Synthesis and Characterization of (PEO)_x~-(V_(0.85)Mo_ (0.15)_2O_5 Nanocomposite Films

1　IntroductionSomeinorganiclayeredcompounds ,suchasMoO3 andV2 O5,belongtoarapidlygrowingfieldofcontempo raryresearchinterest,becausetheycanbeintercalatedbyavarietyofalkaliions (Li+ ,Na+ ,etc .) ,atomsorlargermoleculestoformintercalationhost guestcompounds ,whichareexpectedtobepromisingcandidatematerialsforcathodesofsecondaryLibatteriesandelectrochromicdevices[1] .Polymer layeredoxidenanocompositesareat tractingmuchattentionduetotheirspecialstructureaswellassuperiorelectrical,electrochemical…     

THE NANOCOMPOSITE FILM OF POLYMER INTERCALATION IN V_2O_5 XEROGEL

The nanocomposite films were prepared by poly(ethylene oxide), PEO, intercalation in V_2O_5 xerogel in sol-gel. The synthesis and state of the films are in vestigated by the XRD, IR, SEM, etc. The results show that V_2O_5 xerogel is a layered structure which arranges in c-direction. The interlayer distance of V_2O_5 xerogel increases remarkably when PEO is intercalated in V_2O_5 xero gel interlayer. PEO has strong interaction with V_2O_5 host. The surface of the films is homogeneous without holes and cracks.     

Lithium Insertion in Poly(ethylene oxide)/MoO_3 Xerogel Nanocomposite Films

1　ＩｎｔｒｏｄｕｃｔｉｏｎＧｒｅａｔｅｆｆｏｒｔｓｈａｖｅｂｅｅｎｍａｄｅｉｎｒｅｃｅｎｔｙｅａｒｓｔｏｄｅ ｖｅｌｏｐｎｅｗｉｎｔｅｒｃａｌａｔｉｏｎｈｏｓｔ ｇｕｅｓｔｃｏｍｐｏｕｎｄｓｗｉｔｈｎｏｖｅｌｐｒｏｐｅｒｔｉｅｓａｓｍａｔｅｒｉａｌｓｆｏｒｅｌｅｃｔｒｏｃｈｒｏｍｉｃｄｅｖｉｃｅｓａｎｄｓｅｃ ｏｎｄａｒｙｌｉｔｈｉｕｍｂａｔｔｅｒｉｅｓ[1- 4] .ＣｏｍｐｏｕｎｄｓｂａｓｅｄｏｎＭｏＯ3 ｈａｖｅａｔｔｒａｃｔｅｄｍｏｒｅａｔｔｅｎｔｉｏｎｄｕｅｔｏｔｈｅｉｒｄｅｓｉｒａｂｌｅｃｈａｒ…     

Novel Preparation and XPS Analysis of V_2O_5 Xerogel

1　IntroductionBecauseoftheirspecialphysicochemicalproperties ,V2 O5filmshavebeenfoundawideapplicationinvariousfieldssuchasvoltageswitches ,gassensors ,humiditysen sors ,smartwindows ,cathodeofthelithiumcell[1,2 ] .Sever altechniquesareusedtopreparevanadiumoxidefilmssuchassputtering ,metaloxidation ,andsol gel[3 ] .Theprocessformakingfilmsbydippingasubstrateintosolisofalowcostforobtaininggoodadhesivethinorthickfilms .Thesol gelmethodis ,however ,ofgreateradvan tage ,sincethereisnolossofmateri…     

钼掺杂五氧化二钒纳米带的制备及表征

分别以金属Mo粉为钼源、V2O5为钒源和以MoO3为钼源、NH4VO3为钒源,通过低温水热法合成了不同形貌的钼掺杂V2O5纳米结构。用X-射线衍射(XRD)、扫描电子显微镜(SEM)和能谱(EDS)对产物进行表征。结果表明,反应产物均为正交V2O5纳米带,且纳米带的尺寸均匀,宽度100~400 nm,厚度10~40 nm,长度可达到几十微米。研究还发现它们的掺杂量是不同的,分别为3%和2.1%。     

V2O5/TiO2-SiO2催化剂用于甲醇乙醇合成异丁醛的研究

以溶胶-凝胶法和浸渍法制备V2O5/TiO2-SiO2催化剂,将其应用于甲醇与乙醇一步合成异丁醛的催化反应,并采用BET、XRDI、R测试技术对催化剂的结构进行表征,考察制备方法和焙烧温度对催化剂结构和催化性能的影响.结果表明：采用溶胶-凝胶法制备的催化剂具有较好的催化性能,适宜的焙烧温度为773 K.     

