以多层次聚苯胺颗粒为电极活性物质的超级电容器的电化学性能

以(NH₄)₂S₂O₈为氧化剂用化学氧化法合成了具有多层次结构的聚苯胺颗粒，其二次颗粒由一次颗粒集结而成，一次颗粒的粒径基本上在1 μm以下，一次颗粒由多层微小薄片叠合而成. 用这种聚苯胺为活性物质制成电极，以2 mol•L^-1的H₂SO₄水溶液作电解液，组装成了聚苯胺电极超级电容器. 用循环伏安法、电化学阻抗谱和恒电流充放电技术测试了该超级电容器的电化学性能.在7 mA的充放电电流下，它的比能量可达6.35 Wh•kg^-1，比功率可达132 W•kg^-1，电极材料的比容量可达408 F•g^-1. 在20 mA的充放电电流下，它的比能量可达4.39 Wh•kg^-1，比功率可达328 W•kg^-1，电极材料的比容量可达324 F•g^-1. 在100次的充放电循环中，聚苯胺电极超级电容器的电容量没有下降，电荷充放电效率一直保持在95%左右.     

Porous NiCo2O4 Nanowire Arrays as Supercapacitor Electrode Materials with Extremely High Cycling Stability

In this work, NiCo₂O₄(NCO) was synthesized via microwave hydrothermal method and a further annea- ling treatment. Research results have shown that the surface defects(Co²⁺ site) and pore size of the materials can be adjusted by simply changing the calcination temperatures, and porous nanowire arrays structure can be obtained. The porous structure is conducive to the penetration of the electrolyte and enables the NCO to fully participate in the electrochemical reaction. What's more, the NCO material has ample space to buffer the volume change in the cycle test, improving the cycling stability. The NCO obtained at 350℃ has better performance. It exhibits a specific capacitance of 648.69 F/g at 1 A/g and good rate capability. Especially, at 10 A/g, the specific capacitance can still be maintained at 80.00% after 10000 galvanostatic charge/discharge(GCD) cycles, showing excellent cycling stability.     

单根聚苯胺纳米线导电性的研究

纳米线(管)的模板合成和导电原子力显微镜(C-AFM)结合是一种近期发展起来研究单根一维纳米结构及阵列导电性的有效方法. 本文利用C-AFM测量了阳极氧化铝(AAO)模板电化学合成制备的单根聚苯胺纳米线的电导率, 研究了直径、氧化还原态对单根聚苯胺纳米线电导率的影响. 从I－V曲线可以看到, 其导电性质与半导体类似，但又不同于半导体． 尚未观察到反向击穿现象，可能原因是, 在一定的反向偏压下的离子脱嵌使得它由部分氧化态（导电态）转变为还原态（绝缘态）；电导率随纳米线直径减小而线性地增加；以ClO₄^－离子掺杂的氧化态和还原态比部分氧化态的电导率低二个数量级.     

Pt纳米线阵列的氧还原催化性能

采用阳极氧化铝(AAO)模板法电化学沉积制备了Pt纳米线阵列(Pt NWs)氧还原催化剂, 通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和电化学测试对Pt纳米线阵列催化剂的形貌和电催化性能进行了表征. 循环伏安法(CV)研究表明Pt纳米线阵列催化剂的电化学活性面积大于其几何面积; 旋转圆盘电极(RDE)测试研究发现, 制备的Pt纳米线阵列催化剂的氧还原反应(ORR)曲线的半波电势相对Pt/C的有正移, 并且Pt纳米线阵列催化剂的极限扩散电流比Pt/C大.     

Hybrid Materials Based on Conducting Polymers for Nitrite Sensing: A Mini Review

Well-known as a hazardous compound, nitrite constitute a real threat to the public health. So, there is a pressing need to detect and quantify them in different matrix. Even though conventional analytical methods can be used to address this issue, electrochemistry allows a fast, sensitive, and efficient analysis. Conducting polymers continue to raise great interest among scientific communities due to their properties. Moreover, their combination with carbon nanomaterials, or metallic nanoparticles improves their properties, and provides great results. In this paper, we will focus on some revealing works devoted to the electrochemical detection of nitrite using this kind of materials.     

聚苯胺纳米线修饰的DNA电化学传感器的研究

采用电流密度递减的方法在玻碳电极表面修饰聚苯胺纳米线(PAINW), 以SEM对其形貌进行表征, 测得PAINW的尖端直径在80～100 nm之间. 以乙基-(3-二甲基丙基)碳化二亚胺盐酸盐(EDC)为偶联活化剂, 将5'-磷酸基修饰的寡聚核苷酸片断共价固定在聚苯胺修饰的电极上, 一定条件下, 以亚甲基蓝为电化学杂交指示剂, 采用差分脉冲伏安法对杂交信号进行检测, 实现了对特定序列DNA片段的互补、非互补序列的识别.     

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。     

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.     

