首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
以邻氨基酚(OAP)为功能单体,氯霉素(CAP)为模板分子,用电化学聚合的方法在Pt上合成了CAP分子印迹(MIP)OAP膜(CAP-MIP-OAP/Pt)电极,通过扫描电子显微镜和电化学技术对聚合膜的结构和性能进行了表征。 结果表明,该膜电极对CAP检测有较好的选择性和灵敏度,CAP检测的线性范围为4.33×10-8~3.09×10-6 mol/L,检出限为2.5×10-8 mol/L。  相似文献   

2.
A pyrrole-functionalized monomer 2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole (PyPhPy) was synthesized. The structure of monomer was investigated by Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The chemical polymerization of PyPhPy (CPyPhPy) was realized using FeCl3 as the oxidant. The electrochemical oxidative polymerization of polymer P(PyPhPy) and its copolymer with 3,4-ethylenedioxythiophene poly(2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole-co-3,4-ethylenedioxythiophene) [P(PyPhPy-co-EDOT)] were achieved via potentiodynamic method by using NaClO4/LiClO4 as the supporting electrolyte in CH3CN. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), UV-Visible spectrophotometry (UV-Vis) and thermogravimetry analyses (TGA). Electrical conductivity of CPyPhPy, P(PyPhPy), and P(PyPhPyco-EDOT) were measured by four-probe technique.  相似文献   

3.
We report the successful precipitation polymerization of 2‐hydroxyethyl methacrylate (HEMA) in supercritical carbon dioxide (scCO2) at pressures ranging from 15 to 27 MPa utilizing 2, 2′‐azobisisobutyronitrile (AIBN) as a free radical initiator. The effects of the reaction pressure, initiator concentration, monomer concentration, reaction temperature, and reaction time were investigated. Analyses by scanning electron microscopy (SEM) indicated that in all reaction conditions, polymerization in the absence of stabilizer led to the formation of large aggregates of partially coalesced particles, with diameters of approximate 1–10 µm. Analyses by gel permeation chromatography (GPC) indicated that for the reaction pressure, initiator concentration, monomer concentration, reaction temperature, and reaction time studied there are appreciable effect on product molecular weight. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

4.
徐景坤  Zhen-hong  Wei  Qiang  Xiao  Shou-zhi  Pu 《高分子科学》2006,(3):253-263
The copolymer poly(3-(4-fluorophenyl)thiophene-co-3-methylthiophene) was successfully prepared from mixtures of 3-(4-fluorophenyl)thiophene (FPT) and 3-methylthiophene (MET) via electrochemical oxidation in boron trifluoride diethyl etherate (BFEE) and its mixed electrolytes with acetonitrile (ACN). The influence of monomer concentration ratios on the copolymerization was investigated by using linear sweep voltammetry and cyclic voltammetry. The structure and morphology of these copolymer films were elucidated by UV-Vis, infrared spectroscopy, elemental analysis, thermal analysis and scanning electron microscopy (SEM), respectively. The results showed that the molar ratio of FPT and MeT units, when copolymer was electrodeposited from feed ratio of FPT:MeT = 1:2, was about 1.08:1. In addition, the introduction of ACN into BFEE has little effect on the properties of as-formed copolymers.  相似文献   

5.
A straightforward synthetic route to produce tris(methacrylato)chromium(III), Cr(O2C(CH3)C=CH2)3, by reacting sodium methacrylate with an aqueous solution of CrCl3 gave a blue microcrystalline powder, insoluble in most common solvents. Electronic spectroscopy (UV-Vis), electron paramagnetic resonance (EPR), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), were employed to characterize Cr(O2C(CH3)C=CH2)3. Morphology and elemental composition of this compound were determined using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX), respectively. Spherical particles of approximately 2.5 µm in diameter were obtained. Thermal stability of the product was investigated via thermogravimetric analysis (TGA). The spectroscopic studies revealed that the coordination sphere around the chromium ion corresponds to a chelating bidentate carboxylate-Cr(III) complex. Thermal stability above 350°C, and spherical shape particles of few micrometers in diameter, suggest a potential application of this novel compound as a catalyst in oxidation reactions.  相似文献   

