晶粒尺寸可控的纳米二氧化钛的制备

采用微乳法和溶胶-凝胶法相结合的方法制备纳米二氧化钛,通过改变制备参数可以将纳米二氧化钛的晶粒尺寸控制在6~30 nm之间。采用X射线衍射、透射电镜等表征手段,对不同的制备条件与晶粒尺寸的关系进行研究。通过在可见光下对亚甲基蓝水溶液的降解测试其光催化活性。结果表明:补充结论纳米二氧化钛具有良好的光催化性能。     

SnO2纳米颗粒制备及其对溶胶-凝胶Sb:SnO2薄膜性能的影响

以Sn(OEt)2为起始原料,采用水热晶化法合成了分散性良好的金红石结构的SnO2纳米颗粒.采用X射线衍射对其进行了表征,表明SnO2纳米颗粒的结晶性良好,颗粒尺寸小于10nm.将合成的SnO2纳米颗粒均匀分散到Sb:SnO2镀膜液中,经陈化后制成镀膜溶胶,以溶胶-凝胶浸渍镀膜工艺制备纳米颗粒掺杂Sb:SnO2薄膜.分别采用范德堡(Van Der Pauw)法、UV/VIS分光光度计和FTIR中红外分析仪测量并分析膜层的导电性能、光学性能及结构特征,研究了导电纳米颗粒添加对Sb:SnO2薄膜电性能、光学性能和结构的影响.     

气化法制备二氧化锡纳米粉末结晶机理研究

利用透射电子显微镜(TEM)对气化法制备的纳米SnO2粉末的形貌进行了观察,并对纳米颗粒的结晶机理及各种形貌的形成机制进行了分析.TEM结果表明,纳米二氧化锡粉末绝大部分呈类球状,少量呈针棒状、板片状、矩形及六边形等多面体形貌,这些晶体形貌的形成与氧化过程,内壁摩擦力和高速气流等因素有关.     

Sb掺杂二氧化锡单片纳米带的气敏特性研究

利用热蒸发法制备了纯净的SnO2纳米带及Sb掺杂SnO2纳米带。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、透射电子显微镜(TEM)和气敏测试仪器对其结构和性能进行了表征和测试。结果表明纳米带表面光滑,厚度约为50nm。纯净SnO2纳米带为理想的单晶结构,掺杂Sb后并没有改变二氧化锡的晶体结构和晶胞参数。使用单根Sb掺杂和纯净的SnO2纳米带制作成传感器并进行气敏性能测试,结果显示:Sb掺杂SnO2纳米带对乙二醇和丙酮的最佳响应温度为180℃,在100×10-6浓度下对乙二醇和丙酮的气敏响应分别为10倍和1.2倍;对乙醇的最佳响应温度为200℃,响应为2.6倍。在最佳响应温度,随乙二醇浓度的增加器件气敏响应增强,其响应时间随乙二醇浓度的增加而缩短,在50×10-6及100×10-6时,其响应时间分别为15s和14s。     

施主掺杂BaTiO_3陶瓷中电阻率、晶粒尺寸与氧分压的关系

施主含量不同的 BaTiO_3陶瓷在 H_2气氛中烧结后具有相近的平均晶粒直径。在大气中氧化后,它们仍然具有典型的 U 形电阻率～施主掺杂浓度曲线。这与传统理论不完全一致。本文就晶粒尺寸随氧分压的变化关系提出了新的见解。     

SnO2纳米颗粒制备及其对溶胶-凝胶Sb:SnO2薄膜性能的影响

以Sn(OEt)2为起始原料,采用水热晶化法合成了分散性良好的金红石结构的SnO2纳米颗粒.采用X射线衍射对其进行了表征,表明SnO2纳米颗粒的结晶性良好,颗粒尺寸小于10nm.将合成的SnO2纳米颗粒均匀分散到SbSnO2镀膜液中,经陈化后制成镀膜溶胶,以溶胶-凝胶浸渍镀膜工艺制备纳米颗粒掺杂SbSnO2薄膜.分别采用范德堡(Van Der Pauw)法、UV/VIS分光光度计和FTIR中红外分析仪测量并分析膜层的导电性能、光学性能及结构特征,研究了导电纳米颗粒添加对SbSnO2薄膜电性能、光学性能和结构的影响.     

