不同形态SnO2纳米晶的制备

In this paper, we report our research on morphologically selective synthesis of nanocrystalline SnO2 by the combination of hydrothermal preparation and calcinated process. We firstly prepared SnO2 nanocrystals by the hydrothermal method at 140 ℃ for 3 h, using SnCI4 as the reactant. With the initial pH of 1.8 or 1.34, we prepared uniform and well-dispersed SnO2(tetragonal) nanocrystals, with similar size of about 3 nm, as determined by TEM. However, after being calcinated at 500 ℃ for 2 h, specimen 1 prepared at pH＝1.8 showed the rod-like shape with an average size of 5 nm×20 nm, while the other one(specimen 2)prepaed at pH＝1.34 showed a granular shape with an average size of 10 nm. XRD experiments showed that specimen 1 had a new diffraction peak after calcination, which was contributed by the (023) face of orthorhombic SnO2. The experiment results indicated that the morpholgy of SnO2 nanocrystals after calcination was closely related to the initial acidity of the reaction solution, possibly due to the difference in surface properties, e.g. the difference in crystalline faces exposed to the surface of particals, under different hydrothermal conditions.     

纳米SnO2的制备条件及其光催化活性

纳米粒子;光催化降解;纳米SnO2的制备条件及其光催化活性     

SnO2纳米晶的水热合成及其气敏特性

SnO2 nanocrystal with different crystalline sizes were prepared with SnCl2 2H2O and H2O2 raw materials by a hydrothermal process. The synthesized powders at different reaction temperatures were characterized by means of powder X-ray diffraction, transmission electron microscope, specific surface area and gas sensitivity measurements. The results revealed that the pure SnO2 nanocrystallites synthesized at 120 ℃ have high specific surface area （210.3 m2/g）, and show a high sensitivity to C2H5OH gas. Both traits are beneficial in gas-sensitive detection application.     

微波液相沉淀法制备CeO2纳米晶

以硝酸铈为原料,碳酸氢铵为沉淀剂,用微波加热的方法制备了纳米CeO2超细粉体,用X射线衍射法和透射电子显微镜等检测手段进行表征,结果表明,微波法制备样品的平均晶粒度为8nm,而传统加热法则为16nm,反应时间由60分钟缩短为5分钟,并提高了颗粒的分散性.     

纳米SnO2／ZnO复合氧化物的制备及制备条件对光催化性能的影响

以SnCl4·5H2O、ZnSO4·7H2O、NH3·H2O为原料,采用共沉淀法制备出纳米SnO2/ZnO复合光催化剂,以降解甲基橙为模型反应,考察了不同条件制备的复合氧化物的光催化活性,并用TEM、XRD测试手段对其进行了表征。结果表明,ZnO复合SnO2后,光催化活性明显提高,但是焙烧温度超过900℃后,其光催化活性又大大降低。     

纳米SnO2@TiO2的制备及其光催化性能

以SnCl4和Ti(OBu)4为原料,采用活性层包覆法制备了SnO2@TiO2包覆型复合光催化剂,并用XPS、IR、XRD、TEM和BET等手段进行了表征,以二甲基二氯乙烯基磷酸酯（简称DDVP）稀释液为模拟废水,考察了SnO2@TiO2的光催化活性及降解液初始浓度对反应动力学的影响.结果表明：包覆粒子由锐钛矿型TiO2和金红石型SnO2组成;与纯SnO2、TiO2相比,SnO2@TiO2包覆粒子的光催化活性明显提高,DDVP稀释液被光催化降解属于零级反应,但反应表观速率常数与降解液初始浓度成正比.     

溶剂热法制备纳米晶Sb2O3

以 SbCl3为锑源,采用溶剂热法制备了纳米Sb2O3(1),其结构经XRD和SEM表征.溶剂的种类和体系 pH可以控制1的晶型及形貌.水作溶剂时,1为板状斜方晶型;乙醇作溶剂时,1为单一斜方晶型或立方和斜方混合晶型;用乙醇和乙二醇混合溶剂时,1为斜方晶型;用乙醇和异丙醇混合溶剂时1为单一立方晶型.     

SnO2纳米粒子的制备与表面改性

以SnCl4·5H2O和氨水为原料,用水热法制备了粒度均匀的SnO2纳米粒子,并用γ-氨丙基三乙氧基硅烷(KH-550)对其进行了表面改性. 用X射线衍射(XRD)、透射电子显微镜(TEM)、纳米粒度/Zeta电位测定和元素分析测试技术对粒子进行了表征. 研究结果表明,所制得的SnO2纳米粒子为四方晶系金红石型结构,改性后的纳米粒子均一性进一步提高,粒径分布在8～20 nm,能形成稳定的分散体系.     

SnO2纳米薄膜的制备、显微结构及气敏性能

SnO2纳米薄膜的制备、显微结构及气敏性能;SnO2薄膜;溶胶-凝胶法     

SnO纳米晶须的制备及其性能表征

SnO nanowhiskers were successfully prepared by the pressure thermalcrystallization method using SnCl2·2H2O as raw material, Na2CO3 as mineralizing reagent and cetyltrimethylammoniumbromide as surfactant. Microstructure and morphology of the prepared products has been characterized by means of transmission electron microscopy,selected area electron diffraction and X-ray diffraction. The results showed the particle has rod like apparent structure. The diameter and the length of the particle were 10~40 nm and 100~400 nm, respectively. The influence of some reaction parameters, including the pressure, the surfactant and the reaction duration, on the formation, morphology and particle size of SnO crystallite was discussed. It revealed that increasing the pressure and prolonging the reaction time duration are favorable for the formation of tetragonal stannous oxide whiskers. The mechanism of the formation of SnO nanowhiskers was also simply investigated.     

