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镍氢电池的循环性能与活性物质微结构的研究 总被引:1,自引:0,他引:1
与循环试验大致同步, 用静态(初态和终态)或准动态(增加若干个中间态)的模式对MH/H电池循环性能、电极(包括负极和正极)材料的微结构进行了X射线衍射(XRD)研究, 发现循环性能衰减与正极材料β-Ni(OH)2的点阵参数、平均晶粒尺度、微应变和总的层错几率均随循环周期增加而减小以及负极材料中腐蚀产物A(OH)3和B相出现和增加有一定的对应关系, 发现MH/Ni 电池循环性能的衰减是正极材料和负极材料的结构和微结构随着循环次数的增加发生明显变化, 恶化了正负极材料的电化学性能, 同时消耗和恶化了电解液的综合结果. 为了提高电池的循环性能, 采用不同正极材料的添加剂. 结果表明, CaF2和Lu2O3有明显的效果, 其中CaF2效果最好, 并有广泛的实用性. 相似文献
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Weiwei Zou Jin-Long Zhang Feng Chen Masakazu Anpo Dan-Nong He 《Research on Chemical Intermediates》2009,35(6-7):717-726
The surface of titanium dioxide nanoparticles has been chemically modified with toluene 2,4-di-isocyanate (TDI). The modified titanium dioxide can efficiently absorb visible irradiation. The samples were characterized by means of wide-angle X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), diffuse reflectance UV–Vis spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The as-prepared photocatalyst exhibited good photostability and photocatalytic performance in the degradation of organic compounds. For model organic pollutants, modified titanium dioxide had excellent visible-light photocatalytic performance and the surface chemistry linkage product had high photostability. 相似文献
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Xiao-Li Yuan Jin-Long Zhang Masakazu Anpo Dan-Nong He 《Research on Chemical Intermediates》2010,36(1):83-93
Fe3+ doped mesoporous TiO2 with ordered mesoporous structure were successfully prepared by the solvent evaporation-induced self-assembly process using
P123 as soft template. The properties and structure of Fe3+ doped mesoporous TiO2 were characterized by means of XRD, EPR, BET, TEM, and UV–vis absorption spectra. The characteristic results clearly show
that the amount of Fe3+ dopant affects the mesoporous structure as well as the visible light absorption of the catalysts. The photocatalytic activity
of the prepared mesoporous TiO2 was evaluated from an analysis of the photodegradation of methyl orange under visible light irradiation. The results indicate
that the sample of 0.50%Fe–MTiO2 exhibits the highest visible light photocatalytic activity compared with other catalysts. 相似文献
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将光电化学方法与原位分子印迹技术相结合,通过使用手性布洛芬的对映体S-布洛芬(S-ibuprofen)和R-布洛芬(R-ibuprofen)为模板分子,在原位生长的单晶二氧化钛(TiO_2)纳米棒表面构筑S-ibuprofen和R-ibuprofen分子印迹位点,制备出能够对S-ibuprofen和R-ibuprofen选择性识别和催化氧化的印迹电极。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)和拉曼光谱(Raman)对电极的形貌、结构和组成进行表征,通过电化学阻抗对电极表面的电子传递阻力进行研究,以制备得到的印迹电极为工作电极通过光电化学方法对其印迹位点的光电识别选择性和光电降解选择性进行测试。制备得到的TiO_2为单晶纳米棒阵列,印迹位点成功构筑在TiO_2纳米棒表面且具有很好的择形吸附能力。本工作首次实现了手性医药布洛芬对映体在人工光电催化剂表面的选择性识别和选择性氧化降解。 相似文献
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Xiao-Li Yuan Jin-Long Zhang Bao-Zhu Tian Masakazu Anpo Dan-Nong He 《Research on Chemical Intermediates》2009,35(6-7):693-703
A simple synthetic method was employed to prepare mesoporous titania with anatase crystalline walls and high photocatalytic activity. The properties and structures of mesoporous titania were characterized by means of low angle and wide angle X-ray diffraction (XRD), Fourier transform (FT)-IR spectra, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and N2 adsorption–desorption. The characteristic results clearly show that crystallization rate of the mesoporous titania affects the stability of the mesoporous structure after reflux, and that the anatase crystal in the mesoporous wall of mesoporous titania can stabilize the mesoporous structure. The photocatalytic activity of titania powder was evaluated from an analysis of the photodegradation of methyl orange under UV irradiation. The results indicate that the titania powder with mesoporous structure shows the highest photocatalytic activity. 相似文献
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改性Ag/α-Al_2O_3催化丙烯气相环氧化反应 总被引:1,自引:0,他引:1
制备了以分子氧为氧化剂,对丙烯气相环氧化具有较好催化性能的改性负载银催化剂,并利用氧气程序升温脱附(O2-TPD)技术研究了氧在其表面上的脱附行为.实验结果表明:Ag/α-Al2O3催化剂只能使丙烯完全氧化成二氧化碳和水;当该催化剂用K2O改性后,可获得少量的环氧丙烷;Y2O3改性的Ag/α-Al2O3催化剂,可获得极少量的丙醛和丙酮;将0.1%(w)Y2O3添加到Ag-K2O/α-Al2O3后,可以显著提高催化剂的丙烯环氧化性能.在0.1MPa、245℃、20%C3H6/8%O2/72%N2和气体空速2000h-1的反应条件下,通过20%(w)Ag-0.1%Y2O3-0.1%K2O/α-Al2O3催化剂时,丙烯转化率为4.0%,环氧丙烷的选择性为46.8%.O2-TPD研究表明,少量的Y2O3、K2O或Y2O3-K2O作为助剂添加到20%Ag/α-Al2O3催化剂中时,减少了高温区与丙烯完全氧化有关的吸附氧物种的量,低温区余下的吸附氧物种量不变,有利于丙烯环氧化反应,提高了环氧丙烷的选择性. 相似文献
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