可用至3.5 V的碳纳米管阵列超级电容器

应用化学气相沉积在钽片和不锈钢片表面直接生长碳纳米管阵列(CNTA)制备超级电容器电极,并分别作正、负极组装有机体系扣式电容器.扫描电子显微镜、循环伏安、恒电流充放电和交流阻抗表征、测试材料的微观形貌和电化学性能.结果表明,该电容器可获得高达3.5 V的工作电压,较长的循环寿命,较好的倍率性能.基于CNTA质量的比功率和比能量性能分别为928 kW.kg-1和19 Wh.kg-1.     

聚苯胺改性氮掺杂碳纳米管制备及其超级电容器性能

利用苯胺原位化学聚合合成聚苯胺包覆碳纳米管(CNTs), 再炭化处理制备氮掺杂碳纳米管(NCNTs).激光拉曼(Raman)光谱和X射线光电子谱(XPS)分析及透射电镜(TEM)观察表明, 苯胺包覆碳纳米管经炭化处理后, 得到以碳纳米管为核、氮掺杂碳层为壳, 具有核-壳结构的氮掺杂碳纳米管, 而碳纳米管本征结构未遭破坏. 研究表明, 随着苯胺用量的增大, 氮掺杂碳纳米管的氮掺杂碳层变厚, 氮含量从7.06%(质量分数)增加到8.64%, 而作为超级电容器电极材料, 随着氮掺杂碳层厚度降低, 氮掺杂碳纳米管在6 mol·L^-1氢氧化钾电解液中的比容量从107 F·g^-1增大到205 F·g^-1, 远高于原始碳纳米管10 F·g^-1的比容量, 且聚苯胺改性氮掺杂碳纳米管表现出较好的充放电循环性, 经1000次充放电循环后仍保持初始容量的92.8%~97.1%, 表明氮掺杂碳纳米管不仅通过表面氮杂原子引入大的法拉第电容和改善亲水性使电容量显著增大, 其具有的核壳结构特征也使循环稳定性增强。     

MnO2电沉积直立碳纳米管制备超级电容器

以直立碳纳米管为基底,以pH=6.0的0.1 mol/L Na2SO4为底液,采用电化学沉积法在0.2 mol/L Mn(CH3COO)2溶液中制备了直立碳纳米管与MnO2复合材料. SEM测试结果表明,复合材料表面呈现多孔状结构. 通过循环伏安、恒流充放电、交流阻抗等电化学方法对复合材料修饰电极进行电容性质测试. 结果表明,在1 mol/L KCl溶液中,0～0.6 V(vs.Ag/AgCl参比)电位窗口内此复合材料表现出优良的超电容性能. 直立碳纳米管电极的比电容为16 F/g,在碳纳米管表面沉积上MnO2修饰层后,复合材料电极的比电容增大至330 F/g,比电容量大幅提升近20倍. 同时扫描200圈后,直立碳纳米管与MnO2复合材料的循环伏安曲线变化很小,具有相当好的循环寿命和电容稳定性能.     

MnO2电沉积直立碳纳米管制备超级电容器的研究

以直立碳纳米管为基底,以pH=6.0的0.1mol/L Na2SO4 为底液,采用电化学沉积法在0.2 mol/L Mn(CH3COO)2溶液中制备了直立碳纳米管与二氧化锰复合材料。SEM测试结果表明复合材料表面呈现多孔状结构。通过循环伏安,恒流充放电,交流阻抗等电化学方法对复合材料修饰电极进行电容性质测试。实验结果表明,在1mol/L KCl 溶液中,0-0.6V(vs. 银/氯化银参比)电位窗口内此复合材料表现出优良的超电容性能。直立碳纳米管电极的比电容为16 F/g,在碳纳米管表面沉积上二氧化锰修饰层后,此复合材料电极的比电容增大至330 F/g,比电容量大幅提升近20倍。同时扫描200圈后,直立碳纳米管与二氧化锰复合材料的循环伏安曲线变化很小,说明其具有相当好的循环寿命和电容稳定性能。     

碳纳米管用作超级电容器电极材料

碳纳米管由于具有化学稳定性好、比表面积大、导电性好和密度小等优点,是很有前景的超级电容器电极材料。本文介绍了碳纳米管用作超级电容器电极材料的研究现状,总结了单纯碳纳米管电极材料和碳纳米管复合物电极材料的特点与性能,并探讨了今后碳纳米管电极材料的发展方向。     

