基于不同共溶剂体系对于高电压正极材料LiCoPO4的形貌控制

水分别与乙醇、乙二醇、二乙二醇混合为共溶剂, 通过溶剂热法制备高电压锂离子电池正极材料LiCoPO₄, 研究不同醇类溶剂对于样品的微观形貌和颗粒尺寸的影响。借助X射线衍射、扫描电子显微镜和比表面积测试对样品的成分、晶型、微观形貌和颗粒尺寸进行分析。研究表明, 制备得到的LiCoPO₄颗粒平均尺寸大小与醇类溶剂对于前驱体的溶解度差异相一致, 而与溶剂粘度没有明显联系。通过乙二醇/水制备得到的LiCoPO₄颗粒呈六边形片状, 平均尺寸最小, 而通过乙醇/水和二乙二醇/水制备得到的LiCoPO₄颗粒呈菱形片状形态。此外, 前者结晶度较高且循环性能较好, 0.05C下首圈放电容量为130 mAh/g, 20圈后容量保留率为88%。     

棒状多孔NiCo2O4粉末的可控制备及其电催化性能研究

以NiCl₂·6H₂O, CoCl₂·6H₂O和草酸为原料, 利用氨水为配位剂和溶液pH调节剂, 通过配位共沉淀-热分解法制备了棒状多孔NiCo₂O₄粉末, 采用X射线衍射、扫描电镜、透射电镜以及比表面积仪对前驱体和NiCo₂O₄粉末的形貌和结构进行了表征, 考察了溶液pH对前驱体粉末形貌和分散性的影响; 采用循环伏安法和计时电流法研究了乙醇在棒状多孔NiCo₂O₄粉末修饰的玻碳电极上的电催化性能。结果表明: 前驱体的形貌与溶液的pH有关, 热分解得到的NiCo₂O₄粉末继承了前驱体形貌, 呈多孔棒状, 比表面积为89 m²/g, 平均孔径为12.56 nm。该粉末对乙醇具有良好的电催化活性, 氧化峰电流与乙醇浓度、扫速的平方根均呈直线关系, 表明棒状多孔NiCo₂O₄粉末对乙醇的催化反应机理为扩散控制。     

Sensitivity enhancement for H2 gas detection using a SnO2–Ag2O–PdOx nanocrystalline system

Thick film H₂ sensors were fabricated using SnO₂ loaded with Ag₂O and PdO_x. The composition that gave highest sensitivity for H₂ was in the wt.% ratio of SnO₂:Ag₂O:PdO_x as 93:5:2. The nano-crystalline powders of SnO₂–Ag₂O–PdO_x composites synthesized by sol–gel method were screen printed on alumina substrates. Fabricated sensors were tested against gases like H₂, CH₄, C₃H₈, C₂H₅OH and SO₂. The composite material was found sensitive against H₂ at the working temperature 125 °C, with minor interference of other gases. H₂ gas as low as 100 ppm can be detected by the present fabricated sensors. It was found that the sensors based on SnO₂–Ag₂O–PdO_x nanocrystalline system exhibited high performance, high selectivity and very short response time to H₂ at ppm level. These characteristics make the sensor to be a promising candidate for detecting low concentrations of H₂.     

一种新型球状纳米氧化铁的制备

以Fe(NO₃)₃·9H₂O为原料、以尿素为沉淀剂,用热解前驱体法制备出直径为40~60 nm的球状纳米氧化铁。使用XRD、SEM和EDS等手段对其表征,研究了Fe³⁺浓度、反应温度等因素对纳米氧化铁的粒径和形貌的影响、确定了球状纳米氧化铁的制备条件并分析了球状纳米氧化铁的形成机理。结果表明：随着Fe(NO₃)₃·9H₂O溶液温度的提高纳米氧化铁的结晶度随之提高、粒径增大。Fe(NO₃)₃·9H₂O的浓度对纳米氧化铁样品的粒度和形貌的影响不大。球状氧化铁纳米的形成机理是：铁源在水热条件下水解和结晶生成棕黄色絮状沉淀FeOOH,FeOOH在高温高压条件下溶解和再结晶生成了球状纳米氧化铁。     

