卤离子调控的镍钴基电极材料生长及电容影响研究

超级电容器是很有发展潜力的电化学储能器件,其性能主要取决于电极材料。利用水热法,通过改变加入的卤离子（F^-、Cl^-、Br^-）种类,可以简便地对镍钴（NiCo）基超级电容器电极材料的形貌、物相以及化学组成进行调控。由X射线衍射（XRD）和扫描电镜（SEM）等表征结果可知,F^- 诱导生成纳米片支撑纳米线阵列,成分为稳定的NiCo LDH结构;Cl^-/Br^- 诱导生成纳米线,成分为碱式碳酸钴。从电化学测试结果可知,形貌和晶型对电化学性能有显著的影响。其中Cl^- 调控的电极在120 ℃下反应3 h时,其形貌为纳米线,晶型偏向无定形,此时性能最优;在2 mA/cm²电流密度下不仅具有最大的面积比电容2 940 mF/cm²,且该电极与负极活性炭组装的器件具有1.8 V的大电压窗口和优异的循环稳定性。     

晶须形中空多孔氮掺杂复合碳电极材料的制备及电化学性能研究

中空多孔碳因其低密度、大孔容、高比表面积以及优良的电导率,被视为一种理想的电负极材料。以纳米碳酸钙晶须为模板剂,负载聚多巴胺薄膜与氧化石墨烯,作为碳源与氮源,制备出晶须形中空多孔碳材料（Cw-GO）,应用于锂离子电池负极。碳化过程中,碳酸钙晶须经高温分解释放出大量二氧化碳,刺破碳前体壳层,具有高效扩孔功能。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、氮气吸附-脱附仪对样品形貌和结构进行了表征,利用循环伏安（CV）、阻抗谱（EIS）、循环充放电（GCD）对样品进行电化学性能检测。结果表明,复合材料Cw-GO在500 mA·g^-1的电流密度下,其初始放电比容量可达到1185.9 mA·h·g^-1,在循环200次后,比容量为921.8 mA·h·g^-1,库仑效率基本保持在99.4%,表现出优异的电化学性能。     

Preparation and characterization of covalently bonded biopolymer-polypyrrole hybrid materials

The synthesis of biopolymer-polypyrrole hybrid materials that can possess electrical conducting has been the focus of our laboratory. To date, we have only obtained intimate blends that at best, display ionic bonding interactions. In this paper we report on the preparation of biopolymer-polypyrrole hybrid materials with covalent bonding between the two polymer chains. This has been achieved by preparing several functionalized pyrrole monomers, followed by covalently bonding of these monomer to the biopolymer and finally, polymerizing the pyrrole monomer. The pyrrole monomers used were 4-(3-pyrrolyl)oxobutyric acid, 4-(3-pyrrolyl)butyric acid, 3-(3-pyrrolyl)propylamine and the biopolymers were collagen and chitosan. FTIR data show the presence of covalent bonding between the two polymer chains.     

Preparation and characterization of carbon nanofiber reinforced thermoplastic polyurethane nanocomposites

The effect of CNFs on hard and soft segments of TPU matrix was evaluated using Fourier transform infrared (FTIR) spectroscope. The dispersion and distribution of the CNFs in the TPU matrix were investigated through wide angle X‐ray diffraction (WAXD), field emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM), polarizing optical microscope (POM), and atomic force microscope (AFM). The thermogravimetric analysis (TGA) showed that the inclusion of CNF improved the thermal stability of virgin TPU. The glass transition temperature (T_g), crystallization, and melting behaviors of the TPU matrix in the presence of dispersed CNF were observed by differential scanning calorimetry (DSC). The dynamic viscoelastic behavior of the nanocomposites was studied by dynamical mechanical thermal analysis (DMTA) and substantial improvement in storage modulus (E') was achieved with the addition of CNF to TPU matrix. The rheological behavior of TPU nanocomposites were tested by rubber processing analyzer (RPA) in dynamic frequency sweep and the storage modulus (G') of the nanocomposites was enhanced with increase in CNF loading. The dielectric properties of the nanocomposites exhibited significant improvement with incorporation of CNF. The TPU matrix exhibits remarkable improvement of mechanical properties with addition of CNF. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of well‐controlled porous carbon nanofiber materials by varying the compatibility of polymer blends

