Pd/PANI纳米纤维的液相合成及其对乙醇的电化学行为

以苯胺为单体、PdCl₂为金属前驱体、过硫酸铵为氧化剂,在避光条件下液相化学氧化合成Pd/PANI纳米纤维,用XRD、FESEM、TEM、SAED、HRTEM、FT-IR和UV-vis等手段对其表征,研究了 Pd/PANI纳米纤维修饰玻碳电极对乙醇的电化学行为。结果表明,Pd/PANI纳米纤维的平均直径为20 nm,长度为500 nm;平均直径为6 nm的纳米Pd颗粒单分散分布在PANI纤维中;Pd/PANI纳米纤维修饰电极的ECSA值为54.76 m²/g_Pd,是商用Pd/C催化剂(6.08 m²/g_Pd)的9倍,其j_f/j_b值为1.192。     

钯纳米颗粒在不同碳质材料上的自发沉积与电活性

在无还原剂存在下,氯化钯在Vulcan XC-72碳粉(C)、多壁碳纳米管(MWCNT)和碳球(CM)等碳质材料表面上自发还原为金属钯,从而得到相应的钯纳米颗粒(Pd-C、Pd-MWCNT和Pd-CM)。用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)对这些碳质材料修饰后,采用同样的自发还原方法分别制备出Pd/CTAB-C、Pd/CTAB-MWCNT和Pd/CTAB-CM催化剂。结果表明,CTAB修饰后的MWCNT明显增加了钯纳米颗粒的自发沉积量,粒径大约为9 nm,而在MWCNT上沉积的纳米Pd粒径为19 nm。Pd/CTAB-MWCNT在碱性条件下对乙醇氧化的电流密度达到44.2 m A·cm-2,与其他碳载体负载的Pd纳米催化剂相比,对乙醇氧化具有强而稳定的电催化活性。     

纳米Pd的六角相液晶模板合成及对乙醇的电催化氧化*

构建盐水、环己烷、表面活性剂和助表面活性剂四元体系, 采用六角相液晶为模板在避光温和条件下将Pd²⁺还原制备出纳米Pd催化剂, 用偏光显微分析、XRD、TEM、选区电子衍射 (SAED)和HRTEM等手段对其进行表征, 研究了反应时间对纳米Pd微观形貌和尺寸的影响, 并用循环伏安法研究了纳米Pd修饰玻碳电极对乙醇的电催化活性。结果表明, 避光反应24 h后制备出呈规则形貌的纳米Pd材料, 平均粒径为(31±1) nm, 对乙醇有较高的电催化活性和抗中毒能力。     

银/聚苯胺纳米复合材料的制备及形成机理

采用反胶束原位复合法制备了银/聚苯胺(Ag/PANI)纳米复合材料,并且探讨了Ag/PANI纳米复合材料的形成机理。通过红外光谱、紫外吸收光谱、X射线衍射、扫描电镜和透射电镜对复合物进行了表征。研究结果表明,Ag/PANI复合材料中Ag为纳米粒子,粒径为50 nm,苯胺自吸附在银纳米粒子表面聚合,形成PANI包覆Ag纳米粒子壳-核结构。Ag纳米粒子在PANI中均匀分散,Ag/PANI复合粒子大部分呈现类球形状的表面形貌,复合粒子粒径较PANI有了明显减小。并提出了Ag/PANI复合材料的形成机制。     

花状氧化锌的制备及光电性能的研究

采用聚乙二醇(PEG(2000))辅助的水热合成法制备出了粒径较为均匀的花状氧化锌纳米团簇,并用SEM、XRD对其进行了表征.实验结果表明,表面活性剂(PEG-2000)和氨水的加入量对ZnO纳米团簇的形貌有直接的影响;将ZnO纳米团簇均匀涂在导电玻璃的导电面上,在一定温度下煅烧后制成纳米团簇膜电极,并进行了光电化学研究.     

CTAB诱导的Fe_3O_4/聚苯胺、聚吡咯复合纳米材料的制备与表征

以Fe3O4纳米粒为原料,采用单体苯胺及吡咯进行表面原位聚合反应,分别制备了Fe3O4/聚苯胺(PANI)及Fe3O4/聚吡咯(PPY)两种复合纳米材料,经XRD、FT-IR、SEM表征,表明Fe3O4/PANI复合纳米微球粒径为40～60nm,Fe3O4/PPY纳米材料大小为100nm左右。研究发现在制备过程中,所得复合纳米材料的形貌受添加到聚合反应中十六烷基三甲基溴化铵(CTAB)阳离子表面活性剂的影响显著,在无CTAB的制备过程中,复合纳米材料形成纳米颗粒结构,而在加入CTAB的过程中,所得复合材料则呈丝状纳米结构。结果表明,可以通过调整CTAB的加入与否达到控制Fe3O4/PANI、PPY复合纳米材料形貌的目的。     

