Synthesis of Carbon Nanohorns by Inductively Coupled Plasma

We demonstrate a new pathway for the synthesis of carbon nanohorns (CNHs) in a reactor by using inductively coupled plasma (ICP) and gaseous precursors. Thermal plasma synthesis allows the formation of different carbon allotropes such as carbon nanoflakes, hybrid forms of flakes and nanotubules, CNHs embryos, seed-like CNHs and onion-like polyhedral graphitic nanocapsules. In this study, pressure has the greatest impact on the selectivity of carbon nanostructures: pressure below 53.3 kPa favors the growth of carbon nanoflakes and higher pressures, 66.7 kPa and above, promotes the formation of CNHs. The ratio between methane and hydrogen as well as the global concentration of CH₄?+?H₂ inside the plasma flame are also crucial to the reaction. CNHs are formed preferentially by injection of a 1:2 ratio of H₂ to CH₄ at 82.7 kPa with a production rate of 20 g/h. The synthesis pathway is easily scalable and could be made continuous, which offers an interesting alternative compared to methods based on laser-, arc- or induction-based vaporization of graphite rods.

Graphical Abstract

     

单壁碳纳米管的CVD合成及管径分布

甲烷在以活性氧化铝为载体的Fe、Co、Ni、Ru等催化剂上于850 ℃分解并生成直径为0.8～5 nm的单壁碳纳米管.预先将催化剂在1100 ℃焙烧,能够减少产物中无定形碳的生成.拉曼光谱结果表明,由该法制备的碳纳米管的管径分布主要受温度的影响,较低温度有利于较小直径的单壁碳纳米管的生成和较好的管径选择性.     

单壁纳米碳管的纯化及表征

利用微孔膜及空气氧化法逐步除去电弧放电法制备的单壁纳米碳管(SWCNTs)中的金属催化剂粒子、碳纳米粒子、无定形碳等杂质,并利用热重分析（TGA）、高分辨透射电子显微镜（HRTEM）及拉曼（Raman）光谱,对每一步得到的产物进行分析表征.实验证明,该方法对单壁纳米碳管的纯化是比较有效的,可以得到纯度在90％以上的单壁纳米碳管.     

单壁碳纳米角的氧化、修饰及分散性

研究了影响单壁碳纳米角(SWNHs)分散性的因素, 并初步探讨了其分散机制, 通过氧化及表面修饰等方法增强了SWNHs在水和盐溶液中的分散性. 考察了溶液酸碱度和电解质浓度对SWNHs在水中的分散性以及吐温80对SWNHs在磷酸盐缓冲液(PBS)中的分散性的影响. 结果表明, pH值为6~10时, SWNHs分散良好; 电解质浓度越大, SWNHs的分散性越差; 吐温80能有效改善SWNHs在PBS中的分散性. 比较了3种SWNHs的氧化方法, 红外光谱、 X射线光电子能谱、 透射电镜、 粒度分析及Zeta电位分析结果表明, 氙灯催化过氧化氢氧化SWNHs的方法可引入大量含氧官能团, 显著提高了SWNHs在水中的分散性. 选择两亲性和生物相容性极好的羧基化磷脂聚乙二醇(DSPE-PEG-COOH)修饰氧化处理后的碳纳米角(SWNHox), 并从分散稳定性和Zeta电位两个方面进行了表征, 发现用DSPE-PEG-COOH修饰的SWNHox在PBS中的分散性良好. 该研究为SWNHs应用于药物转运和生物传感奠定了实验基础.     

