二维纳米结构——氧化铋纳米片的制备与表征

利用物理气相沉积法,在氲气和氧气保护下将氧化铋粉末在水平管式炉中常压加热至1050℃,然后降温沉积,在硅衬底上得到了大量具有规则矩形外形的二维纳米结构——片状氧化铋．纳米片的长约1200mm,宽约300nm,厚约10～15nm．采用扫描电镜（SEM）,X-ray能谱仪（EDS）、高分辨透射电镜（HRTEM）等测试手段分析了样品的形貌、成分及微结构．研究分析了衬底放置方式对产物沉积量的影响．     

纳米针状金刚石膜的制备

利用高功率微波等离子体化学气相沉积方法在硅衬底上沉积了多晶金刚石薄膜,然后利用电子束蒸发方法在金刚石薄膜表面上沉积了5 nm厚的Pt薄膜.利用Pt的自组织化效应,再通过氢等离子体照射、氧等离子体刻蚀、王水处理等手段,使金刚石薄膜表面形成了纳米针.利用拉曼光谱和扫描电子显微镜(SEM)表征金刚石薄膜的结构,拉曼光谱显示在1 315 cm^-1处出现纳米金刚石特征峰,SEM显示纳米针均匀地直立在金刚石薄膜表面,每平方厘米大约含有10⁸个纳米针,纳米针的平均高度约为1 μm.     

ZnO纳米棒阵列的可控生长与表征

采用化学溶液法在沉积了ZnO种子层的SnO2:F导电玻璃衬底上,生长了ZnO纳米棒阵列。研究了1,3-丙二胺浓度对纳米棒阵列的形貌结构的影响规律。采用扫描电镜(SEM),X射线衍射(XRD)对ZnO纳米棒的表面形貌和晶格结构进行了表征。SEM结果表明纳米棒阵列垂直衬底表面生长,XRD结果表明纳米棒生长方向沿着[002]晶向,具有单晶结构。1,3-丙二胺浓度对制备得到的纳米棒形貌、长度等有明显调控作用。在优化条件下生长的ZnO纳米棒的长度大约7m,根部直径150nm,尖端直径大约10nm。研究了ZnO纳米棒阵列的光致发光(PL)特性。     

N掺杂和Cu沉积TiO_2纳米管紫外光光电响应研究

研究了用阳极氧化法在钛基底表面上生长致密有序的TiO2纳米管阵列,然后用湿法掺杂N、光化学方法沉积Cu对TiO2纳米管阵列进行改性,并研究改性纳米管对紫外光光电响应的影响.用X射线衍射（XRD）和扫描电镜（SEM）进行晶型和形貌表征.结果显示,改性前后纳米管都为锐钛矿;其内径约90 nm,管壁厚约12 nm,是中空的管状结构;掺杂N和沉积Cu对二氧化钛纳米管的晶型和形貌没有显著影响.测试改性前后TiO2纳米管在紫外光照射下的恒电位电流—时间（—It）关系曲线表明：掺杂N使TiO2纳米管光电性能降低,沉积Cu使TiO2纳米管的光电性能增强.     

WS2纳米带的水热合成与表征

为了制备一维纳米结构的WS2纳米带，提出了一种两步水热法合成方法。以Na2WO4为前驱体水热
合成了WO3·xH2O纳米棒，然后用WO3·xH2O纳米棒与硫脲进行水热反应合成WS2纳米带。初步讨论了两步
水热法合成WS2纳米带的反应机理.用X-射线衍射(XRD), 透射电镜（TEM）和场发射扫描电镜（FE-SEM）
对样品进行了表征.结果显示WS2纳米带的平均带宽约140 nm, 厚度约30 nm，长度约1 μm，比表面积为
97 m2/g.     

锡酸镧(La2Sn2O7)花状纳米结构的水热合成及表征

采用简单、中性的水热法成功地制备了锡酸镧（La2Sn2O7）花状纳米结构,并采用X射线衍射（XRD）、透射电镜（TEM）和漫反射光谱（DRS）等手段对产物的晶体结构、形貌和光学性能进行了分析。结果表明：所得产物为单相烧绿石结构的锡酸镧,并呈现由纳米杆组成的花状纳米结构,纳米杆的直径和长度分别约为20 nm和150nm。由分析DRS光谱可得,锡酸镧花状纳米结构的禁带宽度约为3.85 eV,并对该花状纳米结构的形成机理进行了初步探讨。     