Nanocomposite films of V<Subscript>2</Subscript>O<Subscript>5</Subscript>−MoO<Subscript>3</Subscript> xerogel with poly ethylene oxide intercalation

Poly ethylene oxide (PEO)_x−V₂O₅−V₂O₅−MoO₃ (x=0, 0.5, 1) films were prepared by the sol-gel method. The synthesis and structure of the films were investigated by XRD, TG-DTA, FTIR, etc. The results show that V₂O₅−MoO₃ xerogel has a layered structure and its interlayer space increased from 1.3181 nm at x=0 to 1. 7898 nm at x=1 after the nanocomposite films were dried, and PEO in the interlayer changes the interface structure by forming hydrogen bonds with V=0 bands. CV measurement indicates that the intercalation of PEO improves insertion/extration properties of Li⁺ ions in the interlayer. ZHENG Jin-xia: Born in 1976 Funded by the National Natural Science Foundation of China (No. 50172036) and Natural Science Foundation of Hubei Province(No. 2001ABB083)     

不同钒载量V_2O_5/SiO_2催化剂上异丁烷催化脱氢制异丁烯的研究

采用浸渍法制备了不同钒载量的V2O5/SiO2催化剂,并用XRD、FT-IR、TPR和微反活性评价等手段对催化剂表面钒物种的分散状态和异丁烷脱氢反应性能进行了研究。结果表明,当V2O5负载量低于8%时,催化剂表面主要为还原性能较好、单层分散的孤立与低聚合度的钒氧物种;当V2O5负载量大于8%时,催化剂表面开始形成还原性较差的高聚合度钒氧物种和V2O5晶体。异丁烷脱氢活性测试结果显示,V2O5最佳负载量为8%,此时异丁烷转化率可达34%,异丁烯选择性为95%。     

V_2O_5/V/V_2O_5薄膜退火条件对其的制备及特性的影响

利用间歇通O2的方式,采用射频磁控溅射法在Si3N4衬底上制备V2O5/V/V2O5复合薄膜,研究了不同原位退火条件对薄膜阻值及电阻温度系数(TCR)的影响。结果表明,经过退火处理后的V2O5/V/V2O5复合薄膜方阻值大大降低,电阻-温度曲线呈现良好的线性特性,并具有高TCR值及优良的电学稳定性。利用X射线光电子能谱(XPS)对退火后的V2O5/V/V2O5复合薄膜表面进行V、O元素分析,结果表明,V2O5/V/V2O5复合薄膜各层间的扩散效果显著影响薄膜表面不同价态V离子的含量,低价V离子会随着退火温度的升高及退火时间的延长而增多,薄膜表面对水分子的吸附也随之变强。在实验结果的基础上,利用扩散理论阐述了退火条件对V2O5/V/V2O5复合薄膜电学性能影响的机理。     

Preparation and Optical Properties of V2O5 Nanotube Arrays

V2 O5 nanotube arrays in porous atomic alumina （ PAA ） template were obtained from V2O5 sols prepared by melt quenching method. X-ray powder diffraction and selected area electron diffraction investigations demonstrate that V2O5 nanotubes are orthorhombic. Results by scanning electron mieroscopy and transmission electron microscopy results shove that V2O5 nanotubes with a uniform diameter form highly ordered arrays. The diameter and length of the nanotubes depend on the pore diameter and the thickness of the PAA template used. It is proved that the sol-gel template process is a cost-saving , simple and readily-controlled method to prepare metal oxides nanomaterials .Owing to the quantum size effect. the optical absorption edge of V2O5 nanotubes in PAA ehibits a significant blue shift with respect to that of bulk V2O5.     

V2O5/SiO2多孔玻璃检测SO2的机理研究

以导光多孔氧化硅玻璃为基片 ,采用溶胶 -凝胶法制得了 V2 O5/ Si O2 载敏 SO2 光化学传感器基体。讨论了载敏试剂浓度对载敏玻璃试样透光性的影响、载敏多孔玻璃的感敏特性及其工作机理。结果表明 ,载敏后的多孔玻璃对 SO2有较好的敏感性 ,载敏剂 V2 O5遇 SO2 后 ,4价钒在 4 90 nm处的特征透光率增加 ,5价钒在 5 90 nm处的特征透光率降低 ;一定的湿度和较高的温度有利于载敏多孔玻璃对 SO2 的检测     

Sol—Gel V2O5薄膜的成膜和取向研究

采用溶胶－凝胶法在SiO2/Si衬底上沉积V2O5薄膜,详细介绍了对衬底表面作亲水处理的方法。以不同浓度溶胶,在不同温度和不同气氛下对薄膜进行热处理,得到以＜001＞向为主取向的高取向薄膜,从理论上解释了V2O5薄膜的取向机理,并与相同衬底上的热蒸发和PLD氧化钒薄膜的取向作了比较。     

三氧化二钒废水的处理研究

通过实验处理攀钢三氧化二钒废水，提出其处理流程为一步法和二步法，经过处理出水均可达到《污水综合排放标准》(GB8978—1996)，采用一步法对现有流程进行改造，改造后，每吨水的处理费用增加3．50元。     