The relationships between the compatibility in binary polymer blends and the pore sizes of carbon nanofibers (CNFs) prepared from the blends were investigated. Compatibility was determined by the difference between the solubility parameters of each polymer in the polymer blends. Porous CNFs were prepared by an electrospinning and carbonization process using binary polymer blends, consisting of polyacrylonitrile (PAN) as the carbonizing polymer and poly(acrylic acid) (PAA), poly(ethylene glycol), poly(methyl methacrylate) or polystyrene (PS) as the pyrolyzing polymer. The pore size of the CNFs increased with increasing difference in solubility parameter. The CNFs prepared using the PAN/PAA blend, which had the smallest solubility parameter difference, exhibited a pore size of 1.66 nm compared to 18.24 nm for the CNFs prepared using the PAN/PS blend. The prepared CNF webs with controlled meso‐sized pores showed a stable cycle performance in cyclic voltammetry measurements and improved impedance characteristics. This method focusing on the compatibility in polymer blends was simple to apply and effective for controlling the pore sizes and surface area of CNFs for application as electrode materials in energy storage systems. © 2013 Society of Chemical Industry     

Electrospun carbon nanofiber web electrode: Supercapacitor behavior in various electrolytes

Carbon nanofibers (CNFs) draw great interest due to their noticeable mechanical, electrochemical, and physical properties. In this study, polyacrylonitrile‐based CNFs are obtained via electrospinning technique. Thermal oxidation and low temperature (950 °C) carbonization are applied to the electrospun web in order to achieve CNF. Through the process, Fourier transform infrared‐attenuated total reflectance spectroscopy and Raman spectroscopic results are investigated. The electrochemical properties of the self‐standing CNF webs are examined with electrochemical impedance spectroscopy and cyclic voltammetry. In addition, various electrolyte solutions are studied to investigate the capacitive behavior of CNF webs. Electrolyte type variation has a significant effect on the capacitance results and high capacitance values are achieved in aqueous solution. According to the differing electrolyte types, specific capacitance values (C_sp) are recorded between 204 and 149 F g^?1 where maximum specific capacitance is obtained in 0.5 M H₂SO₄ as 204 F g^?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45723.     

ZnO/PAN基纳米碳纤维膜的制备及其光催化性能的研究（英文）

采用N,N-二甲基甲酰胺(DMF)为极性溶剂溶解醋酸锌(Zn(Ac)_2·2H_2O),然后加入聚丙烯腈(PAN)制得前驱体溶液,采用静电纺丝法制备PAN/Zn(Ac)_2复合纳米纤维膜,将PAN/Zn(Ac)_2复合纳米纤维膜在真空管式炉中经过高温煅烧得到PAN基碳纤维/氧化锌(CF/ZnO)纳米纤维膜,以CF/ZnO纳米纤维膜为光催化剂,亚甲基蓝为污染物,进行光催化降解实验,研究了Zn(Ac)_2含量对PAN/Zn(Ac)_2复合纳米纤维形貌、性能的影响,以及CF/ZnO纳米纤维膜的光催化性能。结果表明:Zn(Ac)_2的掺入并未对PAN的化学结构产生影响,二者属于物理结合,Zn(Ac)_2能较均匀地分布在纤维的内部;随着Zn(Ac)_2含量的增加,CF/ZnO纳米纤维膜对亚甲基蓝的降解率会提高,当Zn(Ac)_2质量分数(相对PAN)为60%时,可见光照射80 min后CF/ZnO纳米纤维膜对亚甲基蓝的降解率达到91.6%。     

新型介孔碳的制备、功能化及应用研究进展

综述了模板法制备孔径可调、高比表面积的介孔碳的合成路线,并介绍了介孔碳的功能化改性方法。同时对其在吸附剂、电极材料、催化材料领域的应用进展进行了概述,最后对介孔碳未来发展的潜在挑战及前景进行了讨论。     

Amorphous carbon nitride thin films for electrochemical electrode: Effect of molecular structure and substrate materials