6.
制备方法对AgInO2结构及光催化性能的影响   总被引:1,自引:0,他引:1  
以离子交换法和"氟化异丙烯膜袋"水热法分别制备了AgInO2,利用XRD、低温氮吸附-脱附、SEM、紫外-可见漫反射光谱(UV-Vis diffuse reflection spectroscopy,DRS)和XPS对不同方法所得到的AgInO2进行了表征;以罗丹明B(RhB)和甲基橙(MO)为目标物,在可见光下考察了2种催化剂的光催化性能。结果表明,利用"氟化异丙烯膜袋"水热法制备的样品由于具有更好的结晶度,且在可见光区有更强的吸收,从而表现出了更好的可见光光催化活性(3 h降解RhB达94%。7 h降解MO达83%)。  相似文献   

7.
以钛酸丁酯和硝酸银为前驱体,采用一步火焰辅助热解法制备了Ag_2O/TiO_2光催化剂并研究了样品在紫外-可见光照射下的光催化制氢性能。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见漫反射吸收光谱(UV-Vis DRS)对样品进行了表征。XRD结果表明TiO_2均为锐钛矿晶型,Ag的引入对XRD结果无明显影响。SEM图显示未修饰的TiO_2是微球形貌,随着引入Ag含量的增加,微球减少直至消失。通过XPS分析和化学沉淀法表明样品中Ag的存在形式为Ag_2O。UV-Vis DRS测试发现引入Ag后提高了样品的光吸收。前驱体中Ag的量影响样品的光催化活性,最高的光催化制氢的活性可以达到相同条件下的P25的15倍。对光催化反应后的样品进行分析,认为在光催化过程中部分Ag_2O通过光生电子转化为Ag形成Ag/TiO_2,进一步提高光催化制氢活性。  相似文献   

8.
采用草酸有机诱导在水热条件下制备了形貌新颖的WO3粉体, 使用XRD, SEM, BET等手段进行结构和形貌表征, 并利用紫外-可见光谱仪(UV-Vis)及测色计对所制备的样品进行光致变色性能测试. 结果表明, 合成的WO3粉体仍为六方相, 以草酸为诱导剂合成的粉体由大小及形状较为均匀的梭形组成, 颗粒长在200~300 nm之间, 宽在30~50 nm左右, 长宽比为4~10之间, 这种特殊的形貌改善了粉体对激发光源的吸收能力, 从而提高了合成的WO3粉体的光致变色性能.  相似文献   

9.
以钛酸丁酯和硝酸银为前驱体,采用一步火焰辅助热解法制备了Ag2O/TiO2光催化剂并研究了样品在紫外-可见光照射下的光催化制氢性能。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见漫反射吸收光谱(UV-Vis DRS)对样品进行了表征。XRD结果表明TiO2均为锐钛矿晶型,Ag的引入对XRD结果无明显影响。SEM图显示未修饰的TiO2是微球形貌,随着引入Ag含量的增加,微球减少直至消失。通过XPS分析和化学沉淀法表明样品中Ag的存在形式为Ag2O。UV-Vis DRS测试发现引入Ag后提高了样品的光吸收。前驱体中Ag的量影响样品的光催化活性,最高的光催化制氢的活性可以达到相同条件下的P25的15倍。对光催化反应后的样品进行分析,认为在光催化过程中部分Ag2O通过光生电子转化为Ag形成Ag/TiO2,进一步提高光催化制氢活性。  相似文献   

10.
以硝酸铟作为前驱体,在蒸馏水和乙二胺的混合溶剂中制备出了InOOH纳米晶,详细地考察了反应溶剂及温度对终产物的影响。利用X射线粉末衍射(XRD)、紫外-可见漫反射光谱(UV-Vis DRS)、扫描电子显微镜(SEM)和透射电镜(TEM)对样品的晶相结构、光吸收性质及其形貌进行了详细的表征。考察了样品在紫外光下及可见光下对液相中的染料罗丹明B(RhB)的光催化降解性能。发现InOOH在紫外光下可以彻底分解RhB,而在可见光下只能使RhB脱色。InOOH在紫外光和可见光下对RhB的分解遵循两种不同的反应机制。  相似文献   

11.
Spherical MCM-41 with various copper and iron loadings was prepared by surfactant directed co-condensation method. The obtained samples were characterized with respect to their structure (X-ray diffraction, XRD), texture (N2 sorption), morphology (scanning electron microscopy, SEM), chemical composition (inductively coupled plasma optical emission spectrometry, ICP-OES), surface acidity (temperature programmed desorption of ammonia, NH3-TPD), form, and aggregation of iron and copper species (diffuse reflectance UV-Vis spectroscopy, UV-Vis DRS) as well as their reducibility (temperature programmed reduction with hydrogen, H2-TPR). The spherical MCM-41 samples modified with transition metals were tested as catalysts of selective catalytic reduction of NO with ammonia (NH3-SCR). Copper containing catalysts presented high catalytic activity at low-temperature NH3-SCR with a very high selectivity to nitrogen, which is desired reaction products. Similar results were obtained for iron containing catalysts, however in this case the loadings and forms of iron incorporated into silica samples very strongly influenced catalytic performance of the studied samples. The efficiency of the NH3-SCR process at higher temperatures was significantly limited by the side reaction of direct ammonia oxidation. The reactivity of ammonia molecules chemisorbed on the catalysts surface in NO reduction (NH3-SCR) and their selective oxidation (NH3-SCO) was verified by temperature-programmed surface reactions.  相似文献   