基于碳纳米管的超级电容器研究进展

综述了基于碳纳米管及其复合材料作超级电容器的电极材料的研究现状,通过对碳纳米管的改性或与其它材料复合,能有效地提高电容器的电容特性。总结了近几年来在开发超级电容器电极材料领域中对碳纳米管的活化和提高碳纳米管的分散性技术、碳纳米管与过渡金属氧化物复合材料、碳纳米管与导电聚合物复合材料以及碳纳米管与石墨烯复合材料研究的进展。     

载氧化钌碳纳米管超级电容器电极

研究了一种采用溶胶-凝胶方法制备超细氧化钌粉末的新方法，该方法制备的氧化钌电极材料在250 ℃热处理后具有570 F•g－1的比电容量并具有典型的多孔特征.通过在碳纳米管表面化学沉积氧化钌的方法制备了不同成分的氧化钌/碳纳米管复合电极,并探讨了其电化学伏安特性和直流充放电特性.该复合电极具有高能量密度特性，同时还具有良好的高功率放电特性.     

直立碳纳米管超级电容器的研究

在石英玻璃基底上,以酞菁裂解法低压气相沉积制备大面积管径均匀、长度一致的直立碳纳米管.分别应用电解质溶液浸润、酸处理和循环伏安扫描等3种不同方法纯化活化该直立碳纳米管,并以活化后的碳纳米管作为原型超级电容器的电极.循环伏安扫描和交流阻抗测试表明,CV曲线呈近似矩形,交流阻抗最大相位角超过80°,该直立碳纳米管的比电容为16~32F/g,乃超级电容器理想的电极材料.     

氧化镍/碳纳米管复合型超级电容器的研制

通过电化学阴极还原的方法制备了氧化镍电极材料。经250℃脱水处理后氧化镍材料表现出法拉第赝电容的电化学特性且材料单电极比容量达到210F·g^-1，优于普通活性炭材料。本文采用催化裂解法制备了碳纳米管电极材料，比容量达到了42F·g^-1。提出了采用电化学法沉积氧化镍和碳纳米管分别作为电容器正负极的新工艺，该工艺制备的复合型超级电容器的工作电位达到了1.6V，且具有良好的大电流放电特性。实验还表明该型氧化镍超级电容器具有极低的自放电率。     

多壁碳纳米管阵列电极的循环伏安行为

用化学气相沉积法在多孔氧化铝模板中沉积有序碳纳米管阵列并制成电极.由循环伏安法实验得知,扩散控制电位下的电活性离子难以常规的扩散速度到达碳纳米管的内壁深处,绝大部分的碳纳米管内壁面积在这样的实验条件下未能充分利用,但临近管口处的一部分内壁对扩散有一定的贡献.对于电极/电解质界面的双电层电容而言,碳纳米管的所有内壁都有所贡献,其电容量可达68.7mF*cm-2(表观面积),表明碳纳米管电极具有制作超级电容器的重要应用价值.     

Facile Approach to Conductive Diamond Submicro-rods Arrays and Their Field Emission Properties

The authors presented a facile approach to prepare highly-ordered sub-micrometer scaled cylindrical diamond arrays based on a chemical vapor deposition method,where the accurate control of the style of crystal seeds dispersion and the growth time are very crucial.The as-prepared diamond array showed good conductivity which was originated from the proper boron doping,and moreover,it exhibited good field emission property with low turn-on field and high emission current.Importantly,this approach can be easily...     

低热固相法制备纳米MnO2/CNT超电容复合电极的循环稳定性

为了改善纳米MnO2超级电容器电极的充放电循环稳定性,以Mn(OAc)2·4H2O、NH4HCO3和碳纳米管(CNT)为原料,采用低热固相反应得到前驱体,再经焙烧和酸处理,制备了一系列CNT含量不同的纳米MnO2/CNT复合电极材料,并用X射线衍射(XRD)、透射电镜(TEM)和Brunauer-Emmett-Teller(BET)比表面积测定方法对其进行了表征.XRD分析结果表明,复合材料中的MnO2为纳米γ-MnO2.研究了复合电极在1 mol·L-1 LiOH电解质中的电化学性能,并与不含CNT的纯纳米MnO2电极进行了比较.结果表明,含CNTs为10%(w,质最分数,下同)和20%的MnO2/CNT复合电极的循环稳定性远优于纯纳米MnO2电极的循环稳定性,其中含10%CNTs的MnO2/CNT复合电极不仪具有良好的循环稳定性,而且在1000 mA·g-1高倍率充放电条件下仍具有200 F·g-1的高比电容.     

