Xiao Zhen Liu

Preparation and Properties of Gd and Sb Doped SnO2 Conductive Nanoparticles

Gd and Sb doped SnO2 conductive nanoparticles were prepared by the coprecipitation method with SnCl4•5H2O, SbCl3 and Gd2O3 as the raw materials. The crystal phase and structure of the prepared conductive nanoparticles were characterized by FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles was 0.29 Ωcm; FTIR spectrum showed that the vibration peak are wide peak in 723 cm-1～451cm-1, the Gd and Sb doped SnO2 conductive nanoparticles have intense absorption in 4000 cm-1～1600 cm-1; Gd and Sb doped SnO2 have a structure of tetragonal rutile; complex doping is achieved well by coprecipitation method and is recognized as replacement doping or caulking doping; TME shows that the particles were weakly agglomerated, the size of the particles calcined at 800°C ranged approximately from 10 to 30 nm.

Effect of Heat Treatment on the Crystal Structure of the Anodic Cerium Oxide Films

The cerium dioxide films were prepared with cerium foils as raw materials by anodization in Na2C2O4-NH3∙H2O-H2O-(CH2OH)2 electrolyte. The anodic cerium oxide films were heat treated in 100~400°C and 0.5~2.5h, respectively. The heat treated anodic cerium oxide films were characterized with X-ray diffraction (XRD). The heat treated anodic cerium oxide film at 100°C is semi crystalline film. The heat treated anodic cerium oxide film at 200°C, 300°C, 350°C, 400°C, respectively for 2h, is the cerium dioxide film respectively, and has a structure of cubic fluorite respectively. The crystal structures of the cerium dioxide films become more complete with the increase of heat treatment temperature in 200 ~ 400 °C. The heat treated anodic cerium oxide film at 400°C for 0.5h, 1h, 1.5h, 2.5h, respectively, is the cerium dioxide film respectively, and has a structure of cubic fluorite respectively. The crystal structures of the cerium dioxide films become more complete with the increase of heat treatment times in 0.5h ~ 2.5h.

Preparation of Cerium Dioxide Film by Anodization in Na2C2O4-NH3∙H2O-H2O-(CH2OH)2 Electrolyte

The cerium dioxide films were prepared with cerium foils as raw materials by anodization in Na2C2O4-NH3∙H2O-H2O-(CH2OH)2 electrolyte. The anodic cerium oxide film was heat treated at 550°C. The cerium dioxide films were characterized with X-ray diffraction (XRD), energy-dispersive analyses of X-ray (EDAX), Fourier transform infrared (FTIR) techniques and scanning electron microcopy (SEM), respectively. The anodic cerium oxide film is semi crystalline film. The heat treated anodic cerium oxide film at 550°C is the fluorite-structured cerium dioxide film, and the crystal structure of the cerium dioxide film becomes more complete than that of the anodic cerium oxide film. The cerium dioxide film is porous film. The water, ethylene glycol and CO2 are adsorbed in the anodic cerium oxide film. The adsorbing water, ethylene glycol and CO2 in the anodic cerium oxide film are removed at 550°C. The cerium dioxide film has strong absorption in the range of 1400~4000cm-1.

Preparation and Properties of Y and Sb Doped SnO2 Conductive Powders

Y is used as a dopant for the first time in preparing conductive powders to improve its performance. Y and Sb doped SnO2 conductive particles are prepared by the complexation-coprecipi-tation method with Sn, Sb2O3 and Y2O3 as the raw materials. The crystal phase and structure of the prepared conductive particles are characterized by FTIR and XRD techniques respectively. The resistivity of the prepared conductive powders are measured with four-point measurement method. The resistivity of Y and Sb doped SnO2 conductive particles is 0.22 Ωcm. FTIR spectrum of Y and Sb doped SnO2 conductive particles shows that the vibration peak are wide peak in 570 cm-1 ~ 400 cm-1, and have intense absorption in 4000 cm-1 ~ 2500 cm-1, respectively.Y and Sb doped SnO2 conductive powders have a structure of tetragonal rutile. The complex doping is achieved well by complexation-coprecipitation method and is recognized as replacement doping or caulking doping.

Preparation and Effect of Heat Treatment Temperature on the Crystal Phase of Anodic Aluminum Oxide Films

The anodic aluminum oxide (AAO) films were prepared by anodization method from the 15 vol. % sulphuric acid solution, and prepared AAO films were heat-treated in the ranges of 25~1000°C. AAO films were characterized by EDAX, SEM and XRD techniques, respectively. The crystal phases of prepared AAO film is amorphous. The apertures of AAO film are in 25~30 nm. AAO films are amorphous when heat treatment temperatures of AAO films are below 800 °C. After the AAO film being heat-treated in the ranges of 850°C~900 °C, the heat-treated AAO film are γ-Al2O3 film. When the AAO film is heat-treated at 950 °C, the part of γ-Al2O3 change into α-Al2O3, and the heat-treated AAO film are mixed film of γ-Al2O3 and α-Al2O3. After the AAO film being heat-treated at 1000 °C, the heat-treated AAO film is α-Al2O3 film.

