化学镀镍法制备碳纳米管

以PdCl2为活化液,用化学镀镍法制备了具有活性中心的镀镍硅模板,通过催化裂解在镀镍硅模板上制备了碳纳米管。讨论了化学镀工艺参数对镀镍硅模板表面活性中心的尺寸和分布的影响。最佳的工艺条件为:在0.17mol·L-1的SnCl2中敏化10min,0.4g·L-1PdCl2中活化2min,50℃施镀3min所得的镍粒子活性中心的粒径为200nm~300nm。用扫描电镜观察到碳纳米管为竹节形状,直径为100nm~110nm。     

焙烧法纯化多壁碳纳米管

自碳纳米管[1 ] 发现以来 ,已在世界范围内掀起了碳纳米管研究和应用的热潮 .其中一些文献报道了纯化单壁碳纳米管的方法 ,如超声波助滤法 [2 ] ,酸洗法 [3,4] ,微孔膜过滤法 [5,6] ,离心法[5] ,氧化法[5,7] ;另有少量文献报道了纯化多壁碳纳米管的方法 ,如氧化法 [5,8] ,石墨插层化合物纯化法 [9] 等 .本文使用焙烧法纯化实验室自制的多壁碳纳米管 .通过 TEM、XRD和比表面积等的测定 ,考察了不同焙烧时间的纯化效果 .采用催化甲烷裂解方法 ,在 6 0 0℃反应 4h制得多壁碳纳米管 ,粗产物收率接近 2 0 % .于干燥、洁净的坩埚中 ,分别称取 6…     

Lix54-100从氨性蚀铜废液中萃取回收铜

我国目前处理印制线路板 (ｐｒｉｎｔｉｎｇｃｉｒｃｕｉｔｂｏａｒｄ ,ＰＣＢ)铜氨蚀刻液废液的方法大多数是通过酸化、碱化等法[1 - 4 ] 使铜从溶液中沉淀出来 ,这需要消耗大量试剂 ,而且处理后的废水不能回用 ,只能排放 ,洗涤沉淀还会产生废水。溶剂萃取法处理ＰＣＢ铜氨蚀刻废液是国外应用的主要处理方法[5] ,可以在回收铜的同时回用蚀刻剂 ,国内刚开始研究[6] 。研究应用较多的萃取剂是Ｌｉｘ5 4 [6 - 9] ,本文探讨用Ｌｉｘ5 4 - 1 0 0从氨性蚀铜废液中萃取回收铜的影响因素。1　实验部分由分析纯的晶体氯化铜与氨水配制成一定浓度的氨…     

n型金刚石薄膜催化生长碳纳米管

研究了n型金刚石薄膜作为催化剂生长碳纳米管的方法.首先采用丙酮裂解化学气相沉积(CVD)法制备均匀的n型金刚石薄膜,然后采用乙醇为碳源的CVD法,在850、900和950℃下,分别在n型金刚石薄膜上制备了碳球、竹节状碳管和多壁碳纳米管.所得产物用扫描电子显微镜、透射电子显微镜、拉曼光谱和X射线光电子能谱表征.实验结果表明产物的形貌与反应温度有关.我们还提出了与金刚石催化生长碳纳米管结果相符的实验机理.     

V2O5电致变色薄膜的Raman光谱

近年来,通过向过渡金属氧化物薄膜注入Ｌｉ 制作可调节光透过率的电变色器件已越来越引起广泛的重视[1、2].由于Ｖ2Ｏ5薄膜的稳定性差,限制了它在实际中的应用.因此,为了获得变色效率高、稳定性和可逆性能好的Ｖ2Ｏ5薄膜,使用了多种制备方法,如磁控溅射法[3、6]、电化学沉积法[7、8]、溶胶凝胶法[9、10]、旋涂法[11、12]、真空蒸镀法[13、14]等.但是,无论那种方法都要解决Ｖ2Ｏ5本身在Ｈ2Ｏ或醇等的电解质溶液中电致变色时的溶解问题,通常采用控制薄膜的沉积温度或者退火处理来提高薄膜的电致变色性能[3、4、11].为了探明薄膜结构与电致变色…     

PANI/MWCNT电极在硫酸锂溶液中电容性能

化学氧化法制备聚苯胺/多壁碳纳米管复合材料(PANI/MWCNT),扫描电镜(SEM)、XRD及IR表征样品结构及形貌,电化学方法测定复合电极循环伏安曲线、恒流充放电曲线及电极交流阻抗.结果表明,PANI/MWCNT电极在1mol/L的Li2SO4溶液中具有较好电容性能,在电流密度为5mA/cm2时,比电容为412F/g.PANI/MWCNT电极较PANI电极有更好的大电流放电能力,50mA/cm2下复合电极的比电容仍达318F/g,为5mA/cm2时该电极比电容的77.2%,而PANI电极的比电容仅为其5mA/cm2时的56.2%.交流阻抗证明碳纳米管降低复合电极的电阻,显著提高大电流放电能力.     

