Yuxi Zhang, Jingtao Liu, Fei Xie, Fengchun Yang, and Xing Zhai. Carboxylic Multiwalled Carbon Nanotubes for the Detection of RHB in Water. Dynamic Systems and Applications 29 (2020) No. 7, 2426 – 2444

https://doi.org/10.46719/dsa20202975

ABSTRACT.
With the increasing serious pollution of dye chemical industry, rapid detection technology for RhB in water environment has gradually aroused concern. As one common detection method, electrochemistry boasts advantages of fast testing, simple operation and low cost, thus enjoying great development potential. In this study, an electrochemical electrode for detecting MWNTs-COOH/GCE in RhB was prepared. Electrochemical performance of the electrode oxidized RhB was studied via CV, EIS, DPV and CC methods. The experimental pH value and voltage were optimized, and stability and anti-interference test were performed. The results indicate that carboxylation increases hydrophilicity of MWNTs, removes unstable oxygen-containing groups so that more activated carbon sites are available. Under the optimal experimental conditions, the linear range of RhB is determined by current-time method to be 0.05-850 µM. The two linear equations are respectively Ip(µA)=0.02078C(µM)+0.04905(R=0.9960) and Ip(µA)=0.01318C(µM)+1.28805(R=0.9962), the detection limit is 2.66 nM, S/N=3. Compared with other electrode materials, MWNTs-COOH/GCE has a lower detection limit and a wider linear detection range, which enjoys a good application prospect for detecting RhB in water.

Keywords: multiwalled carbon nanotubes; electrochemical detection; i-t method; RhB.