原位悬浮乳液聚合制备聚苯胺/纳米金刚石复合微球及结构表征

利用原位乳液聚合的方法合成得到了聚苯胺(PANI)/纳米金刚石复合微球.用X射线衍射(XRD)、热重-差热(Tg-DTA)、透射电子显微镜(TEM)、粒径分析(PSD)、比表面积分析(BET)、红外光谱(FT-IR)及紫外-可见光谱(UV-Vis)等技术分别对获得的PANI/纳米金刚石复合微球进行了结构、形貌、表面表征.结果表明,在PANI/纳米金刚石复合微球中,纳米金刚石为立方相,复合微球介于10～30nm,粒径分布窄,分散性良好,比表面积可达270m2/g,且具有较好的热稳定性.结构分析证实在PANI/纳米金刚石复合物中,PANI与纳米金刚石之间存在氢键键合机制.     

超声诱导CTAB/SDS溶液中纳米Pd粒子的形貌控制及对甲醛的电催化氧化

在十六烷基三甲基溴化铵(CTAB)-十二烷基硫酸钠(SDS)混合乙醇水溶液中,超声辐射PdCl2,合成了纳米Pd粒子,用XRD、TEM、选区电子衍射(SAED)、HRTEM和低温氮吸附-脱附等技术进行了表征,考察了CTAB/SDS组成对纳米粒子形貌的影响,纳米Pd粒子修饰玻碳电极对甲醛的电催化活性也通过循环伏安法进行了研究。结果表明:通过改变CTAB/SDS组成可以调控纳米Pd粒子的粒径和形貌;当CTAB与SDS物质的量之比为1∶1、超声反应60min时,得到呈多边形的纳米Pd粒子,粒径范围在10～20nm之间,比未添加表面活性剂样品的比表面积增大了14m2.g-1,对甲醛有较高的电催化活性。     

PVA对氧化石墨烯/聚苯胺微观形貌及电化学性能的影响

采用原位聚合法制备了不同聚乙烯醇(PVA)表面活性剂添加量的聚苯胺(PANI)以及氧化石墨烯/聚苯胺(GO/PANI)复合材料。借助扫描电镜、X射线衍射、傅立叶变换红外光谱分析等表征手段对材料的物相组成、微观结构和形貌进行了分析。将材料压制电极并组装成扣式电池,利用循环伏安曲线和电化学阻抗谱对材料进行电化学性能检测。探讨了表面活性剂PVA的添加量对PANI以及GO/PANI的微观结构、形貌、电导率及电化学性能的影响。结果表明,当PVA与苯胺(AN)的摩尔比为0.000075时,PVA的引入明显降低了PANI及GO/PANI复合材料的团聚,PVA75/PANI的电导率比纯PANI的电导率提高了2倍,GO/PVA75/PANI复合材料的电导率比未加PVA的GO/PANI复合材料提高了5倍。当PVA与AN的摩尔比为0.000075时,PVA75/PANI和GO/PVA75/PANI复合材料的比电容分别达到986和1 223F/g。     

聚苯胺/聚乙烯醇纳米纤维的制备与表征

以十二烷基苯磺酸(DBSA)为表面活性剂和掺杂剂,通过乳液聚合的方法制备聚苯胺/聚乙烯醇(PANI/PVA)复合乳液用于静电纺丝,制备出超细复合纤维毡,通过SEM、XRD和力学测试表征PANI/PVA超细复合纤维毡的外观形貌、纤维直径、结晶度及其力学性能。结果表明:有机磺酸掺杂后的聚苯胺导电性能达到1.28S/cm;1459cm-1处醌环和苯环上的C=C伸缩振荡峰和1697cm-1处醌环上C=N伸缩振荡峰的聚苯胺特征峰明显;YG006型电子单纤维强力机的测试发现,PANI/PVA纤维集合体的面密度对其力学性能的影响显著;当纺丝工艺条件设定为接收距离18cm、电压24kV时,PANI/PVA纤维直径达到600nm,直径分布小于150nm,PANI微颗粒分散于PVA纤维基体表面。     

