvent and a reducing agent to reduce silver ions to Ag metal. Compared with the WO3nanotube bundles, the composite containing silver has good gas sensing property. The results showed that adding silver into WO3nanotube bundles can improve the gas sensing sensitivity.4. The blue MoO3powders were synthesized utilizing sodium molybdate and sodium dodecylbenzene sulfonic acid as raw materials under180℃for24hours with hydro thermal method. The obtained product was characterized by means of X-ray Diffraction, Scanning Electron Microscope, Raman Spectra. Transmission Electron Microscope, Fourier-Trans form Infrared Spectrography, X-ray Photoelectron Spectroscopy, Energy Dispersive Spectra, the results show that the as-formed product was orthorhombic MoO3with the morphology of nanobelt. Meanwhile, the reaction precursors were investigated, the results showed that MoO3nanobelt could be obtained when the molybdenum source is changed to ammonium molybdate or potassium molybdate. While other conditions remain unchanged, other acids including hydrochloric acid and nitric acid were used in the reaction system As a result, MoO3nanobelt was also not obtained. The results indicate that the dodecylbenzenesulfonate play an important in the morphology of the products. In addition, the application of MoO3nanobelts in supercapacitor was studied.5. The blue MoO3powders were synthesized utilizing sodium molybdate and methylene chloride acid as raw materials under180℃for24hours with hydrothermal method. The obtained product was characterized by means of X-ray Diffraction, Scanning Electron Microscope, Transmission Electron Microscope, the corresponding results show that the product was orthorhombic MoO3with the morphology of nanobelt. Moreover, the reaction precursors were investigated, the results showed that MoO3nanobelt could be obtained when the molybdenum source is changed to or potassium molybdate. Furthermore, other chloromethane including chloroform and tetrachloromethane were used in this reaction system. As a result, MoO3nanobelt also was obtained, the results indicate that methylene chloride affect the morphology of the product. Meanwhile, the application of the obtained MoO3nanobelts in supercapacitor was investigated. |
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