真空加热活化法提高内嵌钴粒子的碳纳米管的水裂解产氢催化活性

采用真空加热活化法制备出高催化活性的内嵌金属钴纳米粒子的碳纳米管材料.通过增加碳纳米管材料的本征碳缺陷位点,显著提升了材料的催化活性(7倍).高分辨透射电子显微镜(HRTEM)、X射线光电子能谱(XPS)和拉曼(Raman)光谱表征结果显示,真空加热活化增加了碳纳米管的本征碳缺陷,并减少了碳纳米管碳层的杂原子含量.电化学表征和电催化水裂解实验结果表明,增加碳纳米管的本征碳缺陷位既可以在碳纳米管上产生更多的催化位点,又可以提高碳纳米管界面的电荷迁移能力,进而提高对水裂解的催化性能.     

程序升温氧化法测定碳纳米管的纯度

利用不同形态碳有不同氧化温度的特性，采用程序升温氧化法，以铂电阻丝热导池为检测器，以纯氧为载气和反应气，通过对碳纳米管(CNTs)与其中夹杂的其它形态碳氧化后生成的二氧化碳气体谱图的测量，达到对CNTs纯度进行定量分析的目的。在氧化升温速度为10℃／min，氧气流量30mL／min～35mL/min的实验条件下，测定用催化裂解法制备的多壁碳纳米管(MWNTs)和单壁碳纳米管(SWNTs)的纯度(纯化后纯度)分别为98．81％和79．47％。     

微波等离子体辅助化学气相沉积法低温合成定向碳纳米管阵列

自碳纳米管被发现以来[1] ,这种准一维纳米新材料由于其优异的力学、电学、储氢等理化性质而显示出非常重要的理论研究与实际应用价值[2 ,3] .碳纳米管阵列更可作为场致发射器件 ,有望应用于冷阴极平板显示器或纳米电子学等前沿领域[4 ] ,成为碳纳米管研究中的热点 .在已有报道的多种制备碳纳米管阵列的方法中 ,以孔性硅或孔性 Al2 O3作为模板剂 ,通过化学气相沉积制备的方法较为普遍[5～ 7] ,但此类方法往往需要在较高温度 (高于 70 0℃[6 ,7] )下进行 ,对于碳纳米管阵列最诱人的应用前景之一平板显示器而言 ,要求在显示玻璃表面直接生长…     

铝基板的界面扩散对薄膜型TiO2光催化活性的影响

以钛酸四丁酯为前驱体, 采用溶胶-凝胶法在铝基板表面制备了纳米晶TiO2薄膜. 运用XRD、SEM和XPS对制得的薄膜进行表征, 并测试了薄膜光催化降解亚甲基蓝(MB)的活性. 结果表明, TiO2薄膜样品在450 ℃焙烧30 min后, 晶粒排列比较致密, 粒径为10-20 nm, 并与铝基板紧密结合; 薄膜与铝基板发生了明显的界面扩散, 薄膜中的Al元素来自铝基板的界面扩散, 且界面层很宽, 扩散层厚度约为75 nm; 界面扩散的发生直接导致了TiO2薄膜的光催化活性下降. 但随着薄膜厚度增加, 铝基板对TiO2薄膜降解亚甲基蓝催化活性的影响不断减小.     

Ru/CNFs 催化剂催化氨分解制氢

 研究了鱼骨式碳纤维 (CNFs) 和管式碳纤维 (CNTs) 负载 Ru 催化剂的氨分解反应活性. 结果表明, Ru/CNFs 催化剂上氨分解活性高于 Ru/CNTs 催化剂. 通过改变 Ru 负载量或载体表面的含氧基团来调节 Ru 的粒径. Ru 的活性位随着 Ru 颗粒尺寸的增大而增加. CNFs 上的含氧基团对 Ru 颗粒的氨分解活性影响很大. 在相同粒径的 Ru 颗粒上, CNFs 表面的含氧基团增加了 Ru 的活性.     