溶胶-凝胶法制备纳米SrBi2Ta2O9的晶化过程和晶粒长大研究

以乙二醇为溶剂，醋酸为催化剂，部分无机盐代替醇盐的溶胶-凝胶工艺制备了不同平均晶粒尺寸的纯SrBi2Ta2O9(SBT)纳米粉末，晶相粉末晶粒大小为4—70nm．用XRD、TG．DTA、TEM系统研究了SBT纳米相的形成过程．通过改变干凝胶的热处理温度和热处理时间，研究了温度与时间参数对SBT晶粒长大的影响规律．研究表明，碳的燃烧和二氧化碳的蒸发对纳米团簇的长大具有一定的阻碍作用．SBT相的晶化行为分为金属．氧团簇向玻璃态转变和玻璃态到晶态的转变过程，玻璃态到晶态的转变温度区间为500—550℃．两个过程的长大激活能分别为：Ea1=0．709eV，Ea2=0．093eV．温度是晶粒长大的主要因素，热处理时间对晶粒长大影响不明显．     

晶粒尺寸对Cr20Ni80电热合金电阻率的影响

通过拉伸变形和再结晶退火改变Cr20Ni80的晶粒尺寸,研究了晶粒尺寸对Cr20Ni80电阻率的影响,并分析了原因。结果表明,材料变形越大,晶粒尺寸越小,其电阻率值就相对较高,且晶粒较大时,晶粒尺寸的变化对电阻率影响较显著。     

纳米级NiZnCu铁氧体粉的晶粒尺寸对瓷体性能影响

用柠檬酸盐溶胶-凝胶法制备的(Ni0.2Zn0.6Cu0.2)Fe2O4铁氧体粉体,通过不同的预烧温度控制粉体的粒径,制得不同晶粒大小的纳米粉体,采用两种烧结工艺实现NiZnCu铁氧体的低温烧结.利用XRD、SEM、TEM,频谱仪等分析了不同初始晶粒尺寸对烧结性能和铁氧体陶瓷电磁性能的影响,总结了烧结后晶粒尺寸对瓷体性能的影响规律,研制出细晶、高磁导率、高电阻率的低温烧结NiZnCu铁氧体陶瓷材料,其初始磁导率≥1000,电阻率比固相法提高了两个数量级.     

Sol-gel法制备铈酸钡纳米粉末

以硝酸钡和硝酸铈为原料,以硝酸铵为助燃剂,以柠檬酸和乙二胺四乙酸为螯合剂,采用溶胶-凝胶法制备BaCeO3纳米粉末.通过TG-DTA和XRD分析前驱体在升温过程中的物相变化,通过SEM研究样品形貌.结果表明,煅烧温度和时间对铈酸钡单相的形成有重要影响;溶液的pH值和硝酸铵浓度对产物样品粒径尺寸和分散度有一定的影响.     

微波法合成锑掺杂SnO2电极（英文）

提出了一种新的氧化物电极制备方法:微波热解法.分别采用微波热解法及刷涂热解法来制备电极.通过SEM、XRD、强化寿命、线性扫描等测试手段对两种电极进行了比较.以酸性红G为目标物考察两种电极的电催化性能.与传统刷涂热解法相比,微波热解法所需操作时间较少(2 h),操作步骤及强度也较低.结果表明,新方法制备得到的电极在表面形貌、氧化物晶型、电极稳定性、氧析出电位及电催化性能等方面,相比于传统方法制备的电极,均有一定程度的提升.     

Preparation of porous SnO2 helical nanotubes and SnO2 sheets

We report a surfactant-free chemical solution route for synthesizing one-dimensional porous SnO₂ helical nanotubes templated by helical carbon nanotubes and two-dimensional SnO₂ sheets templated by graphite sheets. Transmission electron microscopy, X-ray diffraction, cyclic voltammetry, and galvanostatic discharge–charge analysis are used to characterize the SnO₂ samples. The unique nanostructure and morphology make them promising anode materials for lithium-ion batteries. Both the SnO₂ with the tubular structure and the sheet structure shows small initial irreversible capacity loss of 3.2% and 2.2%, respectively. The SnO₂ helical nanotubes show a specific discharge capacity of above 800 mAh g⁻¹ after 10 charge and discharge cycles, exceeding the theoretical capacity of 781 mAh g⁻¹ for SnO₂. The nanotubes remain a specific discharge capacity of 439 mAh g⁻¹ after 30 cycles, which is better than that of SnO₂ sheets (323 mAh g⁻¹).     

