聚苯胺/醋酸纤维素复合膜的制备及其超级电容特性

通过电化学原位聚合法制备多孔网状结构的聚苯胺(PANI)/醋酸纤维素(CA)复合膜电极,该复合膜的内层(与电极接触的一面)呈墨绿色,外层呈白色。采用原子力显微镜(AFM)、扫描电镜(SEM)、红外光谱(FTIR)对其形貌和化学组成进行表征。通过循环伏安、恒电流充放电和电化学阻抗研究了复合膜电极的超级电容特性。结果表明,多孔网状结构的PANI/CA复合材料具有良好的电容性能,其比电容可达到410F/g,并且该超级电容器具有较小的内阻和较好的循环稳定性,300次循环后,容量仍维持在342F/g,比电容的保持率为83.4%。     

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.     

电致变色型导电聚苯胺固态超级电容器的构建与性能研究

以苯胺硫酸溶液为沉积液,导电玻璃(FTO)为基底材料,在-0.2~1.2 V范围内先电位扫描一圈生成聚苯胺(PANI)晶种,然后在-0.2~0.8 V范围内用循环伏安法电沉积导电PANI材料.所得样品用红外光谱和扫描电子显微镜进行结构表征;以最佳循环伏安电沉积条件制备的PANI/FTO为活性电极,以H_2SO_4/聚乙烯醇(H2SO4/PVA)为凝胶电解质组装了电化学电容器,通过循环伏安、恒电流充放电和电化学阻抗法研究了组装电化学电容器的电化学性能.研究结果表明,以H_2SO_4/PVA凝胶电解质,沉积于导电玻璃表面的PANI活性电极材料的面比电容可达172.7 m F/cm~2,并且在2000次充放电以后,比电容值仍可保留初始值的92.8%.以分区沉积有PANI的导电玻璃可组装制备通过变色显示充放电过程的电化学电容器,在充电时,其颜色逐渐从浅绿色向深绿色转变,放电时,颜色逐渐从深绿色向浅绿色转变.     

聚苯胺/介孔碳纳米线复合电极材料的制备和性能

以介孔碳纳米线为基体, 通过电化学方法制备了新型聚苯胺/介孔碳纳米线(PANI/MCFs)复合材料, 采用SEM和TEM等手段对样品的结构和形貌进行了表征. 结果表明, 聚苯胺均匀附在介孔碳纳米线表面, 并填充到纳米线介孔孔道中. 将复合材料组装成三电极体系超级电容器, 用循环伏安、 恒流充放电和交流阻抗等方法对材料的电化学性能进行了测试. 结果显示, 在1 mol/L H₂SO₄溶液中, 复合材料的比电容达到391 F/g, 其循环稳定性也得到显著提高.     

聚苯胺/聚砜复合材料的制备及其超级电容性能

通过化学聚合法,制备出盐酸掺杂聚苯胺（PANI）,将其与聚砜（PSF）溶液混合,定量滴加到玻碳电极上制得PANI/PSF复合膜电极。 采用扫描电子显微镜、红外光谱以及X射线衍射对其结构和形貌进行表征。 根据循环伏安曲线、恒电流充放电曲线和电化学阻抗,研究了其作为电极的超级电容性能。 结果表明,多孔结构的PANI/PSF复合材料具有良好的电容性能,其比电容可达到497 F/g,并且该超级电容器具有较小的内阻和较好的循环稳定性。     

肝素钠掺杂球状聚吡咯的合成及其电化学电容

以生物制剂肝素钠为掺杂剂,由自组装方法合成出平均粒径为100 nm的球状聚吡咯(PPy),用作超级电容器电极材料.透射电镜(TEM)、循环伏安、恒流充放电和电化学交流阻抗测试表明,肝素钠掺杂聚吡咯呈现较好的形貌和电容性质,在电流密度3 mA/cm2下充放电,单电极比电容达到338 F/g.     

