氧化锡多孔纳米纤维的制备及储锂性能

采用高压静电纺丝结合高温煅烧的方法制备了SnO₂多孔纳米纤维, 通过调节前驱体浓度获得具有高孔隙率的疏散型纤维, 利用SEM, TGA, XRD和电化学测试等手段对材料进行了表征. 结果表明, SnO₂多孔纳米纤维具有较好的电化学性质, 作为锂离子电池负极材料的初始可逆容量为717 mA·h/g, 20次循环后电池的充放电容量保持在320 mA·h/g左右.     

静电纺丝制备多孔碳纳米纤维及其电化学电容行为

采用静电纺丝技术,以聚丙烯腈(PAN)/醋酸锌为前驱体制备复合纳米纤维,随后经碳化、酸化获得多孔碳纳米纤维.扫描电子显微镜(SEM)观察发现,碳纳米纤维表面分布大量孔洞.N2吸脱附等温曲线(BET)测试材料比表面积达413m2·g-1.循环伏安法(CV)和恒流充放电(CP)性能测试表明:多孔碳纳米纤维具有较好的电化学性能,在1A·g-1的电流密度下比电容达275F·g-1.相比碳纳米纤维比容量提高了162%.     

静电纺丝法制备煤基纳米碳纤维及其在超级电容器中的应用

以氧化处理的新疆库车原煤、聚丙烯腈(PAN)和N,N-二甲基甲酰胺(DMF)为原料,通过静电纺丝法制备了直径均匀的煤基纳米碳纤维前驱体,经高温碳化、CO2活化得到煤基超级电容器电极材料.使用X射线能谱仪、物理吸附仪、扫描电子显微镜、红外光谱仪和热分析仪等对前驱体及产物进行了表征.结果表明,原煤经过高锰酸钾氧化处理后,部分连接大分子的烷基链被打断,含氧基团明显增多,使原煤在DMF中的溶解度大幅提高.电化学测试结果表明,在电流密度为1 A/g时,煤基活化碳纤维的比电容为259.7F/g,在1000次循环充放电后比电容仍然保持99.2%.     

聚丙烯腈/氧化石墨烯复合纳米纤维的制备与性能研究

以氧化石墨烯为添加物,采用静电纺丝的方法制备不同质量分数的聚丙烯腈/氧化石墨烯(PAN/GO)复合纳米纤维。使用扫描电镜(SEM)、透射电镜(TEM)对复合纳米纤维的微观结构进行观察;采用差示扫描量热仪(DSC)和热重分析仪(TGA)研究复合纳米纤维的热学性能随着氧化石墨烯添加量增加的变化;采用微机控制电子万能试验机对复合纳米纤维的力学性能进行研究。结果表明,加入氧化石墨烯后,纺制的PAN/GO纳米复合纤维会变细,但随着GO添加量的增多出现珠节现象,降低了纤维的粗细均匀度,同时加入GO后对PAN的氧化具有一定的抑制作用,而且GO的加入也使PAN的力学性能增加,当加入量为0.1%时断裂强力增加了一倍,但添加量为1%时,断裂强力又会降低,综合实验结果显示当加入氧化石墨烯的质量分数为0.1%时最适宜。     

Dopant-stimulated CuO Nanofibers for Electro-oxidation and Determination of Glucose

We described the preparation of copper oxide composite nanofibers doped with carbon nanotubes (CuO/C-NFs) or nickel oxide(CuO/NiO-NFs) by electrospinning for direct glucose determination. The interest in exploring practical CuO/C-NFs and CuO/NiO-NFs electrode materials for sensor application was fascinated by the possibility of promoting electron transfer for kinetically unfavorable glucose oxidation reactions at a lower overpotential and thus improving the selectivity of the electrode for glucose in electroanalysis. The morphologies of CuO/C-NFs and CuO/NiO-NFs were characterized by scanning electron microscopy(SEM) and X-ray powder diffraction(XRD). The electrocatalytic performances of glucose were evaluated in detail by cyclic voltammetry(CV) and chronoamperometry. Facile charge transport, enhanced current response(at a lower overpotential of +0.35 V), improved stability and selectivity, as well as excellent resistance towards electrode fouling were observed at CuO/ C-NFs electrode in direct glucose electroanalysis. These merits are attributed to the highly porous three-dimensional network film structure of CuO/C-NFs electrode materials and the potential synergic catalytic effect of CuO and carbon nanotubes in composite nanofibers. This study may provide a new insight into metal oxide-based composite nanofibers obtained via electrospinning for fabricating novel and high performance sensors and devices.     

