共查询到19条相似文献,搜索用时 93 毫秒
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以阳极氧化铝膜 (AAO)作模板 ,制备聚苯胺 (PANI)纳米管和PANI纳米管列阵 ;同时利用溶胶_凝胶法制备ZnO_PANI同轴纳米线和同轴纳米线列阵 .PANI纳米管和ZnO_PANI同轴纳米线的形貌通过透射电子显微镜表征 .PANI纳米管的外径约 3 0nm ,内径约 1 0nm ;ZnO_PANI同轴纳米线直径约 60nm .实验发现 ,较之ZnO纳米线 ,同轴AAO模板中纳米线列阵的可见光发射谱带兰移 ,强度显著增强 ,这可能和PANI链上的NH基团与表面Zn2 +离子之间的相互作用有关 ,以及由于ZnO纳米微粒在PANI上富集、PANI的光生载流子部分转移给ZnO微粒所致 .实验还发现分散在NaOH溶液中的同轴纳米线 ,其可见光发射谱带比AAO模板中同轴纳米线的谱带兰移更甚 相似文献
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聚苯胺负载H4PMo11VO40催化剂的结构和催化性能 总被引:2,自引:0,他引:2
合成了聚苯胺负载的H4PMo11VO40催化剂,利用IR, XRD,ICP,SEM和NH3-TPD等技术对催化剂进行了表征,证实H4PMo11VO40能够负载于聚苯胺载体上,并有效地改善了H4PMo11VO40的酸碱-氧化还原催化性能. 考察了催化剂催化正己醇转化的性能,正己醇氧化生成正己醛和脱水生成正己烯两种产物. 与未负载的H4PMo11VO40相比,聚苯胺负载的4PMo11-VO40催化剂的氧化还原催化性能有所提高,而酸碱催化性能有所降低,并且催化性能随着H4PMo11VO40负载量的增加而提高. 但负载量过高时,正己醛收率反而降低. 其中以C6H4.5NH4PMo11VO40)0.0319催化剂最佳,140 ℃时达到最大正己醇转化率87.6%,正己醛的收率为48.8%,选择性为55.7%. 相似文献
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合成聚苯胺/碳化钨复合材料及聚合机理探讨 总被引:1,自引:0,他引:1
采用在原位聚合苯胺的反应介质中分散碳化钨(WC)的方法制备了掺杂聚苯胺/碳化钨(PANI/WC)复合物,并研究了苯胺在WC表面的聚合机理.通过扫描电镜(SEM)、透射电镜(TEM)、傅立叶红外光谱(FTIR)、拉曼光谱(Raman)和X射线衍射(XRD)对复合物进行了表征.结果表明,苯胺的聚合倾向于在WC颗粒表面进行,形成了PANI包覆WC的复合材料;WC粒子与PANI大分子之间存在强的相互作用,并且复合前后WC的晶型并未发生变化,WC的存在导致红外光谱有明显的蓝移现象,复合后在3446 cm-1处的红外吸收峰变得很弱;在拉曼光谱中,代表醌环C N键的伸缩振动峰红移了9 cm-1,并且强度也有很大程度提高.说明PANI与WC之间有化学键的作用,它们之间的化学键作用发生在C N键的N原子上.聚合反应优先在WC粒子表面进行,生成PANI包覆结构,并提出了PANI/WC复合物的形成机制. 相似文献
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纳米(NH4)3PMo6W6O40的室温固相合成及形成机理 总被引:3,自引:0,他引:3
以H3PMo6W6O40•23H2O和(NH4)2C2O4•H2O为原料,采用室温固相反应合成出(NH4)3PMo6W6O40•6H2O产物,用元素分析、IR、UV-Vis、XRD、TEM、TG-DTA、BET等手段确定其组成、结构和性能.结果表明,产物为纳米粒子,平均粒径为10 nm.纳米粒子保持着杂多阴离子的Keggin特征结构,比表面积为167.6 m2•g-1,且在465 ℃以下具有良好的热稳定性.反应中反应热能、结晶水和生成物H2C2O4•2H2O对形成小粒径的(NH4)3PMo6W6O40纳米粒子起关键作用. 相似文献
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选用B3LYP方法在LanL2MB水平下,对双帽α-Keggin型杂多阴离子[H4As3Mo12O40]-的电子结构和质子的定位进行了密度泛函理论(DFT)研究.结果表明,双帽的形成大大影响了杂多阴离子[As3Mo12O40]5-的电子结构和性质,NBO分析显示参与成帽的三桥氧上的电子密度比双桥氧上的要大,简单地从电荷密度来看,质子将首先在三桥氧上定域成键,但通过比较质子定域在几种桥氧上质子化稳定化能的大小,发现[H4As3Mo12O40]-中的四个质子将在八个双桥氧中的其中四个氧原子上定位,而不是如文献中报道的在四个三桥氧上定域成键.对杂多酸H3PM12O40(M=Mo,W)中质子的定位也进行了理论计算并与文献进行了比较,结果显示,H3PMo12O40中质子是定位在双桥氧上;而H3PW12O40中质子将优先在双桥氧上定位,但也可在端氧上定位;这一结果与文献报道的相一致. 相似文献
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发展和设计高效、廉价和稳定的光催化剂用于抗生素污染物降解仍然存在巨大的挑战。 本文通过一种便捷的水热方法制备了Bi4V2O11/石墨烯复合材料并用于可见光下抗生素污染物光催化降解。 通过自由基追踪实验,确认了光催化降解过程中活性物质为h+和·OH基团。 根据实验结果,提出了相应的反应机理。 石墨烯的引入可以有效地促进光生电子-空穴对的分离,从而增强光催化活性。 该复合催化剂展现出良好的活性和稳定性。 该方法以石墨烯为载体制备了光催化降解材料,为高性能光催化剂的制备提供了参考。 相似文献