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。     

聚苯胺纳米刺/掺氮空心碳球复合材料的制备及电容性能

以掺氮空心碳球（N-HCS）为骨架,通过化学氧化聚合法制备了聚苯胺纳米刺/掺氮空心碳球复合材料（PANI/N-HCS）,采用扫描电子显微镜、透射电子显微镜和红外光谱仪等对样品的形貌、结构等进行了表征. 采用循环伏安、计时电位和交流阻抗等方法在1 mol/L H₂SO₄水溶液中考察了材料的电化学性能. 结果表明,PANI/N-HCS具有良好的电化学性能,在0.5 A/g电流密度下,PANI/N-HCS的比电容达346 F/g;当电流密度为20 A/g时,PANI/N-HCS比电容值为228 F/g,电容保持率为66%;在5 A/g电流密度下,经1000次充放电循环后,电容保持率为76%.     

α-MnO2微球的制备及其电化学电容性质

以Ag片作催化剂在室温下制备了具有较高比表面积(177m2/g)的电化学电容器材料MnO2。XRD测试和SEM分析表明,所制备的MnO2为纳米纤维组成的仙人球状微球结构的α-MnO2。交流阻抗、循环伏安、恒流充放电和循环寿命等电化学测试均表明,所合成的α-MnO2微球在1mol/LNa2SO4水溶液中具有良好的电化学电容性能,单电极比电容可达187.1F/g,经1000次循环后电极容量仍保持在90%以上。     

Amperometric Biosensors for Glucose Based on Layer‐by‐Layer Assembled Functionalized Carbon Nanotube and Poly (Neutral Red) Multilayer Film

Abstract

Multiwalled carbon nanotubes (MWNTs) were treated with a mixture of concentrated sulfuric and nitric acid to introduce carboxylic acid groups to the nanotubes. Conducting polymer film was prepared by electrochemical polymerization of neutral red (NR). By using a layer‐by‐layer method, homogeneous and stable MWNTs and poly (neutral red) (PNR) multilayer films were alternately assembled on glassy carbon (GC) electrodes. With the introduction of PNR, the MWNTs/PNR multilayer film system showed synergy between the MWNTs and PNR, with a significant improvement of redox activity due to the excellent electron‐transfer ability of carbon nanotubes (CNTs) and PNR. The electropolymerization is advantageous, providing both prolonged long‐term stability and improved catalytic activity of the resulting modified electrodes. The MWNTs/PNR multilayer film modified glassy carbon electrode allows low potential detection of hydrogen peroxide with high sensitivity and fast response time. As compared to MWNTs and PNR‐modified GC electrodes, the magnitude of the amperometric response of the MWNTs/PNR composite‐modified GC electrode is more than three‐fold greater than that of the MWNTs modified GC electrode, and nine‐fold greater than that of the PNR‐modified GC electrode. With the immobilization of glucose oxidase onto the electrode surface using glutaric dialdehyde, a biosensor that responds sensitively to glucose has been constructed. In pH 6.98 phosphate buffer, nearly interference‐free determination of glucose has been realized at ?0.2 V vs. SCE with a linear range from 50 µM to 10 mM and response time <10s. The detection limit was 10 µM glucose (S/N=3).     

Self‐Assembled Hollow Polyaniline/Au Nanospheres Obtained by a One‐Step Synthesis

Self‐assembled hollow nanosphere composites of polyaniline and Au nanoparticles (PANI‐p‐TSA/Au) were chemically synthesized from solutions containing p‐toluenesulfonic acid (p‐TSA) with the addition of gold chloride trihydrate as the oxidant. The composite materials were characterized by SEM, TEM, and a range of spectroscopic methods. Spectroscopic characterizations confirmed that the polymeric product is a form of doped PANI, while electron diffraction and X‐ray diffraction showed that elemental Au was present in the PANI‐p‐TSA/Au nanocomposites. The room temperature electrical conductivity of the PANI‐p‐TSA/Au nanocomposites was two orders of magnitude greater than a PANI‐p‐TSA obtained in the presence of ammonium persulfate as the oxidant under the same conditions.

