离子液体电解质种类对活性炭电极超级电容器电化学性能的影响

本文将经水蒸气二次活化的椰壳活性炭（W-AC）作为电极材料,选择1-乙基-3甲基咪唑四氟硼酸盐（[EMIM]BF₄）作为电解质,结果表明W-AC电极的比电容量远高于未活化的椰壳活性炭（R-AC）.使用循环伏安、恒电流充放电、交流阻抗等方法研究了不同种类离子液体电解质对超级电容器电化学性能的影响.不同阴阳离子组成的离子液体作为电解质,直接影响超级电容器的电化学性能. 研究表明,由EMIM⁺和BMIM⁺阳离子与BF₄^-、TFSI^-阴离子构成的离子液体电解质较适用于W-AC电极. 其中在[EMIM]BF₄电解质中,单片电极的比电容量可高达153 F·g^-1;在1-丁基-3-甲基-咪唑四氟硼酸盐（[BMIM]BF₄）电解质中电位窗可达3.5V,能量密度可高达57 Wh·kg^-1.本研究对于构筑高性能超级电容器离子液体的选择提供参考,以满足不同应用领域需求.     

亲水性离子液体[EMIM]BF4对固定化β-葡萄糖醛酸苷酶催化活性的影响

以壳聚糖为固定化载体,采用吸附交联法制备固定化β-葡萄糖醛酸苷酶;以1-乙基-3-甲基咪唑四氟硼酸盐([EMIM]BF4)/缓冲溶液均相体系为介质,研究了亲水性离子液体[EMIM]BF4对固定化酶生物催化甘草酸(GL)合成单葡萄糖醛酸基甘草次酸(GAMG)的影响.实验结果表明,当均相体系中[EMIM]BF4的体积分数为16%,pH为5.4,反应温度为50℃及摇床转速为200 r/min时,酶活力达到最高,并且明显优于纯缓冲溶液体系中的最高酶活.重复利用性实验结果表明,与纯缓冲液介质体系相比,固定化酶在含亲水性离子液体[EMIM]BF4的均相介质中表现出较好的操作稳定性.表观动力学参数和活化能数据表明,亲水性离子液体[EMIM]BF4在催化体系中能够增强酶和底物GL的亲和力,有效稳定酶-底物的过渡态,并降低反应活化能,而使固定化β-葡萄糖醛酸苷酶表现出较高的催化活性.     

间苯二胺的电化学及紫外-可见薄层光谱电化学研究

研究了间苯二胺(MPD)在金电极和SnO₂;F膜电极上的循环伏安行为及在SnO₂;F膜电极上的紫外-可见薄层光谱电化学性质.获得了间苯二胺在SnO₂;F膜电极上电氧化的薄层恒电势电解-吸收光谱图,采用双对数法对紫外-可见薄层光谱电化学数据进行了处理.研究了间苯二胺的光谱及电化学性质,求得了间苯二胺的动力学修饰式量电位E⁰和αn等热力学参数.     

双酚A在纳米金-离子液体复合修饰电极上的电化学行为及测定

该文制备了纳米金-离子液体修饰电极(GNP-[BMIM]PF6/GCE),用红外光谱对GNP和[BMIM]PF6进行了表征.采用交流阻抗法研究了GNP-[BMIM]PF6/GCE的表面电化学特性,同时研究了双酚A(BPA)在该修饰电极上的循环伏安行为.结果表明,BPA在该修饰电极上出现1个氧化峰,无还原峰,为不可逆电化...     

