Determination of Cd(II) by square wave anodic stripping voltammetry using graphene oxide/single-walled carbon nanotubes/Bi2Te3 modified glassy carbon electrode

• Main Authors: Chia-Chi Wahang, 張佳琦
• Other Authors: Ching-Ju Chin
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/b6x74h

碩士 === 國立中央大學 === 環境工程研究所 === 107 === Cadmium is highly toxic and ingestion by humans may harm to humans, such as bone, kidney function, and respiratory system. At present, the method of analyzing heavy metals require pretreatment and long time so it cannot give the results of water quality promptly. However, electrochemical voltammetry is valued due to its advantages of convenient operation, low cost, simplicity and rapid analysis. In this study, determination of Cd(II) by square wave anodic stripping voltammetry using graphene oxide/single-walled carbon nanotubes/Bi2Te3 modified glassy carbon electrode was developed. First, the appropriate voltammetric scanning method is selected, and then the SWCNT/GO ratio was confirmed. The performance of the modified electrode in detecting Cd(II) at 120 s and 360 s was investigated after parameter optimization (electrolyte pH 5, deposition potential -1.1 V). The stability of the electrode was also evaluated. The results showed that the GO/SWCNT/Bi2Te3/GCE can successfully determine Cd(II) by SWASV. At a deposition potential of 120 s, the LOD is 0.99 μg/L; at a deposition potential of 360 s, the LOD is 0.14 μg/L, which is lower than the effluent standard (20–30 μg/L) and the drinking water standard (5 μg/L). Repeatability and reproducibility were 2.6% and 3.7%, respectively. Moreover, the electrode developed in this work is also free from the interference of Pb(II), Zn(II), Cr(III), Cr(VI), As(III), As(V) in water, but the stripping current of Cd(II) is easily affected by high concentration copper due to the low reduction potential of Cu(II). Finally, the analysis of Cd(II) in environmental waters confirmed the good recovery in tap water and groundwater.