12.
A novel inherently conducting polymer, high‐quality polyphenanthrene (PPh) films were synthesized electrochemically by direct anodic oxidation of phenanthrene (Ph) in boron trifluoride diethyl etherate (BFEE) containing a certain amount of trifluoroacetic acid (TFA). The oxidation potential of Ph in this medium was measured to be only 0.63 V versus SCE, which was greatly lower than that determined in acetonitrile + 0.1 mol L?1 Bu4NBF4 (1.55 V vs. SCE). The electrolytes of BFEE containing TFA enable facile anodic oxidation of Ph monomer; however, similar oxidation using acetonitrile never produces such a polymeric material. PPh films obtained from this medium showed good redox activity and stability even in concentrated sulfuric acid. Dedoped PPh films were partly soluble in polar solvent such as CH2Cl2, acetone, tetrahydrofuran, and dimethyl sulfoxide. Fluorescent spectral studies indicate that PPh is a good blue‐light emitter. The structure and morphology of the polymer were studied by UV–vis spectroscopy, FTIR spectroscopy, 1H NMR spectroscopy, and scanning electron microscopy, respectively. The results of quantum chemistry calculations of Ph monomer and the spectroscopies of dedoped PPh indicated the polymerization mainly occurred at C(9) and C(10) positions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3929–3940, 2007  相似文献   

13.
许超  王玲  骆浩  邹定兵  应桃开 《无机化学学报》2007,23(11):1941-1946
以1-正丁基-3-甲基咪唑溴盐离子液体([BMIM]Br)/水体系为反应介质,利用简便的液相沉淀法在室温下合成了钼酸钙(CaMoO4)中空微球体材料。分别利用X-射线粉末衍射(XRD)、场发射扫描电子显微镜(SEM)以及透射电子显微镜(TEM)对产品的相结构及形貌进行表征,发现产品为空心结构的白钨矿型微米级球体,并且该CaMoO4微球体是由粒径为10~20 nm的纳米粒子聚集而成。利用紫外可见(UV-Vis)漫反射谱及室温光致发光(PL)谱测试了产品的光学性质。通过与纯水相、1-乙基-3-甲基咪唑溴盐离子液体([EMIM]Br)/水及1-正己基-3-甲基咪唑溴盐离子液体([HMIM]Br)/水等体系中所得产品的对比,证明了[BMIM]Br对产品的形貌及光学性能等具有重要影响,并对中空微球体形成的机理进行了讨论。  相似文献   

14.
采用硼氢化钠还原法制备了Ag负载CdMoO4光催化剂。运用X射线粉末衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)等测试手段对催化剂的组成和结构进行了表征;采用紫外-可见漫反射光谱(UV-Vis DRS)和X射线光电子能谱(XPS)等技术对催化剂的光响应和表面状态进行了分析,考察了不同Ag负载量对CdMoO4紫外光降解罗丹明B和可见光选择性氧化苯甲醇性能的影响。结果表明,与CdMoO4相比,Ag/CdMoO4具有更高的光催化活性。利用活性物种捕获实验探讨其光催化降解过程的反应机理,实验结果显示O2-·和·OH是光催化降解过程的主要活性物种。  相似文献   

15.
采用硼氢化钠还原法制备了Ag负载Cd Mo O4光催化剂。运用X射线粉末衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)等测试手段对催化剂的组成和结构进行了表征;采用紫外-可见漫反射光谱(UV-Vis DRS)和X射线光电子能谱(XPS)等技术对催化剂的光响应和表面状态进行了分析,考察了不同Ag负载量对Cd Mo O4紫外光降解罗丹明B和可见光选择性氧化苯甲醇性能的影响。结果表明,与Cd Mo O4相比,Ag/Cd Mo O4具有更高的光催化活性。利用活性物种捕获实验探讨其光催化降解过程的反应机理,实验结果显示O2-·和·OH是光催化降解过程的主要活性物种。  相似文献   