Solution-phase synthesis of smaller cuprous oxide nanocubes

Smaller cuprous oxides (Cu₂O) nanocubes were synthesized by solution-phase method at 160 °C, using ethylene glycol reducing Cu(NO₃)₂·3H₂O with poly(vinylypyrrolidone) (pvp) as capping agent. The Cu₂O nanocubes were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray powder diffraction (XRD). SEM showed that most of Cu₂O nanocubes were uniform and monodisperse, with the average edge length about 130 nm. The TEM results were consistent with the SEM results. Selected area electron diffraction (SAED) suggested that as-prepared Cu₂O nanocubes were single crystalline. The geometric shape and size of Cu₂O nanoparticles were greatly affected by the presence of PVP and its molar ratio (in repeating unit) relative to copper nitrate, temperature and the concentration of Cu(NO₃)₂·3H₂O. The mechanism of Cu₂O nanocubes formation was also discussed.     

宽带隙、高折射率聚偏四氟乙烯/TiO2-ZrO2光学膜的制备和表征

以氧氯化锆(ZrOCl₂·8H₂O)为锆源, 钛酸丁酯(Ti(OBu)₄)为钛源, 聚偏氟乙烯(PVDF)为有机添加剂, 采用溶胶–凝胶法在K9玻璃基片上制备PVDF/TiO₂-ZrO₂光学膜, 提高了ZrO₂-TiO₂光学膜的综合性能。然后采用SEM、FT-IR、接触角以及紫外/可见/近红外透射光谱等手段对PVDF/TiO₂-ZrO₂光学膜的组成、光学性能和抗激光损伤阈值进行了研究。SEM测试表明, 在K9玻璃基片上制备了光学膜。PVDF的添加导致水与薄膜的接触角增大。ZrO₂-TiO₂光学膜的光学带隙随ZrO₂含量的增加而略微增大, PVDF/ZrO₂(50mol%)-TiO₂薄膜的光学带隙随PVDF质量分数的增加而增大。另外, ZrO₂-TiO₂光学膜的折射率随ZrO₂摩尔分数的减小而增大, PVDF/ZrO₂(50mol%)-TiO2膜的折射率随PVDF质量分数的增加而增大。     

锂离子电池正极材料LiNi0.8Co0.15Al0.05O2的制备与性能

采用共沉淀法制备粒径10 μm左右的前驱体Ni_0.8Co_0.15Al_0.05（CO₃）_x（OH）_y,然后采用该前驱体和LiOH·H₂O成功制备了锂离子电池正极材料LiNi_0.8Co_0.15Al_0.05O₂（LiNCA）,并详细研究了煅烧氛围、煅烧温度和煅烧方式等条件对LiNCA电化学性能的影响。研究表明,在O₂中煅烧获得的LiNCA放电容量达到170 mAh·g^-1,50次循环后容量保持率达到95%,性能明显优于空气氛围中煅烧得到的LiNCA。在O₂氛围下,700~750℃温度范围煅烧得到的LiNCA性能最好,煅烧温度过高或过低,LiNCA性能均明显下降。将前驱体在O₂氛围中450℃条件预煅烧,然后与LiOH·H₂O在700~750℃混合煅烧的煅烧方式,得到的LiNCA放电容量明显提高,可达190 mAh·g^-1。     

F含量对ZrO2纳米管形貌和相组成的影响

采用阳极氧化法在丙三醇+NH₄F+5vol% H₂O的电解液中制备了高度有序的ZrO₂纳米管阵列, 详细考察了溶液中F含量(0.1~1.1 mol/L)对纳米管形貌﹑相结构和化学组成的影响. 利用扫描电子显微镜(SEM), X射线衍射仪(XRD)和X射线光电子能谱仪(XPS)对不同条件下制备的管径约90~130 nm, 管长约4.8~9.1 μm的纳米管形貌和结构进行了表征. 结果显示, 在含有0.7 mol/L NH₄F的电解液中获得了高度有序且垂直导向的四方相ZrO₂纳米管阵列, 而在较低浓度的电解液中制备的纳米管阵列为无定形结构, 较高浓度下纳米管阵列出现坍塌. 此外, 纳米管近表层处F/O原子比也随F^-浓度的变化而变化.     

