Studies On The Application Of Carbon Nanotubes Film Modified Electrodes In Detection And Reaction Mechanism Of Typical Azo Compound

In this dissertation, a multiwall carbon nanotubes (MWCNT) modified glassy carbon electrode (GCE) was prepared by casting MWCNT suspension on the surface of the GCE. Evaporation of solvent from such a solution yielded robust surface film contained MWCNT. The MWCNT/GCE can greatly catalyze the oxidation of–OH in Sudan I. Consequently, an amperometric sensor for Sudan I was proposed. The amperometric sensor has excellent performance associated with high sensitivity (21.56μA mM-1), low detection limit (3.46×10-8 M) and wide linear range (1.01×10-6~1.22×10-4 M). The MWCNT/GCE can also minimize the fouling effect of the electrode surface and showed very good short-time stabilityAdditionally, the electrochemical reaction mechanism of Sudan I has been investigated at the MWCNT modified GCE (MWCNT/GCE) in phosphate buffer solution (PBS) with various pH values. Cyclic voltammetry, controlled-potential electrolysis and UV-vis spectrophotometry studies showed that the reduction of–N=N– group in Sudan I yields aniline andα-amino naphthol through the intermediate product hydrazo. The whole reaction processes were proved to be the ECE mechanism. When the pH was above 5, another process took place and the ultimate products were same as in acidic solution.