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1.
In2O3 nanoparticles were prepared from or with different indium salts by chemical precipitation under the conditions of various pH values. The crystal structure and ceramic microstructure of the samples were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The results show that the mean grain size of In2O3 is less than 100 nm, and their particle homogeneity and dispersibility are satisfactory. The gas sensitivity defined as Ra/Rg was detected in a static system. The results show that the sensors made by as-prepared nanoparticles has high sensitivity to many gases such as alcohol, HCHO, NH3 , et al. The response time is less than 20 s and the recovery time is lower than 30 s. 相似文献
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以In2O3-SnO2石英光透电极为研究电极，采用薄层光谱电化学方法，测定了铁氰化钾体系在不同电位下的光谱电化学行为． 相似文献
3.
Mo_2N与CoMo/(TiO_2—Al_2O_3)催化剂加氢脱硫与加氢脱氮催化性能比较 总被引：1，自引：0，他引：1
本文在同一条件下分别测试了硫化态的催化剂CoMo/(TiO2—Al_2O_3)及氮化态的Mo_2N催化剂的加氢脱硫和加氢脱氮性能,结果表明,对于噻吩的加氢脱硫反应,硫化态催化剂CoMo/(TiO_2—Al_2O_3)在催化活性及稳定性方面都优于Mo_2N,而Mo_2N在毗啶的加氢脱氮反应中显示了较大优势。 相似文献
4.
Zhi Huang Zhao-bo Chen Nan-qi Ren Dong-xue Hu Dong-huan Zheng Zhen-peng Zhang 《浙江大学学报(A卷英文版)》2009,10(11):1642-1650
To improve the working and living environment of submarine crews, an integrated system of CO2 removal and O2 regeneration was designed to work under experimental conditions for 50 people in a submarine cabin during prolonged voyages. The integrated system comprises a solid amine water desorption （SAWD） unit for CO2 collection and concentration, a Sabatier reactor for CO2 reduction and a solid polymer electrolyte （SPE） unit for O2 regeneration by electrolysis. The performances of the SAWD-Sabatier-SPE integrated system were investigated. The experimental results from the SAWD unit showed that the average CO2 concentration in the CO2 storage tank was more than 96% and the outlet CO2 concentration was nearly zero in the first 45 min, and less than 1/10 of inlet CO2 after 60 min when input CO2 was 0.5% （1000 L）. About 950 L of CO2 was recovered with a recovery rate of 92%-97%. The output CO2 concentration was less than 0.2%, which showed that the adsorption-desorption performance of this unit was excellent. In the CO2 reduction unit we investigated mainly the start-up and reaction performance of the Sabatier reactor. The start-up time of the Sabatier reactor was 6, 8 and 10 rain when the start-up temperature was 187.3, 179.5 and 168 ℃, respectively. The product water was colorless, transparent, and had a pH of 6.9-7.5, and an electrical conductivity of 80μs/cm. The sum of the concentration of metal ions （Ru^3＋, Al^3＋, Pb^2＋） was 0.028% and that of nonmetal ions （Cl^-, SO4^2-） was 0.05%. In the O2 regeneration unit, the O2 generation rate was 0.48 m^3/d and the quantity was 2400 L, sufficient to meet the submariners＇ basic oxygen demands. These results may be useful as a basis for establishing CO2-1evel limits and O2 regeneration systems in submarines or similar enclosed compartments during prolonged voyages. 相似文献
5.
Facile Fabrication of Fe_3O_4@TiO_2@C Yolk–Shell Spheres as Anode Material for Lithium Ion Batteries
Transition metal oxides have been actively exploited for application in lithium ion batteries due to their facile synthesis,high specific capacity,and environmental-friendly.In this paper,Fe_3O_4@TiO_2@C yolk-shell(Y-S) spheres,used as anode material for lithium ion batteries,were successfully fabricated by Stober method.XRD patterns reveal that Fe_3O_4@TiO_2@C Y-S spheres possess a good crystallinity.But the diffraction peaks' intensity of Fe_3O_4 crystals in the composites is much weaker than that of bare Fe_3O_4 spheres,indicating that the outer anatase TiO_2@C layer can cover up the diffraction peaks of inner Fe_3O_4 spheres.The yolk-shell structure of Fe_3O_4@TiO_2@C spheres is further characterized by TEM,HAADFSTEM,and EDS mapping.The yolk-shell structure is good for improving the cycling stability of the inner Fe_3O_4 spheres during lithium ions insertion-extraction processes.When tested at 200 mA/g,the Fe_3O_4@TiO_2@C Y-S spheres can provide a stable discharge capacity of 450 mAh/g over 100 cycles,which is much better than that of bare Fe_3O_4 spheres and TiO_2@C spheres.Furthermore,cyclic voltammetry curves show that the composites have a good cycling stability compared to bare Fe_3O_4 spheres. 相似文献
6.
