碳纳米结构负载铋膜电极测定水中铅和镉

Preparation of carbon-based nanostructure supported bismuth film electrodes for stripping voltammetric determination of Pb(Ⅱ) and Cd(Ⅱ)

将表面具有纳米结构的双面碳导电胶带直接粘附在氧化铟锡(ITO)导电玻璃上,并以其为基底,采用离子溅射法溅射铋膜,制备了一种新型可抛式铋膜电极。该电极可以集成于纸基分析系统中使用,对Pb(II)和Cd(II)具有良好的溶出伏安响应。对电极制备过程的关键技术(溅射时间和溅射电流)进行了优化。在最优条件下,该电极对Pb(Ⅱ)的检测限为5μg/L,对Cd(Ⅱ)的检测限为3μg/L(S/N=3)。相比于电沉积法制备的铋膜修饰电极,该电极具有更好的重现性,并可实现批量制备。应用该电极对实际水样中Pb(Ⅱ),Cd(Ⅱ)进行测定,其结果与原子吸收光谱法的测定值一致。

A type of disposable bismuth film electrodes was fabricated by sputtering bismuth on an ITO glass which was attached with nanostructured conductive carbon tape. The proposed electrode was available to differentiate Cd （Ⅱ） and Pb （Ⅱ） ions based on stripping voltammetric analysis. After optimization, Cd（Ⅱ） and Pb （Ⅱ） could be measured in the linear range from 0 to 500 μg/L with the detection limits of 3 μg/L and 5 μg/L （S/N = 3）, respectively. Compared to those fabricated by electrochemical deposition approach, bismuth film electrodes via sputtering have better reproducibility and take the advantage of mass production. The electrode-byelectrode and batch-by-batch reproducibility were satisfactory. These electrodes were applied to quantifY Cd（Ⅱ） and Pb （Ⅱ） in real samples with results in agreement with those obtained by atomic absorption spectrometry （AAS）.