Pt/PAn/GC电极的制备及对甲酸电催化氧化性能的研究

利用循环伏安法电聚合导电高分子聚苯胺，并制备了Pt／PAn／GC电极和Pt／GC电极，优化了苯胺在玻碳电极上的聚合条件，用在H2SO4中的循环伏安曲线对其进行了表征，Pt／PAn／GC电极的制备提高了Pt的分散度，增加了催化剂Pt的利用率。实验结果表明Pt／PAn／GC电极对甲酸电氧化的催化活性明显高于Pt／GC电极和Pt电极，正向扫描和反向扫描时对应的氧化峰电位分别是0．68V、0．45V。峰电流为54．23mA／cm^2和84．23mA／cm^2，为Pt／GC电极的修饰电极1．7倍和1．9倍，为Pt片电极的3．8倍和4．9倍，有效地提高了铂微粒的催化活性，并得到聚合苯胺的最佳条件为扫描速度50mV／s、扫描上限1．2V。     

甲醛在nano-Pt/GC电极上的电催化氧化研究

应用循环伏安法制备了nano-Pt/GC电极,并用SEM和电极在H2SO4中的循环伏安曲线对其进行了表征。结果表明,该方法制备的电极表面铂粒子分布较为均匀,粒径大小约为140nm,电极具有较大比表面积。电化学实验表明,该电极对甲醛电氧化的催化活性明显好于铂片电极。修饰电极的催化活性与铂粒子的沉积条件有关,铂微粒在电极表面的最佳沉积条件为循环次数100次和沉积速度5mV/s。     

甲醇在碳载纳米Pt电极上的电化学研究

应用循环伏安法制备了nano-Pt/GC修饰电极,优化了铂微粒在电极表面的沉积条件,并用扫描电子显微镜(SEM)和在硫酸中的循环伏安曲线对其进行了表征。结果表明铂微粒较为均匀地分散在玻碳电极表面,粒径约为140nm,电极具有很大的比表面积。循环伏安实验结果表明nano-Pt/GC电极对甲醇电氧化的催化活性明显高于铂片电极,在该修饰电极上甲醇正向扫描和反向扫描时的氧化峰电位分别是0.67V和0.49V,峰电流为61.00mA/cm2和50.50mA/cm2,分别是铂片电极上的3.13倍和3.10倍,有效地提高了金属铂的利用率,铂微粒在电极表面的最佳沉积条件是循环次数为100次和沉积速度为5mV/s。     

纳米ZrO2负载Pd-Ni催化剂催化氯苯加氢脱氯性能研究

采用负载法制备了一系列纳米ZrO₂负载金属Ni、Pd催化剂，通过XRD、TEM和SEM等技术对催化剂进行了表征，并以氯苯的加氢脱氯为探针反应，考察了催化剂的加氢脱氯性能和反应温度、碱的用量、催化剂镍的含量等因素对催化活性的影响。结果发现，在80 ℃、NaOH和氯苯物质的量的比为1的反应条件下，Ni质量分数为10%和Pd为0.05%的Pd-Ni/ZrO₂催化剂效果最佳，反应9 h后氯苯的转化率可达到100%。     

钛硼基储氢电极材料的制备及其电化学性能研究

TiB2作为过渡金属和非金属间化合物,在碱性电解液中能够产生较高的电化学容量.采用电弧炉熔炼法制备了以Ti和B为基础的TiMB2(M=Co、Ni)活性电极材料,并对它们的充放电性能、充放电前后XRD衍射图谱及电化学性能进行了测试与分析.     

