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以氯化血红素(Ⅰ) 为原料, 经过脱铁、 酯化、 催化加氢、 水解、 酸胺缩合以及络合金属合成了化合物Co(Ⅱ)-[2,7,12,18-四甲基-3,8-二乙基-13,17-丙酰基氨乙基联二硫基乙氨基甲酰乙基-29,34-二甲氧甲酰基]-卟啉[Co(Ⅱ)MPDTEP, V]. 对产物的结构行了表征, 分析了反应时间和反应温度对化合物[2,7,12,18-四甲基-3,8-二乙基-13,17-丙酰基氨乙基联二硫基乙氨基甲酰乙基-29,34-二甲氧甲酰基]-卟啉(MPDTEP, Ⅳ)产率的影响. 将化合物Ⅴ通过自组装修饰于金电极表面, 修饰的金电极通过傅里叶红外光谱(FTIR)和电化学方法进行表征, 研究了其对氧气的电催化还原效果. 相似文献
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天青I修饰电极在pH=5.5的HAc-NaAc缓冲溶液中,在0.3~-0.7V电位范围内表现出可逆的氧化还原行为,其表面式量电位E0'=-0.21V,表观电极反应速率常数ks'=0.69s-1,该电极对血红蛋白的还原过程具有良好的催化作用。实验结果表明,由电沉积构成的修饰电极较吸附法制备的修饰电极具有更好的稳定性。 相似文献
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采用循环伏安法研究了负载金属配合物MnSALEN(SALEN=N,N-双水杨醛缩乙二胺)的磷铝分子筛APO-5复合催化剂修饰玻碳电极在水溶液中对分子氧的还原反应的电催化行为.结果表明,氧气的还原峰电位随扫描速率的增大负移,Ep~lnv呈线性关系;其还原峰电流随扫描速率的增大而增强,ip~v1/2呈直线关系.这说明分子氧在修饰电极PS/MnSALEN/APO-5/GCE上的还原是扩散控制的.根据Ep~lnv和ip~v1/2的线性关系计算出中性电解质溶液中分子氧在此修饰电极上的还原反应的电子转移数n接近4.即氧气在此修饰电极上被还原为水. 相似文献
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以氧化石墨烯(GO)为原料、丙酮肟(DMKO)为还原剂和氮掺杂剂,采用化学还原法制备了不同氮掺杂含量的石墨烯(NG). 利用场发射透射电子显微镜(FETEM)、紫外-可见(UV-Vis)光谱、傅里叶变换红外(FTIR)光谱、X射线光电子能谱(XPS)、zeta 电位和纳米粒度分析、循环伏安(CV)和旋转圆盘电极(RDE)等手段对材料的形貌、结构、成分和电化学性质进行表征. 结果显示:DMKO能有效地还原GO,且通过调节GO与DMKO的质量比,可以得到不同还原效果的NG,其氮含量范围为4.40%-5.89%(原子分数);GO与DMKO的质量比为1:0.7时制备的氮掺杂石墨烯(NG-1)在O2饱和0.1 mol·L-1 KOH溶液中对氧还原反应(ORR)的电催化性能最佳,其ORR峰电流为0.93 mA·cm-2,电子转移数为3.6,这归因于其较高含量的吡啶-N增加了材料的ORR活性位点. 此外,石墨化-N由于其较高的电子导电性倾向于产生较高的氧还原峰电流,而吡啶-N较低的超电势倾向于产生较正的氧还原峰电位. 与商用Pt/C相比,该材料展现出了优异的抗CH3OH“跨界效应”的特性. 相似文献
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采用新型单核铜配合物高氯酸咪唑N-2-羟基乙基二乙烯三胺合铜(Ⅱ)(Cu[L(ImH)](ClO4)2)修饰热解石墨(PG)电极表面制得了Cu[L(ImH)]/PG电极,并采用循环伏安法和电位阶跃实验研究了该电极对氧的催化还原作用. 结果表明,该电极在中性和碱性条件下对氧气的催化还原具有良好的稳定性,还原峰电流随电位扫描速度的增大而增强,Ip~v1/2呈线性关系. 根据电位阶跃实验的I~t-1/2曲线,计算出电极反应的电子转移数约为4, 推断氧气在该电极上的还原是经历了4电子过程还原为水,催化机理属于混合控制的ECE (E电极反应, C化学反应)过程. 相似文献
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Lorella Guadagnini Marco Giorgetti Fabrizio Tarterini Domenica Tonelli 《Electroanalysis》2010,22(15):1695-1701
A study on the performances of mixed hexacyanoferrates of Cu and Pd (CuPdHCFs), potentiodynamically grown on glassy carbon surfaces, was carried out. Morphological (SEM‐EDX analysis) and electrochemical characterizations were performed, and the electrocatalytic ability of films with various compositions was tested by chronoamperometry. CuPdHCFs were found to display good electrocatalytic performances, with a maximum sensitivity of 45.3 mA M?1 cm?2 at 0.0 V vs. SCE (depending on the Cu and Pd ratio), against the value of 9.1 mA M?1 cm?2 obtained with pure copper hexacyanoferrate (CuHCF). Additionally, mixed hexacyanoferrates showed a higher pH and operational stability. The key role of Cu in Cu‐based hexacyanoferrates was investigated and highlighted. 相似文献
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M. Yousef Elahi H. Heli S. Z. Bathaie M. F. Mousavi 《Journal of Solid State Electrochemistry》2007,11(2):273-282
The electrocatalytic oxidation of glucose was investigated on a nickel-basedchemically modified electrode (Ni(II)-curcumin) prepared by electropolymerization of Ni-curcumin complex (curcumin=1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) in alkaline solution. Reaction kinetic and mechanism were investigated by using cyclic voltammetry (CV) and chronoamperometry (CA) techniques and steady-state polarization measurements. Cyclic voltammetry studies indicated that in the presence of glucose the anodic peak current of surface redox mediator was increased, followed by decrease in the corresponding cathodic current. This indicates that glucose was oxidized at the surface of this modified electrode. The results were explained based on the concept of electrocatalytic reactions that occur in this chemically modified electrode. The diffusion coefficient of glucose and the rate constant of the catalytic oxidation of glucose were found to be 6.7×10−6 cm2 s−1 and 6.5×103 M−1 s−1, respectively. It has shown that by using the Ni-curcumin modified electrode, glucose can be determined with good response and low detection limit. 相似文献
