| Rare earth elements possess excellent physical and chemical properties, and have important applications in various fields of national economy and modern technology. China is a great nation in the respect of rare earth resource, but the research and applications of Rare-earth high-tech products are relatively poor, which have seriously hampered the transfer and development of China's rare earth industry to the high-end industrial chain. so the researches and applications on rare earth functional materials are vital important to the development of national economy. Pore structure nanomaterials have attracted wide attention due to their novel morphologies, special chemical properties as well as their potential applications in adsorption, catalysis, nanodevices, and drug or micro molecule transport systems. So, in this paper hierarchically porous La2(MoO4)3 microstructures have been facilely fabricated via a ultrasound route for the first time and their electro-catalytic performance to methanol in alkaline medium are research. CeO2 single hole nan-tubes are prepaired with the precursor Ce(OH)CO3 by hydrothermal method which the cross-section is hexahedron and the influence with ionic liquid are discussed.1. Fabrication of Hierarchically Porous La2(MoO4)3 Micro/nano MaterialsHierarchically porous La2(MoO4)3 microstructures assembled with single-crystalline nanoflakes have been facilely fabricated via a surfactant-assisted ultrasound route for the first time. Various synthesis conditions were examined, such as the surfactant concentration, the molecular structure of surfactants, and the pH value. The obtained single-crystalline hierarchically porous microstructures were characterized by X-ray diffraction (XRD), (field-emission) scanning electron microscopy [(FE)SEM], transmission electron microscopy (TEM), nitrogen adsorption/desorption isotherms. It has been revealed that a minimum concentration of sodium dodecylsulfate (SDS) was required for the formation of single-crystalline hierarchically porous La2(MoO4)3 microstructures. When the SDS concentration is above 0.02 mol/L, the hierarchically porous microstructures become more perfect, and the size is also increased with the increasing SDS concentration. Under the same sonication, similar hierarchically porous microstructures were obtained when a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), was used instead of the anionic surfactant SDS, indicating that the hydrophobic alkyl chains play a key role in the formation of the hierarchically porous La2(MoO4)3 microstructures. It is also found that the hierarchically porous La2(MoO4)3 microstructures can only be obtained within an optimal pH range of 8.0—9.0 under sonication. Based on the collaborative action of surfactants and sonication, a formation mechanism of hierarchically porous La2(MoO4)3 microstructures was proposed. Furthermore, the BET surface area of La2(MoO4)3 microstructures can be controlled by changing the surfactant concentration, which will provide an important path to adjust the function of La2(MoO4)3 microstructures.2. The Electrocatalysis Properties of the Hierarchically Porous La2 (MoO4)3The electrochemical properties and their electro-catalytic performances to methanol in alkaline medium of hierarchically porous La2(MoO4)3 and the bulk La2(MoO4)3 are research comparatively using CV and constant potential method in this paper. It has been revealed that the electrochemical stability of hierarchically porous La2(MoO4)3 is very good. And the current density of hierarchically porous La2(MoO4)3 is bigger than the bulk La2(MoO4)3 in the same conditions, this result is revealed by Chronoamperom- etry method. The study also revealed that the hierarchically porous La2(MoO4)3 has a good catalytic to methanol in alkaline solution. The oxidation is an irreversible oxidation. With the increasing rate of scanning, peak current increase gradually, peak currents and scan rate'square-root is a good linear relationship. We found that the hierarchically porous La2(MoO4)3 is a better electricity catalyst to methanol than bulk La2(MoO4)3 in alkaline solution. This research will be further expanded the application of La2(MoO4)3 in the electrochemical fields.3. Fabrication of One-dimensional and Single-hole CeO2 Nanotubes and the Effect of Ionic Liquids on Their PropertiesCe(OH)CO3 with different morphology has been synthetized by adjusting the urea concentration. Then the CeO2 nanotube is synthetized by hydrothermal method with Ce(OH)CO3. It has been revealed that the spindle-like Ce(OH)CO3 is a good precursors for synthetizing CeO2 nanotube with the hexagonal cross-section. The other synthesis conditions were examined such as sodium hydroxide concentration and the reaction temperature and so on. The result showed that a maximal concentration of sodium hydroxide was required for the formation of single-hole CeO2 nanotube.The temperature of hydrothermal is very important. With the increase of reaction temperature, the aperture diameter is increasing. Finally the ionic liquids was reperfused into the ceria nan-tubes. The result shows that phase of the ionic liquids is changed. Besides, the absorption property of CeO2 single hole nan-tubes which has been filled with ionic liquid was researched and found that absorption spectrum of CeO2 was red shift. This paper try to explain the phenomenon preliminarily. This research is expected to provide a new perspective to the pore structure nanomaterial and other functions materials which was loaded in pore structure nanomaterial. |
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