16.
采用湿化学合成路线以巯基乙酸为包覆剂,水为溶剂制备了六方相ZnIn2S4。应用能谱分析(EDS)、X射线衍射(XRD)、透射电镜(TEM)、扫描电镜(SEM)和紫外-可见光谱对产物的组成、结构、形貌和光学性质进行了表征。结果表明,所得到的ZnIn2S4具有层状形貌。这些层状物是由ZnIn2S4纳米粒子前驱体在热处理过程中聚集生长而成的。另外,以ZnIn2S4纳米粒子前驱体为起始原料,借助表面活性剂的导向作用在固/液界面成功地实现了ZnIn2S4的形貌控制生长,得到了具有棒状、棒簇状、管簇状形貌的ZnIn2S4。根据实验结果,初步讨论了可能的表面活性剂辅助的ZnIn2S4形貌控制生长的机制。  相似文献   

17.
利用溶剂热法在不同反应溶剂中制备了不同尺寸的Bi2S3纳米管和纳米棒.利用XRD、SEM、TEM、选区电子衍射(SAED)和高分辨透射电镜(HRTEM)对其结构和形貌进行了表征.结果表明,所制备的产物是结晶良好的正交相Bi2S3,反应溶剂的表面张力、粘度大小和反应溶剂中的比例影响纳米粉体的形貌和尺寸.紫外-可见光吸收光谱测量表明,由于尺寸效应所有粉体的吸收谱相对于正交相的Bi2S3块体都出现蓝移.  相似文献   

18.
采用三步阳极氧化法和一步循环伏安电沉积法制备了还原氧化石墨烯(rGO)修饰的Y型TiO_2纳米管(rGO/Y-TiO_2NTs)电极。通过场发射电子扫描显微镜(FESEM)、X射线能谱(EDS)、X射线衍射(XRD)、紫外可见漫反射光谱(UV-Vis DRS)及拉曼光谱(Raman)等对电极样品进行了表征。以rGO/Y-TiO_2NTs电极为光阳极,测试了不同循环伏安沉积圈数对电极光电流响应的影响,考察了在1.0 V偏压下电极对氨氮的光电催化氧化性能。结果表明,高度有序的Y-TiO_2NTs为锐钛矿型,具有大的比表面积,表面修饰平滑透明rGO薄膜后可显著提高其光电催化效率,沉积圈数为30时电极在30 min内对氨氮的光电催化氧化效率为95.9%。  相似文献   

19.
The o-aminophenol (OAP)-H_2O_2-horseradish peroxidase (HRP) voltammetric enzyme-linked immunoassay new system has extremely high sensitivity. HRP can be measured with a detection limit of 6.0×10~-(10) g/L and a linear range of 1.0×10~(-9)—4.0×10~(-6) g/L. The pure product of H_2O_2 oxidizing OAP catalyzed by HRP was prepared with chemical method. The enzyme-catalyzed reaction has been investigated with electroanalytical chemistry, UV/Vis spectrum, IR spectrum, ~(13)C NMR, ~1H NMR, mass spectrum, elemental analysis, etc. Under the selected enzyme-catalyzed reaction conditions, the oxidation product of OAP with H_2_O2 catalyzed by HRP is 2-aminophe-noxazine-3-one. The processes of the enzyme-catalyzed reaction and the electroreduction of the product of the enzymecatalyzed reaction have been described.  相似文献   

20.
Various nanosized zinc aluminate(ZnAl2O4) samples were prepared by a conventional and a mi- crowave method both with and without using Opuntia dilenii haw plant extract,and were charac- terized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),high resolution scanning electron microscopy(HRSEM),energy dispersion scanning(EDX),temperature dependent conductance measurements, thermoelectric power measurements, ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy,and photoluminescence spectroscopy.The formation of a pure ZnAl2O4 phase was confirmed by XRD and FT-IR.A change in morphology from nanosized plates to nanosized sheets with,respectively,the conventional and microwave heating methods was clearly shown by HRSEM.UV-Vis diffusion reflectance spectroscopy measured the band gaps of ZnAl2O4 nanosized plates and nanosized sheets as 3.5 and 3.9 eV,respectively.The synthesized ZnAl2O4 was single crystalline and has three photoluminescence emissions at 482,528,and 540 nm.ZnAl2O4 nanosized sheets prepared by the microwave method showed higher catalytic activity for the oxida- tion of benzyl alcohol(85% conversion) than ZnAl2O4 nanosized plates prepared by the convention- al method(60% conversion).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号