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M. Jafarian F. Forouzandeh I. Danaee F. Gobal M. G. Mahjani 《Journal of Solid State Electrochemistry》2009,13(8):1171-1179
Nickel and nickel–copper alloy modified glassy carbon electrodes (GC/Ni and GC/NiCu) prepared by galvanostatic deposition
were examined for their redox processes and electro-catalytic activities towards the oxidation of glucose in alkaline solutions.
The methods of cyclic voltammetry (CV) and chronoamperometry (CA) were employed. The cyclic voltammogram of NiCu alloy demonstrates
the formation of β/β crystallographic forms of the nickel oxyhydroxide under prolonged repetitive potential cycling in alkaline
solution. It is also observed that the overpotential for O2 evolution increases for NiCu alloy modified electrode. In CV studies, NiCu alloy modified electrode yields significantly
higher activity for glucose oxidation compared to Ni. The oxidation of glucose was concluded to be catalyzed through mediated
electron transfer across the nickel hydroxide layer comprising of nickel ions of various valence states. The anodic peak currents
show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion-controlled process.
Under the CA regime, the reaction followed a Cottrellian behavior, and the diffusion coefficient of glucose was found to be
1 × 10−5 cm2 s−1, in agreement with diffusion coefficient obtained in CV studies. 相似文献
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The mechanism of catalytic reduction of peroxydisulfate on the palladized aluminum electrode modified by Prussian blue (PB/Pd‐Al) was studied. The charge transfer‐rate limiting step as well as overall reduction reaction of S2O82? is found to be a one‐electron and two‐electron abstraction respectively. The modified electrode is exploited for the hydrodynamic amperometry of peroxydisulfate. It is found that the calibration graph is linear in the S2O82?concentration range 5×10?6–1.5×10?3 mol L?1. The detection limit of the method was 2.4×10?6 mol L?1 S2O82. The method was successfully used for the determination of S2O82? in decolorizing powders 相似文献
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Dr. Manju P. Maman Dr. Tamilselvi Gurusamy Dr. Arun K. Pal Dr. Rajkumar Jana Dr. Kothandaraman Ramanujam Dr. Ayan Datta Dr. Sukhendu Mandal 《Angewandte Chemie (International ed. in English)》2023,62(27):e202305462
The fixing of N2 to NH3 is challenging due to the inertness of the N≡N bond. Commercially, ammonia production depends on the energy-consuming Haber-Bosch (H−B) process, which emits CO2 while using fossil fuels as the sources of hydrogen and energy. An alternative method for NH3 production is the electrochemical nitrogen reduction reaction (NRR) process as it is powered by renewable energy sources. Here, we report a tiara-like nickel-thiolate cluster, [Ni6(PET)12] (where, PET=2-phenylethanethiol)] as an efficient electro-catalyst for the electrochemical NRR at ambient conditions. Ammonia (NH3: 16.2±0.8 μg h−1 cm−2) was the only nitrogenous product over the potential of −2.3 V vs. Fc+/Fc with a Faradaic efficiency of 25%±1.7. Based on theoretical calculations, NRR by [Ni6(PET)12] proceeds through both the distal and alternating pathways with an onset potential of −1.84 V vs. RHE (i.e., −2.46 V vs. Fc+/Fc) which corroborates with the experimental findings. 相似文献