Preparation and Electrochemical Performance of Praseodymium Doped SnO2 Particles as Negative Electrode Material of Lithium-Ion Battery

Pr doped SnO2 particles as negative electrode material of lithium-ion battery are synthesized by the coprecipitation method with SnCl4·5H2O and Pr2O3 as raw materials. The structure of the SnO2 particles and Pr doped SnO2 particles are investigated respectively by XRD analysis. Doping is achieved well by coprecipitation method and is recognized as replacement doping or caulking doping. Electrochemical properties of the SnO2 particles and Pr doped SnO2 particles are tested by charge-discharge and cycle voltammogram experimentation, respectively. The initial specific discharge capacity of Pr doped SnO2 the negative electrode materials is 676.3mAh/g. After 20 cycles, the capacity retention ratio is 90.5%. The reversible capacity of Pr doped SnO2 negative electrode material higher than the reversible capacity of SnO2 negative electrode material. Pr doped SnO2 particles has good lithiumion intercalation/deintercalation performance.

Preparation of Electrodeposited Mo-Ni Coating in Weak Acid Solution

Mo-Ni coatings were prepared on Ni alloy by electrodeposition method. The effects of sodium fluoride mass concentration, sodium chloride mass concentration, sodium molybdate mass concentration and pH value on deposition rate of Mo-Ni coating were researched, respectively. The morphology of Mo-Ni coatings were characterized with scanning electron microcopy (SEM). When sodium fluoride mass concentration is 12 g/L, deposition rate of Mo-Ni coating is as high as 0.3781 mg/cm2·min. When sodium chloride mass concentration is 22.3 g/L, deposition rate of Mo-Ni coating is as high as 0.2108 mg/cm2·min. When sodium chloride mass concentration, sodium molybdate mass concentration and pH value are 22.3 g/ L, 12 g/L and pH 5 respectively, deposition rate of Mo-Ni coating is as high as 0.2123 mg/cm2·min. There are many cracks and pits on the surface Mo-Ni coating deposited in the bath without adding NaCl or NaF, and coating surface is very uneven. The surface Mo-Ni coating deposited in the bath adding NaCl is smooth, and the grains of Mo-Ni coating is small. The surface Mo-Ni coating deposited in the bath adding NaF is smooth, and there are many nodules on the surface Mo-Ni coating.

Effect of Preparation Conditions on the Performance of Electrodeposited Mo-Ni Coating

Mo-Ni coatings were prepared on Ni alloy by electrodeposition method. The effects of electrodeposition temperature, current density, stir speed and electrodeposition time on deposition rate and microhardness of Mo-Ni coating were researched, respectively. Deposition rate of Mo-Ni coating decreases with the increase of electrodeposition temperature in 35 °C ~ 60 °C. Deposition rate and microhardness of Mo-Ni coating increases with the increase of current density respectively in 15 A/dm2 ~ 17.5 A/dm2. Deposition rate and microhardness of Mo-Ni coating decreases with the increase of stir speed respectively in 200 r/min to 400 r/min. Deposition rate and microhardness of Mo-Ni coating decreases with the increase of electrodeposition time respectively in 30 min ~ 40 min. When electrodeposition parameters: temperature 35 °C, current density 17.5 A/dm2, stir speed 200 r/mi, pH 5 and time 30 min, deposition rate and microhardness of Mo-Ni coatin are as high as 0.269 mg/ cm2·min and 502.4 HV respectively.

Preparation and Properties of Eu, Sb Doped SnO2 and Quartz Compound Conductive Powders

Eu, Sb doped SnO2 and quartz compound conductive powders are prepared by the coprecipitation method with SnCl4·5H2O, SbCl3, Eu2O3 and quartz powders as the raw materials. The crystal phase and structure of the prepared conductive particles are characterized by FTIR and XRD techniques respectively. The resistivity of the prepared conductive powders are measured with four-point measurement method. The resistivity of Eu, Sb doped SnO2 and quartz compound condu-ctive powders is 0.37 Ωcm. FTIR spectrum of Eu, Sb doped SnO2 and quartz compound conductive powders shows that there are the vibration peaks in 546.14 cm-1, 489.95 cm-1, 466.71 cm-1, 430.34 cm-1 and 418.92 cm-1 respectively, and have intense absorption in 4000 cm-1 ~ 1100 cm-1. Eu, Sb doped SnO2 conductive powders have a structure of tetragonal rutile. The complex doping is achieved well by coprecipitation method and is recognized as replacement doping or caulking doping. The composition of compound conductive powders are Eu, Sb doped SnO2 conductive powders and quartz powders.

Preparation and Performance of Electrodeposited Cr-Pr Coating

Cr-Pr coating was prepared by electrodeposition method. The microhardness, wear weight loss and friction coefficient of Cr-Pr coating were studied respectively. The Cr-Pr coating were characterized with ICP-AES, EDAX, XRD and SEM techniques, respectively. The microhardness and the wear weight loss, friction coefficient of the Cr-Pr coatings are higher and lower respectively than that of the Cr coating. The microhardness of the Cr-Pr is as high as 805.2 HV, which is higher 3.74% than that of the Cr coating (776.2 HV). The wear weight loss of Cr-Pr is lower 1.33 times than that of Cr coating. The friction coefficient of Cr coating and Cr-Pr coating are 0.884 and 0.723 respectively. There are crystalline CrC in Cr-Pr coating. The nodules on Cr-Pr coating surface are smaller than that of Cr coating surface, and furrows and spalling are lower on the worn surface of Cr-Pr coating than that of the Cr coating.