邻仲丁基苯酚在多壁碳纳米管修饰碳糊电极上电化学行为的研究

研究了邻仲丁基苯酚(osBP)在多壁碳纳米管修饰碳糊电极(MWCNTs/CPE)上的电化学行为。结果表明:在pH=8.0的B-R缓冲溶液中,osBP在MWCNTs/CPE上发生的氧化反应是一个受扩散控制的不可逆等电子等质子过程。氧化峰电流与osBP浓度在1.0×10-6～2.0×10-4 mol/L之间呈良好的线性关系(R2=0.9990),检出限(S/N=3)为1.15×10-7 mol/L。建立的差分脉冲伏安法用于水样分析,加标回收率为85.3%～98.0%。     

Nafion-多壁碳纳米管复合膜修饰玻碳电极测定岩白菜素的研究

研制了以Nafion分散多壁碳纳米管的化学修饰电极,研究了岩白菜素在该修饰电极上的电化学行为和电化学动力学性质.发现修饰电极对岩白菜素有显著的电催化作用,岩白菜素的氧化过程是单电子单质子过程,岩白菜素在该修饰电极上的扩散系数、速率常数分别为6.02×10~(-6) cm~2·s~(-1)、5.54×10~(-3) mol·L~(-1)·s~(-1). 通过优化各项参数,建立了一种直接测定岩白菜素的电分析方法.该方法的线性范围为1.44×10~(-7) ～1.92×10~(-6) mol·L~(-1)和4.18×10~(-5) ～1.06×10~(-4) mol·L~(-1),检出限为1.02×10~(-7) mol·L~(-1),同支电极测定10次的相对标准偏差为4.6%,可用于岩白菜素样品的含量测定.     

掺杂硒修饰碳糊电极伏安法测定对乙酰氨基酚

采用循环伏安法制备了掺杂硒修饰碳糊电极,用循环伏安法和差分脉冲伏安法研究了对乙酰氨基酚在掺杂硒修饰碳糊电极上的电化学行为,建立了掺杂硒修饰碳糊电极测定对乙酰氨基酚的电化学方法。在pH 4.6的0.1mol·L-1乙酸-乙酸钠缓冲溶液中,对乙酰氨基酚在+0.61V呈现一个灵敏的氧化峰。对乙酰氨基酚的浓度在6.0×10-7~1.5×10-4 mol·L-1范围内与其氧化峰电流呈线性关系,检出限(3s/k)为2.8×10-7 mol·L-1。方法用于药品中对乙酰氨基酚的测定,测定结果与药典法测定值相符,测定值的相对标准偏差(n=5)在2.1%~2.5%之间。     

聚L-半胱氨酸/多壁碳纳米管复合修饰电极同时测定邻苯二酚和对苯二酚

将羧基化多壁碳纳米管分散在L-半胱氨酸溶液中并滴涂在玻碳电极表面.将上述电极在pH 6.9的B-R缓冲溶液中,于-1.0～2.5 V的电位范围内进行电聚合,制备了聚L-半胱氨酸/多壁碳纳米管复合修饰电极(Pol-L-Cys/MWCNTs/GCE).研究发现,邻苯二酚和对苯二酚在聚L-半胱氨酸/多壁碳纳米管复合修饰电极上分别出现了一对氧化还原峰,且两者的氧化峰电位差达101 mV,提出了用微分脉冲伏安法同时测定邻苯二酚和对苯二酚的方法.氧化峰电流与邻苯二酚和对苯二酚的浓度在1.0×10-5～1.0×10-3mol·L-1呈线性关系,检出限(3S/N)均达1.0×10-5mol·L-1.修饰电极用于模拟样品中邻苯二酚和对苯二酚的测定,回收率在82.0%～107.0%之间.     

多壁碳纳米管修饰电极差分脉冲伏安法测定酪氨酸

制备了多壁碳纳米管修饰玻碳电极,研究了酪氨酸在该电极上的电氧化行为并优化了测定条件.试验表明:与裸玻碳电极相比,该修饰电极明显降低了酪氨酸的氧化电位,提高了酪氨酸的氧化峰电流;利用差分脉冲伏安法测定其峰电流和酪氨酸的浓度在3.0×10-6～1.0×10-4mol·L-1范围内呈线性关系,检出限(S/N=3)为1.6×10-7mol·L-1;一些常见物质对测定无干扰.此方法已应用于人尿中酪氨酸的测定,测定结果的相对标准偏差(n=6)在3.1%～4.5%之间,加标回收率在93.8%～111.8%之间.     

