共查询到19条相似文献,搜索用时 46 毫秒
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纳米碳管电极上氧的电催化还原 总被引:5,自引:0,他引:5
以聚四氟乙烯为粘结剂制成了多壁纳米碳管(MWNT)电极.采用恒电位阶跃法和循环伏安法研究了MWNT电极在碱性溶液中的电化学行为,并对碱性溶液中溶解氧在该电极上的电化学还原行为进行了研究.实验结果表明: MWNT电极具有比石墨电极更高的孔隙率和电化学表面积;MWNT电极上O2还原成的反应为准可逆过程;在5~50 mV•s-1的扫描速率范围内,阴极峰电流与扫描速度成线性关系,表明MWNT电极上O2还原成的反应受吸附控制;对碱性溶液中的氧还原反应, MWNT比石墨具有更高的催化活性. 相似文献
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研制了单壁碳纳米管(SWCNTs)修饰玻碳电极。用交流阻抗谱法(EIS)和扫描电镜(SEM)研究了电极膜性能,应用循环伏安法(CV)、计时库仑法(CC)、计时电流法(CA)研究了蒿甲醚在修饰电极上的电化学行为。结果表明,SWCNTs修饰电极对蒿甲醚的还原有良好的电催化活性,其还原反应为双电子过程,电极反应的扩散系数及速率常数分别为6·67×10-4cm2·s-1及8·54×10-2mol·L-1·s-1。在优化实验条件下,还原峰的峰电位位于-0·85V,其峰电流与蒿甲醚浓度在6·71×10-7~2·45×10-4mol·L-1范围内呈良好线性,检出限达4·02×10-7mol·L-1,相对标准偏差(n=10)为4·2%,可用于蒿甲醚样品的含量测定。 相似文献
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在含20%乙醇的Britton-Robinson缓冲液介质(pH=7.2)中,采用循环伏安法在玻碳电极和银电极上比较了血红素对青蒿素还原的催化作用. 由于血红素和青蒿素加合物的形成及血红素中Fe2+的催化作用,青蒿素在玻碳电极和银电极上的还原过电位分别降低了0.32和0.09 V,还原活化能分别降低了62.1和17.6 kJ/mol. 还比较了血红素和配合物EDTA-Fe3+对青蒿素的催化还原效果,结果表明,EDTA-Fe2+的催化作用远低于血红素. 进一步证实了血红素在青蒿素的药理研究中起着关键作用. 相似文献
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酸性溶液中离子注入钯的玻璃碳电极上硝基苯的电化学还原 总被引:3,自引:0,他引:3
用循环伏安法在离子注入钯的玻璃碳电极上,研究了硝基苯在0.5mol/L硫酸溶液中的电还原过程,通过AES测量了离子注入电极的表面组成和各元素的浓度-深度分布,在40keV下,注入剂量为1×l0 ̄(17)离子/cm_2的钯注入到玻璃碳(GC)中可产生钯原子最大百分含量为20%的近表面区。原基体注入钯后比未注入的GC对硝基苯(NB)的电还原有更高的活性,用气相色谱法检测到NB的还原产物苯胺,讨论了硝基苯在酸性溶液中电化学还原机理。 相似文献
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The colloidal Au nanoparticles-deoxyribonucleic acid (Au(nano)-DNA) film modified glassy carbon electrode (GCE) has been fabricated and the electrochemical reduction of dioxygen (O(2)) at this modified GCE has been studied in 0.2 mol/L air-saturated acetate buffer (pH=5.2) using cyclic voltammetry (CV), chronocoulometry (CC), linear scan voltammetry (LSV) and rotating disk electrode (RDE) as diagnostic techniques. The modified electrode shows excellent enhancement effect towards the reduction of dioxygen to hydrogen peroxide (H(2)O(2)), and the overpotential is lower than that at bare GCE. A well-defined dioxygen reduction peak appeared at about -0.24 V. Based on experimental results, a reaction mechanism is proposed and discussed. 相似文献
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V. V. Novikova S. P. Starodubova M. Yu. Chaika T. A. Kravchenko 《Russian Journal of Electrochemistry》2013,49(3):278-284
Silver particles are formed by electrochemical deposition on the carbon electrode surface. It is found that the deposition process occurs according to the progressive nucleation mechanism, which results in formation of silver particles with the size of 95 to 190 nm as dependent on the electrodeposition time. The values of silver particle size and support surface coverage by metal obtained on the basis of microphotographs indicate that cathodic polarization in the presence of dissolved oxygen results in particle size redistribution due to the reaction of silver particle dissolution with further deposition simultaneously with oxygen electroreduction. The reaction of molecular oxygen electroreduction on a carbon electrode with deposited dispersed silver occurs via a mixed two- and four-electron mechanism. The observed limiting reaction current is of diffusion nature. 相似文献
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Kh. B. Kushkhov M. K. Vindizheva R. A. Karashaeva 《Russian Journal of Electrochemistry》2006,42(8):830-835
The mechanism of electroreduction of cerium ions in equimolar KCl-NaCl melt is explored at 973 K. The effect of the anionic composition of the melt on the electroreduction of cerium ions is studied. It is shown that the electrodeposition of metal cerium from halide melts on a silver electrode is the primary electrochemical process that occurs at potentials more positive than those corresponding to the supporting-electrolyte decomposition. The electroreduction of chloride complexes of cerium on a silver electrode in the melt in both steady-and non-steady-state polarization modes at rates below V ≤ 0.5 V/s is limited by the diffusion delivery; at higher polarization rates, the charge-transfer stage predominates. 相似文献
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A gold electrode modified with copper complexes containing a tridentate aromatic amine compound (bis(6-methyl-2-pyridylmethyl)amine ethyl sulfide, which is a model for the nitrite reduction centre of copper-containing nitrite reductase, catalyzed electrochemically the reduction of nitrite to nitrogen monoxide under acidic conditions. 相似文献