辣根过氧化物酶修饰电极在离子液体[EMIM]BF4中的直接电化学

将壳聚糖(Chi)-辣根过氧化物酶(HRP)-多壁碳纳米管(MWCNTs)的复合物修饰在玻碳电极(GCE)表面, 制备了HRP修饰电极(Chi-HRP-MWCNTs/GCE), 并将其用于在亲水性离子液体1-乙基-3-甲基咪唑四氟硼酸([EMIM]BF4)中HRP的直接电化学研究. 紫外可见光谱和红外光谱表明, HRP在复合物内保持了其原始构象. 电化学研究表明, 该修饰电极在[EMIM]BF4中的循环伏安图上出现了一对峰形良好、几乎对称的氧化还原峰, 式量电位为－0.247 V (vs. Ag/AgCl), 说明包埋在Chi-MWCNTs中的HRP与电极之间发生了直接电子传递; HRP在电极表面直接电子转移的速率常数ks为3.12 s－1; 在65 ℃的[EMIM]BF4中HRP仍然保持其活性; HRP修饰电极对过氧化氢的还原具有电催化作用, 其表观米氏常数Km为5.6×10－5 mol•L－1, 催化电流与过氧化氢浓度在5.0×10－7～5.0×10－5 mol•L－1范围内呈线性关系, 检出限为2.0×10－7 mol•L－1. 该研究为非水相生物传感器的构制提供了一种新途径.     

基于纳米银/碳纳米纤维复合材料的增强效应电化学测定多贝斯

将银纳米粒子(AgNPs)电沉积在碳纳米纤维(CNFs)修饰玻碳电极表面制备纳米银/碳纳米纤维修饰玻碳电极(AgNPs/CNFs/GCE).采用扫描电镜考察其表面形态,在K3[Fe(CN)6]-K4[Fe(CN)6]体系中用循环伏安法和电化学阻抗法研究AgNPs/CNFs/GCE的电化学行为.采用循环伏安法和方波伏安法...     

EuCl_3在氯化1-丁基-3-甲基咪唑中的电化学性质

应用循环伏安法研究了Eu3+在亲水性离子液体—氯化1-丁基-3-甲基咪唑([BMIM]Cl)中的电极过程.实验表明,工作电极为玻碳电极时,[BMIM]Cl的电化学窗口为-1.7～0.80V(vs.Ag/AgCl).Eu3+在[BMIM]Cl中被还原为Eu2+,此电极反应受电荷迁移和物质扩散共同控制.当体系温度从55℃升高到75℃时,Eu3+在[BMIM]Cl中的扩散系数D从3.75×10-9cm2/s变化到1.32×10-8cm2/s,该反应活化能Ea为62.6kJ/mol.     

化学修饰电极的研究——Ⅰ.等离子体聚合法制备聚乙烯二茂铁膜电极

化学修饰电极是当前电化学领域中十分活跃的崭新研究方向^[1~4].它的出现扩展了电化学的研究和应用范围,有广阔的发展前途,已在电子转移、光电转换、催化、立体选择性有机合成以及选择富集测定等方面显出其优越性.最近,在多种化学修饰电极类型中,令人特别感兴趣的是具有电活性的聚合物膜电极.制备聚合物膜电极的方法很多^[5~10],用等离子体聚合法可得高度交联的超薄膜,且化学和热稳定性均好^[10,11].     

[C14MIM]Br离子液体对聚丙烯超临界CO2发泡性能的影响

本文对PP/[C₁₄MIM]Br体系的熔融过程和对CO₂的吸收, 以及[C₁₄MIM]Br在PP基体中的分散状态进行了研究, 并初步考察了[C₁₄MIM]Br对PP发泡性能的影响.     

Nafion-离子液体-修饰碳糊电极在抗坏血酸和尿酸存在下选择性测定多巴胺

用Nafion和亲水性离子液体溴化1-辛基-3-甲基咪唑([OMIM]Br)作修饰剂制作了Nafion-离子液体-修饰碳糊电极;在0.1 mol/L磷酸盐缓冲溶液(pH 7.40)中,用循环伏安法(CV)和方波伏安法(SWV)研究了多巴胺在该修饰电极上的电化学行为,建立了抗坏血酸和尿酸存在下选择性测定多巴胺的新方法.研究表明,该修饰电极降低了多巴胺氧化、还原反应的过电位,增大了其氧化、还原反应的峰电流,而抗坏血酸和尿酸在该修饰电极上无响应;在方波伏安曲线上,多巴胺的氧化电流与其浓度在3.0×10-8～2.0×10-6 mol/L范围内呈线性关系,检出限为1.0×10-8 mol/L.该法可用于注射液和模拟生物样品中多巴胺的测定.     