纳米银修饰电极的制备

在圆柱形电解槽中,采用直流电沉积方法在导电玻璃上沉积银纳米材料,制备了Ag／ITO、Ag／CNTs／ITO复合电极,并以制得的复合电极作工作电极,测定两种电极在磷酸缓冲溶液中的循环伏安响应曲线。实验结果表明,纳米银修饰的电极具有很好的电化学活性。     

聚苯胺修饰电极对甲醇的电催化氧化研究

应用电化学方法制备了Pt/PAn/GC电极,优化了苯胺在玻碳电极上的聚合条件,并对其进行了表征.结果表明,铂微粒在聚苯胺膜电极上具有很高的分散度,电极具有很大的比表面积,Pt/PAn/GC电极对甲醇电氧化的催化活性明显高于Pt/GC电极和Pt电极,在该电极上甲醇正向扫描和反向扫描时的氧化峰电流为58.68mA/cm2和50.00mA/cm2,为Pt/GC电极的1.6倍和1.7倍,为Pt电极的3.0倍和3.1倍,从而有效地提高了铂的催化活性,并得到在玻碳电极上聚合苯胺的最佳条件为扫描速度50mV/s,扫描上限1.2V.     

纳米银修饰电极的电化学性能初探

在圆柱形电解槽中,采用直流电沉积方法在导电玻璃上沉积银纳米材料,制备了Ag/I-TO、Ag/CNTs/ITO复合电极,并以制得的复合电极做工作电极,测定两种电极在磷酸缓冲溶液中的循环伏安响应曲线。CNTs具有很高的比表面积,除了对银离子的反应具有催化作用外,还可能对带有负电荷的SCN-离子具有吸附作用。实验结果表明：银修饰的碳纳米管导电玻璃电极具有很好的电化学活性,可用于检测SCN^-。     

菁染料单分子膜覆盖的铂电极的电化学特性

L-B膜作为一种单分子膜技术已经得到了广泛的应用。最近很多人用电化学方法研究覆盖有L-B膜电极的特性。许多工作证明了脂肪酸L-B膜具有很强的抑制离子透过和抑制电子隧道电流的能力。而不具备这种性能的L-B膜,则被归之于膜中含有大量针孔所致。Kuhn曾在脂肪酸L-B膜中引入带有共轭双键的偶氮化合物。Zaba     

甲醇在聚苯胺载铂电极上的电催化氧化

用循环伏安法在玻碳电极上电聚合导电高分子聚苯胺用于附载Pt,提高了Pt的分散度。发现甲醇在Pt／PAN／GC电极和Pt／GC电极上均能自发解离出强吸附中间体CO,证实聚苯胺膜的存在有利于提高电极对甲醇的电催化氧化活性,CO在Pt／PAN／GC电极上的氧化峰电流明显高于Pt／GC电极。通过比较甲醇的电催化氧化活性可知,Pt/PAN／GC电极催化氧化甲醇的峰电流为58．68mA/cm^2和50．00mA／cm^2,是Pt／GC电极氧化峰电流的1．6倍和1．7倍。     

Preparation and electrochemistry of cadmium pentacyanonitrosylferrate film modified glassy carbon electrode

A glassy carbon (GC) electrode surface was modified with a cadmium pentacyanonitrosylferrate (CdPCNF) film as a novel electrode material. The modification procedure of the GC surface includes two consecutive procedures: (i) the electrodeposition of metallic cadmium on the GC electrode surface from a CdCl₂ solution and (ii) the chemical transformation of the deposited cadmium to the CdPCNF films in 0.05 M Na₂[Fe(CN)₅NO] + 0.5 M KNO₃ solution. The modified GC electrode showed a well-defined redox couple due to [Cd^IIFe^III/II(CN)₅NO]^0/−1 system. The effects of supporting electrolytes and solution pH were studied on the electrochemical behavior of the modified electrode. The diffusion coefficients of alkali-metal cations in the film (D), the transfer coefficient (α) and the charge transfer rate constant at the modifying film | electrode interface (k_s), were calculated in the presence of various alkali-metal cations. The stability of the modified electrode was investigated under various experimental conditions.     