聚苯胺/TiO2复合纳米膜电极的制备及其光电性能

采用原位化学氧化法,在酸性TiO2溶胶中未加分散剂制备了聚苯胺修饰的TiO2稳定溶胶,并以涂刮法在柔性导电塑料薄膜上成膜。利用FT-IR、XRD、TEM、选区电子衍射、紫外-可见光谱、光电流-电压曲线对所制备的复合溶胶及复合膜进行了表征。结果表明TiO2与聚苯胺之间实现了结构上的复合,聚苯胺的引入改善了TiO2膜对太阳光的利用率,提高了TiO2膜的光电响应性能。这种用复合溶胶制备聚苯胺/TiO2复合膜的方式扩大了成膜基底的范围。     

Large-scale preparation of polyaniline nanospheres anchored with thiol-stabilized gold nanoparticles

Reported herein is the preparation of a new nanostructured composite consisting of PANI(SH) (where PANI(SH) is poly(aniline-co-4-aminothio phenol)) and gold nanoparticles (AuNPs)) via "seed"-induced bulk polymerization. The PANI(SH)-AuNPs composite was designated as PANI(SH)-Au-NS(P). The composite was characterized in terms of its morphology and structural, thermal, and electrochemical properties. The field emission scanning electron microscopy (FESEM) image of PANI(SH)-Au-NS(P) revealed the presence of PANI(SH) nanospheres (sizes: approximately 150-250 nm) with finely distributed AuNPs (approximately 10 nm). The usefulness of PANI(SH)-Au-NS(P) as an electrocatalyst towards the oxidation of methanol was tested.     

Templated synthesis of polyaniline nanotubes with Pd nanoparticles attached onto their inner walls and its catalytic activity on the reduction of p-nitroanilinum

In this paper, polyaniline (PANI) nanotubes with palladium nanoparticles (NPs) attached onto their inner walls were synthesized via a templating method which contains three steps. First, electrospun polystyrene (PS) nanofibers were coated with nearly monodispersed Pd NPs (d = 3.411 nm, σ = 0.687 nm, d is the average diameter of Pd NPs and σ is the standard deviation of their diameters) through in situ reduction of Pd²⁺ ions on the surface of sulfonated PS nanofibers. Then we used a self-assembly method to coat the composite with a PANI layer. The final product was obtained after the removal of PS nanofibers by diluting them in tetrahydrofuran. The morphology of samples was analyzed by scanning electron microscopy and transmission electron microscopy and the structure was characterized by Fourier transform infrared, ultraviolet–visible spectra, X-ray diffraction patterns and X-ray photoelectron spectroscopic patterns. Inductively coupled plasma atomic spectra were used to show the weight percentage of Pd nanoparticles. Its catalytic activity on the reduction of p-nitroanilinum was also investigated and compared to Pd/C catalyst and Pd/MWNTs.     

A highly porous NiO/polyaniline composite film prepared by combining chemical bath deposition and electro-polymerization and its electrochromic performance

A highly porous NiO/polyaniline (PANI) composite film was prepared on ITO glass by combining the chemical bath deposition and electro-polymerization methods, successively. The porous NiO film acts as a template for the preferential growth of PANI along NiO flakes, and the NiO/PANI composite film has an intercrossing net-like morphology. The electrochromic performance of the NiO/PANI composite film was investigated in 1?M LiClO(4)+1?mM HClO(4)/propylene carbonate (PC) by means of transmittance, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The NiO/PANI thin film exhibits a noticeable electrochromism with reversible color changes from transparent yellow to purple and presents quite good transmittance modulation with a variation of transmittance up to 56% at 550?nm. The porous NiO/polyaniline (PANI) composite film also shows good reaction kinetics with fast switching speed, and the response time for oxidation and reduction is 90 and 110?ms, respectively.     

Preparation and characterization of polyaniline-copper composites by electrical explosion of wire

Polyaniline-copper composites with a polyacrylic acid (PAA) were synthesized by electrical explosion of wire. Polyaniline (PANI) and PAA were put into the explosion medium, deionized water (DIW) and ethanol, stirred for 24 hrs and sonicated for 2 hrs. These solutions were used as base liquids for explosion process to fabricate Cu nanoparticle. Optical absorption in the UV-visible region of PANI and PANI/PAA-Cu composites was measured in a range of 200-900 nm. X-ray diffraction was used to analyze the phase of the composites. XRD pattern showed the PANI was amorphous and copper was polycrystalline. Two phases of Cu and Cu2O were formed in aqueous solution while single Cu phase was obtained in ethanol solution. Field emission scanning electron microscope was used to observe the microstructure of the composites. The synthesized composites were extensively characterized by Fourier Transform Infrared (FTIR) spectroscopy and electrical measurements.     