     

新型聚中性红膜修饰碳糊电极的制备、表征及应用

运用一种新型的化学引发-电聚合方式将中性红膜固定到碳糊电极表面,制备出聚中性红薄膜修饰碳糊电极(PNR/CPE)。利用循环伏安法(CV)和交流阻抗谱(EIS)对修饰电极的电化学性能进行研究,借助于扫描电子显微镜(SEM)对修饰电极表面进行表征,并采用红外吸收光谱法(IR)和紫外可见吸收光谱法(UV-Vis)对PNR薄膜结构进行测试。结果表明,中性红成功地固定在碳糊电极表面,修饰电极的表面呈现特定的立体化结构,表面的电活性位点增多,电催化性能增大。在优化条件下,将该电极应用于鲱鱼精DNA(hs DNA)的检测,PNR电极上出现了1对较强的氧化还原峰,峰电流与其浓度在1.0×10~(-6)~8.0×10~(-5)mol/L范围内呈良好的线性关系,检出限为1.0×10~(-7)mol/L。     

Glassy carbon electrodes modified by multiwalled carbon nanotubes and poly(neutral red): A comparative study of different brands and application to electrocatalytic ascorbate determination

The electrochemical behaviour of glassy carbon electrodes coated with multiwalled carbon nanotubes (MWCNT) from three different sources and with different loadings has been compared, with a view to sensor applications. Additionally, poly(neutral red) (PNR) was electrosynthesised by potential cycling on bare glassy carbon and on MWCNT-modified glassy carbon electrodes, and characterised by cyclic voltammetry and scanning electron microscopy. Well-defined voltammetric responses were observed for hexacyanoferrate (II) oxidation with differences between the MWCNT types as well as from loading. The MWCNT and PNR/MWCNT-modified electrodes were applied to the oxidative determination of ascorbate, the electrocatalytic effects observed varying according to the type of nanotubes. Comparison was made with electrodes surface-modified by graphite powder. All modified electrode configurations with and without PNR were successfully employed for ascorbate oxidation at +0.05 V vs saturated calomel electrode with detection limits down to 4 μM; good operational stability and storage stability were also obtained.     

超级电容器用聚吡咯纳米粒子的比容量衰减机理研究

基于化学氧化聚合法制备了粒径约为40nm的掺杂对甲苯磺酸(TSA)的聚吡咯(PPy)复合纳米粒子.采用XRD、EDS、SEM和TEM研究了产物的结构和形貌特征,并用循环伏安、恒流充放电等方法测试了纳米粒子的电化学性能.结果表明PPy/TSA具有良好的快速充放电能力,在10 mA/cm2时比容量达到268Fg-1,但在1000次循环后发现其比容量下降了25.5%.用CV测试了PPy/TSA电极在第一次循环和第1000次循环的伏安曲线图,发现经过1000次循环后PPy/TSA电极的氧化峰逐渐消失,并且非法拉第电流减小.交流阻抗测试表明,PPy/TSA纳米粒子在反复充放电循环后,其界面电荷传递电阻增加,高频段双层电容值降低,但低频段的赝电容值却有所增加.通过比表面积测量发现,聚合物链的反复氧化-还原过程还可导致平均孔径减小、比表面积下降.红外和拉曼光谱也证实PPy纳米粒子在充放电过程中会发生降解,生成一种含氧的醌式结构,这表明聚合物电极材料比容量的下降可能与PPy主链的不可逆氧化和结构碎片化有关.     

Electrocatalytic reaction of hydrogen peroxide and NADH based on poly(neutral red) and FAD hybrid film

A simple method to immobilize poly(neutral red) (PNR) and flavin adenine dinucleotide (FAD) hybrid film (PNR/FAD) by cyclic voltammetry is proposed. The PNR/FAD hybrid film can be easily prepared on an electrode surface involving electropolymerization of neutral red (NR) monomers and the electrostatic interaction between the positively charged PNR and the negatively charged FAD. It exhibits electroactive, stable, surface-confined, pH-dependent, nano-sized, and compatible properties. It provides good electrocatalytic properties to various species. It shows a sensitivity of 5.4 μA mM(-1) cm(-2) and 21.5 μA mM(-1) cm(-2) for hydrogen peroxide (H(2)O(2)) and nicotinamide adenine dinucleotide (NADH) with the linear range of 0.1 μM-39 mM and 5 × 10(-5) to 2.5 × 10(-4) M, respectively. It shows another linear range of 48.8-355.5 mM with the sensitivity of 12.3 μA mM(-1) cm(-2) for H(2)O(2). In particular, the PNR/FAD hybrid film has potential to replace some hemoproteins to be a cathode of biofuel cells and provide the biosensing system for glucose and ethanol.     