循环伏安法制备聚苯胺/活性炭超级电容器膜电极

采用电化学循环伏安法,在柔性石墨纸基底材料上合成了聚苯胺/活性炭(PANI/AC)复合薄膜。 通过SEM观察了不同扫描圈数下复合薄膜的表面形貌,通过循环伏安(CV)、交流阻抗(EIS)、恒流充放电等电化学测试方法,研究了聚苯胺/活性炭复合电极的电性能。由SEM图谱可知,不同扫描圈数下,聚苯胺/活性炭的形态也有所不同,电化学测试结果表明,以柔性石墨纸为基底材料,扫描圈数在3圈时,不仅比容量较高,达504 F·g^-1,而且循环稳定性较好,经2000次循环后,容量衰减仅为初始容量的14%。     

预处理玻碳电极线性扫描伏安法测定槲皮素的研究

运用循环伏安法、线性扫描伏安法等测试技术研究了槲皮素在预处理玻碳电极上的电化学行为,建立了一种直接测定槲皮素的电化学分析方法。结果表明,与裸玻碳电极相比,预处理玻碳电极能显著提高槲皮素的氧化峰电流。在优化的实验条件下,氧化峰电流与槲皮素浓度在1.0×10-7～2.0×10-5mol/L范围内呈良好的线性关系,最低检测限为6.2×10-8mol/L。该方法简便、快捷、准确、灵敏度高。本法用于芦丁水解产物槲皮素的测定,效果良好。     

Electrooxidation of sulfide by cobalt pentacyanonitrosylferrate film on glassy carbon electrode by cyclic voltammetry

A glassy carbon (GC) electrode was modified with cobalt pentacyanonitrosylferrate (CoPCNF) film. Cyclic voltammetry (CV) of the CoPCNF onto the GC (CoPCNF/GC) shows a redox couple (Fe^III/Fe^II) with a standard potential (E^0′) of 580 mV. The current ratio I_pa/I_pc remains almost 1, and a peak separation (ΔE_p) of 106 mV is observed in 0.5 M KNO₃ as the supporting electrolyte. Anodic peak currents were found to be linearly proportional to the scan rate between 10 and 200 mV s⁻¹, indicating an adsorption-controlled process. The redox couple of the CoPCNF film presents an electrocatalytic response to sulfide in aqueous solution. The analytical curve was linear in the concentration range of 7.5 × 10⁻⁵ to 7.7 × 10⁻⁴ M with a detection limit of 4.6 × 10⁻⁵ M for sulfide ions in 0.5 M KNO₃ solution.     

铂纳米空球修饰玻碳电极对甲醛的电催化氧化行为

以纳米硒球为模板,H₂PtCl₆为前驱体,以抗环血酸为还原剂,SDSN作稳定剂,在室温下批量制备了铂纳米空球(Pt_Hollow)及其修饰玻碳(GC)电极(Pt_Hollow/GC)。使用XRD、SEM和TEM等检测技术表征了其形貌与结构,结果表明,所制备的铂纳米空球分散性好,粒径比较均匀,约为120 nm;球壳多孔,壳厚<10 nm,由多维、多级的多晶铂原子团簇所构建。以甲醛为探针分子,采用循环伏安及计时电流等常规电化学方法比较了电活性面积基本一致的Pt_Hollow/GC和电沉积铂纳米粒子(Pt_nano)修饰GC电极(Pt_nano/GC)催化甲醛氧化的性能,结果显示,位于0.64 V处的氧化峰电流密度,前者是后者氧化峰电流密度的1.5倍;氧化电流密度为0.5 mA·cm^-2处的氧化电位,前者比后者负移了约30 mV。实验结果表明,与Pt_nano/GC电极相比,甲醛在Pt_Hollow/GC电极上氧化的活化能低,反应速度快,催化活性高。所得结果为直接甲醛燃料电池阳极催化剂的研制提供了一定的实验与理论依据。     

Cathodic electrochemical analysis of methyl parathion at bismuth-film-modified glassy carbon electrode