Co1-xS-MnS@CNTs/CNFs的制备及其氧还原电催化性能

氧还原反应是燃料电池中重要的阴极反应,但由于动力学迟缓等问题导致其效率低。碳基材料具有导电性高、稳定性好、比表面积大等优点,常被应用于电催化氧还原反应。然而其在电催化氧还原反应中效率较低,对碳基材料进行Co、Mn掺杂有望提高其氧还原效率。本文采用静电纺丝技术制备出含有Co,Mn双金属的碳纳米纤维,经热解和硫化后碳纳米纤维上形成许多包裹Co_1-xS和MnS纳米颗粒的碳纳米管（记为Co_1-xS-MnS@CNTs/CNFs）,垂直生长在碳纳米纤维表面。通过X射线衍射、场发射扫描电子显微镜、高分辨透射电子显微镜、X射线光电子能谱对Co_1-xS-MnS@CNTs/CNFs的形貌、结构和组成进行表征,发现仅在Co_1-xS和MnS同时存在的情况下碳纳米纤维表面才能生长碳纳米管。小颗粒的MnS为碳纳米管的生成提供成核位点,大颗粒的Co_1-xS促进碳纳米管生长,最终形成Co_1-xS-MnS@CNTs/CNFs。碳纳米管的形成不仅在金属颗粒表面形成一道屏障,防止其聚集、溶解,而且提高了碳纳米纤维的导电性,使其电催化性能及稳定性得到很大提升。电催化测试证明,Co_1-xS-MnS@CNTs/CNFs相较于不含金属的碳纳米纤维（CNFs）及含单金属的硫化锰碳纳米纤维（MnS/CNFs）或硫化钴碳纳米纤维（Co_1-xS/CNFs）具有更优异的电催化氧还原（ORR）性能,且在氧还原反应过程中表现出高效的四电子转移。其甲醇耐受性及长期稳定性显著优于商业Pt/C电催化剂。     

Nanostructured films from phthalocyanine and carbon nanotubes: surface morphology and electrical characterization

We report on the investigation of the surface morphology and DC conductivity of nanostructured layer-by-layer (LbL) films from nickel tetrasulfonated phthalocyanine (NiTsPc) alternated with either multi-walled carbon nanotubes (MWNTs/NiTsPc) or multi-walled carbon nanotubes dispersed in chitosan (MWNTs+Ch/NiTsPc). We have explored the surface morphology of the films by using fractal concepts and dynamic scale laws. The MWNTs/NiTsPc LbL films were found to have a fractal dimension of ca. 2, indicating a quasi Euclidean surface. MWNTs+Ch/NiTsPc LbL films are described by the Lai-Das Sarma-Villain (LDV) model, which predicts the deposition of particles and their subsequent relaxation. An increase in the wetting contact angle of MWNTs+Ch/NiTsPc LbL films was observed, as compared with MWNTs/NiTsPc LbL films, which presented an increase in the fractal dimension of the first system. Room temperature conductivities were found be ca. 0.45 S/cm for MWNTs/NiTsPc and 1.35 S/cm for MWNTs+Ch/NiTsPc.     

Rapid in situ growth of oriented titanium‐nickel oxide composite nanotubes arrays coated on a nitinol wire as a solid‐phase microextraction fiber coupled to HPLC–UV

An oriented titanium‐nickel oxide composite nanotubes coating was in situ grown on a nitinol wire by direct electrochemical anodization in ethylene glycol with ammonium fluoride and water for the first time. The morphology and composition of the resulting coating showed that the anodized nitinol wire provided a titania‐rich coating. The titanium‐nickel oxide composite nanotubes coated fiber was used for solid‐phase microextraction of different aromatic compounds coupled to high‐performance liquid chromatography with UV detection. The titanium‐nickel oxide composite nanotubes coating exhibited high extraction capability, good selectivity, and rapid mass transfer for weakly polar UV filters. Thereafter the important parameters affecting extraction efficiency were investigated for solid‐phase microextraction of UV filters. Under the optimized conditions, the calibration curves were linear in the range of 0.1–300 μg/L for target UV filters with limits of detection of 0.019–0.082 μg/L. The intraday and interday precision of the proposed method with the single fiber were 5.3–7.2 and 5.9–7.9%, respectively, and the fiber‐to‐fiber reproducibility ranged from 6.3 to 8.9% for four fibers fabricated in different batches. Finally, its applicability was evaluated by the extraction and determination of target UV filters in environmental water samples.     

