碳纤维组合超微园盘电极的伏安特性与理论验证

Voltammetric Characteristics and Theory Proofing for Ensembles of Ultra-micro Disc-electrode of Carbon Fibers

用 1 2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K3Fe(CN) 6 K4Fe(CN) 6 和Cd2 + /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 。

The ultra-micro disc-electrode was combined by adhering 12-carbon fibers of 7 mum diameter to the external surface of an organic glass capillary of 1 mm diameter. Utilizing organic glass capillary as salt bridge of reference electrode, the ultra-micro disc-electrode was combined with Ag/AgCl-electrode and Pt-wire auxiliary electrode into three-electrode system. The cyclic voltammetric characteristics and the step scanning voltammetric characteristics of the ensembles of ultra-micro disc-electrode were determined in the solution systems of K3Fe(CN)(6)/K4Fe(CN)(6) and Cd2+/KCl. Experimental results proved that this electrode possess the good functions of ensembles of ultra-micro disc-electrode. The experimental curves were fully consistent with those calculated from theory. Because the interval between single electrodes was longer thin their diameters their diffusion layer of each electrode was not influenced the conten of cadmium in industrial sewage was determined. Measured value was consistent with that of polarographic result.