Electropolymerization of O-Phenylenediamine in an Ionic Liquid

Ionic liquid like 1-ethyl-3-methylimidazolium bromine ([EMIM]Br) has been used as electrolyte for the electropolymerization of O-phenylenediamine at glassy carbon electrode by cyclic voltammetry. It is found that poly (O-phenylenediamine) film modified electrode has favorable electrochemical activity in acid solution.     

Electrocatalytic reduction of dioxygen on a glassy carbon electrode modified with adsorbed cobaloxime complex.

The preparation and electrochemical properties of a glassy carbon (GC) electrode modified with cobaloxime complex were investigated. The complex of the type [CoIII(DO)(DOH)pn)Cl2] where (DO)(DOH)pn = N2,N2'-propanediylbis-2,3-butanedione-2-imine-3-oxime) was adsorbed irreversibly and strongly on the surface of preanodized glassy carbon electrode. Electrochemical behavior and stability of modified GC electrode were investigated by cyclic voltammetry. The electrocatalytic reduction of dioxygen has been studied using this modified glassy carbon electrode by cyclic voltammetry, chronoamperometry and rotating disk electrode voltammetry as diagnostic techniques. The modified electrode showed excellent eletrocatalytic ability for the reduction of dioxygen to hydrogen peroxide in acetate buffer (pH 4.0) with overpotential 1.0 V lower than the plain glassy carbon electrode. The formal potential for this modified electrode is not shifted to more negative potentials by repeated reduction-oxidation cycles in oxygen-saturated supporting electrolyte solution. The apparent electron transfer rate constant (kS), the transfer coefficent (alpha) and the catalytic rate constant of O2 reduction at a GC modified electrode were determined by cyclic voltammetry and rotating disk electrode voltammetry and were found to be around 2.6 s(-1), 0.33 and 2.25 x 10(4) M(-1) s(-1). Based on the results, a catalytic mechanism is proposed and discussed.     

苯甲酰甲酸在玻碳电极[EMIM]Br离子液中的电化学特性

The direct electrochemical reduction of benzoyl formic acid was investigated in ionic liquid, 1-ethyl-3-methyl-imidazolium bromide ([emim]Br), using cyclic voltammetry and chronocoulometry. The diffusion coefficient (D) and the transfer coefficient (α) of benzoyl formic acid in [emim]Br were obtained.     

铁铂核壳纳米粒子修饰玻碳电极制备及对亚硝酸盐还原的电催化性能

通过循环伏安法（CV）在玻碳（GC）电极表面电沉积出分布较为均匀的纳米Fe粒子,制得纳米Fe粒子修饰的GC（纳米Fe/GC）电极,再经“电荷置换”制得具有Fe核Pt壳结构的纳米粒子修饰的（纳米PtFe/GC）电极。 SEM结果显示,纳米Fe/GC和纳米PtFe/GC表面粒子的形貌均呈立方体形,分布较为均匀,粒径在60 nm左右。 纳米PtFe/GC电极对亚硝酸盐的还原具有很高的电催化活性。 3种电极的电催化活性顺序依次为：纳米Fe/GC＜纳米Pt/GC＜纳米PtFe/GC。 相对于纳米Pt/GC电极,纳米PtFe/GC电极的起始还原电位（Ei）正移了0.14 V,还原峰电流（ip）增大了3倍。     

Characterization of a 2‐Benzo[c]cinnoline Modified Glassy Carbon Electrode by Raman Spectroscopy,Electrochemical Impedance Spectroscopy,and Ellipsometry

This work describes the characterization of the grafted 2‐benzo[c]cinnoline (2BCC) molecules at a glassy carbon (GC) electrode surface by voltammetry and spectroscopy. Attachment of the molecule to the carbon substrate was achieved by the electrochemical reduction of 2‐benzo[c]cinnoline diazonium salt (2BCC‐DAS). GC electrode modification was carried out in aprotic solution with 2BCC diazonium salt. Dopamine (DA) and ascorbic acid (AA) were used to prove the surface modification to see the blockage of the electron transfer. The presence of 2BCC at the GC electrode surface was characterized by cyclic voltammetry and Raman spectroscopy. Raman spectroscopy was used to monitor molecular bound properties of the adsorbates at the 2BCC‐GC surface and confirm the attachment of 2BCC molecules onto the GC surface. The thickness of the 2BCC film on GC was also investigated by ellipsometric measurement.     

