An iron(III)-containing ionic liquid: characterization, magnetic property and electrocatalysis

The present work reports on the synthesis, characterization and performance of a new iron(III)-containing ionic liquid [(C4H9)2-bim][FeCl4] (Fe-IL, bim = benzimidazolium) as an electrocatalyst for nitrite and bromate reduction. The melting point of Fe-IL is 70 °C. Thermal behavior of the Fe-IL was studied by differential scanning calorimetry and thermalgravimetry. The value of magnetic moment and its temperature dependence were measured. A conductive carbon paste electrode (Fe-IL/CPE) comprised of Fe-IL and carbon powder was fabricated by the direct mixing method. The Fe-IL has double functions—a binder and an electrocatalyst. The electrochemical behavior and electrocatalysis of Fe-IL/CPE have been studied by cyclic voltammetry. The Fe-IL/CPE shows excellent electrocatalytic activities toward nitrite and bromate reduction. The detection limit and the sensitivity are 0.01 μM and 100.58 μA μM−1 for nitrite, and 0.01 μM and 83.11 μA μM−1 for bromate detection, respectively. This work demonstrates that the Fe-IL may become a new kind of functional material in constructing chemicals and biosensors.