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介绍了超微半球电极上具有简单反应时的半微分循环伏安理论。理论表明,超微电极上半微分电流与电活性物质的浓度成正比,并据此提出了一种利用超微半球电极上半微分曲线进行电化学分析测量的新方法。该法具有灵敏度高、分辨率好等特点。 相似文献
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对插型阵列微带电极的制作及其电化学特性研究 总被引:1,自引:0,他引:1
用微电子光刻方法制作了对插型阵微带电极(IDA),并通过SEM对IDA电极进行了表征,将微Ag/AgCl参比电极和微铂丝对电极固定在IDA电极附近,构成了微电解池,考察了该电极的循环伏安及计时电流特性,并用微带电极的扩散理论和Cottrell 公式对IDA电极的准稳太电流进行了处理,指出了它们之间产生偏差的原因,研究了IDA电极的“发生-收集”效应,测定了该电极的屏蔽因子、反馈因子和收集效率。 相似文献
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Blaedel等曾证明管式电极在层流条件下的扩散电流方程,随后在管式电极上对极谱催化电流进行了研究,但该理论只适用于化学反应非常快及非常慢的情况。Koichi等运用与Blaedel不同的处理方法,导出了通道电极上更为精确的催化电流方程。 相似文献
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用12根直径7μm碳纤维均匀胶结在外径1mm、内径0.4mm的有机玻璃毛细管外围,形成组合超微园盘电极。并与Ag/AgCl参比电极和铂丝辅助电极构成复合三电极系统。在K3Pe(CN)6/K4Pe(CN)6和Cd^2 /KCl溶液体系中,测定了这种复合式的组合超微电极的循环伏安特性和阶梯扫描伏安特性。理论计算与实验曲线一致。该电极系统具有良好的组合超微电极的性能。由于单电极间距离远大于本身直径,扩散场互不干扰,因此,组合超微电极的响应具有加和性。应用这种复合超微电极,测定了工业污水中的镉含量,与普通极谱法测定结果一致。 相似文献
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选择以钛为基体,锡、钌、锰的氧化物为中间层,二氧化锰为表面层,用热分解方法制备了二氧化锰电催化剂,用EDS、SEM、XRD对电极进行表征.电催化剂表层主要是β-MnO2;通过SEM图片,用BMP图形文件计算出该电极的分形维数(D=2.4240(200),D=2.4258(1000)).说明该电极表面粗糙度高,符合多孔催化剂的要求,同时用分子轨道理论讨论了MnO2的稳定性,结合放氧反应机理和双位垒模型探讨了电极组成对动力学参数的影响.结果表明,此种电催化剂性能良好. 相似文献
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本文报道超微盘电极上双电位阶跃计时电流和计时库仑法理论,用自制的微机多功能电分析仪及亚铁氰化钾、氯化钾体系进行验证,实验结果与理论相符合. 相似文献
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本文提出了超微盘电极上准稳态可逆波循环伏安理论, 并对环形氧化还原波的性质进行了深入的讨论, 选择K~4Fe(CN)~6KCl体系在铂微盘电极上对理论进行验证, 实验结果与理论相符合。 相似文献
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本文推导了微环电极上常规脉冲伏安法电流方程式,对伏安曲线的性质进行了探讨.利用K~4Fe(CN)~6·KCl体系及金和铂微环电极对理论进行了验证,理论与实验结果相符. 相似文献
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线性扫描伏安法研究 II: 超微盘电极上催化电流理论 总被引:1,自引:0,他引:1
本文提出了超微盘电极上线性扫描伏安法催化电流理论及恒电位催化电流方程式,证实在k~1~1~z值足够大的条件下, 两种方法具有相同的电流-电位方程式。对理论进行了验证, 测定了亚铁氰化钾-氨基比林-氢氧化钾体系的化学反应速率常数(k~f)。 相似文献
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阶梯扫描催化伏安法及其卷积和导数的研究 总被引:2,自引:0,他引:2
本文系统研究了静态电极下阶梯扫描平行催化伏安法及其各阶导数卷积和导数的理论。推导了这一伏安法的催化电流及其各阶导数卷的导数的理论方程, 在此基础上建立了一组简便测定化学反应速率常数的新方法。并以Ti(IV)-KClO3,Ti(IV)-NH2OH, Yb(III)-KNO3和YB(III)-NaNO2四个平行催化体系从实验上验证了理论的正确性, 同时用本文提出的新方法测定了这四个体系的化学反应速率常数,结果良好. 相似文献
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Sumio Hamada Makoto Itoh Hiroaki Matsuda Joseph Yamada 《Journal of Electroanalytical Chemistry》1978,91(1):107-114
A new electrolysis cell for the use in hydrodynamic voltammetry is devised, in which a stationary disk or ring electrode is immersed coaxially in a rotational flow produced by a uniformly rotating disk (rotor) and works as an indicator electrode. Theoretical equations of the limiting diffusion currents at such a disk or ring electrode are derived. The theoretical predictions for the dependence of the limiting diffusion current upon various experimental variables, i.e., the rotation speed of the rotor, the bulk concentration of depolarizer, the geometrical parameter of the electrode and the viscosity of the solution, are verified experimentally for the reduction of ferricyanide ions. 相似文献
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The mechanism of the electrogenerated chemiluminescence of luminol in aqueous alkaline solution based on the rotating ring—disc electrode system is discussed. The disc electrode is maintained at a negative potential and the ring electrode at a symmetrically changing double-step potential. Hydrogen peroxide generated at the disc electrode by the reduction of oxygen is immediately transported to the ring electrode because of electrode rotation. Hydrogen peroxide and luminol are oxidized at the ring electrode during the positive pulse of the double-step potential. These oxidation processes generate a superoxide radical and a luminol radical as intermediates. The luminol radical reacts with the superoxide radical (or oxygen) emitting light. 相似文献
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《Electrophoresis》2018,39(19):2460-2470
This study uses negative dielectrophoresis and AC electroosmosis as a driving mechanism and presents an electrically driven microconcentrator that concentrates the sample in the region exterior to the electrodes (termed as exterior‐electrode electrically driven microconcentrator in this paper). The proposed microconcentrator uses a 3‐D face‐to‐face electrode pair; the top electrode is a relatively large planar electrode, and the bottom electrode is formed with three to six long and thin electrodes connected into an open ring. The sample is brought to the vicinity of the open electrode at the bottom by electroosmotic flow; then, negative dielectrophoresis is used to push the sample away from the electrode and concentrate it in the region surrounded by the open ring electrode. Concentration using an exterior‐electrode electrically driven microconcentrator offers promise for convenient use in conjunction with relevant detection systems. The results indicate that for the proposed exterior‐electrode electrically driven microconcentrator, the optimal frequency is 100 kHz and the optimal voltage is 13 Vp‐p. The corner concentration process at the corners of the bottom open electrodes enables the multi‐corner electrodes to exhibit better concentration results than that exhibited by semicircular‐shaped electrodes. The concentration performance is most favorable when the shape of the open electrode at the bottom is a five‐vertex electrode, enabling a concentration enhancement factor of 55 times for a latex particle solution and 11 times for E. coli. The experimental results also demonstrate that the concentration phenomenon in this study is not induced by non‐specific adsorption and can be repeated multiple times. 相似文献