V2O5薄膜的结构和光电性能研究

在O2 /Ar混合气氛中 ,用脉冲磁控溅射金属V靶沉积出非晶的V2 O5薄膜。对所沉积的薄膜进行 4 5 0℃退火。利用X射线衍射、原子力显微镜、分光光度计和电阻测量等手段对薄膜的结构和性能进行了分析 ,从 2 0 0nm～ 2 5 0 0nm光谱的透射和反射测量结果 ,计算出薄膜的吸收系数。结果表明 ,V2 O5薄膜纯度高 ,结晶好 ,高低温电阻变化 2个量级。光学能隙为2 4 6eV。     

Electrochromism: An emerging and promising approach in (bio)sensing technology

Electrochromism (EC) is a unique property of certain materials that undergo an electrochemical-induced change in colouration. During the last decades, electrochromic materials (ECMs) have been applied in a variety of technologies ranging from smart windows to information displays and energy storage devices. More recently, ECMs have attracted the attention of the (bio)sensing community thanks to their ability to combine the sensitivity of electrochemical methods with the intuitive readout of optical sensors. Although still a nascent technology, EC-based sensors are on the rise with several targets (e.g. cancer biomarkers, bacteria, metabolites and pesticides), which have already been detected by (bio)sensors using ECMs as transducers. In this review, we provide the reader with all the information to understand EC and its use in the development of EC-based biosensors.     

V2O5薄膜制备,结构及光学性质研究

Ｖ２Ｏ５薄膜是全固态电致变色器件扣锂离子储存层和很好个候选材料之一。本研究采用反应蒸发、优化实验条件,在加热基片上沉积了性能理想的Ｖ２Ｏ５薄膜,分别采用ＸＲＤ,ＡＥＳ,ＸＰＳ和紫外－近红外分光光度计研究了薄膜的晶态结构、组份、钒离子价态和光学等特生。研究结果表明,刚制备的薄为非晶结构,经过一定温度热处理后开始结晶,薄膜的组分为ＶＯ２．４６,含有少量的Ｖ＾＋４;吸收光谱存在两个不同的变化区域,高能区     

五氧化二钒气凝胶阴极材料的研究进展

五氧化二钒(V2O5)气凝胶由于其特殊的结构备受人们的关注.综述了V2O5的结构、性能、制备,与有机、无机材料的复合及其在锂离子二次电池、电致变色器件、催化、传感器等方面的应用,并且较为详细地介绍了V2O5阴极材料在国内外的研究现状和发展前景.     

碳酸氢铵沉钒新工艺实验研究

以石煤湿法提钒工艺萃取和反萃取所得富钒液为原料,分析了富钒液中V2O5、酸度以及杂质含量,研究了使用铵盐替代氨水的沉钒新工艺。研究结果表明：以杂质含量高、杂质种类复杂的富钒液为原料,采用40％碳酸氢铵为沉钒剂进行沉钒,控制加入量为理论量的1.4倍,溶液pH值为0.9,反应温度60℃,能够稳定制备出纯度为99．5％的V2O5,沉钒率达96.9％以上,母液沉降温度22℃,降低了氨氮含量,工业试验效果良好。     

Electrochromic Systems and the Prospects for Devices

Many inorganic and organic materials exhibit redox states with distinct electronic (UV‐vis) absorption bands. When the switching of redox states generates new or different visible region bands, the material is electrochromic. Electrochromic materials are currently attracting much interest in academia and industry for both their fascinating spectroelectrochemical properties and their commercial applications. In this review some of the most important examples from the major classes of electrochromic materials are highlighted. Examples of their use in both prototype and commercial electrochromic devices are illustrated including car mirrors, windows and sun‐roofs of cars, windows of buildings, displays (see Figure), printing, and frozen‐food monitoring.     

纳米结构V2O5空心微球的制备与表征

以自制的二乙酰丙酮氧钒(VO(aca)2)为原料,通过软模板法组装出聚乙烯吡咯烷酮(PVP)/钒前驱体核壳结构的复合微球.对复合微球进行热处理后制备得φ(0.5～1.0)μm五氧化二钒(V2O5)中空微球.分别采用扫描电镜(SEM)、透射电镜(TEM)和X射线衍射仪(XRD)对最终产物的球形外观、中空结构和物相组成进行了表征,结合VO(acac)2、溶解于乙二醇的PVP、溶解于乙二醇的VO(acac)2与复合微球的红外光谱(FTIR)和复合微球的差热曲线(DTA),探讨了V2O5中空微球形成的机理.对影响实验的因素如PVP和VO(acac)2的浓度、保温时间等进行了研究.结果表明:通过严格控制PVP和VO(acac)2的浓度能够确保V2O5球壳结构的形成;当总反应时间在75～90 min范围内时,所得空心球的几何外形和表面形貌均较为理想.     