反应液加入H2O2制备本征SnO2高阻薄膜

在反应液中加入H2O2,用超声喷雾热分解技术制备了SnO2高阻薄膜.结合XRD图谱,方块电阻测试,透光率测试以及Tauc曲线分析的结果,发现反应液中加入H2O2制备的SnO2薄膜,膜质较好,样品在(200)晶面有明显的择优取向;电阻率有明显提高,为12～13 Ω·cm;透光率与一般的透明导电膜并没有很大差别.     

纳米TiO2粉体抗菌、抗病毒性能研究

通过细菌定量杀灭实验和HbsAg的抗原性破坏实验,考察自制的纳米TiO2粉体的抗菌、抗病毒性能并探讨其抗菌抗病毒的机制.结果表明,在不同温度、pH和光源条件下TiO2均表现出很好的抗菌、抗病毒效果.ESR研究发现在无光条件下自制纳米TiO2也能产生对抗菌起主要作用的OH.     

SnO2和SnO2-Ag薄膜的电学特性

用磁控溅射法在集成了铂加热电极的Si基膜片型微结构单元上制备了SnO     

Silver layer instability in a SnO2/Ag/SnO2 trilayer on silicon

Trilayers of SnO₂/Ag/SnO₂ deposited on oxidized Si (100) substrates at room temperature become unstable after annealing at 100 °C and 200 °C, exhibiting five phenomena - formation of internal Ag hillocks, cracking of the top SnO₂ layer above internal Ag hillocks, penetration of Ag/Ag grain boundaries by SnO₂ leading to grain pinch-off, formation of Ag whiskers and islands on the free surface of the SnO₂ through the cracked top layer, and void formation in the Ag layer. The possible driving forces and evolution path for the observed instabilities resulting from thermal expansion mismatch stresses and the reduction in interfacial energy are discussed.     

High-rate deposition of Sb-doped SnO2 films by reactive sputtering using the impedance control method

SnO₂ films doped with Sb (ATO) were deposited both on unheated glass substrates and on glass substrates that had been heated at 200 °C by reactive sputtering of an Sb-Sn alloy target with a plasma control unit (PCU) and mid-frequency (mf, 50 kHz) unipolar pulsing. The PCU feedback system monitors the oxidation states of target surface by detecting the sputtering cathode voltage (impedance control method). The mf pulse wave is approximately square-shaped; this helps to reduce arcing on the target when high power density is applied on the cathode. In case of the ATO depositions on the heated substrate at 200 °C in the “transition region” of reactive sputtering, the deposition rate was 280 nm/min, the lowest resistivity of the ATO films was 4.6 × 10^− 3 Ω cm and the optical transmittance was over 80% in the visible region of light.     

Lithographic patterning of benzoylacetone modified SnO2 and SnO2:Sb thin films

The synthesis of directly UV-photopatternable pure and antimony-doped organo-tin materials is presented. UV-photopatternability has been achieved by using the synthesized benzoylacetone modified tin and antimony 2-isopropoxyethoxides. Photopatterned pure and antimony-doped organo-tin films are crystallized by thermal annealing in order to obtain conductive SnO₂ and Sb:SnO₂ thin films. The molar ratio between benzoylacetone and metal alkoxides has to be 2 in order to obtain crack-free, good-quality structures. The effects of UV-irradiation, increasing antimony doping level and benzoylacetone concentration on the electrical properties of the single-layered films are analyzed. The highest obtained conductivity was 20 S/cm. Benzoylacetone concentration and UV-irradiation has only a negligible effect on the film electrical conductivities.     

Characterizations of SnO2 and SnO2:Sb thin films prepared by PECVD

Structural characterizations of tin oxide (SnO₂) thin films, deposited by plasma-enhanced chemical vapor deposition (PECVD), were investigated with scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that the films are porous, the crystalline structure transforms from crystalline to amorphous phase as deposition temperature changes from 500°C to 200°C, and the chemical component is non-stoichiometric (Sn:O is 1.0716 prepared at 450°C with a value of O₂ flow 3.5 l/min). Sheet resistance of the thin films decreases with increasing of deposition temperature. Whereas, sheet resistance increases with increasing of oxygen flow. Tin oxide doped with antimony (SnO₂:Sb) thin films prepared by same method have a better selectivity to alcohol than to carbon monoxide; the maximum sensitivity is about 220%. The gas-sensing mechanism of SnO₂ thin films is commentated.