Synthesis of Nanocrystalline, Redispersable Antimony-Doped SnO2 Particles for the Preparation of Conductive, Transparent Coatings

Nanocrystalline, redispersable Sb-doped SnO2 with Sb contents from 0.1–10 mol% (with respect to Sn) and a primary particle size of about 5 nm was prepared from SnCl4 and SbCl3 in solution by a growth reaction. The aggregation of the particles was avoided by in situ surface modification with amino carbonic acids. The stabilizing effect of the surface modification could be maintained during the following hydrothermal crystallization step (150°C, 10 bar). The resulting nanocrystalline particles are fully redispersable in aqueous suspensions at pH 11; solid contents up to 40 wt% can be achieved.Such aqueous dispersions were used to prepare transparent, conductive coatings on glass by spin coating. After thermal densification (1 hour at 550°C) transparent coatings of 220 nm thickness were obtained. A minimum specific electrical resistance of 2.5 · 10–2 cm for Sb contents between 4 and 5 mol% was measured, the transparency in the visible range against air was 90%.     

气相合成SnO2超微粒薄膜研究

用直流气体放电活化反应蒸发法在玻璃基片上沉积的SnO2超微粒薄膜,研究其过程中各工艺参数对薄膜结构的影响及作用机理.结果表明, SnO2超微粒薄膜粒径随氧分压增加而增大;蒸镀时间的延长有助于SnO2的生成,也使薄膜发生晶化;而增加放电电压,则薄膜出现外延单晶生长趋势.     

SnO2-SnS2复合纳米粒子的制备及光电性质研究

采用离子交换法制备了SnO₂-SnS₂复合纳米粒子.用XRD、TEM和X-EDAS测定了样品的组成、结构、形貌和尺寸,结果表明,样品为SnS₂部分包覆SnO₂的球形复合纳米粒子,其平均粒径为5nm.研究了该复合纳米粒子的紫外-可见漫反射光谱和光电化学性质,观察到SnO₂-SnS₂复合纳米粒子的光吸收比SnO₂的明显向长波区扩展;制成工作电极后的光电流值和光电转换效率(IPCE)都比相应的纯组分纳米粒子电极显著提高.     

制备条件对Sb/SnO2超细粉水分散性的影响

制备条件对Sb/SnO2超细粉水分散性的影响     

反相胶束微乳液法制备氧化钇纳米微晶

纳米结晶;反相胶束微乳液法制备氧化钇纳米微晶     

作为锂离子电池负极材料的三维有序大孔SnO2的 制备及表征

通过聚苯乙烯(PS)胶晶模板法合成了三维有序大孔(3DOM) SnO2. 运用扫描电镜、热重分析、X射线衍射、电化学充放电等多种方法对其结构和性能进行了表征和研究. SEM图表明PS胶晶模板微球排列规整, 大小均匀(直径275±10 nm), 形成多层六方紧密堆积排列; 煅烧除去模板后的3DOM SnO2呈三维多孔网络结构, 具有圆型和六边形的孔隙形貌, 其孔径大小为(215±10) nm; 孔壁由SnO2纳米晶粒组成, 壁厚为20～30 nm. XRD图谱表明经过煅烧除去模板后, 形成了纯SnO2相. 当作为锂离子电池负极材料时, 3DOM SnO2表现出较好的充放电容量和库仑效率. 此外, 这种合成方法简单、经济, 可进一步应用于其它锂离子电池材料的合成.     

均匀沉淀法制备纳米氧化锡粒子

以 CO(NH2 ) 2 、Sn Cl4· 5 H2 O为原料 ,采用均匀沉淀法制备了纳米 Sn O2 粒子。以 TG-DTA、XRD、TEM等测试手段 ,对纳米 Sn O2 的粒子结构和形貌进行了研究。结果表明 ,在 6 0 0℃下热处理得到的粒子结晶性能良好。改变反应条件 ,制备出了粒径分布窄、分散性良好的纳米 Sn O2 粒子 ,其平均粒径为 15 nm。同时对均匀沉淀法形成纳米 Sn O2 粒子的机理进行了初步探讨     

CeO2/SnO2纳米材料的制备与气敏性能研究

本文应用溶胶-凝胶法制备了7种不同成分和煅烧温度的CeO2/SnO2材料,应用X射线衍射方法对其中的3种进行了结构表征和粒度分析,运用自组装的气敏性能设备检测了该7种不同成分的CeO2/SnO2材料的气敏性能,简要分析了其气敏机理。结果表明:掺杂CeO2有利于SnO2晶粒的细化;掺杂CeO2和La2O3可改变或提高SnO2气敏材料对某些气体的气敏性能;煅烧温度在600℃~800℃之间,掺杂2?O2的CeO2/SnO2气敏材料,随煅烧温度上升,气敏性能下降;煅烧温度600℃、掺杂5?O2的CeO2/SnO2气敏材料,对乙醇具有较高的灵敏度和选择性,具有开发应用价值;CeO2/SnO2气敏材料的气敏机理为表面电导控制型。