低热固相法制备纳米MnO2/CNT超电容复合电极的循环稳定性

To improve the charge/discharge cycle stability of a nanostructured manganese dioxide electrode for supercapacitor applications, a series of nano-MnO2/carbon nanotube (CNT) hybrid electrode materials with different mass fractions of CNTs were prepared. The materials were prepared using a room-temperature solid-grinding reaction betweenMn(OAc)2·4H2Oand NH4HCO3 in the presence of CNTs to obtain a precursor. This was followed by calcination and an acid-treatment process and the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) surface analysis. XRD results indicated that the MnO2 in the composites was nanostructured 酌-MnO2. Electrochemical performance of the MnO2/CNT composite electrodes in 1 mol·L-1 LiOH alkaline aqueous electrolyte was studied and compared to a pure nano-MnO2 electrode without CNTs. The MnO2/CNT composite electrodes with 10% or 20% (w, mass fraction) CNTs showed far superior cycle stability than the pure MnO2 electrode. The MnO2/CNT composite electrode with 10% CNTs exhibited good cycling stability and also a high specific capacitance of 200 F·g-1 at a high charge/discharge current rate of 1000 mA·g-1.     

Controlled Synthesis of Water‐Dispersible Faceted Crystalline Copper Nanoparticles and Their Catalytic Properties

We report a solution‐phase synthetic route to copper nanoparticles with controllable size and shape. The synthesis of the nanoparticles is achieved by the reduction of copper(II) salt in aqueous solution with hydrazine under air atmosphere in the presence of poly(acrylic acid) (PAA) as capping agent. The results suggest that the pH plays a key role for the formation of pure copper nanoparticles, whereas the concentration of PAA is important for controlling the size and geometric shape of the nanoparticles. The average size of the copper nanoparticles can be varied from 30 to 80 nm, depending on the concentration of PAA. With a moderate amount of PAA, faceted crystalline copper nanoparticles are obtained. The as‐synthesized copper nanoparticles appear red in color and are stable for weeks, as confirmed by UV/Vis and X‐ray photoemission (XPS) spectroscopy. The faceted crystalline copper nanoparticles serve as an effective catalyst for N‐arylation of heterocycles, such as the C? N coupling reaction between p‐nitrobenzyl chloride and morpholine producing 4‐(4‐nitrophenyl)morpholine in an excellent yield under mild reaction conditions. Furthermore, the nanoparticles are proven to be versatile as they also effectively catalyze the three‐component, one‐pot Mannich reaction between p‐substituted benzaldehyde, aniline, and acetophenone affording a 100 % conversion of the limiting reactant (aniline).     

Facile Fabrication of Nanoparticles Confined in Graphene Films and Their Electrochemical Properties

The development of novel nanostructured electrode materials with high performance and based on abundant elements is a key element in the societal pursuit of sustainable energy. Graphene‐based structures with rich macroporosity and high conductive networks are promising components to develop novel electrode materials. Herein, we described a facile procedure to confine Ni(OH)₂ particles in a graphene film, leading to a new sandwich‐like hybrid structure. The hybrid film offers simultaneously ordered ion diffusion channels and high electrical conductivity, which facilitate the improvement of both electrode kinetics and electrochemical stability, thus leading to high capacitance, fast rate capability, and stable cycle life as supercapacitor materials. This work provides a facile pathway for optimized structures for electrode materials, and represents a benefit for the global issues of energy shortage and environmental pollution.     