五氧化二钽薄膜的制备及其I-U特性

本文利用脉冲直流反应磁控溅射的方法制备了五氧化二钽 (Ta2 O5)薄膜 ,俄歇电子能谱仪测试了薄膜的成分含量 ,椭偏仪测试了Ta2 O5薄膜的厚度和折射率 ,XRD分析了薄膜的晶体结构 ,并且分别研究了氧气含量、基底温度等成膜工艺对薄膜的影响。研究结果表明薄膜的成分主要是由氧气含量决定的。利用金属 绝缘体 (介质膜 ) 金属 (MIM)结构初步对Ta2 O5薄膜进行了电学性能的测试 :皮安电流电压源测试了薄膜的I U特性 ,制备出的薄膜折射率在 2 1～ 2 2 ,MIM的I U特性曲线显示了较好的对称性和低的漏电流密度     

Elastic Properties of Vanadium Pentoxide Aggregates and Topological Defects

We study the aqueous solution of vanadium pentoxide by using topology methods. The experiments by Zocher, Kaznacheev, and Dogic exhibited that in the sol phases of V₂O₅–H₂O, the tactoid droplets of V₂O₅ can coalesce. In the magnetic field, this effect is associated with a gauge field action, viz. we consider coalescence (“junction,” in the topologically more convenient term) of droplets as annihilation of topological defects, concerning with the tactoid geometry. We have shown, that in the magnetic field, the tactoid junction is mainly caused by non-Abelian monopoles (vortons), whereas the Abelian defects almost do not annihilate. Taking into account this annihilation mechanism, the estimations of time-aging of the V₂O₅–H₂O sols may be specified.     

Synthesis of Vanadium Nitride by a One Step Method

Vanadium nitrides were prepared via one step method of carbothermal reduction and nitridation of vanadium trioxide. Thermalgravimetric analysis （TGA） and X-ray diffraction were used to determine the reaction paths of vanadium carbide, namely the following sequential reaction： V2O3→V8C7 in higher temperature stage, the rule of vanadium nitride synthesized was established, and defined conditions of temperature for the production of the carbides and nitrides were determined. Vanadium oxycarbide may consist in the front process of carbothermal reduction of vanadium trioxide. In one step method for vanadium nitride by carbothermal reduction and nitridation of vanadium trioxide, the nitridation process is simultaneous with the carbothermal reduction. A one-step mechanism of the carbothermal reduction with simultaneous nitridation leaded to a lower terminal temperature in nitridation process for vanadium nitride produced, compared with that of carbothermal reduction process without nitridation. The grain size and shape of vanadium nitride were uniform, and had the shape of a cube. The one step method combined vacuum carborization and nitridation （namely two step method） into one process. It simplified the technological process and decreased the costs.     

过氧化法常压干燥制备的V_2O_5气凝胶的性能探究

以V2O5晶体粉末、H2O2(30%(质量分数))为原材料,采用溶胶-凝胶法,通过溶剂替换工艺在常压下成功地制备了纳米多孔结构的V2O5气凝胶材料.采用扫描电镜(SEM)、透射电镜(TEM)、比表面积仪(BET)、粉末X射线衍射(XRD)、傅立叶红外分光光度计(FTIR)和拉曼光谱仪(Raman)等方法分别观察和测试了V2O5气凝胶材料的形貌、晶态结构及分子振动.SEM、TEM观察表明,常压干燥制备的V2O5气凝胶呈比较规则的具有层状结构的纤维网络状结构;XRD分析表明,由于结合水插入层间而使V2O5气凝胶的层间距有明显的增加;BET测试结果表明,常压干燥制备的V2O5气凝胶材料的平均孔径为16nm,最大孔径为78nm.     

胶体五氧化二锑研究现状及发展方向

对胶体五乳化二锑的研究现状进行了回顾，详细概述了胶体五乳化二锑的各种制备方法及其特点和适用范围，讨论了两种成胶理论。针对目前存在的问题，对胶体五乳化二锑的研究方向及研究重点提出了几点建议。