碳纳米管修饰的空心多孔NiO/SnO_2纳米复合材料对丙酮传感性能的优化（英文）

通过静电纺丝法制备中空多孔的Ni O/SnO_2复合纳米纤维,在复合纤维表面装饰碳纳米管,在此基础上制备气敏传感器器件。利用TGA确定了复合材料热分解温度和热处理工艺;利用SEM、XRD、TEM、XPS分别对复合材料的形貌、结构、尺寸、表面成分进行了表征。使用WS-30A气敏元件测试仪对气敏元件响应进行了测试。结果表明,CNTs修饰的Ni O/SnO_2复合纳米材料制备的气敏传感器降低了丙酮检测的最佳工作温度为160℃,提高了检测灵敏度,对50μL/L丙酮的响应达到25.25,对检测丙酮有快速的响应(～8.2 s)以及恢复性能(～10.5 s),同时在30 d的长期稳定性测试中也体现了良好的稳定性。证明了装饰CNTs的Ni O/SnO_2复合材料在检测丙酮方面的潜在价值,同时也进一步讨论了CNTs,中空多孔结构的Ni O/SnO_2提高检测性能的作用机理。     

石墨烯/SnO2纳米纤维复合材料的制备及吸波性能的研究

采用静电纺丝、超声混合和热处理等方法制备石墨烯/SnO_2纳米纤维复合材料,然后使用X射线衍射(XRD)、电子显微镜(SEM/TEM)和矢量网络分析仪(VNA)等设备对其微观结构和吸波性能进行表征。结果表明:当厚度为3.0mm时,石墨烯/SnO_2纳米复合纤维材料在11.7GHz频率下的反射损耗(RL)可以达到极值-48.1dB,且低于-10dB的频宽可以达到6.1GHz。由于RL值低于-10dB,表示超过90%的入射电磁波可以被吸收,故石墨烯/SnO_2纳米纤维复合材料具有较好的吸波性能。     

石墨烯/SnO2/Cu复合材料微观组织及性能研究

采用微波水热合成法对石墨烯进行表面改性,形成石墨烯/SnO2纳米复合物;将其用于粉末冶金法制备石墨烯/SnO2/Cu复合材料。采用多种分析测试手段对复合材料的微观组织及性能进行研究。结果表明,石墨烯表面吸附的SnO2纳米颗粒不会在复合材料制备过程中脱落,并可有效抑制石墨烯团聚,提高复合材料的致密度、硬度和热导率等性能。本文制备的石墨烯/SnO2/Cu复合材料致密度为91.0%,硬度为166HBW,热导率139W/(m℃),远高于Graphene/Cu复合材料。Graphene/SnO2/Cu复合材料中,界面结合良好,无开裂和界面反应;基体Cu中的刃型位错、形变孪晶以及石墨烯表面的SnO2纳米颗粒,是导致复合材料电导率下降的主要原因。     

Ag-TiO2/SnO2纳米薄膜的制备及其光催化降解罗丹明B的性能

以光还原法沉积Ag修饰TiO2/SnO2,制各Ag-TiO2/SnO2纳米薄膜,讨论紫外光照时间、光照强度、AgNO3浓度等工艺条件对光催化活性的影响.用XRD和SEM对薄膜的结构、表面形貌和化学组成进行表征,以罗丹明B为模拟污染物对光催化性能进行测定.结果表明,最佳条件下制备的Ag-TiO2/SnO2薄膜,Ag担载量为0.51%(at%),Ag簇直径在30～90 nm之间.薄膜具有较高的光催化活性,对罗丹明B的降解率是修饰前TiO2/SnO2薄膜的1.92倍,是相同质量TiO2/ITO薄膜的2.54倍.催化活性的提高,源于反应机制的改变.薄膜中Ag-TiO2异质结的引入,一方面进一步促使光生电荷分离,另一方面加速了氧气与激发电子的还原反应.     