化学修饰电极的研究XVIII,四苯基钴卟啉化学修饰玻碳电极的热处理及其对氧的催化还原

本文研究四苯基钴卟啉化学修饰玻碳电极的热处理,经热处理的这种电极[(PCo/GC)h]具有对氧催化还原的异常高的稳定性和活性.在纯O2饱和的0.05mol.L^-^1H2SO4溶液中经循环伏安(CV)扫描3000次(100mV/s),其催化活性未见明显降低.研究了热处理温度(500-1000℃)对(PCo/GC)h电极电催化性能的影响.用紫外可见光谱对热处理产物的结构进行了分析.用CV法及旋转圆盘电极研究了O2在(PCo/GC)h电极上电催化反应动力学,测定了速率常数.在该电极上O2的还原反应为二电子还原成H2O2的不可逆过程.     

氯过氧化物酶-聚L-赖氨酸/GC电极的电化学特性

应用电化学方法在玻碳电极上修饰聚L-赖氨酸膜,以1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐做交联剂,固定氯过氧化物酶.修饰电极的循环伏安曲线呈现一对可逆的氧化还原峰,表明聚L-赖氨酸能够很好地促进氯过氧化物酶在电极表面的直接电子传递,这是一个受吸附控制并伴随有质子转移的准可逆电子传递过程.该电极有很好的稳定性,并能显著地电催化氧的电化学还原反应.     

Electrochemical studies of chloroperoxidase on poly-L-lysine film modified GC electrode

<正>Poly-L-lysine(PLL) was first electrodeposited onto the surface of a glassy carbon(GC) electrode.The PLL modified electrode was used to immobilize chloroperoxidase(CPO) via 1-[(3-dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride(EDC).The electrochemical behaviors of immobilized CPO on PLL/GC electrode were investigated by cyclic voltammetry(CV).The CV results obtained showed that CPO was successfully immobilized on the PLL/GC electrode and a fast direct electron transfer between CPO and PLL-GC electrode was achieved with a formal redox potential of -0.23 V vs.SCE.The CPO-PLL/GC modified electrode showed a good catalytic activity for electrocatalytical reduction of O_2,promising for a broad range of CPO-catalyzed transformations.     

Studies on the electrochemical behavior of cytochrome c and its interaction with DNA at a Co/GC ion implantation modified electrode

The electrochemical behavior of cytochrome c (cyt c) and its interaction with DNA at a Co/glassy carbon (GC) ion implantation modified electrode were studied by linear sweep and cyclic voltammetry. In 0.005 mol dm(-3) Tris-0.05 mol dm(-3) NaCl buffer solution (pH = 7.10), a sensitive reduction derivative peak of cyt c was obtained by linear sweep voltammetry. The peak potential was 0.032 V (SCE). The peak current was proportional to the concentration of cyt c. The electrode process was quasi-reversible with adsorption. The electrode reaction rate constant k and the electron transfer coefficient a of cyt c were 4.42 s(-1) and 0.47, respectively. AES and XPS experiments showed that Co was implanted into the surface of the GC electrode (GCE). The implanted Co formed Co-C, which catalyzed the reduction of cyt c. The reaction of DNA with cyt c led to an electrochemically active complex, which resulted in an increase in the reduction current of cyt c. After adding DNA into the solution containing cyt c, the electrode process was still quasi-reversible with adsorption.     

5-硝基-1,4-萘醌在玻碳电极上的电化学行为研究

采用循环伏安法和线性扫描伏安法,研究了5-硝基-1,4-萘醌在玻碳电极上的电化学行为.结果表明,在丙酮的稀硫酸溶液中,5-硝基-1,4-萘醌在0.0V、-0.8V(vs.SCE)处各有一个还原峰,分别为硝基、醌的不可逆电极反应;5-硝基-1,4-萘醌在电极表面的传质为线性扩散,电还原过程由扩散控制,并求得传递系数分别为...