6-巯基嘌呤在多壁碳纳米管修饰玻碳电极上的电化学行为及其分析应用

将固体多壁碳纳米管置于10g·L-1叫六偏磷酸钠溶液中,通过超声搅拌制成均匀分散的悬浮液.取此悬浮液10μL,滴加于经抛光的玻碳电极的表面,在红外灯下烘干后即制成多壁碳纳米管修饰的玻碳电极(CNT/GCE).在pH 7.0的磷酸盐缓冲介质中,6-巯基嘌呤(6-MP)在0.357 V(vs.Ag/AgC1)处出现一灵敏的氧化峰,其峰电流(Ip)与6-MP浓度在5×10-7～1×10-4mol·L-1叫之间呈线性关系,检出限为5.0×10-8mol·L-1.应用此方法测定了3个模拟血清样品中6-MP含量,并测得方法的回收率在98.0%～104.7%之间.在6-MP浓度水平为1×10-5mol·L-1叫的条件下,测得方法的RSD(n=10)为4.2%.     

纳米CeO2修饰碳糊电极微分脉冲伏安法对盐酸克伦特罗的测定

研究了盐酸克伦特罗(CLB)在纳米CeO2修饰碳糊电极上的电化学行为.结果表明:在0.10 mol·L-1的HClO4溶液中,CLB于+0.40 V(vs SCE)左右处产生1对准可逆的氧化还原峰.与裸碳糊电极相比,CLB在修饰电极上的电流响应明显增大,据此建立了尿样中CLB的微分脉冲伏安测定方法.线性范围为5.0×10-9 ～6.0×10-6 mol·L-1(r=0.998 2,n=7),检出限为2.5×10-9 mol·L-1(3sb),加标回收率为96% ～104%.     

盐酸左氧氟沙星在聚L-精氨酸/多壁碳纳米管修饰电极上的电化学行为

运用循环伏安法、线性扫描伏安法、计时电量法等研究了盐酸左氧氟沙星在聚L-精氨酸/多壁碳纳米管修饰电极上的电化学行为。实验表明:盐酸左氧氟沙星在聚L-精氨酸/多壁碳纳米管修饰电极上的电极反应过程为等电子等质子吸附控制的不可逆过程,在pH=6.0的Na2HPO4-NaH2PO4支持电解质中,其氧化峰电流与浓度在7.0×10-6~1.0×10-4mol·L-1范围内呈良好的线性关系,相关系数R为-0.9992,检出限为5.0×10-6mol·L-1,样品测定回收率为98.26%~101.70%。     

辣根过氧化物酶在碳纳米管-离子液体修饰碳糊电极上的直接电化学研究

以室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐([EMIM]PF6)为粘合剂与多壁碳纳米管(Multi-walled carbon nanotubes,MWCNTs)、石墨粉相混合制备新型碳糊电极,并在该电极表面修饰辣根过氧化物酶(HRP)制成新型碳糊酶电极(HRP-MWCNTs-CILE)。应用循环伏安法(CV)和计时电流法(it)研究了该修饰电极的直接电化学行为。结果表明,该修饰电极在pH 6.0的0.05 mol/L磷酸缓冲溶液中,其循环伏安曲线上出现了1对准可逆的氧化还原峰,为HRP中Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰。该修饰电极对过氧化氢具有良好的催化活性、抗干扰能力和稳定性。在最佳条件下,修饰电极对H2O2的测定线性范围为7.0×10-6~3.0×10-3mol/L,检出限(S/N=3)为2.5×10-6mol/L。该传感器具有制备简单、成本低廉、响应快等特点,具有较好的应用前景。     