Patterned Growth of Vertically Aligned Polypyrrole Nanowire Arrays

A facile strategy for preparing vertically aligned polypyrrole (PPy) nanoarrays with precisely controlled density and quantity is presented. The method involves two steps: (1) the fabrication of the patterned substrate via electron beam lithography and (2) the controlled growth of PPy nanowires via electrochemical polymerization on the patterned substrate. The electrical property of a single PPy nanowire is investigated via in situ conducting probe atomic force microscopy.     

Lignosulfonate‐Modified Electrode for Electrocatalytic Reduction of Acidic Nitrite

Sodium lignosulfonate (LS) undergoes oxidative electropolymerization on a glassy carbon (GC) electrode from sulfuric acid solution to form a chemically modified electrode exhibiting anionic character and redox activity. Cyclic voltammetry reveals the existence of two redox systems at E°′ values of +0.29 and +0.53 V, respectively. Peak currents are proportional to the scan rate as expected for surface confined systems. The GC|poly‐LS electrode shows electrocatalytic activity toward the reduction of acidic nitrite. When operating in a constant potential amperometric mode (at 0.0 V, vs. Ag/AgCl), a linear relationship between nitrite concentration and reduction current is observed over the range of 1 to 250 μM. The detection limit reaches 0.3 μM (S/N=3). The electrode may be practically applied for nitrite determination in human saliva.     

Electrocatalytic Dioxygen Reduction at Glassy Carbon Electrode Modified with Polyaniline Grafted Multiwall Carbon Nanotube Film

The work details the electrocatalysis of oxygen reduction reaction (ORR) in 0.5 M H₂SO₄ medium on a modified electrode containing a film of polyaniline (PANI) grafted multi‐wall carbon nanotube (MWNT) over the surface of glassy carbon electrode. We have fabricated a novel modified electrode in which conducting polymer is present as connected unit to MWNT. The GC/PANI‐g‐MWNT modified electrode (ME) is fabricated by electrochemical polymerization of a mixture of amine functionalized MWNT and aniline with GC as working electrode. Cyclic voltammetry and amperometry are used to demonstrate the electrocatalytic activity of the GC/PANI‐g‐MWNT‐ME. The GC/PANI‐g‐MWNT‐ME exhibits remarkable electrocatalytic activity for ORR. A more positive onset potential and higher catalytic current for ORR are striking features of GC/PANI‐g‐MWNT‐ME. Rapid and high sensitivity of GC/PANI‐g‐MWNT‐ME to ORR are evident from the higher rate constant (7.92×10² M^?1 s^?1) value for the reduction process. Double potential chronoamperometry and rotating disk and rotating ring‐disk electrode (RRDE) experiments are employed to investigate the kinetic parameters of ORR at this electrode. Results from RDE and RRDE voltammetry demonstrate the involvement of two electron transfer in oxygen reduction to form hydrogen peroxide in acidic media.     

聚苯胺/贵金属复合纳米材料的可控合成及催化应用

导电高分子/贵金属复合纳米材料因其在催化、传感、表面增强拉曼、光热治疗等诸多领域的应用前景而受到广泛关注.本文主要介绍我们课题组近年来利用可控合成策略制备的负载型和包埋型两种结构聚苯胺/贵金属复合纳米材料,以及利用复合纳米材料的结构和功能特性,对其在多相催化领域的应用、结构与催化性能之间构效关系的探索.     

石墨烯-聚苯胺杂化超级电容器电极材料

聚苯胺是一类具有超高比电容的导电高分子材料, 利用其与石墨烯的协同效应, 改善各自的固有缺点, 可以制得高性能的超级电容器. 本文综述了石墨烯-聚苯胺杂化电极材料的制备方法和石墨烯表面性质对电极材料电化学性能的影响, 讨论了优化杂化电极的结构与性能.     

Electrocatalytic Oxidation of Nitrite at Gold Nanoparticle-polypyrrole Nanowire Modified Glassy Carbon Electrode

A novel chemically modified electrode based on the dispersion of gold nanoparticles on polypyrrole nanowires has been developed to investigate the oxidation behavior of nitrite using cyclic voltammetry, differential pulse voltammetry and chronoamperometry techniques. The diffusion coefficient (D), electron transfer coefficient (α) and charge transfer rate constant (k) for the oxidation of nitrite were determined. The modified electrode exhibited high electrocatalytic activity toward the oxidation of nitrite. The catalytic peak current was found to be linear with nitrite concentrations in the range of 8.0×10^?7?2.5×10^?3 mol·L^?1 with a detection limit of 1.0×10^?7 mol·L^?1 (s/n=3). The proposed method was successfully applied to the detection of nitrite in water samples with obtained satisfactory results. Additionally, the sensor also showed excellent sensitivity, anti‐interference ability, reproducibility and stability properties.     

自支撑三维功能化石墨烯/聚苯胺电极材料的制备及超级电容性能

采用水热法制备了三维石墨烯(3D-G),并以十八胺(ODA)为接枝剂对部分还原的氧化石墨烯进行氨基化处理,再利用原位聚合法在氨基化石墨烯表面生长聚苯胺,制备了十八胺功能化石墨烯/聚苯胺(G-ODA/PANI).对材料进行了结构表征、电化学性能分析和材料结构的比电容贡献分析.结果显示,电极材料的电容贡献大部分体现为材料的表面电容,G-ODA/PANI电极片在1 A/g电流密度时的比电容最高可达1080 F/g,是未功能化石墨烯/聚苯胺电极材料(G/PANI)的2.57倍,且循环稳定性也有很大的提高,循环10000周后的比容量保持率为90.8%,比G/PANI高9.6%.     