特殊形貌磷酸锆钠粉体的制备与表征

采用水热法、以八水合氧氯化锆和多聚磷酸钠为原料、水为介质, 一步制备出了单相Na₂Zr(PO₄)₂粉体。利用XRD、SEM、TG-DSC等检测方法, 系统地考察了水热条件和煅烧温度对磷酸锆钠粉体微观结构的影响。结果表明, 原料摩尔配比为n(ZrOCl₂•8H₂O) : n(Na₅P₃O₁₀)=1:2、无需调变pH值的中性条件下, 于140℃水热14 h, 即可制得分散性较好、尺寸较均一、由片组装而成的类线团形貌的Na₂Zr(PO₄)₂粉体; 适当延长水热时间和提高水热温度均有利于粉体的形成, 且温度越高, 形成该粉体所需水热时间越短。高温煅烧会使Na₂Zr(PO₄)₂粉体发生热分解, 其形貌也被破坏。利用生长基元模型解释了水热法生成该磷酸锆钠粉体的机理。     

纳米立方LiF的液相制备及表征

以NH₄F和LiOH·H₂O为原料、无水乙醇为溶剂和结晶控制剂,采用液相法合成前驱体低温烧结制备纳米级LiF粉末。利用X射线粉末衍射、扫描电镜、透射电镜和激光粒度仪等分析手段对样品进行表征。结果表明,前驱体的主要成分为LiF、NH₄F和LiOH·H₂O;热分析结果表明,NH₄F的分解温度约为190℃。在220~400℃烧结后得到的样品具有单一的LiF立方晶体结构,颗粒饱满,大小均匀,形貌良好,粒径的平均尺寸为80 nm。     

Structural, electrical and optical characteristics of SnO2:Sb thin films by ultrasonic spray pyrolysis

Antimony-doped tin oxide (SnO₂:Sb) thin films were fabricated by an ultrasonic spray pyrolysis method. The effect of antimony doping on the structural, electrical and optical properties of tin oxide thin films were investigated. Tin(II) chloride dehydrate (SnCl₂·2H₂O) and antimony(III) chloride (SbCl₃) were used as a host and a dopant precursor. X-ray diffraction analysis showed that the non-doped SnO₂ thin film had a preferred (211) orientation, but as the Sb-doping concentration increased, a preferred (200) orientation was observed. Scanning electron microscopy studies indicated that the polyhedron-like grains observed for the non-doped SnO₂ thin films became rounder and decreased in size with the Sb-doping concentration. The lowest resistivity (about 8.4 × 10^− 4 Ω·cm) was obtained for the 3 at.% Sb-doped films. Antimony-doping led to an increase in the carrier concentration and a decrease in Hall mobility. The transmittance level in the near infrared region was lowered with the Sb-doping concentration.     

阳极支撑质子导体电解质固体氧化物燃料电池的制备及其性能研究

本研究采用高温固相反应法合成了BaCe_0.7Zr_0.1Y_0.2O_3-d (BCZY7)质子导体氧化物, 对材料的物相结构和微观形貌进行表征和分析, 并将BCZY7作为固体氧化物燃料电池(SOFC)的电解质, 通过浸渍法和共烧结法成功制备了阳极支撑的NiO-BCZY7/BCZY7/La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ(LSCF)-BCZY7钮扣式电池。以氢气(含3vol% H₂O)为燃料, 空气为氧化剂, 对电池的电化学性能进行测试。结果表明, 在600、550、500 ℃时, 电池的最高功率密度分别为203, 123, 92 mW×cm^-2, 而传统(ZrO₂)_0.92(Y₂O₃)_0.08基SOFC在600 ℃时通常只有几十毫瓦的单位面积输出, 质子导体电解质可以极大改善SOFC的中低温性能, 缓解SOFC工作温度高的问题。     