碳纳米管-离子液体-木质素磺酸钠复合物修饰电极同位镀铋膜测定水中铅和镉

采用涂覆法制备多壁碳纳米管(MWCNTs)-离子液体([BMIM]PF6)-木质素磺酸钠(LSS)修饰玻碳电极(GCE),然后在其表面同位镀铋膜,研究Pb(Ⅱ)和Cd(Ⅱ)在该修饰电极上的阳极溶出伏安行为。实验表明,Pb、Cd在该修饰电极上分别于-0.44V、-0.73V产生灵敏的溶出峰,Pb(Ⅱ)和Cd(Ⅱ)分别在3.0×10-8～1.0×10-6mol·L-1和2.0×10-8～8.0×10-7mol·L-1浓度范围内与其溶出峰电流呈良好的线性关系,检出限分别为4.1×10-9mol·L-1、6.9×10-9mol·L-1。该修饰电极制备简单,重现性好,用于河水中铅和镉的测定,效果良好。     

The Colloidal Stabilization of Carbon with Carbon: Carbon Nanobubbles as both Dispersant and Glue for Carbon Nanotubes

The superior physical properties of carbon nanotubes (CNTs) have led to their broad application. Intrinsically, CNTs tend to agglomerate from hydrophobic interactions, which is highly undesirable for solution processing and device fabrication. Commonly, a stabilizer consisting of organic surfactants or polymers is used to disperse CNTs. Recently, we synthesized nitrogen‐doped carbon hollow nanospheres (25–90 nm), termed carbon “nanobubbles”. They bear superior dispersability in water and distinctive graphitic order. Herein, we describe the nanobubble‐assisted dispersion of CNTs in aqueous solution upon sonication. This process relies on the π–π interaction between the two aromatic carbon nanostructures, which can process their carbon mixture in water into conductive filter membranes, ink, and discs. This stabilization can be extended to other aromatic carbons. In addition, the π–π interaction may create a new type of carbon p–n junction that can be used to improve charge separation.     

Adsorption of Carbon Dioxide on Activated Carbon

The adsorption of CO2 on a raw activated carbon A and three modified activated carbon samples B, C, and D at temperatures ranging from 303 to 333 K and the thermodynamics of adsorption have been investigated using a vacuum adsorption apparatus in order to obtain more information about the effect of CO2 on removal of organic sulfur-containing compounds in industrial gases. The active ingredients impregnated in the carbon samples show significant influence on the adsorption for CO2 and its volumes adsorbed on modified carbon samples B, C, and D are all larger than that on the raw carbon sample A. On the other hand, the physical parameters such as surface area, pore volume, and micropore volume of carbon samples show no influence on the adsorbed amount of CO2. The Dubinin-Radushkevich (D-R) equation was the best model for fitting the adsorption data on carbon samples A and B, while the Preundlich equation was the best fit for the adsorption on carbon samples C and D. The isosteric heats of adsorption on carbon samples A, B, C, and D derived from the adsorption isotherms using the Clapeyron equation decreased slightly increasing surface loading. The heat of adsorption lay between 10.5 and 28.4 kJ/mol, with the carbon sample D having the highest value at all surface coverages that were studied. The observed entropy change associated with the adsorption for the carbon samples A, B, and C (above the surface coverage of 7 ml/g) was lower than the theoretical value for mobile adsorption. However, it was higher than the theoretical value for mobile adsorption but lower than the theoretical value for localized adsorption for carbon sample D.     

一维新型碳的同素异形体:碳链

碳链是一种完全一维的、具有电子轨道sp杂化结构的新型碳的同素异形体。正是由于碳链的独特的一维结构,使其拥有区别于富勒烯、石墨烯和碳纳米管的化学键,从而表现出更加优异的性能,如:理论预言碳链的机械强度是石墨烯的几倍;碳链的导热也类似于石墨烯和碳纳米管;碳链是具有直接带隙的半导体材料,且带隙的大小可以通过其长度来调控,其长度越长,带隙越小。尽管关于碳链的研究早在19世纪已经启其端绪,但是一直进展缓慢。直到近期,关于碳链的研究才有了几次突破性的进展,引起了学术界的广泛讨论。本文介绍了碳链的概念、结构和特殊的物理性质,在此基础上进一步介绍了碳链的几种典型的合成方法以及应用前景,重点阐述了近期碳链研究上的几次重大突破,并对于碳链研究的未来进行了展望,希望能引起国内外同行的关注。     

Growth of Single-walled Carbon Nanotubes on Substrates Using Carbon Monoxide as Carbon Source