纳米碳纤维载铂作为质子交换膜燃料电池阳极催化剂

采用化学还原法合成了微结构不同的纳米碳纤维(板式、鱼骨式、管式)载铂催化剂(分别记为Pt/p-CNF、Pt/f-CNF、Pt/t-CNF). 通过高分辨透射电镜(HRTEM)和X射线衍射(XRD)等分析技术对催化剂的微观结构进行了表征, 并利用循环伏安(CV)法分析了催化剂的电化学比表面积(ESA). 在此基础上, 制备了膜电极(MEA), 通过单电池测试了催化剂的电催化性能. 结果表明: 铂纳米粒子在不同的纳米碳载体上表现出不同的粒径, 在板式、鱼骨式和管式纳米碳纤维上的铂纳米粒子平均粒径分别为2.4、2.7和2.8 nm. 板式纳米碳纤维载铂催化剂作单电池阳极时表现出良好的电催化性能, 其对应的最高功率密度可达0.569 W·cm^-2, 高于鱼骨式纳米碳纤维载铂催化剂和管式纳米碳纤维载铂催化剂对应的最高功率密度(分别为0.550和0.496 W·cm^-2). 同时, 也制备了碳黑(Pt/XC-72)载铂催化剂. 相比于Pt/XC-72, 纳米碳纤维载体上的铂纳米颗粒有较小的粒径、较好的分散和较高的催化活性, 说明纳米碳纤维是质子交换膜燃料电池(PEMFCs)催化剂的良好载体.     

ZnO掺杂的SnO_2纳米纤维的制备、表征及气敏机理(英文)

以二水氯化亚锡(SnCl2·2H2O)为盐原料,采用静电纺丝的方法制备了SnO2纳米纤维.为了研究ZnO掺杂对SnO2形貌、结构及化学成分的影响,分别制备了不同含量ZnO掺杂的SnO2/ZnO复合材料.利用热重-差热分析(TG-DTA)、X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱仪、扫描电镜(SEM)及能量色散X射线(EDX)光谱对材料的结晶学特性及微结构进行了表征.制备的SnO2/ZnO复合材料是由纳米量级的小颗粒构成的分级结构材料.ZnO含量不同,对应的SnO2/ZnO复合材料结构不同.表征结果表明ZnO的掺杂量对SnO2材料的形貌及结构均起着重要作用.将制备的不同ZnO含量的SnO2/ZnO复合材料进行气敏测试,测试结果表明,Sn:Zn摩尔比为1:1制作的气敏元件对甲醇的灵敏度优于其它摩尔比的气敏元件.讨论了SnO2/ZnO复合材料气敏元件的敏感机理.同时针对Sn:Zn摩尔比为1:1时表现出最好的气敏响应,分析了其原因,包括Zn的替位式掺杂行为、ZnO的催化作用、过量ZnO对SnO2生长的抑制作用以及SnO2与ZnO晶粒界面处的异质结.     

树枝化聚合物催化剂的合成与应用

树枝化聚合物具有大量的分子内空腔、密集的表面官能团和纳米尺寸等特点,是均相催化剂的理想载体。树枝化聚合物催化剂结合了均相催化剂和多相催化剂的优点,能使反应在温和条件下达到高活性和高选择性。本文介绍了树枝化聚合物的合成,重点论述了树枝化聚合物催化剂的合成与催化作用,并展望了这类新型催化剂的发展前景。     