酚醛树脂原位催化裂解制备低维碳纳米结构

以Ni（NO₃）₂·6H₂O为催化剂前躯体,原位催化裂解酚醛树脂制备了碳洋葱、竹节碳和碳纳米管等低维碳纳米结构;用粉体X-射线衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）等手段对低维碳纳米结构进行了表征。结果表明;当Ni（NO₃）₂·6H₂O与苯酚物质量比小于0.01时,Ni催化剂易分散,碳纳米管易生成,管径均一、分布稠密;当Ni（NO₃）₂·6H₂O与苯酚物质量比大于0.04时,Ni催化剂易团聚,碳纳米管管径分布较宽,分布稀疏;当Ni（NO₃）₂·6H₂O与苯酚物质量比为0.10时,Ni催化剂团聚现象严重,难以生成碳纳米管;提出了碳洋葱、竹节碳和碳纳米管不同碳纳米结构可能的形成机理。     

微波辅助溶剂热法制备磷酸钙微球和多面体

磷酸钙材料具有良好的生物相容性, 被广泛应用于生物材料领域。本研究以Ca(CH₃COO)2、NaH₂PO₄?2H₂O和双亲嵌段共聚物PLA-mPEG为原料, 通过微波辅助120℃水热反应30 min, 合成了自组装结构磷酸钙微球。以相同的反应原料, 在水和乙二醇混合溶剂中, 通过微波辅助120℃溶剂热反应30 min, 制备了具有多面体结构的磷酸钙。通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)和热重分析(TG)对所制备样品的物相和形貌进行了表征。研究发现乙二醇的加入对磷酸钙的结构和形貌具有显著的影响。以牛血红蛋白为模型, 研究了所制备的两种不同磷酸钙材料的蛋白吸附效果。磷酸钙材料的牛血红蛋白吸附量随装载溶液中牛血红蛋白浓度的增加而增大, 随样品制备过程中的乙二醇加入量的增加而减小。     

Preparation of nanocrystalline SnO2 thin film coated Al2O3 ultrafine particles by fluidized chemical vapor deposition

Fluidized chemical vapor deposition (FCVD) technology was developed for coating SnO₂ thin film on Al₂O₃ ultrafine particles. TEM and HREM analysis found that SnO₂ films with different structures were deposited by controlling the coating temperature, reactant concentration, etc. Nanocrystalline SnO₂ film was coated at 573.15 K by gas phase reaction of SnCl₄ with H₂O. EPMA and EDS studies indicated that the distribution of SnO₂ inner and outer of the agglomerates was uniform. Nucleation and film deposition were coexisted mechanism during the FCVD coating process. The fraction of SnO₂ in the composite particles increased with increasing coating temperature, SnCl₄ concentration, and coating time. The mass fraction of SnO₂ in the composite particles increased strongly with the ratio of P_H2O and P_SnCl4 at low mole ratio of H₂O with SnCl₄, but increased little under the conditions of excess H₂O with respect to SnCl₄.     

固相化学法制备纳米Ce0.75Zr0.25O2粉体的表征及应用（英文）

以Ce2(CO)3,ZrOCl2.8 H2O和H2C2O4.2 H2O为原料,第一次成功地采用了机械力活化固相化学法制备纳米Ce0.75Zr0.25O2粉体。以XRD、TEM分析及XPS等测试手段对Ce0.75Zr0.25O2粉体的结构和形貌进行了表征,结果表明,产物为单一立方相的球形粉体,平均粒径小于20nm,比表面积为85.4m2/g。通过TG-DTA分析,对合成过程中可能发生的化学反应机理进行了分析。对Ce0.75Zr0.25O2氧化物固溶体在三效催化剂中的活性进行了评价。     