Photosensitizing Electron Transfer Processes of Fullerenes,Carbon Nanotubes,and Carbon Nanohorns

In this account, studies on the photosensitizing electron transfer of nanocarbons, such as fullerenes, single‐walled carbon nanotubes (SWCNTs), and carbon nanohorns (CNH), performed in our laboratory for about 15 years in the early 21st century have been briefly reviewed. These novel nanocarbons act as excellent electron acceptors, when they are linked to light‐absorbing electron donors, such as porphyrins or phthalocyanines. For such molecule–nanocarbon hybrids, the direct confirmation of fast, transient, electron‐transfer phenomena must be performed with time‐resolved spectroscopic methods, such as transient absorption spectral measurements, in addition to fluorescence time‐profile measurements in the wide‐wavelength regions. Careful use of these methods affords useful information to understand photoinduced electron‐transfer mechanisms. In addition, kinetic data obtained by these methods can assist in the construction of light‐active devices, such as photovoltaic cells and solar H₂‐generation systems.     

单壁碳纳米管的控制生长与生长动力学

正结构决定性能,作为典型一维碳材料的单壁碳纳米管具有非常独特的光电性质,因而,单壁碳纳米管的结构控制制备一直是人们关注的热点问题,也成为该领域最具挑战的课题之一~(1,2)。目前,化学气相沉积方法是可控制备碳纳米管的主要方法,在化学气相沉积反应过程中,碳源在催化剂表面裂解成核,进而生长出结构不同、长度各异的单壁碳纳米管。为深入探索碳纳米管的生     

共价接枝硅酞菁-多壁碳纳米管的合成及光电性能

采用酰胺反应把硅酞菁(SiPc)共价接枝到多壁碳纳米管(MWCNT)上,得到MWCNT-Pc,用紫外可见,红外光谱,拉曼光谱,X射线光电子能谱,热重分析等进行了表征,结果表明碳纳米管上每约457个碳原子接枝一个酞菁分子;为研究共价接枝的MWCNT-Pc体系中光激发的电子流动情况,探讨了Pc静电组装到MWCNT后的荧光淬灭的情况,结果显示SiPc的光激发电子向MWCNT转移;同时采用喷涂法构筑了ITO/MWCNT-Pc光电极,并在光伏电池中研究了其光电性能,在AM1.5光照条件下,光电流及光电压分别为0.434 V和0.158 mA·cm-2,在320 nm处的IPCE达19.8%。本研究目的在于制备碳纳米管衍生物并构筑基于碳管的复杂的功能纳米结构材料,为其应用奠定基础。     

单壁碳纳米角电化学应用

单壁碳纳米角具有独特的性质,如大的比表面积、良好的导电性和生物相容性等,在某些领域应用广泛. 本文结合作者课题组工作,综述了单壁碳纳米角电化学应用现状,并展望其今后的发展趋势.     

Electrochemical Properties of Nanocomposite Based on Polytriphenylamine Derivative and Single-Walled Carbon Nanotubes

One-step synthesis of the stable dispersion of conjugated poly(4,4',4"-tris(N,N-diphenylamine) triphenylamine)—single-walled carbon nanotubes nanocomposite is carried out by the oxidative polymerization of the monomer of the triphenylamine derivative with a high density of free radicals of 4,4',4"- tris(N,N-diphenylamine)tripenylamine in the presence of the single-walled carbon nanotubes in concentrated formic acid. Benzoyl peroxide is used as an oxidant. Electroconductive film coatings are prepared by applying stable dispersion onto the Ni substrate. The coatings show a high specific electrochemical capacity and stability in long-term cycling in the aprotic 1 M LiClO₄/propylene carbonate electrolyte.

     

Carbon Nitride Nanowire Bundle and Tubes：Solid-state Synthesis,Characterization and Photoluminescent Properties

Graphite-like carbon nitride nanowire bundles were synthesized from melamine via the solid state thermolysis at relatively low temperature(400 °C).Hexagonal carbon nitride tubes were prepared for the first time by heating the nanowire bundles at 550 °C in argon atmosphere.The forming process of tubes and transformation of the molecular structures from s-triazine rings to tri-s-triazine units were analyzed.The blue and yellow-green emission photoluminescent(PL) properties of the products were investigated in...     