Bismuth-film electrode (BiFE) was prepared by ex situ depositing bismuth onto glassy carbon electrode for the detection of organophosphate (OP) pesticides, using methyl parathion (MP) as a model analyte. The sufficiently wide negative potential window available made the BiFE a potentially suitable electrode for application in the field of cathodic electrochemical detection of OPs. The BiFE showed similar or even favorable behavior compared to that of mercury and bare electrode. Operational parameters, including the deposition potential and time of bismuth film, pH of the analytic solution and concentration of surfactant, cetyltrimethyl ammonium bromide (CTAB) have been optimized. Under the optimum experimental conditions, the cathodic voltammetric response was proportional to the concentration of MP range from 3.0 to 100 ng mL⁻¹, with a correlation coefficient of 0.9981. The detection limit was 1.2 ng mL⁻¹ (threefold standard deviation of a blank). Due to the easy preparation and regeneration of BiFE together with its good reproducibility and stability, the combination of the promising BiFE and cathodic voltammetric performances opens new opportunity for fast, simple, and sensitive analysis of OP compounds in samples.     

Nafion修饰玻碳电极伏安法测定痕量锡

报道了一种用Nafion修饰玻碳电极测定痕量锡的新方法。研究了Nafion膜的有关特性和测定的优化条件,当富集时间为3min时,峰电流与Sn(Ⅳ)浓度在1×10-9~1×10-7mol/L的范围呈良好的线性关系,检测限为2.46×10-10mol/L。该法用于实际水样中痕量锡的测定,平均回收率为97.24%。     

EDTA modified glassy carbon electrode: Preparation and characterization

EDTA-phenoxyamide modified glassy carbon electrode (EDTA-GC) was prepared at a glassy carbon electrode by surface synthesis. In the first step, nitrophenyl was grafted to the glassy carbon (GC) surface via the electrochemical reduction of its tetraflouroborate diazonium salt. In the second step, nitrophenyl-modified electrode (NP-GC) was subjected to the cathodic potential scan to reduce the nitro to amine group. p-Aminophenyl modified glassy carbon electrode (AP-GC) was dipped into a EDTA solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide (EDC) as an activating agent. Thus formed ((2-anilino-2-oxoethyl){2-[bis(carboxymethyl)amino]-ethyl}amino)acetic acid modified GC electrode was denoted as EDTA-GC and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ellipsometry and X-ray photoelectron spectroscopy (XPS). Complexation of the EDTA-GC surface with Pb²⁺ ions was investigated if this electrode could be used as a metal sensor.     

Electrocatalytic reduction of oxygen at glassy carbon electrode modified by polypyrrole/anthraquinones composite film in various pH media

The electrocatalytic reduction of dioxygen by one mono and four dihydroxy derivatives of 9,10-anthraquinone (AQ) incorporated in polypyrrole (PPy) matrix on glassy carbon electrode has been investigated. The electrochemical behaviour of the modified electrodes was examined in various pH media and both the formal potential of anthraquinones and reduction potential of dioxygen exhibited pH dependence. AQ and PPy composite film showed excellent electrocatalytic performance for the reduction of O₂ to H₂O₂. pH 6.0 was chosen as the most suitable medium to study the electrocatalysis by comparing the peak potential of oxygen reduction and enhancement in peak current for oxygen reduction. The diffusion coefficient values of AQ at the modified electrodes and the number of electrons involved in AQ reduction were evaluated by chronoamperometric and chronocoulometric techniques, respectively. In addition, hydrodynamic voltammetric studies showed the involvement of two electrons in O₂ reduction. The mass specific activity of AQ used, the diffusion coefficient of oxygen and the heterogeneous rate constants for the oxygen reduction at the surface of modified electrodes were also determined by rotating disk voltammetry.     

聚苯胺/聚乙烯复合电极的制备及性能测定

以低密度聚乙烯（PE）为基体材料,乙烯-醋酸乙烯共聚物（EVA）为增韧剂,聚苯胺（PAn）和炭黑（CB）为导电添加剂制备复合电极板,探讨了原料配比对物理力学性能、电学性能的影响。结果表明,原料配比PE∶EVA∶CB=75%∶5%∶20%时,电极的电阻最小,但是其韧性不佳;当原料配比PE∶EVA∶（CB＋PAn）=85%∶5%∶10%时,复合电极板具有最好的韧性能。