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21.
Preparation of AgSnO2 composite powders by hydrothermal process 总被引:2,自引:0,他引:2
Silver-tin oxide powders were synthesized by the hydrothermal method with Ag(NH3)2^+ solution and Na2SnO3 solution as raw materials and Na2SO3 as reductant. The precipitation conditions of Na2SnO3 solution and the reduction conditions of Ag(NH3)2^+ were also investigated. The powders prepared were characterized by differential thermal analysis (DTA), X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and energy spectrum analysis, The results show that pH value of the solution is a key parameter in the formation of Sn(OH)4 precipitate and the reduction reaction of Ag(NH3)2^+ can release H^+ ions, which results in synchronous precipitation of Sn(OH)6^2- as Sn(OH)4. The reduction of Ag(NH3)2^+ and precipitation of Na2SnO3 occur simultaneously and the coprecipitation of silver and tin oxide is reached by the hydrothermal method. The silver-tin oxide composite powders have mainly flake shape of about 0.3 μm in thickness and there exists homogeneous distribution of tin oxide and silver in the powder synthesized. 相似文献
22.
Ag/SnO2电接触材料的制备及烧结条件对密度的影响 总被引:1,自引:0,他引:1
以AgNO3和Sn(Ⅳ)盐为原料,采用水热还原法合成了银氧化锡(Ag/SnO2)复合粉体.复合粉体经压片、烧结制得片状Ag/SnO2电接触材料.通过XRD和SEM等手段对制得的Ag/SnO2复合粉体进行表征,系统考察了烧结时间、烧结温度、SnO2含量等因素对Ag/SnO2电接触材料密度的影响.结果表明,所得Ag/SnO2粉体为高度分散的球形颗粒; Ag/SnO2粉体经压片后,于750℃烧结3h所得电接触材料的密度最大;且材料的相对密度随其中SnO2含量的增加而略有降低,当SnO2含量在8%~16%(质量分数)之间时,所得Ag/SnO2电接触材料的相对密度均达到了97%以上. 相似文献
23.
Mesoporous Ce0.5Zr0.5O2 mixed oxide with high specific surface area was synthesized under basic condition in the presence of non-ionic surfactant PEG-4000. The effect of synthesis conditions, such as synthesis temperature and the molar ratio of PEG-4000/([ Ce] + [ Zr] ), on specific surface area were investigated. The products were characterized by transmission electron microscopy, powder X-ray diffraction, and nitrogen adsorption-desorption measurements, respectively. The results showed that synthesis temperature and the molar ratio of PEG-4000/([ Ce] + [ Zr] ) had great influence on specific surface area. Under the optimum synthesis conditions, the prepared Ce0.5Zr0.5O2 mixed oxide presented cubic fluorite-type structure and possessed high surface area of 148.6 m2·g^-1 with wormlike pores. 相似文献
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本文从数学上推导出金氰化过程中,当氰化速度达到最大时,游离CN^-浓度和O2浓度的比值,所得结果与实际一致。 相似文献
30.
铅在碱性木糖醇体系中的电沉积行为 总被引:1,自引:0,他引:1
探讨铅在碱性木糖醇体系中的电沉积行为;采用循环伏安法研究碱性木糖醇体系的电化学稳定性以及铅在阴极的电沉积过程;利用线性扫描伏安法求解体系的表观活化能、表观传递系数和交换电流密度;采用计时电流法判断铅在电极上的成核方式。结果表明:在扫描电压范围-1.3~0.75V(vsHg/HgO)内,木糖醇在碱性溶液中无氧化还原反应;由线性扫描伏安法求得表观活化能为35.15kJ/mol,表观传递系数为1.56,交换电流密度为9.65×10-5A/cm2;铅的成核方式遵循三维成核,并取决于过电位。 相似文献