聚苯胺/聚四氟乙烯导电复合膜的电化学制备和表征分析

在聚四氟乙烯(PTFE)微孔膜上电化学制备硫酸和磺基水杨酸(SSA)共掺杂的导电聚苯胺(PANI)复合膜,采用四因素三水平的正交设计法优化工艺条件,并在其上继续沉积银,研究了沉积银电流密度和时间及拉伸对复合膜电导率的影响。采用拉曼光谱、X射线衍射和扫描电镜对复合膜进行了表征。结果表明,在最佳工艺条件下制备的PTFE-PANI复合膜电导率可达36.9S/cm,此复合膜经20mA/cm2沉积4min的银可使其电导率显著提高到5379S/cm。对最优条件制备的PANI-PTFE和PANI-PTFE-Ag复合膜进行适当程度的拉伸均可提高其电导率,PT-FE系列复合膜展现出较优异的力学性能。拉曼光谱表明PTFE、PANI和银复合良好。复合膜有一定的结晶度,经拉伸后复合膜结晶度增大,电导率显著提高;PANI在PTFE上呈颗粒状生长,颗粒尺寸均匀,直径约为200nm,Ag呈树枝状镶嵌、覆盖在PANI颗粒间,与PANI复合很好并形成三维导电网络。     

阳极氧化铝模板上扩散聚合法制备聚苯胺纳米管(线)阵列

以多孔阳极氧化铝（AAO）为模板，利用扩散聚合法让苯胺单体溶液和氧化剂溶液在一维纳米孔道中相互扩散，在孔内形成聚苯胺（PANI）纳米管和纳米线阵列。利用SEM、TEM、IR和XRD等检测技术对阵列进行表征。结果表明，聚合反应优先发生在孔壁上，并沿孔壁逐层生长，直至形成实心的纳米线阵列。在孔径为60nm的AAO模板内，扩散聚合40min可形成聚苯胺纳米管阵列，2h后形成聚苯胺纳米线阵列；聚苯胺纳米管（线）中同时包含结晶相和无定型相结构。用二探针法测量PANI／AAO复合阵列电阻，计算出单根聚苯胺纳米线的电导率为21．4S／cm。此外，对扩散聚合过程中聚苯胺纳米管（线）阵列的形成原因进行了初步分析和探讨。     

Heulandite/polyaniline hybrid composite for efficient removal of acidic dye from water; kinetic,equilibrium studies and statistical optimization

Heulandite/polyaniline (HU/PANI) composite was prepared by mechanical mixing from natural heulandite and synthesized polyaniline. HU/PANI was characterized by XRD, SEM, TEM, FT-IR, and UV–Vis spectroscopy. The product is of polycrystalline nature with an average crystallite size of 25.7?nm and optical band gap of 1.69?eV. HU/PANI shows higher efficiency in the removal of light green SF dye than natural HU or PANI in the dark and under artificial illumination. The equilibrium time was attained after 360 and 480?min in the dark and under illumination, respectively. The results fitted well with pseudo second order and Elovich kinetic models. The adsorption isotherm in the dark fitted well with Langmuir isotherm model and the calculated q_max was 44.6?mg/g. Using illumination, the data fitted better with the Freundlich and Temkin model than with the Langmuir model. Based on response surface analysis, the predicted conditions for maximum removal of light green SF dye in the dark (70.9%) were 5.5?mg/L, 24?mg, 3, and 430?min for dye concentration, HU/PANI dose, pH, and contact time, respectively. Whereas, under light illumination (97%) at operating conditions of 15?mg/L, 15?mg, 3, and 589?min, respectively. The composite also shows high efficiencies in the removal of other types of acidic and basic dyes.     

Synthesis of a carbon-coated NiO/MgO core/shell nanocomposite as a Pd electro-catalyst support for ethanol oxidation

Carbon coated on NiO/MgO in a core/shell nanostructure was synthesized by the single-step RAPET (reaction under autogenic pressure at elevated temperatures) technique, and the obtained formation mechanism of the core/shell nanocomposite was presented. The carbon-coated NiO/MgO and its supported Pd catalyst, Pd/(NiO/MgO@C), were characterized by SEM, HR-TEM, XRD and cyclic voltammetry. The X-ray diffraction patterns confirmed the face-centered cubic crystal structure of NiO/MgO. Raman spectroscopy measurements provided structural evidence for the formation of a NiO/MgO composite and the nature of the coated carbon shell. The high-resolution transmission electron microscopy images showed the core and shell morphologies individually. The electrocatalytic properties of the Pd/(NiO/MgO@C) catalyst for ethanol oxidation were investigated in an alkaline solution. The results indicated that the prepared Pd–NiO/MgO@C catalyst has excellent electrocatalytic activity and stability.