Poly(neutral red) on passivated nickel films. New insights through EQCM measurements

Poly(Neutral Red) (PNR) has been electrogenerated on a passivated Ni surface. PNR was chosen due to the fact that its electroactivity region overlaps with the Ni dissolution/deposition process. Therefore, both electrochemical processes can compete and by this way, there are evidences about the formation of a Ni(OH)₂/PNR composite. It was investigated by classical EQCM and the instantaneous mass/charge ratio (F(dm/dQ)) analysis shed light on the active/passive transition and nickel trans-passive dissolution mechanisms.     

聚中性红/纳米二氧化硅复合修饰电极直接测定抗坏血酸

用滴涂法和电化学聚合法制备了聚中性红/纳米二氧化硅修饰电极(PNR/nano-SiO2/GCE),并用循环伏安法和交流阻抗法研究了修饰电极表面的电化学行为。实验表明,该修饰电极对抗坏血酸(AA)表现出良好的电催化氧化性能,探讨了复合修饰电极协同增效作用的机理。用线性扫描伏安法研究了AA浓度与峰电流之间线性关系,在pH2.0的磷酸盐缓冲溶液中,AA氧化峰电流在1.8×10-6～5.0×10-3mol/L浓度范围内呈良好的线性关系,检出限为5.4×10-7mol/L(S/N=3)。该修饰电极制备简单,可用于药品及果蔬食品中抗坏血酸的直接测定。     

Direct MALDI‐MS analysis of the disulfide bonds in peptide using thiosalicylic acid as a reactive matrix

The ability of a thiol‐containing molecule, thiosalicylic acid (TSA), to function as a reactive matrix for matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry analysis of peptides has been investigated. Although TSA has reducing characteristics, the use of TSA did not cause a reduction‐induced MALDI in‐source decay, probably because of the weak interactions between the thiol group in TSA and the carboxyl oxygen in the peptide. In contrast, when peptides containing disulfide bonds were analyzed by MALDI with TSA as the matrix, the disulfide bond was partially cleaved owing to the reaction with TSA, producing TSA‐adducted peptides. The reaction between the disulfide bond and TSA was suggested to be occurred in solution. The comparison of the MALDI mass spectra obtained using conventional matrix and TSA allows us to count the number of disulfide bonds in the peptides. Copyright © 2017 John Wiley & Sons, Ltd.     

Characterisation of poly(neutral red) modified carbon film electrodes; application as a redox mediator for biosensors

The polymer redox mediator, poly(neutral red) (PNR), has been synthesised and characterised electrochemically to investigate the best electropolymerisation and mediation conditions for application in enzyme biosensors and to clarify the mechanism of action. Neutral red was electropolymerised by potential cycling on carbon film electrode substrates by allowing the monomer to be oxidised during the full 20 cycles of polymerisation or reducing the positive limit of the potential window after the first 2 cycles to impede monomer oxidation with a view to obtaining longer polymer chains and a lesser degree of branching. Comparison was made with glassy carbon substrates. The PNR films on carbon film electrodes were characterised using cyclic voltammetry and electrochemical impedance spectroscopy, as well as in glucose biosensors prepared with PNR. Glucose oxidase enzyme was immobilised by encapsulation in silica sol-gel and compared with that obtained by cross-linking with glutaraldehyde. The biosensors were evaluated by chronoamperometry in 0.1 M phosphate buffer saline solution, pH 7.0, and showed evidence of electron transfer between the enzyme cofactor flavin adenine dinucleotide and PNR dissolved in the enzyme layer competing with PNR-mediated electrochemical degradation of H₂O₂ formed during the enzymatic process. This paper is dedicated to Professor Dr. Algirdas Vaskelis on the occasion of his 70th birthday.