稀土化合物纳米粒子和纳米棒的水热合成和表征

通过水热处理合成了稀土氟化物（LaF3、PrF3、NdF3、SmF3）纳米粒子和稀土氢氧化物（Pr(OH)3）纳米棒，并对产物进行了透射电镜（TEM）、X射线衍射（XRD）和热重-差热分析（TG-DTA）表征.讨论了水热反应温度、溶液pH值和氟与稀土镧元素的摩尔比对LaF3纳米粒子粒径的影响.结果表明，稀土氟化物纳米粒子具有球形或类球形的形貌，平均粒径为35～39 nm.水热合成的氢氧化镨为典型的纳米棒形貌，具有均匀的直径，平均直径为24 nm, 平均长度为130 nm.水热合成的稀土化合物纳米材料具有较高的结晶度和纯度.     

Au-TiO2纳米管阵列的制备及其在降解制糖废水中的应用

采用阳极氧化法在纯钛表面制备出了TiO2纳米管阵列薄膜.以罗丹明B为目标降解物,20W紫外灯（λ =253.7 nm）作为光源,探讨了制备Au-TiO2纳米管阵列（Au-TNTs）的最佳工艺,并采用扫描电镜（SEM）、X射线衍射物相分析（XRD）、能谱分析（EDS）等对样品进行了表征.结果表明,以1g/L HAuC14＋ 30 g/L H3BO3为沉积液,当沉积电压为2.5V、超声条件下电沉积时间为60 s时,可制得理想稳定的Au-TNTs;Au掺入量占薄膜质量的16.71％,Au的掺入并没有改变TiO2纳米管阵列的表面形貌及晶型,但却显著提高了TiO2纳米管阵列的光催化活性.将Au-TNTs用于制糖废水的光催化降解,结果发现：当光照时间为30 h、pH值为1时,Au-TNTs对制糖废水的光催化降解率可达89.59％,比TNTs高出80％.Au-TNTs对制糖废水的光催化降解过程符合一级动力学过程.     

表面覆盖钛薄膜的纳米片状碳膜场发射特性(英文)

利用石英管型波等离子体化学气相沉积装置在Si衬底上沉积了纳米片状碳膜,然后采用电子束蒸镀方法在碳膜表面沉积了一层2 nm厚的Ti膜,并在高真空系统中测量了覆盖Ti膜前后的纳米片状碳膜的场发射特性.研究表明:覆盖Ti膜的纳米片状碳膜因表面生成碳化钛而改性,使得场发射特性得到改善;表面覆盖Ti膜后,阈值电场由2.6 V/μm下降到2.0 V/μm,当电场增加到9 V/μm时,场发射电流由12.4 mA/cm2增加到20.2 mA/cm2.     

水热沉积锗纳米棒的生长机理

以锗、二氧化锗为锗源,于400℃和7.1～8.0MPa的水热条件下在铜片上沉积出了单晶锗纳米棒。对不同金属基片作为衬底的实验结果表明铜片衬底在纳米棒的形成过程中起到了重要作用,对二氧化锗、锗分别作为原料的实验结果表明二氧化锗在锗纳米棒的形成过程中起到了关键作用,提出了锗酸铜辅助生长机理,初步解释了水热沉积锗纳米棒的生长过程。     

Preparation and structure characteristics of nano-Bi2O3 powders with mixed crystal structure

The nano-Bi2O3 powders were prepared by a chemical precipitation method with Bi(NO3)3, HNO3 and NaOH as reactants. The structural characteristics and morphology of nano-Bi2O3 powders were investigated by X-ray diffraction and transmission electron microscopy, respectively. The results show that under the optimum condition that 300g/L Bi(NO3)3 reacts at 90℃ for 2 h, the Bi203 powders with 60 nm on the average and 99.5% in purity are obtained. The prepared nano-Bi2O3 powders contain a mixed crystal structure of monoclinic and triclinic instead of traditional structure of monoclinic α-Bi2O3. And the mixed crystal structure is stable in air. The reason for the appearance of the mixed crystal structure may be that the ionic radius ratio of Bi^3 to O^2- changes easily during the formation of nano-Bi2O3 particles by a chemical precipitation method.     

