Nanocrystallite δ ′ ZrW 1.6 Mo 0.4 O 8 was prepared in the precursor route synthesis. The characterization by means of powder X ray diffraction (XRD) and selected area electron diffraction (SAED) showe...Nanocrystallite δ ′ ZrW 1.6 Mo 0.4 O 8 was prepared in the precursor route synthesis. The characterization by means of powder X ray diffraction (XRD) and selected area electron diffraction (SAED) showed it crystallized in a orthorhombic crystal system with a =0.896 9(7) nm, b =0.701 1(8) nm, c =0.596(1) nm. The possible space group is Pnnm (58) or Pnn2 (34). The compound crystallizes in a metastable phase during the synthesis process depending on temperature and crystallization time.展开更多
In this work,azobenzene mesogen-containing tin thiolates have been synthesized,which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors.Based on the preorga...In this work,azobenzene mesogen-containing tin thiolates have been synthesized,which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors.Based on the preorganized tin thiolate precursors,Sn S nanocrystals encapsulated with in-situ N-doped carbon layer have been achieved through a simple solventless pyrolysis process with the azobenzene mesogenic thiolate precursor served as Sn,S,N,and C sources simultaneously.Thus prepared nanocomposite materials as anode of lithium ion batteries present a large specific capacity of 604.6 m Ah·g^（-1）at a current density of 100 m A·g^（-1）,keeping a high capacity retention up to 96% after 80 cycles,and display high rate capability due to the synergistic effect of well-dispersed Sn S nanocrystals and N-doped carbon layer.Such encouraging results shed a light on the controlled preparation of advanced nanocomposites based on liquid crystalline metallomesogen precursors and may boost their novel intriguing applications.展开更多
Zirconium tungsten oxyfluoride,ZrWO4F2,was firstly synthesized with the pr ecursor route.The composition of the compound was determined by combi ning the results of ICP and XPS.The in dexed powder X-ray diffraction pa...Zirconium tungsten oxyfluoride,ZrWO4F2,was firstly synthesized with the pr ecursor route.The composition of the compound was determined by combi ning the results of ICP and XPS.The in dexed powder X-ray diffraction pattern of this compound indicates t hat it is a pure phase,orthorhombic c rystal system,space group D 22 =P2 1 22and a=15.32（2）*!,b=13.877（7）*!,c=8.42（2）*!.Combining the results of the DTA-T GA curves from room temperature to 700℃and XRD patterns in different temperatures the mechanism was revealed during the solid precursor（1）been heated to 700℃.The zirconium tu ngsten oxyfluoride was considered t o be a metastable com-pound.The ascertaining of annealin g time and temperature is the key of handling.展开更多
基金Supported by the National Natural Science Foundation of China(No. 2 98710 0 6 ) .
文摘Nanocrystallite δ ′ ZrW 1.6 Mo 0.4 O 8 was prepared in the precursor route synthesis. The characterization by means of powder X ray diffraction (XRD) and selected area electron diffraction (SAED) showed it crystallized in a orthorhombic crystal system with a =0.896 9(7) nm, b =0.701 1(8) nm, c =0.596(1) nm. The possible space group is Pnnm (58) or Pnn2 (34). The compound crystallizes in a metastable phase during the synthesis process depending on temperature and crystallization time.
基金Project supported by the National Natural Science Foundation of China(Grant No.21574062)the Huaian High-Technology Research Institute of Nanjing University,China(Grant No.2011Q1)
文摘In this work,azobenzene mesogen-containing tin thiolates have been synthesized,which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors.Based on the preorganized tin thiolate precursors,Sn S nanocrystals encapsulated with in-situ N-doped carbon layer have been achieved through a simple solventless pyrolysis process with the azobenzene mesogenic thiolate precursor served as Sn,S,N,and C sources simultaneously.Thus prepared nanocomposite materials as anode of lithium ion batteries present a large specific capacity of 604.6 m Ah·g^（-1）at a current density of 100 m A·g^（-1）,keeping a high capacity retention up to 96% after 80 cycles,and display high rate capability due to the synergistic effect of well-dispersed Sn S nanocrystals and N-doped carbon layer.Such encouraging results shed a light on the controlled preparation of advanced nanocomposites based on liquid crystalline metallomesogen precursors and may boost their novel intriguing applications.
文摘Zirconium tungsten oxyfluoride,ZrWO4F2,was firstly synthesized with the pr ecursor route.The composition of the compound was determined by combi ning the results of ICP and XPS.The in dexed powder X-ray diffraction pattern of this compound indicates t hat it is a pure phase,orthorhombic c rystal system,space group D 22 =P2 1 22and a=15.32（2）*!,b=13.877（7）*!,c=8.42（2）*!.Combining the results of the DTA-T GA curves from room temperature to 700℃and XRD patterns in different temperatures the mechanism was revealed during the solid precursor（1）been heated to 700℃.The zirconium tu ngsten oxyfluoride was considered t o be a metastable com-pound.The ascertaining of annealin g time and temperature is the key of handling.