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A sensitive and selective electrochemical method for the determination of epinephrine(EP) was developed using a modified carbon paste electrode(MCPE) with 2,2’-[3,6-dioxa-1,8-octanediylbis(nitriloethylidyne)]-bis-hydroquinone(DOH).Cyclic voltammetry was used to investigate the redox properties of this modified electrode at various solution pH values and at various scan rates.In differential pulse voltammetry,the modified electrode could separate the oxidation peak potentials of EP and uric acid(UA) present in the solution but at the unmodified CPE the peak potentials were indistinguishable.This method was also examined for determination of EP in EP injection. 相似文献
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The chemically modified electrode constructed by chemically cross-linking of redox mediator thionin with toluene diisocyanate(TDI) directly at the surface of a spectrographic graphite electrode shows a significant electrocatalytic activity to the oxidation of reduced nicotinamide adenine dinucleotide(NADH) with oxidation overpotential reduced by 310mV.In the potential range from-0.1 to 0.3V,the adsorbed thionin -TDI behaves as a one electron and one proton reversible redox process. The modified electrode achieves a steady-state current of NADH within 20s and the detection limit is about 1.5μm. 相似文献
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Copper hexacyanoferrate (CuHCF) film‐modified carbon paste electrode (CPE) has been prepared from various electrolytic aqueous solutions using consecutive cyclic voltammetry. The cyclic voltammograms showed the direct deposition of CuHCF films from the mixing of Cu2+ and Fe(CN)63? ions and each time with one of the six cations: H+, Na+, K+, NH4+, Mg2+, and Al3+. The CuHCF film showed a single redox couple that exhibited a cation effect (Na+, K+, Mg2+, and NH4+) and anion effect (Cl?, NO3?, SO42?, ClO4?, and BrO3?) in the cyclic voltammograms. Voltammetric studies have indicated that in presence of nitrite, the cathodic peak current of CuHCF increases, followed by a decrease in the corresponding anodic current. This indicated that nitrite was reduced by the redox mediator immobilized on the electrode surface via an electrocatalytic mechanism. The process of reduction and its kinetics were investigated by using cyclic voltammetry, differential pulse voltammetry, chronoamperometry and chronocoulometry techniques. The electrocatalytic ability about 800 mV can be seen. The rate constant of the catalytic reduction of nitrite was found to be 7.9×105 cm3 mol?1 s?1. Linearity range obtained was 5×10?5?8.4×10?3 by cyclic voltammetry and 8×10?6?1.3×10?3 and 4×10?3?2×10?2 by differential pulse voltammetry. 相似文献
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Peroxidase‐like layered double hydroxide (LDH) nanoflakes were synthesized directly and facilely by a one‐pot chemical method, hydrothermal treatment. The as‐prepared LDHs were characterized by transmission electron microscopy, scanning electron microscopy, X‐ray diffraction, Fourier transform IR, and cyclic voltammetry. The functionalized LDHs immobilized on the glassy carbon electrode exhibited a well‐defined pair of redox peaks, excellent electrocatalytic activity toward the reduction of hydrogen peroxide without inhibition of dissolved oxygen and a higher affinity for H2O2, just like the peroxidase. The low apparent Michaelis–Menten constant was only 242 μM. The electrochemical response to H2O2 shows a linear range of 12–254 μM with the calculated detection limit of 2.3 μM at a signal‐to‐noise ratio of 3. Furthermore, compared with most metal hexacyanoferrates, the peroxidase‐like LDHs are very stable in neutral and alkaline solution. The electrochemical and electrocatalytic behavior of the functionalized LDHs indicate that they may be useful to explore man‐made mimics of enzyme in electrochemical biosensors. 相似文献