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以丁酮和1,2-丙二醇为原料,活性炭负载硅钨酸(H4SiW12O40/C)为催化剂,催化合成了丁酮1,2-丙二醇缩酮。正交试验筛选出最佳反应条件为:丁酮200mmol,n(丁酮):n(1,2-丙二醇)=1.0:1.4,ω(催化剂)=1.2%(以反应物质量计),反应时间1h。在此最佳反应条件下,丁酮1,2-丙二醇缩酮的收率可达71.13%。 相似文献
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原位溶液聚合聚苯胺与聚苯乙烯溶液共混复合材料的制备及表征 总被引:2,自引:0,他引:2
以DNSA掺杂剂,在醇(或酮)-水介质中采用原位溶液聚合法制备出了聚苯胺,以溶液共混法制备出了聚苯胺/聚苯乙烯复合材料,采用红外光谱、热失重、元素分析、扫描电镜对产物进行了表征。结果显示:掺杂的聚苯胺电导率最高为0.65 S/cm,优于常用的DBSA,具有一定实用价值和理论意义。该复合材料表面电阻率最低为101Ω/□数量级,并在一定范围内可调,可用于电磁屏蔽,适合于聚合物表面使用。 相似文献
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阳极氧化铝模板法可控制备金属纳米线和纳米管阵列的生长机制 总被引:2,自引:0,他引:2
利用阳极氧化铝模板(AAO)进行Ni的电化学沉积, 通过在溶液中引入螯合剂控制电解质的有效浓度和电沉积的过电位, 实现了Ni纳米线和纳米管阵列的可控制备. 通过分析电沉积过程中纳米线和纳米管在不同位置生长速率(侧壁(Vw)和底端(Vb))的控制因素, 我们提出了纳米线和纳米管生长的可能机制. 当电解质浓度高而还原电位更负(如-1.5 V)时, 或者当电解质浓度低而还原电位较负(如-0.5 V)时, Vw>Vb, 可以获得Ni纳米管阵列; 当电解质浓度高而还原电位较负(如-0.5 V)时, 或者当电解质浓度低而还原电位更负(如-1.5 V)时, Vw≈Vb, 可以获得Ni纳米线阵列. 这种生长机制适用于多种金属纳米管或者纳米线阵列的可控制备. 相似文献
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Yingke ZhouHulin Li 《Journal of solid state chemistry》2002,165(2):247-253
Highly ordered LiCo0.5Mn0.5O2 nanowire arrays were prepared using porous anodic aluminum oxide (AAO) template from sol-gel solution containing Li(CH3COO), Co(CH3COO)2, and Mn(CH3COO)2. Electron microscope results showed that uniform length and diameter of LiCo0.5Mn0.5O2 nanowires were obtained, and the length and diameter of LiCo0.5Mn0.5O2 nanowires are dependent on the pore diameter and the thickness of the applied AAO template. X-ray diffraction and electron diffraction pattern investigations demonstrate that LiCo0.5Mn0.5O2 nanowires are a layered structure of LiCo0.5Mn0.5O2 crystal. X-ray photoelectron spectroscopy analysis indicates that the most closely resembling stoichiometric layered LiCo0.5Mn0.5O2 material has been obtained. 相似文献
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本文制备了PANI纳米点阵列, 利用导电原子力显微镜(C-AFM)表征了其形貌和导电性能, 在室温下观察到PANI纳米点的库仑台阶(Coulomb staircase)现象, 并利用库仑阻塞效应的理论进行了初步的分析. 相似文献
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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1335-1346
Abstract In this work, we describe a new approach to catalyze the template polymerization of conducting polyaniline (Pani). Electrostatic layer‐by‐layer (ELBL) self‐assembly of a polyelectrolyte and a biomimetic catalyst, hematin has been utilized to construct a nanocomposite film catalyst. Poly(dimethyl diallylammonium chloride) (PDAC) and hematin have been used as polycation and counter anions, respectively. The absorption spectra by