We report on the effect of molecular structure and substrate material on amorphous carbon nitride (a-CN:H) electrode properties including film adhesion to the substrate and electrochemical properties. Films were prepared by neutral beam enhanced chemical vapor deposition on different substrate materials (p-type Si, Cu, Ti, and Pt) below room temperature. When depositing on Si, doping nitrogen into carbon improved the electrochemical properties despite weak adhesion to the substrate. Nitrogen in a-CN:H formed two different bonding configurations: incorporation into aromatic carbon rings and hydrogen nitride by infrared (IR) spectroscopy. Therefore, delocalization of π bonds by incorporation of nitrogen affected the electrochemical improvement of the a-CN:H electrode. For samples deposited on a different metal substrate, the adhesion to substrate increased as a function of decreasing oxygen concentration on the metal substrate surface; the Pt substrate performed well with no delamination in our evaluation. The electrochemical properties were improved only in the case of deposition on Pt. Moreover, Pt surface modification by hydrogen beam was also effective; consequently, the electrochemical property of the a-CN:H electrode was superior to the graphite electrode with high temperature annealing. The observed increases in IR spectra of aromatic clusters were in line with the electrochemical improvements of a-CN:H.     

新型介孔碳的制备、功能化及应用研究进展

综述了模板法制备孔径可调、高比表面积的介孔碳的合成路线,并介绍了介孔碳的功能化改性方法。同时对其在吸附剂、电极材料、催化材料领域的应用进展进行了概述,最后对介孔碳未来发展的潜在挑战及前景进行了讨论。     

四氧化三钴超级电容器电极材料的制备与研究

电极材料是决定电化学电容器性能的一个主要方面,研究与开发高性能的电极材料是人们的研究重点之一.碳电极材料比电容较小;钌等贵重金属氧化物电极材料比电容量虽然很高,但昂贵的价格限制了其实际应用.因此价格低廉、环境友好、同样具有较高氧化还原电容的过渡金属氧化物成为目前超级电容器的研究热点之一.以硝酸钴为原料,以柠檬酸为模板水热合成了前驱体,200 ℃热处理后得到了四氧化三钴.循环伏安、恒流放电等电化学测试表明,200 ℃所得四氧化三钴电极在6 mol/L氢氧化钾溶液中和-0.1～0.5 V (vs. SCE) 电位范围内,具有较好的循环稳定性能,单电极比电容达到442 F/g.为开发高性能的超级电容器电极材料提供了参考.     

AgO有序阵列结构电极材料的制备与表征

在浓氢氧化钠溶液中,通过电化学方法氧化银纳米颗粒制备得到AgO有序阵列结构电极材料。性能表征表明,所制备的AgO材料具有独特的直通孔阵列结构,有利于电解质溶液在孔隙中的扩散,可直接用作Al/AgO电池阴极,无需黏结剂等。与常规AgO阴极材料相比,同等条件下,以AgO有序阵列结构材料为阴极所组成电池的放电性能大幅提高,3 C倍率下质量比容量可达422.6 mA·h·g^-1,电极活性材料的利用率为97.8%,7 C倍率下质量比容量依然有387.8 mA·h·g^-1,活性物质利用率89.7%。同时,循环性能相比传统电极也得到大幅提升,在第10个循环时依然保持着405.2 mA·h·g^-1的质量比容量。制备方法易于操作且高效环保,有利于工业化生产;所得材料具有独特结构和性能优势。     

Effect of carbon nanofiber additives on thermal behavior of phase change materials

Thermal performance of nanocomposite carbon nanofibers filled paraffin wax was studied experimentally and analytically. The transient temperature response of made nanocomposite was measured during its solidification process and the cooling rate was predicted. It was found that nanocomposite thermal conductivities were enhanced significantly causing the cooling rate to increase. An analytical model was introduced based on one-dimensional heat conduction approach to predict the effective thermal conductivity for the new nanocomposites and its findings showed good agreement with the experimental data. Also, a comparative study was performed to investigate the effect of carbon nanofibers surface characteristics on thermal performance of paraffin wax.     