以钼磷杂多酸作为光催化还原剂制备了表面负载钼磷杂多酸的纳米金溶胶（PMo12-NGs）,并将此PMo12-NGs修饰到具PVP膜的玻碳电极表面,考察该修饰电极的电化学行为．实验结果表明,用光催化还原法可直接制备得到杂多酸负载量大且均匀性好的纳米金,由此制备的纳米金修饰电极具有PMo12的良好的电化学行为,且电化学响应和电极稳定性优于单独PMo12修饰电极,该修饰电极对IO3^-等有明显的电催化还原作用,其催化速率常数k可达1．34×10^5mol^-1·L·s^-1． 相似文献
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A series of Li_(1-x)Na_xV_3O_8 materials was prepared by solution reaction followed by calcination method and their electrochemical performances in 2 M Li_2SO_4-water-ethanol solution as negative electrodes for aqueous electrolyte lithium ion battery were studied and compared each other.X-ray diffraction analysis revealed that partially substituting sodium for lithium in LiV_3O_8 could increase the interlayer distances of (100) plane.Cyclic voltammetric experiments have demonstrated that the Li~ insertion and extraction kinetics of Li_(0.7)Na_(0.3)V_3O_8 is superior to that of LiV_3O_8.Charge/discharge results showed that the discharge specific capacity of Li_(0.7)Na_(0.3)V_3O_8 electrode is higher than that of LiV_3O_8 electrode. 相似文献
9.
The TiO2thin films have attracted attention be-cause of their remarkable optical and electronic prop-erties[1,2]. They are used in a wide variety of applica-tions such as photocatalysts[3,4], gas sensors[5,6]andsolar cells. Titania exists mainly in three … 相似文献
10.
以Ti(OC4H9)4为原料,采用溶胶-凝胶法制备出光催化剂纳米TiO2和TiO2-Fe2O3复合粉体,并用制得的样品在紫外光催化条件下对刚果红、碱性品红、酸性蓝等三种水溶性染料溶液进行降解实验,讨论了两种催化剂对染料的光催化降解脱色效果。结果表明TiO2-Fe2O3复合粉体对酸性蓝和刚果红的降解效果好于纳米TiO2,两者对碱性品红的降解效果相当。 相似文献
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采用复合化学镀方法制备了镍-磷-氧化铁纳米复合材料镀层。通过孔隙率、耐腐蚀性、硬度、耐磨性等性质试验,结果表明:纳米复合镀层致密性、耐腐蚀性和耐磨性等均优于A3钢片,甚至优于Ni-P镀层。 相似文献
13.
采用DSC研究了稀土化合物氧化镧、硬脂酸镧对LLDPE(线性低密度聚乙烯)非等温结晶行为的影响。随着氧化镧和硬脂酸镧浓度的增加,LLDPE的结晶度出现下降的趋势。氧化镧可起到异相成核的作用,使LLDPE的结晶速率增快,冷却结晶峰向高温移动,而硬脂酸镧没有改变结晶峰的位置,对结晶速率没有影响。广角XRD(X射线衍射)结果显示氧化镧和硬脂酸镧没有使LLDPE的晶型产生变化,但在有氧化镧的体系中,LLDPE在110和200晶面的晶粒尺寸有明显增大。力学实验显示,氧化镧使LLDPE的拉伸强度略有降低,断裂伸长率则有较大幅度的下降。硬脂酸镧对LLDPE的拉伸强度影响不大。却使断裂伸长率有大幅度提高。 相似文献
14.