Y掺杂的ZnO纳米纤维材料的制备及其气敏传感器作用机理

采用静电纺丝法成功制备了Y掺杂的ZnO纳米纤维.并通过X射线衍射(XRD),扫描电子显微镜(SEM),能量色散X射线(EDX),透射电子显微镜(TEM)以及热重差热分析(TG-DTA)等手段对样品的结构和形貌进行了表征分析.同时用纯的ZnO和Y掺杂的ZnO纳米纤维制备了传感器,对浓度为(1-200)×10^-6 (体积分数)丙酮的气敏特性进行了测试分析.测试结果表明,可以通过简单控制纳米纤维中Y的含量,来微调该传感器的气敏特性.同时也发现通过Y掺杂, ZnO纳米纤维对丙酮的气敏特性有所改善,表现出很高的响应.纯ZnO和Y掺杂ZnO制成的传感器对几种潜在干扰气体表现出良好的选择性,比如氨气、苯、甲醛、甲苯以及甲醇.本文最后也讨论了该传感器的气敏作用机理.     

Synthesis of Poly（N-vinylpyrrolidone） Nanofibers Containing Gold Nanoparticles via Electrospinning Technique

Poly(N-vinylpyrrolidone)(PVP)nanofibers containing gold nanoparticles were prepared by electrospinning method.This simple route was used to prepare composites on a large scale,and the syntheses are simple.The optical property of gold nanoparticles in PVP aqueous solution was investigated by UV-Visible absorption spectra.The morphology of the fibers and the distribution of particles were characterized by transmission electron microscopy.The structure of the composite was characterized by Fourier transform infrared spectroscopy.     

纳米储能纤维复合过滤膜的制备及性能

以静电纺丝技术制备的同轴聚甲基丙烯酸十八烷基酯(PSMA)/聚对苯二甲酸乙二酯(PET)纳米储能纤维为支撑层,经聚偏氟乙烯(PVDF)涂覆成膜和溶剂化处理,制备了一种低压高水通量的纳米储能纤维复合过滤膜(NFCM),其中以水或乙醇为凝固溶液的复合过滤膜分别记为NFCM@H2O或NFCM@EtOH.分析并讨论了不同溶剂处理方式对NFCM力学性能和表面形貌的影响,表征了膜的纯水通量和抗污性能,用扫描电子显微镜(SEM)观察了膜的横断面形貌.结果表明,PSMA/PET纳米储能纤维具有明显的吸放热行为,熔融温度和热焓值分别为36.5℃和10.7J/g,NFCM的熔融温度和热焓值分别为36℃和2.7J/g.NFCM的形貌结构、纯水通量和截留率与溶剂处理方式相关,NFCM@EtOH膜的水通量介于100~1400L/(m2·h)之间,而NFCM@H2O膜的水通量仅在40~220L/(m2·h)之间.NFCM的拉伸强度由初始0.925MPa(PVDF)提高到4.28MPa以上.NFCM中的相变材料对膜过滤性能有重要影响,并在过滤温度低于50℃时具有减缓作用.     

Molybdenum Carbide‐Embedded Multichannel Hollow Carbon Nanofibers as Bifunctional Catalysts for Water Splitting

With the environmental pollution and non‐renewable fossil fuels, it is imperative to develop eco‐friendly, renewable, and highly efficient electrocatalysts for sustainable energy. Herein, a simple electrospinning process used to synthesis Mo₂C‐embedded multichannel hollow carbon nanofibers (Mo₂C‐MCNFs) and followed by the pyrolysis process. As prepared lotus root‐like nanoarchitecture could offer rich porosity and facilitate the electrolyte infiltration, the Mo₂C‐MCNFs delivered favourable catalytic activity for HER and OER. The resultant catalysts exhibit low overpotentials of 114 mV and 320 mV at a current density of 10 mA cm^?2 for HER and OER, respectively. Furthermore, using the Mo₂C‐MCNFs catalysts as a bifunctional electrode toward overall water splitting, which only needs a small cell voltage of 1.68 V to afford a current density of 10 mA cm^?2 in the home‐made alkaline electrolyzer. This interesting work presents a simple and effective strategy to further fabricating tunable nanostructures for energy‐related applications.     

