Hydrazine Hydrate In The Ionic Liquid Electrochemical Behavior Of Gas Sensor Research

Ionic liquids (ILs) are salts, which consist of ions, and are liquid around the roomtemperature. Compared with traditional organic solvents, they show many uniqueproperties both in physics and chemistry. Room-temperature ionic liquids attract moreand more interests for chemical researches especially electrochemistry. Hydrazine is akind of important materials in industry, medicine, agriculture and so on. On the otherhand, it is harmful to health, environment and equipment. This thesis focused on theelectrochemical behavior of hydrazine in ionic liquid (BmimPF6) at different kinds ofelectrodes, including metal electrodes and cobalt tetraaminophthalocyanine (CoTaPc)modified electrode. And then, an electrochemical hydrazine gas sensor, usingBmimPF6 thin films as the electrolyte, was developed. Some conclusions obtained areshowed in follow:1) The electrochemical behavior of hydrazine on Au microelectrode withBmimPF6 as the electrolyte was studied by cyclic voltammetry. Results suggested thathydrazine could be oxidized at the potential of 0.94 V vs. Pt with the apparent electronnumber of 0.8. The electrochemical reaction was under the diffusion control ofhydrazine in BmimPF6. And also, an electrochemical hydrazine gas sensor, usingBmimPF6 thin films as the electrolyte, was fabricated. The sensor showed a linearresponse to the hydrazine gas concentrations in the range of 1.1~25.4μmol/L, with agood stability and reproducibility.2) The electrochemical behaviors of hydrazine in BmimPF6 on Pt, Cu and Auelectrodes are studied. Results suggested that the oxidized surface layer of Cuelectrode will influence the redox behavior of hydrazine, and the reaction mechanismof hydrazine at Pt and Cu electrodes are complicate.Ag is the most suitable one as the working electrode in three mental ones.Ag+(IL)/Ag(s)could be produced at the potential of 0.16V. Ag+(IL) obtained cancatalyze the oxidation of hydrazine with the electron number of 1. Theelectrochemical reaction was under the diffusion control of hydrazine.3) Electrochemically prepared thin films of CoTaPc were used as surface modifiers for glassy carbon electrodes. The CoTaPc films on glassy carbon electrodes showexcellent electrocatalytic activity toward the oxidation of hydrazine in BmimPF6.Hydrazine could be oxidized at the potential of 0.28 V. The electrochemical reactionwas under the diffusion control of hydrazine in BmimPF6. The modified electrodesshow a linear response to the hydrazine concentrations in the range of 0-14.9 mmol·L-1, with a good stability and reproducibility.