采用纳米粒子二元复配填充改性及冷压烧结工艺,制备了Al_2O_3/CaCO_3/PTFE三元复合材料,对其力学性能进行了探讨。实验结果表明,纳米粒子的填充显著提高了PTFE的摩擦磨损性能、硬度、抗蠕变性能及拉伸强度,降低了断裂伸长率。当Al2O3质量分数为20%、CaCO_3质量分数为10%时,PTFE复合材料综合力学性能优异。 相似文献
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以聚乙烯吡咯烷酮为保护剂,制备三角形银纳米粒子溶胶。用紫外灯对三角形银纳米粒子溶胶进行光诱导实验。利用透射电子显微镜、紫外-可见吸收光谱和拉曼光谱仪研究了不同光照时间下的银胶纳米粒子的光谱特性和表面形貌,以PATP为探针分子检测银胶纳米粒子的表面增强拉曼散射光谱。实验结果表明：随着光照时间的增多,银纳米粒子溶胶颜色变化显著;紫外-可见吸收光谱吸收峰出现＂蓝移＂;透射电子显微镜图显示银纳米粒子由三角形逐渐转变成截角三角形银纳米粒子、球形银纳米粒子;表面增强拉曼散射的增强效应随着光照时间的变化逐渐减小。 相似文献
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以4.5 G PAMAM（4.5代聚酰胺-胺型）树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以及X射线衍射分析对其进行了表征。结果表明,照射时间相同时,以30 s为例,当4.5 G PAMAM与HAuCl4物质的量比为5时,得到的金纳米粒子最小;随着4.5 G PAMAM与HAuCl4物质的量比值的减小,金纳米粒子变大,且发生了不同程度的聚集。 相似文献
17.
采用溶胶-凝胶法制备了复合型Fe2O3-TiO2-SiO2光催化荆利用FTIR、XRD等测试手段对其结构进行了表征。通过研究Fe“掺入量、催化荆用量、光催化降解时间及催化剂吸附实验、催化反应动力学实验，探讨了光催化剂降解头孢氨苄的条件。实验结果表明：在自然光照的条件下。该催化荆对试液中头孢氨苄的吸附率达48％。120min紫外光照射可使头孢氨苄降解率达90％，降解率随着催化剂用量增加而增加。Fe^3＋掺杂量为2．5％的催化荆催化活性最好。头孢氨苄光催化降解反应中。速率常数（K）与头孢氨苄的初始浓度Cod呈0．40级的动力学关系。 相似文献
18.
磁流体对工业废水中Cr（Ⅵ）的吸附 总被引：1，自引：0，他引：1
采用共沉淀法制备了粒径为10nm的Fe3O4磁性微粒,分散于水中生成饱和磁化强度35mT的水基磁流体,用此磁流体对模拟与实际废水中Cr（Ⅵ）进行了吸附研究。结果表明,吸附的最佳实验条件为pH=3,温度为45℃,吸附时间为0．5h。用Langmuir等温模型和假二级动力学模型探讨了磁流体对Cr（Ⅵ）的吸附机理,该过程为单离子层吸附。在最佳实验条件下,磁流体对实际制革废水中Cr（Ⅵ）的饱和吸附量达66．5mg／g,废水中残N／Cr（Ⅵ）浓度为0．2mg／L,低于工业废水排放的国家标准（0．5mg／L）。 相似文献
19.
采用非醇盐溶胶-凝胶工艺在Al_2O_3基片上旋转涂敷制得掺Sb的SnO_2薄膜。再经直流溅射制得掺Pt的Sb:SnO_2薄膜,探讨了不同Pt添加量对气敏性能的影响。结果表明,对Pt的溅射时间为90s时,元件对50ppm浓度乙醇气体的灵敏度高达43。经选择性研究表明,该元件有较好的选择性和优异的酒敏特性。 相似文献
20.
Alumina membranes without pinholes and cracks were prepared by the sol-gel process using anunordum aluminium sulphate as the starting material. The effects of different preparing conditions on morphology characteristics of the membrane were investigated by scanning electron microscopy and 3D rotational microscopy. The preparing conditions include the amounts of drying control chemical additives （DCCA）, sintering procedure and sol-gel concentration. The results showed that PVA is a good crack-preventing reagent and the morphology of supported membranes was affected by ninny factors, including Al2O3 concentration, PVA/Al2O3 ratio, heating rate, membrane thickness and intrinsic defects of the substrate surface. 相似文献