Pt/TiO2纳米纤维的制备及其对甲醇的电催化氧化活性

采用静电纺丝技术结合还原浸渍法制备了Pt/TiO₂纳米纤维电催化剂, 通过X射线衍射(XRD)分析、扫描电镜(SEM)、透射电镜(TEM)和X射线能谱(EDS)等测试手段对样品的晶相、形貌、微结构和化学组成进行了表征. 测试结果表明, TiO₂纳米纤维为锐钛矿和金红石组成的混晶, Pt 纳米颗粒均匀地分布于TiO₂纳米纤维的表面, 且Pt 颗粒大小较均一, 平均粒径为4.0 nm, Pt/TiO₂纳米纤维中Pt 的质量分数约为20%. 采用三电极体系的循环伏安和计时电流电化学分析方法研究了样品在酸性溶液中对甲醇的电催化氧化活性, 结果表明, 与负载相同质量分数Pt 的Pt/P25 和商业Pt/C 催化剂相比较, Pt/TiO₂纳米纤维催化剂对甲醇呈现出较高的电催化氧化活性和更好的稳定性.     

High Strength Electrospun Single Copolyacrylonitrile (coPAN) Nanofibers with Improved Molecular Orientation by Drawing

High-performance carbon nanofibers are highly dependent on the performance of their precursors, especially polyacrylonitrile (PAN).In this work, the copolymer of PAN (coPAN) was synthesized for electrospinning. A self-assembling set-up was used for the stretching of single coPAN nanofibers. FTIR and Raman spectroscopies were used to characterize the chemical structure of coPAN nanofibers. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to monitor the morphology of single coPAN nanofibers under different drawing times. Micro-tensile test was used to determine the mechanical properties of single coPAN nanofibers. The results indicated that the drawing led to an increase in degree of molecular orientation along the fiber axis from 0.656 to 0.808, tensile strength from 304 MPa to 595 MPa, and modulus from 3.1 GPa to 12.4 GPa. This research would provide fundamental information of high-performance electrospun coPAN nanofibers and offer opportunities for the preparation of high-performance carbon nanofibers.     

Hydrothermal Synthesis of Ce-doped ZnO Heterojunction Supported on Carbon Nanofibers with High Visible Light Photocatalytic Activity

Ce/ZnO decorated carbon nanofibers(CNFs) heteroarchitectures(Ce/ZnO/CNFs) have been synthesized using electrospinning technique followed hydrothermal method, which have a high visible light photocatalytic activity. The samples were characterized by means of SEM, FTIR and XRD. The photocatalytic performance of Ce/ZnO/CNFs was tested with the methylene blue in the presence of visible light irradiation. In this work, we have analyzed the effects of Ce doping amount, initial methylene blue(MB) concentration and dosage of Ce/ZnO/CNFs on photocatalytic efficiency of the composite. The results showed that the photocatalyst containing 1.0% Ce in molarity(CZC1) obtained by autoclaving at 150℃ has the best photocatalytic degradation of MB than other as-synthesized samples. Ce/ZnO/CNFs catalysts exhibit a good stability and reusability, which would be an economical and environmentally friendly photocatalyst for various practical applications.     

碳源对鱼骨式纳米碳纤维及其负载的钯催化剂性能的影响

分别以甲烷、一氧化碳和乙烯为碳源合成了3种鱼骨式结构的纳米碳纤维(FCNF-C1,FCNF-CO和FCNF-C2),并作为载体制备了3种钯催化剂(Pd0.5%),考察了在对苯二甲酸加氢精制中的催化活性,通过N2吸附-脱附、X射线衍射、程序升温脱附、电子透射显微镜及CO化学吸附等方法对载体以及催化剂的结构进行了表征.结果表明,从不同碳源合成的纳米碳纤维(CNF)具有相似的直径和鱼骨式石墨层排列方式,但其物理化学性能差异较大,其中CO作为碳源得到的CNF具有最大的比表面积,最高的石墨化程度和最多的表面含氧基团;不同碳源的鱼骨式CNF负载的钯催化剂的活性为:Pd/FCNF-CO>Pd/FCNF-C1>Pd/FCNF-C2,与Pd分散度的顺序一致.CNF的织构、晶体结构和表面化学等协同载体效应,决定了Pd金属在CNF上的分散状态以及催化性能,而CNF的石墨层排列方式对其影响很小.     