等离子喷涂纳米复合Ag/SnO2电触头材料放电性能研究

采用化学共沉淀法和高能球磨法制备纳米Ag-12%SnO2混合粉末,用等离子喷涂法将混合粉喷涂在Cu基表面,制备纳米复合Ag/SnO2涂层。测试涂层的物理性能和真空条件下的电性能,利用SEM观察分析放电后的表面组织结构。结果表明,纳米复合Ag/SnO2涂层越厚,密度越小,电阻率越大,而硬度与SnO2分布状况有关;涂层表面平整度影响耐电压强度值的分布;纳米复合Ag/SnO2涂层的分散电弧性能好,电弧烧蚀速率小。     

SnO2表面改性对Ag/SnO2复合粉末烧结组织及性能的影响

采用沉积法和蒸发法分别对SnO2粉末进行WO3、Bi2O3 CuO表面改性处理,并用化学镀方法制备Ag/SnO2复合粉末.通过粉末冶金的方法对Ag/SnO2复合粉末进行烧结实验,并通过光学显微镜、扫描电镜观察烧结体的金相组织及复合粉末的形貌,对SnO2表面改性方法及添加剂种类对Ag/SnO2烧结性能和组织的影响进行了研究.结果表明:沉积法改性使烧结体组织中的SnO2分布更均匀,且能明显提高烧结体Ag/SnO2的致密度.Bi2O3 -CuO改性可消除SnO2的网络状分布,而WO3改性则显著改善电弧侵蚀后的表面组织.     

稀土Y掺杂Ti/SnO2+MnOx/PbO2电极的电化学性能研究

采用热分解和电沉积的方法制备了稀土元素Y掺杂Ti/SnO2+MnOx/PbO2耐酸阳极.用XRD、SEM表征了电极的物相和表面形貌,用CV、EIS测定了电极的电化学性能,并研究了Y掺杂对电极在强酸性溶液中使用寿命的影响.结果表明:Y以Y2O3的形式与SnO2形成半导体固溶体,使电极在高电流密度(4 A/cm2)下的预期使用寿命达到70 h;同时该电极的析氧电位高达2.1 V,且电极表面呈蘑菇状,电催化性较好,Ti/SnO2+Y2O3+MnOx/PbO2电极是一种较理想的耐酸阳极材料.     

反应合成法制备Ag/SnO2复合材料中的反应路线

采用反应合成法制备Ag/SnO2复合材料,并从电子-原子层次详细阐述反应中合金中间化合物向富集区转变、寻找过渡态最后生成稳定相的过程。结果表明：Sn的活化性能高于Ag,氧源的参与对反应过程起主导作用,且初始反应混合物中分解游离态的O是氧化反应能持续、彻底进行的另一个重要途径,最后预测出完整的反应路径     

十二烷基硫酸钠对IrO2-Ta2O5/SnO2- Sb-Mn/Ti电极电催化性能影响

采用涂刷-热分解法制备不同浓度阴离子表面活性剂十二烷基硫酸钠（SDS）的IrO2-Ta2O5/SnO2- Sb-MnO2/Ti电极,通过扫描电子显微镜（SEM）和X射线衍射仪（XRD）对其微观形貌及物相组成进行分析;应用循环伏安、极化等测试手段,表征制备电极的电催化活性.结果表明,适量添加十二烷基硫酸钠能够改善IrO2-Ta2O5/SnO2-Sb-Mn/Ti电极的微观形貌,提高电催化活性.在本实验条件下,SDS最佳添加量是1.6 g/L,结晶化度高达99.83%.利用苯酚电催化降解实验和强化寿命测试进一步考察所制电极的电催化活性与稳定性,结果显示,在电流密度15 mA/cm2条件下电解180 min,SDS的加入使苯酚去除率由原来的68.5%提高到79.2%.COD去除率由60.1%提高到 67.5%,电催化性能得到提升,电极强化寿命由52 h延长至68 h.     

真空退火对等离子喷涂Ag/SnO2涂层组织和性能的影响

采用等离子喷涂技术在Cu基体表面制备了Ag/SnO2涂层,并研究了真空退火对涂层组织和性能的影响。结果表明,在退火过程中,Ag/SnO2涂层内部银基体再结晶和晶粒长大过程持续进行,SnO2颗粒在银基体中也进行了重新分布; 800 ℃退火时涂层与基体出现了冶金结合的现象。随着退火温度的提高,Ag/SnO2涂层硬度显著降低,而涂层电导率的变化趋势与硬度相反。     

SnO2@TiO2核-壳纳米线的制备及其光催化性能研究

本文通过固-液-气(VLS)生长机制,利用化学气相沉积法(CVD)制备SnO₂纳米线。利用原子层沉积(ALD)以钛酸四异丙酯为前驱体在SnO₂纳米线表面沉积不同厚度的TiO₂壳层,形成SnO₂@TiO₂核-壳纳米线结构。通过中间Al₂O₃插层,分别制备出金红石和锐钛矿两种不同晶型的TiO₂,从而制备出两种不同复合结构的SnO₂@TiO₂核-壳纳米线。实验研究该复合结构中TiO₂的厚度与晶型对紫外光下光催化降解甲基橙溶液活性的影响。     

