La0.7Sr0.3MnO3（LSMO） nanorods were synthesized by a method combining sol-gel with molten salts at 950 ℃ for 10 h, which employed KCl＋NaCl（mass ratio 4：1） as eutectic molten salts. The morphologies and magnetic ...La0.7Sr0.3MnO3（LSMO） nanorods were synthesized by a method combining sol-gel with molten salts at 950 ℃ for 10 h, which employed KCl＋NaCl（mass ratio 4：1） as eutectic molten salts. The morphologies and magnetic properties of the resulting LSMO nanorods were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and vibrating sample magnetometer（VSM） measurements. It was found that the obtained perovskite manganite LSMO was a uniform nanorod with a diameter of about 50 nm and a length of longer than 500 rim. The Curie temperature（To） of the LSMO nanorod used here was 262 K, much lower than that of bulky single crystal LSMO（360 K）. The low Curie temperature might be a result of the great disorder near the grain boundary, which could be observed clearly from the TEM picture.展开更多
Using FFC-Cambridge Process to prepare Si from SiO2 is a promising method to prepare nanostructured and highly pure silicon for solar cells.However,the method still has many problems unsolved and the controlling effec...Using FFC-Cambridge Process to prepare Si from SiO2 is a promising method to prepare nanostructured and highly pure silicon for solar cells.However,the method still has many problems unsolved and the controlling effect of the cell voltage on silicon product is not clear.Here we report in this article that nano cluster-like silicon product with purity of 99.95%has been prepared by complete conversion of raw material SiO2,quartz glass plate,using constant cell voltage electrolysis FFC-Cambridge Process.By analysis of XRD,EDS,TEM,HRTEM and ICP-AES as well as the discussion from the thermodynamics calculation,the morphology and components of the product based on the change of cell voltage are clarified.It is clear that pure silicon could be prepared at the cell voltage of 1.7 2.1 V in this reaction system.The silicon material have cluster-like structure which are made of silicon nanoparticles in 20 100 nm size.Interestingly,the cluster-like nano structure of the silicon can be tuned by the used cell voltage.The purity,yield and the energy cost of silicon product prepared at the optimized cell voltage are discussed.The purity of the silicon product could be further improved,hence this method is promising for the preparation of solar grade silicon in future.展开更多
A new technique of magnesia electrolysis from bischofite in Qinghai salt lakes was investigated experimentally. Magnesia was prepared by ammonia processing. On an electrolysis cell of about 100 A capacity at 700degree...A new technique of magnesia electrolysis from bischofite in Qinghai salt lakes was investigated experimentally. Magnesia was prepared by ammonia processing. On an electrolysis cell of about 100 A capacity at 700degreesC, magnesium metal was obtained with a current efficiency of 90.23% and a specific energy consumption of 11.5 kW(.)h. The new technique has the advantages of energy saving, high current efficiency and environmental amity.展开更多
Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 wer...Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.展开更多
基金Supported by the National Natural Science Foundation of China (No.20801016)Natural Science Foundation of Heilong-jiang Province, China(No.B2007-8)+1 种基金Research Fund for the Doctoral Program of Higher Education of China for New Teach-ers(No.20070217060)Basic Research Fund of Harbin Engineering University, China(No.HEUFT05019)
文摘La0.7Sr0.3MnO3（LSMO） nanorods were synthesized by a method combining sol-gel with molten salts at 950 ℃ for 10 h, which employed KCl＋NaCl（mass ratio 4：1） as eutectic molten salts. The morphologies and magnetic properties of the resulting LSMO nanorods were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and vibrating sample magnetometer（VSM） measurements. It was found that the obtained perovskite manganite LSMO was a uniform nanorod with a diameter of about 50 nm and a length of longer than 500 rim. The Curie temperature（To） of the LSMO nanorod used here was 262 K, much lower than that of bulky single crystal LSMO（360 K）. The low Curie temperature might be a result of the great disorder near the grain boundary, which could be observed clearly from the TEM picture.
基金supported by the Solar Energy Initiative of the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KGCX2-YW-395)
文摘Using FFC-Cambridge Process to prepare Si from SiO2 is a promising method to prepare nanostructured and highly pure silicon for solar cells.However,the method still has many problems unsolved and the controlling effect of the cell voltage on silicon product is not clear.Here we report in this article that nano cluster-like silicon product with purity of 99.95%has been prepared by complete conversion of raw material SiO2,quartz glass plate,using constant cell voltage electrolysis FFC-Cambridge Process.By analysis of XRD,EDS,TEM,HRTEM and ICP-AES as well as the discussion from the thermodynamics calculation,the morphology and components of the product based on the change of cell voltage are clarified.It is clear that pure silicon could be prepared at the cell voltage of 1.7 2.1 V in this reaction system.The silicon material have cluster-like structure which are made of silicon nanoparticles in 20 100 nm size.Interestingly,the cluster-like nano structure of the silicon can be tuned by the used cell voltage.The purity,yield and the energy cost of silicon product prepared at the optimized cell voltage are discussed.The purity of the silicon product could be further improved,hence this method is promising for the preparation of solar grade silicon in future.
基金The work was financially supported by the National Science Foundation of China (20166003).
文摘A new technique of magnesia electrolysis from bischofite in Qinghai salt lakes was investigated experimentally. Magnesia was prepared by ammonia processing. On an electrolysis cell of about 100 A capacity at 700degreesC, magnesium metal was obtained with a current efficiency of 90.23% and a specific energy consumption of 11.5 kW(.)h. The new technique has the advantages of energy saving, high current efficiency and environmental amity.
基金Project supported by the National Natural Science Foundation of China(51564015)
文摘Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.