共振增强拉曼光谱技术在单壁碳纳米管表征中的应用

共振增强拉曼光谱技术是表征和研究单壁碳纳米管(SWNTs)的有力工具, 它既能用于SWNTs的几何结构表征, 又能反映SWNTs的电子态密度信息. 特别指出的是, 由于共振拉曼效应, 它能够灵敏地检测单根SWNT的局域信息. 本文首先概述了SWNTs拉曼光谱的RBM峰、G峰、D峰和G'峰的特征和应用, 然后综述了共振增强拉曼光谱在SWNTs的结构表征、形变测量、缺陷测量和温度测量中的应用和进展, 最后讨论了共振拉曼光谱在SWNTs表征方面所面临的机会和挑战.     

Individualized p‐Doped Carbon Nanohorns

A facile approach to individualize spherically aggregated pristine carbon nanohorns (pr‐CNHs) was established. Specifically, we found that treatment of pr‐CNHs with chlorosulfonic acid generates positively charged polarized species, which disintegrate toward individualized carbon nanohorns (in‐CNHs). Interestingly, the isolated in‐CNHs were revealed to be p‐doped owing to the adsorption of chlorosulfonate units. The findings were confirmed by data derived from high‐resolution transmission electron microscopy imaging, Raman and ultraviolet photoemission spectroscopy, and additionally supported by theoretical calculations and thermogravimetry.     

碳微线圈的合成、表征及形态研究

以镍为催化剂,在助剂噻吩的作用下,采用乙炔高温热解法合成了规则、均匀、具有双螺旋结构的碳微线圈.用同一次实验所得的产物,从水平与垂直两个方向研究了碳微线圈形态的变化与分布规律,并进一步通过改变反应器的结构做了比较实验,结合SEM,TEM,SAED和XRD等表征手段对这一规律进行分析研究.结果表明,反应气流的流向以及催化剂在反应过程中发生的物理和化学变化是导致碳微线圈形态变化的两个重要原因.另外,对碳微线圈的结构、生长机理以及噻吩的作用进行了初步研究.     

乙炔二茂铁的合成表征和电化学性质测定

选择了一条反应条件温和且比较经济的反应途径,在惰性气氛中合成了一系列二茂铁衍生物的重要合成中间体——乙炔二茂铁。通过UV、IR、^1H NMR对化合物进行了表征,运用CV测定了电化学性质。该实验作为综合化学实验,有助于学生了解化学研究的一般过程,掌握惰性气氛合成技术及柱色谱分离方法,提高学生综合分析问题和解决问题的能力。     

无机-无机纳米复合材料的构筑与性能

无机-无机纳米复合材料以其独特的光学、电学、催化性能和广泛的应用受到人们的关注,成为纳米材料领域的研究热点.本论文主要研究了核壳结构的二氧化硅/银复合材料的制备和性能.     

Salen型化合物的合成、表征及性质

设计合成了两种新型Salen配体H2L1(N,N?-3-二甲氧基-邻羟苯亚甲基-4,5-二甲氧基-1,2-苯二胺)、H2L2(N,N?-3-二甲氧基-邻羟苯亚甲基-4,5-二硝基-1,2-苯二胺)及相应的镍、铜、锌金属配合物ML1、ML2(M=Ni,Cu,Zn),并分别采用核磁共振(1HNMR)波谱、紫外-可见(UV-Vis)吸收光谱、红外(IR)光谱、质谱(MS)和元素分析进行了表征.探究了配体及其配合物的荧光性质.研究发现,与H2L1相比,配体H2L2由于引入强的吸电子基团―NO2,其荧光强度减弱.相对于配体,锌离子的配位则导致其配合物的荧光强度增强,而镍和铜离子的嵌入则使得配合物ML1、ML2(M=Ni,Cu)荧光猝灭.对电化学性质的研究表明,CuL1的氧化还原过程为准可逆的单电子过程;与H2L2相比,配体H2L1由于引入强的给电子基团―OCH3,其溶液的导电性降低.     