Synthesis of γ-Al2O3 nanoparticles by chemical precipitation method

Highly pure active γ-Al₂O₃ nanoparticles were synthesized from aluminum nitrate and ammonium carbonate with a little surfactant by chemical precipitation method. The factors affecting the synthesis process were studied. The properties of γ-Al₂O₃ nanoparticles were characterized by DTA, XRD, BET, TEM, laser granularity analysis and impurity content analysis. The results show that the amorphous precursor Al(OH)₃ sols are produced by using 0.1 mol/L Al(NO₃)₃ · 9H₂O and 0.16 mol/L (NH₄)₂CO₃ · H₂O reaction solutions, according to the volume ratio 1.33, adding 0.024% (volume fraction) surfactant PEG600, and reacting at 40 °C, 1 000 r/min stirring rate for 15 min. Then, after stabilizing for 24 h, the precursors were extracted and filtrated by vacuum, washed thoroughly with deionized water and dehydrated ethanol, dried in vacuum at 80°C for 8 h, final calcined at 800 °C for 1 h in the air, and high purity active γ-Al₂O₃ nanoparticles can be prepared with cubic in crystal system, O _H ⁷ -FD3M in space group, about 9 nm in crystal grain size, about 20 nm in particle size and uniform size distribution, 131. 35 m²/g in BET specific surface area, 7 – 11 nm in pore diameter, and not lower than 99.93% in purity. Foundation item: Project(03JJY3015) supported by the Natural Science Foundation of Hunan Province     

纳米Al2O3改性环氧胶黏剂和钢铁附着机理的研究

通过拉拔法测定纳米Al₂O₃改性环氧胶黏剂和钢铁之间的附着强度,并结合环氧胶的表面能参数测定以及X射线光电子能谱(XPS)分析,对纳米Al₂O₃提高环氧胶和钢铁附着力的机理进行研究.表面能测定结果表明,添加纳米Al₂O₃使环氧胶的极性增加;XPS能谱分析结果表明,当纳米Al₂O₃质量分数达到2%时,环氧胶中形成新的羧基极性基团;进一步研究发现,当纳米Al₂O₃质量分数为1%时未形成新的羧基基团,当纳米Al₂O₃质量分数为8%时单位接触面积上新的羧基基团的数目较2%时少,这与附着强度的变化规律是一致的.因此,纳米Al₂O₃改性的环氧胶黏剂与钢铁的附着强度的增强是由于Al₂O₃与环氧胶的相互作用形成了新的羧基极性基团．     

Pressureless reactive sintering mechanism of nanocrystalline Bi2O3-Y2O3 solid electrolyte

The nanocrystalline Bi2O3-Y2O3 solid electrolyte material was synthesized by pressureless reactive sintering process with Bi2O3 and Y2O3 nano mixed powder as raw materials, which was prepared by a chemical coprecipitation process. The study on the behavior of nano δ-Bi2O3 formation and its grain growth showed that the solid solution reaction of Y2O3 and β-Bi2O3 to form δ-Bi2O3occurs mainly in the initial stage of sintering process, and nano δ-Bi2O3 crystal grains grow approximately following the rule of paracurve ((D-D0)2=K.t) during sintering process. After sintered at 600℃ for 2 h, the samples could reach above 96% in relative density and have dense microstructure with few remaining pores, the δ-Bi2O3 grains are less than 100 nm in size.     

MoO3 薄膜的MoS2 氧化法制备、器件组装 及其电致变色性能

以MoS_2为原料,通过超声波辅助液相剥离块体MoS_2,得到了MoS_2纳米片。将其分散于乙醇中,然后旋涂至氟掺杂氧化锡(FTO)导电玻璃上,煅烧后得到MoO_3薄膜,并组装成电致变色器件,研究了器件的电致变色性能。结果表明,所制备出的MoO_3纳米片的厚度约为50～60 nm,所制备的电致变色器件在580 nm波长处,透过率调制幅度达到最大值16.2%,器件的着色时间为3.0 s,褪色时间为9.2 s。     

Luminescent properties of BaO-La2O3-B2O3 glasses with dopant

The luminescent properties of glasses synthesized in air atmosphere by conventional high temperature process were stud{ed. The emissions spectra of Eu^2 and Eu^3 were observed in BaO-La2O3-B2O3-Eu2O3 glasses.The results show that the broad emission peaks at 430 nm correspond to 5d→4f emission transition of Eu^2 , the sharp emission peaks at 592, 616, 650 and 250 nm correspond to 5^D0→1Fj(j=1--4) emission transition of Eu^3 ,respectively, which indicates that the BaO-La2O3a-B2O3-Eu2O3 glass can convert ultraviolet and green omponents of sunlight into blue and red light so as to increase the intensity of blue and red light, respectively. The luminescent in--tensity of Eu^2 increases with increasing the molar ratio of Tb^3 in BaO-La2O3-B2O3-Eu2O3a-Tb4O3 glasses, whereas the luminescent intensity of Eua^3 decreases. So the luminescent intensity of Eu(Ⅲ,Ⅱ) is influenced by Tb^3 .These phenomena can be explained by electron transfer mechanism; Eu^3 (4f6) Tb^3 (4f^8)→Eu^2 (4f′) Tb^4 (4f′). Taking advantage of the luminescent properties of BaO-La2O3-B2O3-Eu2O3 glasses, light-conversion glass for agriculture can be produced.     