不同磺酸掺杂聚苯胺的制备及在超级电容器中的应用

以MnO₂为氧化剂,采用乳液聚合法,用三种不同的磺酸型表面活性剂制备掺杂聚苯胺(PANI)。通过扫描电子显微镜(SEM)、傅里叶变换红外(FTIR)光谱以及X射线衍射(XRD)等手段对其结构及形貌进行表征;用所得的掺杂聚苯胺制作电极,组装成对称扣式超级电容器,用循环伏安法(CV)、电化学阻抗(EIS)和恒电流充放电技术进行电化学性能研究。结果表明,磺酸表面活性剂的引入有利于PANI纳米纤维的形成和分散,掺杂Nafion的PANI纤维直径在30-40 nm之间,纤维交织成多孔的疏松结构;当放电电流为0.1 A·g^-1时,以PANI-Nafion、PANI-SDS(十二烷基磺酸钠)、PANI-SDBS(十二烷基苯磺酸钠)为电极材料的超级电容器比容量分别为385.3、359.7、401.6 F·g^-1,均高于未掺杂PANI的比容量(235.8 F·g^-1);其中, PANINafion的循环稳定性最好, 1000次循环后其比容量保持率高达70.7%。     

Enhanced Electrocatalysis for the Reduction of Hydrogen Peroxide at New Multiwall Carbon Nanotube Grafted Polydiphenylamine Modified Electrode

A new modified electrode having multiwall carbon nanotube (MWNT) grafted with polydiphenylamine (PDPA) as electrocatalytic layer is fabricated. FESEM image of the modified electrode shows a different morphology indicating the grafting of PDPA over MWNT. This morphology is in quite contrast from the conventional bilayer MWNT/conducting polymer modified electrode. The multiwall carbon nanotube grafted polydiphenylamine (MWNT‐g‐PDPA‐ME) shows excellent electrocatalytic activity towards the reduction of hydrogen peroxide. The combined presence of MWNT and PDPA as a single unit provides better sensitivity than the bilayer configuration (MWNT/PDPA‐ME). This modified electrode shows accelerated electron transfer at the interface with minimized surface fouling and surface renewability. The advantages of MWNT‐g‐PDPA‐ME over the bilayer electrode are demonstrated with chronoamperometric studies. The amperometric response to H₂O₂ obtained at ?300 mV (vs. SCE) is rapid and highly sensitive as evident from the higher (2.83×10^?3 cm³ mol^?1 s^?1) rate constant for the diffusion reduction process.     

聚苯胺的电化学现场ESR-电导同步测量

本论文工作通过设计新型的电解池 ,首次实现了导电聚合物的电化学现场ESR_电导同步测量 .从获得的聚苯胺ESR信号及膜电阻随电极电势变化的精细图象看出 ,极化子晶格的形成与消亡决定了聚苯胺的导电行为 .从不同电势下聚苯胺的ESR饱和行为也得到Curie自旋与Pauli自旋相互转化的新证据 .     

CdSe纳米线阵列的制备及其表征(英)

通过在含有SeSO₃^2-和Cd²⁺的室温水溶液中，用模板-电沉积法在纳米孔阵列阳极氧化铝膜(AAM)模板中制备了高有序性的CdSe纳米线阵列，并对其形貌、结构和组分进行了表征。扫描电子显微镜(SEM)和透射电子显微镜(TEM)结果表明，纳米线阵列中的CdSe纳米线具有相同的长度和直径，分别对应于使用的AAM模板的厚度和孔径；X-射线衍射(XRD)和X-射线能谱(EDAX)结果表明，CdSe纳米线中Cd和Se的化学组成非常接近于1∶1，其结构为立方CdSe。另外，对模板-电沉积法制备CdSe纳米线的机理进行了讨论。     

A MnOOH‐Polyaniline Nanocomposite Modified Gold Electrode for Electrochemical Sensing of Nitrite

A novel non‐enzymatic nitrite sensor was fabricated by immobilizing MnOOH‐PANI nanocomposites on a gold electrode (Au electrode). The morphology and composition of the nanocomposites were investigated by transmission electron microscopy (TEM ) and Fourier transform infrared spectrum (FTIR ). The electrochemical results showed that the sensor possessed excellent electrocatalytic ability for NO₂⁻ oxidation. The sensor displayed a linear range from 3.0 μmol•L⁻¹ to 76.0 mmol•L⁻¹ with a detection limit of 0.9 μmol•L⁻¹ (S/N = 3), a sensitivity of 132.2 μA •L•mol⁻¹•cm⁻² and a response time of 3 s. Furthermore, the sensor showed good reproducibility and long‐term stability. It is expected that the MnOOH‐PANI nanocomposites could be applied for more active sensors and used in practice for nitrite sensing.