掺Bi2O3,B2O3,V2O5和B2CuO4对Sm(Mg1/2Ti1/2)O3性质及显微结构的影响

实验添加多种助烧结剂于以固态反应法制备的钐镁钛微波介电陶瓷Sm(Mg1/2Ti1/2)O3,并研究对烧结体的相对密度、相变化、介电常数、频率温度系数(TCF)、品质因子及微观结构性质的影响。尝试分别加入10 mol%的Bi2O3、B2O3、V2O5及B2CuO4可有效降低陶瓷孔隙率使其致密化,更可大幅下降块材烧结温度,使之可以顺利导入低温共烧陶瓷制程(Low-Temperature Co-fired Ceramics;LTCC),但会破坏钙钛矿晶体结构,引起材料微波特性降低。在实验中原料混合粉末以1 100℃煅烧2 h后研磨,再成型后以1 300℃烧结6 h。结果显示以添加Bi2O3具有最高的密度及Q×f与介电常数,达6.47 g/cm3和26 000 GHz及30.19。     

H2-CO—CO2气氛中添加V2O3二步法制备碳化铁的动力学分析

在853-973K以及H2-CO—CO2气氛中,研究了添加质量分数为1％的V2O3对二步法制备碳化铁的影响。结果表明,添加V2O3对还原转化速率影响不大,对碳化转化速率有明显的促进作用,并且随着温度的升高,添加V2O3对碳化反应终点转化率的影响越来越显著。应用有固体产物层的未反应核模型分析反应的动力学过程,结果表明,还原和碳化反应过程都由界面化学反应控制,添加V2O3对界面化学反应有促进作用。     

温度对V2O3系材料电子结构的影响

采用自洽场离散变分Xα（SCC-DV-Xα）方法对（V0.9950Cr0.0025Al0.0025）2O3体系分别处于25℃及200℃时的电荷分布、态密度、能级结构等进行了研究。结果表明,温度对电子结构的影响导致材料的电导率发生显著变化,变化趋势与实验结果相一致,对钒系PTC材料的进一步研制具有理论指导意义。     

Thermal behavior and lithium ion conductivity of L2O-Al2O3-TiO2-SiO2-P2O5 glass-ceramics

A lithium ion conductive solid electrolyte, L2O-Al2O3-TiO2-SiO2-P2O5 glass with NASICON-type structure have been synthesized and transformed into glass-ceramic through thermal-treatment at various temperatures from 700 to 1 000 ℃ for 12 h. The differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and complex impedance techniques were employed to characterize the samples. The experimental results indicated that the capability of glass forming in this system is superior to that of L2O-Al2O3-TiO2-P2O5. The glass has an amorphous structure and resultant glass-ceramic mainly consisting of LiTi2(PO4)3 phases. Impurity phases AlPO4, TiO2, TiP2O7 and unidentified phase were observed. With the enhanced heat-treatment temperature, grain grew gradually and lithium ion conductivity of glass-ceramics increased accordingly, the related impedance semicircles were depressed gradually and even disappeared, which could be analytically explained by the coordinate action of the ’Constant phase element’ (CPE) model and the ’Concept of Mismatch and Relaxation’ model (CMR). When the sample is devitrified at 1 000 ℃, the maximum room temperature lithium ion conductivity comes up to 4.1×10-4 S/cm, which is suitable for the application as an electrolyte of all-solid-state lithium batteries.     

SiC/Al2O3复相纳米粉体的制备及其微波介电性能的研究

以溶胶-凝胶、碳热还原法制备了S IC/A L2O3纳米复相粉体,研究了处理温度对粉体相组成的影响及其在8.2~12.4 GH Z频率范围的介电性能。凝胶先驱体经1 700℃处理可得到S IC/A L2O3复相粉体,粉体为300~400 NM的球形颗粒,由晶粒尺寸约为45 NM的S IC和A L2O3纳米微晶组成;研究结果表明:A L原子未能固溶于S IC晶格中,导致随着粉体中A L含量的增加,复相粉体中A L2O3的量增加,粉体的复介电常数和介电损耗角正切降低。     

Keggin型配合物H_5PMo_(10)V_2O_(40)催化剂催化氧化反应研究

以钼酸钠、偏钒酸钠、磷酸二氢钠为原料合成H5PMo10V2O40.通过IR进行表征,确认所合成的化合物中多酸阴离子仍保留Keggin结构.将新合成的H5PMo10V2O40杂多酸应用到苯甲醛氧化合成苯甲酸反应中,考察了催化剂用量、氧化剂30%H2O2的用量、反应时间、反应温度等对苯甲酸收率的影响.最佳工艺条件为催化剂苯甲醛=1.9×10-31(摩尔比),n(H2O2)n(苯甲醛)=6.5 1,反应时间2.5 h,反应温度80℃.苯甲酸的收率达到85%以上.