Self-cleaning glass coated with Fe^3＋ -TiO2 thin film

The self-cleaning glass coated with Fe^3 -TiO2 photocatalytic thin film was prepared by sol-gel process from the system Ti(OC4H9),-NH(C2H4OH)2-C2H5OH-H2O containing FeCl3. The microstructure and properties of the film were studied using differential thermal analysis-thermogravimetry(DTA-TG), X-ray diffration (XRD) and scanning electron microscope(SEM). The transmittance of the self-cleaning glass was measured by using UV-Vis spectrometer. The effects of content of Fe^3 and the thickness of Fe^3 -TiO2 thin film on the photocatalytic ac-tivity were examined. The results show that the photocatalytic thin films are mainly composed of Fe3O4 and TiO2 particles within 10-100 nm. The appropriate amount of Fe^3 is effective for improving the photocatalytic activities of TiO2. The best photocatalytic activity is obtained when the molar ratio of Fe^3 to TiO2 is 0. 005 and the glass is coated with 9 layers.     

Properties of plasma sprayed NiCrAlY+(ZrO2+Y2O3) coating on refractory steel surface

NiCrAlY+(ZrO₂+Y₂O₃) thermal barrier coating was prepared on the surface of refractory steel 1Cr18Ni9Ti with plasma spraying technique. The phases and microstructure of the thermal barrier coating were determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the bonding between thermal barrier coating and substrate is sound. The surface hardness of 1Cr18Ni9Ti reaches up to 1 000 HV, but that of substrate is only 300 HV. The patterns sprayed with CoNiCrAlY+(ZrO₂+Y₂O₃) ceramic coating have a good heat insulation effect at 800 °C for heat insulation temperature difference reaches 54 °C, which increases the operating temperature and service life of refractory steel. Foundation item: Project (5040202140) supported by Scientific Research Common Program of Beijing Municipal Commission of Education     

Molar heat capacities of La2Mo2O9 and La1.9Sr0.1MO209-δ

The molar heat capacities of La2Mo209 and La1.9Sr0.1MO209-δ were obtained using the differential scanning calorimetry （DSC） technique in a temperature range from 298 to 1473 K. The DSC curve of La2Mo209 showed an endothermal peak around 834 K corresponding to a first-order monoclinic-cubic phase transition, and the enthalpy change accompanying this phase transition is 5.99 kJ/mol. No evident endothermal peak existed in the DSC curve of La1.9Sr0.1MO209-δ, but a broad thermal anomaly existed in its heat capacity curve at around 832 K. In addition, the heat capacity values of La2Mo209 and La1.9Sr0.1MO209-δ began to decrease at 1196 and 1330 K, respectively. The non-transitional heat capacity values of La2Mo209 and La1.9Sr0.1MO209-δ were formulated using multiple regression analysis in two temperature ranges.     

沉淀法制备形貌可控YVO_4:Eu~(3+),Bi~(3+)粉体及其发光性能

采用沉淀法合成了YVO4:Eu3+,Bi3+荧光粉,利用XRD,SEM和TEM对样品的结构和形貌进行表征,并用荧光光谱仪测试了样品的激发和发射光谱。X射线衍射图分析表明,所制得的荧光粉与YVO4的物相一致,样品属于体心四方相。其扫描电镜和透射电镜照片显示颗粒为纺锤形,大小比较均匀,长径为250nm左右,短径为100nm左右。在275nm近紫外光激发下,该荧光粉的发光峰分别归属于Eu3+的5 D0→7 F1(596nm),5 D0→7F2(617nm,621nm),5 D0→7F3(654nm),5 D0→7F4(702nm)辐射跃迁。最强发射位于617nm左右,属于红光。研究了Eu3+浓度对样品发光强度的影响。随着Eu3+浓度的增加,发射峰强度增大,当Eu3+摩尔分数为12%时,峰值强度最大。Bi3+对Eu3+的发光有一定的敏化作用,当Bi3+摩尔分数达到5%时,敏化作用最强。