Gemini表面活性剂的合成、表征及性能测定——油田化学专业综合实验

介绍一个油田化学专业综合实验,通过该实验可了解Gemini表面活性剂的发展现状,掌握阳离子型Gemini表面活性剂BQAS的合成及纯化方法,了解结构表征的原理和方法,掌握表面性能和缓蚀性能的评价方法。     

电弧放电法制备大面积高纯单壁碳纳米管薄膜

介绍了一种制备大面积高纯度单壁碳纳米管(SWCNT)薄膜的新方法. 利用改进的电弧放电法, 在真空放电室内分别安装两枚石墨极板, 使之形成一个球冠型电容器. 使用这种新型装置, 可以在两枚球冠型石墨极板之间产生一个合适的附加电场和成膜基板, 通过控制放电时间, 可在阴极的球冠型石墨极板上制备出厚度从数微米至1毫米不等的SWCNT薄膜. 场发射扫描电子显微镜(FESEM)、高分辨透射电子显微镜(HRTEM)、拉曼光谱和热重分析(TGA)的表征结果表明, 这个方法可以高效地制备具有高纯度的SWCNT薄膜.     

单根(7,5)蛇形单壁碳纳米管的拉曼光谱(英文)

研究了单根(7,5)蛇形单壁碳纳米管的拉曼光谱特征,观察到了环呼吸振动峰(RBM)、环呼吸振动的倍频峰(2RBM)、介于中间频率的振动峰(IMF)、无规振动峰(D)、剪切振动峰(G)、中间频率振动峰(M)、剪切振动和环呼吸振动的和频峰(G+RBM)、面内横向光学声子和纵向声学声子的和频峰(iTOLA)、无规振动的二次共振峰(G′或者2D)以及其它一些归属不清楚的拉曼峰.不同激发波长和不同激发偏振拉曼光谱研究表明,这些拉曼光谱峰显示出了非常强的激发能量和激发偏振的选择性.     

Immobilization and Characterization of Glucose Oxidase on Single-Walled Carbon Nanotubes and Its Application to Sensing Glucose

The negatively charged （at pH 8.2） glucose oxidase （GOx, pI ca. 4.2） was assembled onto the surface of single-walled carbon nanotubes （SWNT）, which was covered （or wrapped） by a layer of positively charged polyelectrolyte poly（dimethyldiallylammonium chloride） （PDDA）, via the electrostatic interaction forming GOx-PDDASWNT nanocomposites. Fourier transform infrared （FTIR）, UV-Vis and electrochemical impedance spectroscopy （EIS） were used to characterize the growth processes of the nanocomposites. The results indicated that GOx retained its native secondary conformational structure after it was immobilized on the surface of PDDA-SWNT. A biosensor （Nafion-GOx-PDDA-SWNT/GC） was developed by immobilization of GOx-PDDA-SWNT nanocomposites on the surface of glassy carbon （GC） electrode using Nafion （5%） as a binder. The biosensor showed the electrocatalytic activity toward the oxidation of glucose under the presence of ferrocene monocarboxylic acid （FcM） as an electroactive mediator with a good stability, reproducibility and higher biological affinity. Under an optimal condition, the biosensor could be used to detection of glucose, presenting a typical characteristic of Michaelis-Menten kinetics with the apparent Michaelis-Menten constant of KM^app ca. 4.5 mmol/L, with a linear range of the concentration of glucose from 0.5 to 5.5 mmol/L （with correlation coefficient of 0.999） and the detection limit of ca. 83 μmol/L （at a signal-to-noise ratio of 3）. Thus the biosensor was useful in sensing the glucose concentration in serum since the normal glucose concentration in blood serum was around 4.6 mmol/L. The facile procedure of immobilizing GOx used in present work would promote the developments of electrochemical research for enzymes （proteins）, biosensors, biofuel cells and other bioelectrochemical devices.