Nickel oxide coated on ultrasonically pretreated carbon nanotubes for supercapacitor

Nickel oxide/carbon nanotubes (NiO/CNTs) composite materials for supercapacitor are prepared by chemically depositing nickel hydroxide onto carbon nanotubes pretreated by ultrasonication and followed by thermal annealing at 300 °C. A series of NiO/CNTs composites with different weight ratios of nickel oxide versus carbon nanotubes are synthesized via the same route. The high-resolution TEM and SEM results show that a lot of nicks, which favored the nucleation of the nickel hydroxide formed on the outer walls of carbon nanotubes due to ultrasonic cavitations, and then nickel oxide coated uniformly on the outer surface of the individual carbon nanotubes. The NiO/CNTs electrode presents a maximum specific capacitance of 523 F/g as well as a good cycle life during 1,000 cycles in 6 M KOH electrolyte. The good electrochemical characteristics of NiO/CNTs composite can be attributed to the three-dimensionally interconnected nanotubular structure with a thin film of electroactive materials.     

碳纳米管表面的无钯活化化学镀镍研究

本文提出碳纳米管表面无钯活化的化学镀镍方法.碳纳米管经硝酸氧化和碱中和后表面生成羧基,利用羧基吸附镍离子,之后吸附的镍离子被化学还原为镍的纳米微粒并成为化学镀镍的催化活性中心.红外吸收光谱和电子显微镜观察等证实了上述活化过程的机理.实验表明,新的活化方法对碳纳米管表面化学镀是切实可行的,文中同时对化学沉积层的不同形貌进行讨论.     

Enhanced Conductivity and mechanical properties of polyimide based nanocomposite materials with carbon nanofibers via carbonization of electrospun polyimide fibers

Carbon nanofibers (CNF) have been obtained by the thermal treatment of the electrospun polyimide fibers in our present work. The carbon structure and surface morphology of the as-received CNFs were investigated using X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Investigations of the nanocomposite materials fabricated using these CNFs as conductive fillers and polyimide as matrix show that the presence of CNFs can improve both the mechanical and electrical properties of the material. The conductivity of the nanocomposite films increases with increases in the CNF content and a percolation threshold of about 6.3 vol % (0.0785 in weight fraction) is calculated according to percolation theory.     

Adsorption of ammonia and water on functionalized edge-rich carbon nanofibers

The preparation, characterization and ammonia and water adsorption properties of edge-rich carbon nanofibers (CNFs) were studied, including platelet CNFs (PCNFs) and cup-stacked CNFs (CSCNFs). Since PCNFs and CSCNFs have many chemically active exposed edges, functionalization by oxidizing the edges was carried out by ozone stream and by nitric acid. Transmission electron microscopy, N₂ adsorption isotherms and temperature-programmed desorption analysis showed that the nitric acid treatment partly destroyed the graphite structure of the PCNFs and created acid functional groups and micropores, whereas the ozone treatment created functional groups without damaging the structure. Ammonia adsorption isotherms clarified that NH₃ adsorption on PCNFs and CSCNFs occurred mainly on oxygen-containing groups, whereas the adsorption on activated carbon fibers (ACFs) occurred on both oxygen-containing groups and the carbon surface without the functional groups, and the CSCNFs showed larger amounts of adsorbed ammonia compared to the PCNFs. Especially at a relatively low pressure range (<0.2 atm), the PCNFs/CSCNFs/ACFs showed the same ammonia adsorption mechanism; that is, the one-to-one interaction between oxygen atoms in the functional groups and hydrogen atoms in ammonia molecules. In addition, the adsorption on the ACFs appeared to occur mainly by interaction with the carbon surface at relatively high pressure (0.3–1.0 atm). Our experimental results and previous findings suggest that NH₃ adsorption on PCNFs is due mainly to NH…O hydrogen bonding between oxygen-containing groups and ammonia rather than to chemical bonding.     

不同活性炭负载的镍基催化剂上废塑料裂解制碳纳米管性能

以椰壳炭、竹炭和木炭三种活性炭为载体,采用浸渍法制备炭负载金属镍的催化剂,考察其在废塑料裂解制备碳纳米管过程中的催化反应性能;采用X射线衍射、扫描电镜、透射电镜、拉曼光谱仪、同步热分析仪、比表面积分析仪等手段分析了催化剂和产物碳纳米管的形貌和结构。结果表明,椰壳活性炭为载体制备的镍基催化剂上碳纳米管产量最高、石墨化程度最好。以椰壳活性炭为载体制备的镍基催化剂为例,研究了反应温度和镍负载量对其催化性能的影响。     

水热条件下碳纳米管/硫氧镁化合物纳米复合材料的制备和表征

碳纳米管(CNT)因其完美的结构,优良的力学性能以及低的密度[1~3]而将会成为一种新型的结构复合材料增强剂。可是,研究发现,碳纳米管几乎不溶于所有的溶剂,而且,在结构复合材料中,碳纳米管与基体没有很好的连接性[4]。这些都很大的阻碍了碳纳米管在结构复合材料中的应用。为了解