The growth of single-walled carbon nanotubes(SWCNTs) on substrates has attracted great interests because of the potential applications in various fields. Carbon monoxide(CO) was used as the carbon source for the growth of SWCNTs on silicon substrates. Random or oriented SWCNTs can be produced by varying the CO flow rate. When the flow rate of CO was as low as 20 sccm(sccm:standard cubic centimeter per minute), dense SWCNT networks with clean surface were produced. When the flow rate was above 50 sccm, vertically aligned SWCNT(VA-SWCNT) arrays were grown. Well-aligned VA-SWCNT arrays were obtained in the temperature range of 650-800℃ and the content of large-diameter(above 1.7 nm) tubes in the array increased with the temperature. The height of the array was affected by the growth temperature, the CO flow rate, and the growth time. These findings indicate CO can be used as an efficient carbon source for the growth of SWCNTs on substrates under low flow rates.     

埃洛石纳米管模板法一步法制备一维碳纳米管/碳纳米棒混合纳米碳材料

利用埃洛石纳米管(HNTs)特有的中空纳米结构,以及丰富的界面化学性质,以聚乙烯醇(PVA)为碳源,采用浸渍填充纳米孔方法实现了一步制备一维碳纳米管(CNTs)/碳纳米棒(CNRs)混合纳米碳材料。考察模板剂(HNTs)和碳源(PVA)之间的比例关系对混合纳米碳材料的结构影响,利用XRD、FTIR、Raman、N2吸附-脱附测试、TEM、SEM以及电阻率和分散性等表征手段分析混合纳米碳材料的结构变化。结果发现,PVA填充含量的增加将导致产物中CNRs的质量分数增加;当PVA和HNTs质量之比为1∶1时,所制备的CNTs/CNRs的孔体积达到最大值2.142 cm~3·g-1,比表面积达到583 m~2·g-1,并且表现出较好的电导率和分散性,表明低的PVA填充比例制备的混合碳材料中CNTs含量较高。     

Ni/γ-Al2O3催化剂上CH4-CO2重整体系中积碳-消碳的研究

用动态热重技术和色谱技术联用以及XRD和TEM等表征手段,研究了Ni/γ-Al     

二氧化碳与低碳经济发展

由于二氧化碳无色无味,又存在于大气中,因此它在植物生长中的重要性被人类忽略了。其实二氧化碳是光合作用的反应物,是植物生长的重要原料;又是一种新型绿色肥料。人类应该着力开发以二氧化碳为原料的新型肥料发展低碳经济。     

Carbon clusters

Some of the most significant discoveries and achievements concerning the mass spectra and gas phase ion chemistry of carbon clusters are reviewed. These include (1) nanosecond and femtosecond laser ionizations; (2) ion structures through ion/molecule reactions, ion chromatography, and computational methods; (3) carbon cluster cooling through radiative decay, dissociative decay, and thermionic emission; (4) mechanisms and energetics of fragmentation reactions; (5) endohedral fullerenes including recent data on ion beam implantation, and (6) ion chemistry as a function of the fullerene charge state.     

碳纳米管含量对炭炭复合材料组织及力学性能的影响

炭纤维上原位合成了均匀生长且具有伸张形貌的碳纳米管,借助化学气相渗透制备了碳纳米管增强的炭炭复合材料,研究了不同含量的碳纳米管对炭炭复合材料组织和力学性能的影响。结果表明：炭纤维上生长碳纳米管改变了热解炭的沉积行为,诱导了各向同性热解炭的生成,且随着碳纳米管含量的增加,各向同性热解炭的厚度增加,但是复合材料的d002值却明显降低。微量的碳纳米管即可显著提高复合材料的力学强度,随着其含量的增加,复合材料的力学强度和模量迅速提高,但材料的断裂行为却急剧恶化,断裂模式由最初的假塑性断裂转变为脆性断裂。     

Palladium-Catalyzed Addition of Carbon Monoxide and Carbon Tetrachloride to 1-Octene in Supercritical Carbon Dioxide

The Pd-catalyzed addition of carbon monoxide and carbon tetrachloride to 1-octene gave coadduct [alkyl 2-( 2, 2, 2-trichloroethyl)octanoate] as the major product in supercritical carbon dioxide by using pyridine as the base. It was found that the selectivity and the yield of coadduct were greatly affected by the pressure of carbon dioxide, the reaction temperature and the amounts of alcohol and base used.