SnO2 dendrites-nanowires for optoelectronic and gas sensing applications

SnO₂ dendrites-nanowires were grown on Au coated Si substrates using evaporation condensation method. The morphology, structural, chemical composition and thermal analysis were examined using scanning electron microscopy, X-ray diffraction, energy dispersive analysis of X-ray and Fourier transformation infrared spectroscopy, and thermal gravimetric analysis, respectively. The optical constants, the thickness and the surface roughness of the prepared nanostructured films were determined by spectroscopic ellipsometry measurements. A three layers model was used to fit the calculated data to the experimental ellipsometric spectra. The obtained optical constants were compared with those obtained by other preparation methods. The sensing properties of the obtained SnO₂ nanostructure were carried out for NO₂ gas. The optimal operation temperature was 200 °C and the sensor sensitivity was 40, 56, 83 and 121 for 10, 15, 25 and 50 ppm, respectively.     

P-type transparent conducting SnO2:Zn film derived from thermal diffusion of Zn/SnO2/Zn multilayer thin films

Highly transparent, p-type conducting SnO₂:Zn thin films are prepared from the thermal diffusion of a sandwich structure of Zn/SnO₂/Zn multilayer thin films deposited on quartz glass substrate by direct current (DC) and radio frequency (RF) magnetron sputtering using Zn and SnO₂ targets. The deposited films were annealed at various temperatures for thermal diffusion. The effect of annealing temperature and time on the structural, electrical and optical performances of SnO₂:Zn films was studied. XRD results show that all p-type conducting films possessed polycrystalline SnO₂ with tetragonal rutile structure. Hall effect results indicate that the treatment at 400 °C for 6 h was the optimum annealing parameters for p-type SnO₂:Zn films which have relatively high hole concentration and low resistivity of 2.389 × 10¹⁷ cm^− 3 and 7.436 Ω cm, respectively. The average transmission of the p-type SnO₂:Zn films was above 80% in the visible light range.     

Novel SnO2/MnO co-doped phosphate glasses with tunable luminescence properties

In the present work, novel SnO₂/MnO co-doped phosphate glasses are prepared and their tunable luminescence properties are presented. Under excitation at 267 nm, all co-doped glasses exhibit an assembly of SnO₂ blue emission at 420 nm and MnO red emission around 600 nm. With the increasing of MnO concentration, intensity of the SnO₂ blue emission decreases while that of MnO red emission increases. With the increasing of SnO₂ concentration, both SnO₂ and MnO emissions are greatly enhanced, resulting in the white light emitting.     

SnO2 增强相对AgCuOIn2O3 电触头材料显微组织与性能的影响

采用反应合成法结合塑性变形工艺制备了不同SnO₂含量的AgCuOIn₂O₃SnO₂电触头材料,利用扫描电镜和金相显微镜表征了材料的微观形貌及显微组织,分析对比了不同SnO₂含量的材料金相组织及其增强相的分布均匀性,并利用X射线衍射分析了材料的物相结构。测量了材料的抗拉伸强度、硬度、电阻等性能。结果表明：添加适量的SnO₂能使组织中的孔隙尺寸缩小、其他缺陷明显减少。氧化物弥散分布在银基体中,极大地改善了AgCuOIn₂O₃电触头材料的显微组织均匀性。在SnO₂含量不变时,材料的电阻率随塑性变形程度增加而有所降低;随着SnO₂含量增多,电阻率呈现先降低后升高的趋势,最后趋于定值,约为2.4 μΩ·cm。添加SnO₂后各试样材料的硬度均显著升高,SnO₂含量为1%（质量分数）的材料具有最优的抗拉伸强度和延伸率。     

N-doped carbon nanotubes synthesized in high yield and decorated with CeO2 and SnO2 nanoparticles

Nitrogen doped multiwalled carbon nanotubes (CN_xNTs) with high yield and purity have been successfully prepared from n-propylamine precursor with Co_xMg_1−xMoO₄ catalyst. The maximum yield of the CN_xNTs is 920%. SnO₂ and CeO₂ nanoparticles are decorated on the surface of CN_xNTs without any acid treatment due to the inherent interface activity. The TEM images reveal that SnO₂ and CeO₂ nanoparticles were anchored on the surface of the CN_xNTs uniformly, and the XPS results indicate that the doped nitrogen atoms of CN_xNTs play significant roles in immobilizing SnO₂ and CeO₂ nanoparticles, and the mechanism of the composite process has been discussed. The electrooxidation performance of the composites for NO at the modified electrodes was investigated. The CN_xNTs-based composites show greater activity and sensitivity than the conventional CNTs-based composites for NO electrooxidation, which render them excellent electrode materials for NO detection and other potential applications.     