Electrical Conductivity,Oil Absorption and Electric Heating of Carbon Black-modified Carbon Nanofibers

Carbon-black-modified carbon nanofibers were prepared by electrospinning, and the effects of the carbon black content and processing temperature on the physical and chemical properties of the resulting composites were investigated. The results showed that the conductivity of carbon-black-modified nanofibers increased with the carbon black content. The addition of carbon black in a 20% mass ratio increased the conductivity of the composite(0.75 S/cm) by 230% compared with the undoped nanofiber(2.47 S/cm), while the adulteration with 5% CB allowed the preservation of the mechanical properties of the composites. The fabricated carbon-black/carbon-nanocomposite fibers exhibited excellent oil absorption and electrothermal conversion performance. Furthermore, the conductivity and oil absorption capacity increased with increasing carbonization temperature. With a carbonization temperature of 1000℃(5% carbon black), the voltage was 31 V, the current was 0.66 A, and the surface temperature of the composite reached 234.1℃. The overall enhancement in physical properties upon the addition of even low amounts of carbon black makes these composites advantageous for future industrial applications.     

Carbon-Anchored Molybdenum Oxide Nanoclusters as Efficient Catalysts for the Electrosynthesis of Ammonia and Urea

The electrochemical NO₃⁻ reduction and its coupling with CO₂ can provide novel and clean routes to synthesize NH₃ and urea, respectively. However, their practical application is still impeded by the lack of efficient catalysts with desirable Faradaic efficiency (FE) and yield rate. Herein, we report the synthesis of molybdenum oxide nanoclusters anchored on carbon black (MoO_x/C) as electrocatalyst. It affords an outstanding FE of 98.14 % and NH₃ yield rate of 91.63 mg h⁻¹ mg_cat.⁻¹ in NO₃⁻ reduction. Besides, the highest FE of 27.7 % with a maximum urea yield rate of 1431.5 μg h⁻¹ mg_cat.⁻¹ toward urea is also achieved. The formation of electron-rich MoO_x nanoclusters with highly unsaturated metal sites in the MoO_x/C heterostructure is beneficial for enhanced catalytic performance. Studies on the mechanism reveal that the stabilization of *NO and *CO₂NOOH intermediates are critical for the NH₃ and urea synthesis, respectively.     

聚乙烯吡咯烷酮/四氧化三铁复合纳米纤维的制备与表征

采用静电纺丝方法制备了聚乙烯吡咯烷酮/四氧化三铁复合纳米纤维, 并用透射电子显微镜(TEM)、X射线衍射(XRD)、热失重分析(TGA)和振动磁力分析进行了表征, 探讨了复合物的结构及其性能.     

N-Doped Carbon Nanofibers Encapsulating CoO@Co9S8 Nanoparticles: Preparation from S-Rich Co32 Coordination Cluster Precursors by Electrospinning and Application for Superior Li-ion Storage

Thiacalixarene-supported Co₃₂nanoclusters encapsulated in polyacrylonitrile nanofibers(Co₃₂@PAN-NFs) by electrospinning have been utilized as precursors to fabricate N-doped CoO@Co₉S₈ carbon nanofibers(CoO@Co₉S₈@CNFs) for superior Li-ion storage. The S-rich Co₃₂ clusters capped by organic sheets afforded the well dispersed cobalt oxide/sulfide nanoparticles embedded in carbon nanofiber composites by direct calcination. The N-doped CoO@Co₉S₈@CNFs nanocomposites have been utilized as anode materials for lithium ion battery with the reversible capabilities being of 1051.8, 967.6, 894.7, 782.7, 669.5 and 525.4 mA·h/g at 0.1, 0.2, 0.5, 1, 2 and 3 A/g, respectively. The CoO@Co₉S₈@CNFs also showed a relatively high stable capacity of 551.7 mA·h/g at the current density of 1 A/g after 200 cycles of rate experiments. The as-obtained N-doped CoO@Co₉S₈@CNFs nanocomposites exhibited superior reversible capacity, rate performance, Coulomb efficiency(74.5% vs. 63.9%) and cyclic stability comparing with the CoO@Co₉S₈@C derived from simple annealing of Co₃₂ templates.