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61.
A chemically modified electrode was successfully fabricated by means of depositing a thin layer of nickel hexacyanoferrate (NiHCF) on an amine adsorbed graphite paraffin wax composite electrode using a new approach. The electrode was further coated with Nafion. The electrochemical characteristics of the modified electrode were studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified electrode catalyzed dopamine (DA) oxidation in the concentration range of 1.5×10?6 to 1.2×10?3 M without the interference from ascorbic acid (AA). A detection limit of 4.9×10?7 M was obtained for DA in the presence of AA with a correlation coefficient of 0.9972 based on S/N=3. Flow injection analysis was used for the determination of dopamine with excellent reproducible results. The analytical utility of the sensor was evaluated for detection of DA in urine. 相似文献
62.
4-Aminobenzoic acid (4-ABA) was covalently grafted on a glassy carbon electrode (GCE) by amine cation radical formation during the electrooxidation process in 0.1 M KCl aqueous solution. X-ray photoelectron spectroscopy (XPS) measurement proves the presence of 4-carboxylphenylamine on the GCE. Electron transfer processes of Fe(CN)63− in solutions of various pHs at the modified electrode are studied by both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Changing the solution pH would result in the variation of the terminal group's charge state, based on which the surface pKa values were estimated. The copper hexacyanoferrate (CuHCF) multilayer films were formed on 4-ABA/GCE prepared in aqueous solution, and which exhibit good electrochemical behavior with high stability. 相似文献
63.
采用共沉淀法制备了Co3O4/Ce0.8Pr0.2O2催化剂,并将其用于乙醇水蒸气重整制氢反应,考察了Co3O4负载量以及Pr掺杂对催化剂性能的影响.采用X射线衍射、程序升温还原、热重分析和透射电子显微镜对催化剂的结构和表面性质进行表征.结果表明,催化剂中部分Co进入到载体的晶格中,使载体发生畸变产生更多的氧空位;载体中Pr掺杂有利于生成更多的氧空位,提高了催化剂的抗积碳性能,同时Pr掺杂可以增强Co3O4与载体之间的相互作用,提高金属Co的抗烧结性能;15%Co3O4/Ce0.8Pr0.2O2催化剂具有最好的催化活性,在反应温度为400℃,空速80 000 mL/(g.h),n(H2O)∶n(EtOH)=3的条件下可将乙醇完全转化;10 h稳定性测试结果表明该催化剂具有较好的稳定性. 相似文献
64.
《Journal of Coordination Chemistry》2012,65(14):1527-1535
Two new complexes, {[Pr(2-IBA)3?·?2,2′-bipy]2·[Pr(2-IBA)3?·?2,2′-bipy]2?·?0.5C2H5OH?·?H2O} (1) and [Pr(2-IBA)3?·?phen]2 (2) (2-IBA?=?2-iodobenzoate; 2,2′-bipy?=?2,2′-bipyridine; phen?=?1,10-phenanthroline) were synthesized, and their crystal structures were determined by X-ray diffraction. Complex 1 consists of two binuclear molecules [Pr(2-IBA)3?·?2,2′-bipy]2 (a) and [Pr(2-IBA)3?·?2,2′-bipy]2 (b), half uncoordinated ethanol and one uncoordinated water. In the two molecules (a) and (b), the coordination environment of central ions is similar. The Pr13+ ion in molecule (a) and Pr23+ ion in molecule (b) are nine-coordinate with seven oxygen atoms from five 2-IBA ligands and two nitrogen atoms from one 2,2′-bipy molecule. The crystal structure of complex 2 is similar to that of binuclear [Pr(2-IBA)3?·?2,2′-bipy]2 in complex 1. 相似文献
65.
Continuous Flow Determination of Blood Alcohol Using Biamperometric Monitoring of Enzymatic Reaction
《Analytical letters》2012,45(7):1099-1113
Abstract Ethanol was determined by reaction with NAD in the presence of alcohol dehydrogenase in a continuous flow system. NADH produced was allowed to react with hexacyanoferrate (III) in the presence of diapharase. The concentration of the produced hexacyanoferrate (II) was monitored biamperometrically using open tubular carbon electrodes. A level of 1.5 × 102 mg/100 ml ethanol was detected, with an average precision of 4% relative standard deviation. The ethanol level in blood samples was determined, obtaining a 0.08 correlation coefficient with gas chromatography results. 相似文献
66.
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68.
在R-G理论的基础上,考虑了无辐射弛豫过程对位相信号的影响,推导出新的位相公式。研究结果表明,位相(ψ)与吸收系数(β)、热扩散长(μs)、弛豫时的延迟时间(τ)和快弛豫与慢弛豫时的热量比(R)有关。并用此公式解释了稀土化合物PrF3和叶绿素b的位相谱。PrF3的位相由f-f跃迁的吸收系数决定,而叶绿素b两个吸收带之间的位相差是由快弛豫与慢弛豫时放出的热量比不同产生的。 相似文献
69.
70.
六氰合铁酸铜钴薄膜修饰铂电极的电化学、XRD及XPS研究 总被引:4,自引:0,他引:4
采用循环伏安法在铂电极上电聚合了六氰合铁酸铜钴薄膜,并用电化学、XRD 和XPS对该薄膜进行了表征。研究表明此薄膜属于取代型的多核六氰合铁酸盐,由 Cu~(2+),Co~(2+)和Fe~(2+)共同占据晶格格点。通过改变Cu~(2+),Co~(2+)和 Fe~(3+)在沉积液中的比例可以改变聚合膜的性质。随沉积液中Cu~(2+)含量的增加 ,聚合膜中铜的含量相应增加而晶格常数则逐渐减小,但保持着面心立方的晶格对 称性。当沉积液中Cu~(2+):Co~(2+):Fe~(3+) = 1:1:2时,得到的聚合膜具有比较 典型的性质,该薄膜修饰的铂电极在pH 4~10之间均能保持着稳定的电化学响应。 其对一价阳离子的选择性顺序为K~+ > Li~+ > Na~+ > NH_4~+,与单组分的六氰铁 酸酮和六氰合铁酸钴都存在着较大的差别。XPS实验表明氧化态薄膜中铁元素以Fe (III)存在,并且在X射线的照射下很快转化为Fe(II)。 相似文献