Plasma electrolytic oxidation preparation and characterization of SnO2 film

SnO₂ film is firstly prepared by plasma electrolytic oxidation technology in sodium stannate solution. The structure and photocatalytic property of the film are characterized by SEM, XRD and UV-Vis spectrophotometer. Rough and porous netlike film formed on the substrate. The XRD result showed the oxide was pure SnO₂. The absorption edge of the film was determined as 420 nm. Photocatalytic degradation of rhodamine indicated SnO₂ film was an effective photocatalyst.     

Ag/SnO2电接触材料的制备及其燃弧特性研究

以Ag粉和自制SnO_2为原料,采用机械合金化和热挤压拉拔工艺制备Ag/SnO_2电接触材料。采用冷压焊工艺设备制备了Ag/SnO_2铆钉元件。采用X射线衍射仪(XRD)对Ag粉、自制SnO_2及Ag/SnO_2复合粉体进行物相分析;采用扫描电子显微镜(SEM)对电寿命测试前后Ag/SnO_2铆钉元件的表面形貌进行了表征。并考察了不同电气参数对Ag/SnO_2铆钉元件的燃弧特性、电弧侵蚀形貌、质量损失及其失效退化模式等特性研究。结果表明:Ag/SnO_2电接触材料在电弧作用下相比于纯Ag表现出更高的燃弧时间和燃弧能量,平均闭合与断开燃弧时间分别为51.78和25.86 ms,比纯Ag多出4.87和2.78 ms;同理,平均闭合、断开燃弧能量分别为988.14和493.85 mJ,比纯Ag高出104.93和58.76mJ;随着循环操作次数的增加,Ag/SnO_2电接触材料的总质量损失为负值,其失效退化模式主要表现为液滴飞溅与SnO_2颗粒上浮。     

Spectroscopic and crystal-field analysis of energy levels of Eu in SnO2 in comparison with ZrO2 and TiO2

We have carried out systematic crystal-field energy level calculations of Eu³⁺ ions doped in SnO₂ based on experimentally acquired luminescence spectra. In addition, with an aim of revealing systematic trends in spectra and crystal-field effects for Eu³⁺ ion in similar hosts, we have analyzed the TiO₂ (anatase):Eu³⁺ spectra as well. The obtained crystal-field parameters yield very good agreement between the calculated and observed energy levels. Emphasis has been put on analysis of the crystal-field-induced J-mixing effects and their roles in getting proper sets of crystal-field parameters and energy levels. A more general theory concerning J-mixing effects has been proposed and the relevant results will be valuable to understanding of the spectral characteristics of Eu³⁺ f-f transition spectra in other hosts. Relations between the maximum crystal-field splitting of some selected J-manifolds with J = 1 and J = 2 and crystal-field invariants have been re-visited and re-derived. The corresponding numbers of crystal-field parameters influencing the splitting of these manifolds have been taken into account in every case. The derived equations have been tested in applications to three systems (SnO₂, TiO₂ (three sites) and ZrO₂). Consistent results have been obtained, which confirms validity of the performed crystal-field analysis and opens a way for possible applications of the suggested calculating technique to other rare-earth ions.     

MeO掺杂AgSnO2电接触材料的结构与性能

采用机械合金化技术将不同用量的CuO或Fe_2O_3粉掺入银和SnO_2粉中制备Ag/SnO_2(x)-MeO(y)复合粉体,并辅以热压成型工艺制得Ag/SnO_2(x)-MeO(y)电接触材料。采用扫描电镜、X射线衍射仪、电阻测试仪、硬度计及拉伸试验机等测试仪器对材料的组织结构、物理和力学性能进行了表征。结果表明:随着掺杂剂用量的增加,Ag/SnO_2(x)-MeO(y)材料的密度逐渐降低,且CuO较Fe_2O_3更利于提高材料的导电性。2种掺杂剂均能显著改善Ag/SnO_2(x)-MeO(y)材料的塑性变形能力。Ag/SnO_2(11.2%)-CuO(0.8%)(也即CuO用量为0.8%)材料的电阻率达到最低值2.35μΩ·cm,延伸率约为9.1%,比Ag/SnO_2材料的延伸率提高近93.6%,综合性能最优。