Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite elec...Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite electrode has high specific surface area and high current density. The electrode modified by transition metallic ions has improved catalysis behavior that can catalyze the V（Ⅱ）-V（Ⅴ） redox reaction showed by cyclic voltammograms. This article studied the impedance of the modified electrode by electrochemical impedance spectroscopy （EIS）, and approved that the electrode modified by Co^2＋ and Mn^2＋ has a lower charge transfer resistance than the non-modified electrode. The effect of average particle size distribution is at lower frequencies that the slope of Warburg impedance is reduced by large particle size distribution. The voltage efficiency of the Co^2＋ modified electrode test cell is 81.5%, which is higher than that of the non-modified electrode.展开更多
采用直接滴涂法制备多孔磁性微球/过氧化物酶(PMMS/POD)修饰的碳糊电极。运用电化学阻抗法、循环伏安法和稳态安培法对该修饰电极进行表征和研究。系统地考察了底液pH值,扫描速率对修饰电极影响,找出最佳实验条件。计算出扩散系数D为5.0...采用直接滴涂法制备多孔磁性微球/过氧化物酶(PMMS/POD)修饰的碳糊电极。运用电化学阻抗法、循环伏安法和稳态安培法对该修饰电极进行表征和研究。系统地考察了底液pH值,扫描速率对修饰电极影响,找出最佳实验条件。计算出扩散系数D为5.03×10-10cm2.s-1,表征酶活性的米氏常数为0.069 m mol.L-1.在优化条件下,该H2O2传感器的响应时间小于10s,考察了该修饰电极对H2O2稳态安培响应,在0.1m mol.L-1～0.8 m mol.L-1浓度范围内,稳态安培电流与H2O2浓度成较好线性关系,检测限为0.03 m mol.L-1(S/N=3).展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 90510001).
文摘Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite electrode has high specific surface area and high current density. The electrode modified by transition metallic ions has improved catalysis behavior that can catalyze the V（Ⅱ）-V（Ⅴ） redox reaction showed by cyclic voltammograms. This article studied the impedance of the modified electrode by electrochemical impedance spectroscopy （EIS）, and approved that the electrode modified by Co^2＋ and Mn^2＋ has a lower charge transfer resistance than the non-modified electrode. The effect of average particle size distribution is at lower frequencies that the slope of Warburg impedance is reduced by large particle size distribution. The voltage efficiency of the Co^2＋ modified electrode test cell is 81.5%, which is higher than that of the non-modified electrode.
文摘采用直接滴涂法制备多孔磁性微球/过氧化物酶(PMMS/POD)修饰的碳糊电极。运用电化学阻抗法、循环伏安法和稳态安培法对该修饰电极进行表征和研究。系统地考察了底液pH值,扫描速率对修饰电极影响,找出最佳实验条件。计算出扩散系数D为5.03×10-10cm2.s-1,表征酶活性的米氏常数为0.069 m mol.L-1.在优化条件下,该H2O2传感器的响应时间小于10s,考察了该修饰电极对H2O2稳态安培响应,在0.1m mol.L-1～0.8 m mol.L-1浓度范围内,稳态安培电流与H2O2浓度成较好线性关系,检测限为0.03 m mol.L-1(S/N=3).