柔性Ag@TiO2/碳纳米纤维膜的制备及光催化性能

首先通过静电纺丝、预氧化煅烧法制备出自支撑的柔性TiO₂/碳纳米纤维膜(TiO₂/CNFs),然后在AgNO3溶液中通过光沉积法制备出三元复合Ag@TiO₂/CNFs光催化剂。该纤维膜可以直接从废水中取出,减少了过滤、离心等工艺步骤。同时,TiO₂分散在碳纤维中,防止了纳米颗粒的团聚。相对于纯粉体TiO₂,三元复合Ag@TiO₂/CNFs膜对可见光的吸收明显提高,并表现出优异的光催化性能。当Ag占膜质量的理论百分比为1%时,Ag@TiO₂/CNFs对罗丹明B的降解效果最好,光照150 min后降解率可达到95.30%。     

Preparation of porous carbon nanofibers derived from graphene oxide/polyacrylonitrile composites as electrochemical electrode materials

Porous carbon nanofibers (CNFs) derived from graphene oxide (GO) were prepared from the carbonization of electrospun polyacrylonitrile nanofibers with up to 15 wt.% GO at 1200 °C, followed by a low-temperature activation. The activated CNFs with reduced GOs (r-GO) revealed a specific surface area and adsorption capacity of 631 m²/g and 191.2 F/g, respectively, which are significantly higher than those of pure CNFs (16 m²/g and 3.1 F/g). It is believed that rough interfaces between r-GO and CNFs introduce oxygen pathways during activation, help to produce large amounts of all types of pores compared to pure activated CNFs.     

Synthesis of a novel carbon nanofiber structure for removal of lead

A new structure of carbon nanofibers was synthesized by chemical vapor deposition method. Kaolin was used as substrate and cyclohexanol and ferrocene as carbon source and catalyst, respectively. The morphology of the product was studied by scanning electron microscopy. Carbon nanofiber was modified with a mixture of nitric acid and sulfuric acid to enhance its adsorption capacity. The presence of functional groups on the treated adsorbent was assessed by FT-IR spectroscopy. The surface activity of the oxidized sample was estimated by Boehm’s titration. The pH_(PZC) of the samples was also measured. The adsorbent was then used for adsorption of Pb²⁺ at different experimental conditions. The optimized capacity of 211mg·g^?1 was obtained. Kinetic and thermodynamic of the reaction were studied. It was concluded that the adsorption process is spontaneous and endothermic. Equilibrium data were well fitted to the Langmuir model and the pseudo-second-order kinetic model described the adsorption process.     

夹心型生物碳电极材料的制备及超级电容器性能

选择板栗壳为碳源(CC),炭化后用KOH活化,制得CC700-OH电极材料.通过SEM、TEM、XRD以及BET等对其形貌和性能进行了表征与测试,发现CC700-OH具有孔/片穿插的夹心结构.在电流密度为1 A/g时,比电容为540 F/g,在电流密度为10 A/g下,循环6000圈后比电容仍可保持初始值的98％.在二...     

Characterisation of activated nanoporous carbon for supercapacitor electrode materials

Commercial nanoporous carbon RP-20 was activated with water vapor in the temperature range from 950 °C to 1150 °C. The XRD analysis was carried out on nanoporous carbon powder samples to investigate the structural changes (graphitisation) in modified carbon that occurred at activation temperatures T ? 1150 °C. The first-order Raman spectra showed the absorption peak at 1582 cm⁻¹ and the disorder (D) peak at 1350 cm⁻¹. The low-temperature N₂ adsorption experiments were performed at −196 °C and a specific surface area up to 2240 m²g⁻¹ for carbon activated at T = 1050 °C was measured. The cell capacitance for two electrode activated nanoporous carbon system advanced up to 60 F g⁻¹ giving the specific capacitance ∼240 F g⁻¹ to one electrode nanoporous carbon ∣1.2 M (C₂H₅)₃CH₃NBF₄ + acetonitrile solution interface. A very wide region of ideal polarisability for two electrode system (∼3.2 V) was achieved. The low frequency limiting specific capacitance very weakly increases with the rise of specific area explained by the mass transfer limitations in the nanoporous carbon electrodes. The electrochemical characteristics obtained show that some of these materials under discussion can be used for compilation of high energy density and power density non-aqueous electrolyte supercapacitors with higher power densities than aqueous supercapacitors.