Hydroxyl-terminated Polyethylenes Bearing Functional Side Groups: Facile Synthesis and Their Properties

A series of hydroxyl-terminated polyethylenes(HTPE) bearing various functional side groups(e.g. carboxyl, ester and butane groups)were synthesized by the combination of ring-opening metathesis polymerization(ROMP) and visible light photocatalytic thiol-ene reaction. The products are named as α,ω-dihydroxyl-poly[(propionyloxythio)methinetrimethylene](HTPE~(carboxyl)), α,ω-dihydroxyl-poly[(methylpropionatethio)methinetrimethylene](HTPE~(ester)) and α,ω-dihydroxyl-poly[(butylthio) methinetrimethylene](HTPE~(butane)), respectively. The investigation of ROMP indicated that the molecular weight of resultant hydroxyl-terminated polybutadiene(HTPB) can be tailored by varying the feed ratios of monomer to chain transfer agent(CTA). The exploration of the photocatalytic thiol-ene reaction between HTPB precursor and methyl 3-mercaptopropionate revealed that blue light as well as oxygen accelerated the reaction. 1 H-NMR and ~(13) C-NMR results verified all the double bonds in HTPB can be modified, and the main chain of resultant polymer can be considered as polyethylene. Subsequently, relationship between the structure of side groups and the thermal properties of functional PEs was studied. And the results suggested that the T_g was in the order of HTPE~(butane)HTPE~(ester)HTPE~(carboxyl). Greater interaction between side groups resulted in higher T_g. Moreover, all the functional PE samples exhibited poor thermostability as compared to HTPB. Finally, the promising applications for functional PEs were explored. HTPE~(carboxyl) can be utilized as a smart material with p H-responsive properties due to its p H-dependent ionization of carboxyl side groups. HTPE~(butane) can be employed as a macro-initiator for building the triblock copolymer due to the presence of active hydroxyl end groups. HTPE~(ester) can serve as a plasticizer for PVC which can enhance the ductility of PVC without obviously sacrificing strength.     

氧化镍的合成及其超级电容性能

采用直接沉淀法制备了β-Ni(OH)2前驱体,经热处理后得到样品粉末。采用XRD、SEM和BET测试技术对样品进行了物性表征。结果表明,样品为立方相的NiO。用循环伏安、恒流充放电和交流阻抗研究了其超级电容性能。结果表明,所制备的NiO具有典型的法拉第赝电容特性。当pH值为11～12,沉淀温度为30℃条件下制备出Ni(OH)2前驱体,经300℃热处理3h后得到的NiO的比容量最大。当充放电电流密度为3×10-3A/cm2时,电极材料的比容量达到346F/g,电极电化学反应的电极电阻和液接电阻分别为0.24和0.085Ω,且具有良好的循环寿命。5×10-3A/cm2循环100次后,比电容为291.5F/g,充放电效率为93.5%。     

CuO纳米结构阵列的简易合成及其光催化性质

利用一种简便的一步反应路线, 通过调节反应温度, 选择性地合成出两种有序排列的氧化铜纳米阵列, 即成束的一维(1D)纳米带和紧密排列的二维(2D)纳米片. 系统研究了产物的物相和形貌随反应时间的演变情况, 结果表明两种氧化铜纳米结构阵列分别是通过氧化→生长→脱水和氧化→脱水→生长过程形成的, 其中动力学因素控制的成核与生长过程决定了氧化铜纳米结构的最终形貌. 模拟太阳光辐射光催化降解有机染料罗丹明B(RhB), 测试了所制备的氧化铜纳米结构阵列的光催化活性. 本工作为制备新颖的多级纳米结构材料提供了一种简单且经济的合成路线, 这些纳米材料将在多个领域体现出重要的应用潜力.     

银通孔阵列的模板电沉积制备及折射率传感性能

以聚苯乙烯微球的单层和双层胶体晶体为模板,通过模板电沉积银,移除模板后得到单层和双层银通孔阵列,并用作基于增强光透射(EOT)的等离子传感器.结果表明,与单层银通孔阵列相比,双层通孔阵列的传感灵敏度和品质因子都有很大提升,最高分别达到559.71 nm/RIU(RIU:Refractive index unit)和14.28 RIU~(-1).     

1,2-二芳基乙炔的简便合成及其结构与性能关系研究

1,2-Diarylacetylenes have been synthesized by a facile method consisting of an addition of diaryl ketone with acetyl chloride and the elimination of resultant ethene chloride. Correlation between physical properties and structure of the 1,2-diarylacetylene has been studied by differential scanning calorimeter （DSC）, refractor and electro-optical parameter test instrument. The results show that birefringence was increased with inserting cyclohexyl into the skeleton, but mesophase range, melting and clearing points were reduced with introducing the ethylene bridge in the molecule, and birefringence, viscosity, clearing point and mesophase range could all be decreased with perfluoro alkyl/alkoxyl terminal instead of alkyl/alkoxyl moiety.