UV‐VIS‐NIR spectroscopy showed that a conductive form Pani was formed, not only as a coating on the surface of the ELBL composites, but was also formed in solution. Furthermore, it was found that the reaction rate was affected by pH and concentration of hematin in the multilayers. The feasibility of controlled desorption of hematin molecules from the LBL assembly was explored and demonstrated by changing pH and hematin concentration. It is believed that hematin sandwiched between positively charged polyelectrolytes in the composite films was slowly released into the solutions and then used to catalyze the template polymerization of aniline with SPS, resulting in a water soluble form of Pani. The polymerization rate of aniline in solution was enhanced with decreasing pH of the solutions due to increased desorption of hematin nanoparticles from the multilayers. These ELBL hematin assemblies demonstrated both a way to functionalize surfaces with conductive Pani and a potential method of reusability of the catalyst for improved cost effectiveness. 相似文献
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<正>4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of H_3PMo_(12)O_(40)under solvent-free conditions. 相似文献
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Aligned Zn1-xMgxO nanowire arrays were successfully prepared on Si(111) substrates via the chemical vapor deposition (CVD) method with a mixture of ZnO, Mg, and activated carbon powders as reactants. The microstructures and optical properties of the synthesized Zn1-xMgxO nanowire arrays were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis X-ray (EDAX), and photoluminescence (PL) spectrum analytic apparatus, respectively. While Mg content was achieved or less approximately 0.29 (x, atomic ratio) in ZnO lattice, the crystal lattice of the synthesized samples exhibited wurtzite structure. The Mg atoms were distributed into the ZnO crystal as the interstitial and displaced atoms, and there was no phase separation in preparing Zn1-xMgxO nanowire arrays. However, as the Mg content was up to 0.53 (x) in the fabricated Zn1-xMgxO samples, a clear phase separation phenomena appeared in the Zn1-xMgxO crystal. Compared with the PL spectrum of the pure ZnO nanowire arrays, the analytic results showed that a blue-shift of the near-band edge emission with increasing Mg content was observed in the Zn1-xMgxO arrays. And the relative intensities of green peak at ca 535 nm and UV emission peak at ca 376 nm were all restrained. 相似文献