清液体系高性能T型分子筛膜的制备及表征

采用二次生长法, 在廉价大孔α-Al₂O₃管状载体上通过变温热浸渍涂晶法获得连续致密的晶种层, 在摩尔配比为1SiO₂:0.05Al₂O₃:0.26Na₂O:0.09K₂O:30H₂O清液体系中120℃水热晶化16 h成功制备出T型分子筛膜。实验考察了小晶种液浓度, 晶化时间对T型沸石分子筛膜的形貌和性能的影响。XRD和SEM结果表明, 晶化过程中晶种的外延生长和新的晶核成核过程同时进行, 晶种的外延生长和新核的诱导作用产生协同作用, 缩短T型沸石膜的生长时间。将制备的T型沸石分子筛膜用于75℃渗透汽化分离10wt%水/异丙醇体系, 其渗透通量和分离系数分别达到2.96 kg/(m²·h)和6400。     

溶剂热法制备Cu2ZnSnS4粉末及其表征

采用溶剂热法, 以CuCl₂·2H₂O、Zn(Ac)₂·2H₂O、SnCl₄·5H₂O作金属源, 硫脲作硫源, 乙二醇作溶剂, PVP作表面活性剂, 制备了Cu₂ZnSnS₄(CZTS)粉末。利用XRD、SEM、Raman、TEM、EDS、UV-Vis吸收光谱探讨了反应温度和反应时间对制备CZTS粉末的相结构、成分、形貌以及光学性能的影响。结果表明: 反应温度和反应时间对CZTS粉末的颗粒形貌和光学性能影响较大, 最佳合成温度为230℃, 反应时间24 h。该条件下生成的CZTS粉末相较为纯净、结晶完全, 形貌为表面嵌有薄片的微球, 各元素原子比接近化学计量比, 光学带隙为1.52 eV, 与太阳能电池所需的最佳带隙接近。并对其形成机理进行了初步探讨。     

Structural and ionization effects on the adsorption behaviors of some anilinic compounds from aqueous solution onto high-area carbon-cloth

The adsorption of anilinic compounds; aniline, p-toluidine, 1-napthylamine and sodium salt of diphenylamine-4-sulfonic acid from solutions in H₂O, in 1 M H₂SO₄ or in 0.1 M NaOH onto activated carbon-cloth was studied by in situ UV spectroscopy. A specially designed adsorption cell was used for this purpose. The adsorption processes were found to follow first-order kinetics and the rate constants were determined. The pH at the point of zero charge of the carbon-cloth surface was measured as 7.4. The highest rates and extents of adsorption were observed from H₂O solutions for aniline, p-toluidine and 1-napthylamine and from solution in 1 M H₂SO₄ for the sodium salt of diphenylamine-4-sulfonic acid. The adsorption behaviors of these four anilinic compounds in the three solutions (in H₂O, in 0.1 M NaOH and in 1 M H₂SO₄) were explained in terms of electrostatic and dispersion interactions between carbon-cloth surface and the anilinic species. The adsorption isotherm data for the anilinic compounds were derived at 30 °C and treated according to Langmuir and Freundlich models. The Freundlich model was found to represent the experimental isotherm data better than Langmuir model.     

空气浴条件下三水醋酸钠相变材料的储热性能实验

三水醋酸钠（CH₃COONa3H₂O）作为一种无机相变储能材料,具有潜热值高、导热性能好等优点,但是其在凝固过程中过冷度大制约了CH₃COONa3H₂O的应用。为了调节CH₃COONa3H₂O在空气浴条件下的过冷度,本文选用Na₂HPO₄12H₂O、Na₂CO₃10H₂O、Na₄P₂O₇10H₂O、Na₃PO₄12H₂O、Na₂SiO₃9H₂O、Na₂S₂O₃9H₂O和Na₂B₄O₇10H₂O这7种无机水合盐材料作为成核剂,采用步冷曲线法在高低温试验箱中进行过冷度调节实验和热循环实验。结果表明：在空气浴条件下,质量分数为96% CH₃COONa3H₂O+2% Na₂HPO₄12H₂O+2%羧甲基纤维素的复合相变材料过冷度最小,为5.6℃;将复合相变材料进行25、50和75次热循环后,其相变点温度几乎维持不变,过冷度随循环次数增加而逐渐增大,相变潜热值随循环次数的增加逐渐减小。本研究丰富了CH₃COONa3H₂O相变材料的过冷度调节方案,为其工程化应用提供了参考。