Preparation And Electrochemical Catalytic Properties Of Ionic Liquid Functionalized Mesoporous Silica Modified Electrode

Mesoporous silica had incomparable advantages such as high surface area, controllable pore size, thermal and mechanical stability, etc. which were of considerable interest for those potential applications in electrochemical sensors and biosensor. Room temperature Ionic liquids（RTILs）modified mesoporous silica, which can be imparted to the charge and other functional properties.We design a new pattern Ionic liquid functionalized mesoporous silica modified electrode, which had high surface area, ion-exchange, high ionic conductivity and broad electrochemical windows characteristic. Also, we studied the catalytic properties of ionic liquid functionalized mesoporous silica modified electrode.First, we design a new pattern Ionic liquid functionalized mesoporous silica via modified1-Propyl-3-methylimidazolium chloride（[PMIM]Cl） on the inert material mesoporous silica（Siliceous mesocellular foam, MCF）. The imidazolium-based ionic liquid functionalized mesoporous silica MCF（MCF-IL） was synthesized and used for construction of modified glass carbon electrode fixed by PVA, which denoted as MCF-IL/PVA. The immol/Lobilization of ferricyanide on the surface of MCF-IL/PVA electrode was successfully achieved due to strong interaction between imidazolium-based ionic liquid and ferricyanide, the resulting electrode was denoted as MCF-IL-Fe（CN）₆^3-/PVA. In order to explore the advantage of ionic liquid functionalized group immol/Lobilizing ferricyanide on performance of hydrogen peroxide biosensor over other traditional cationic modification group, aminated MCF（MCF-NH₂） was also prepared and tested as the constrative model. Cyclic voltammol/Letry of absorption studies showed that the redox currents of Fe（CN）₆^3- on MCF-IL/PVA electrode was higher and stabilized faster than that on MCF-NH₂/PVA one. After successive potential cycling, the electrode behaved well catalytically response to H₂O₂. Compare to MCF-NH₂-Fe（CN）₆^3-/PVA electrode, the MCF-IL-Fe（CN）₆^3-/PVA electrode showed a better electrocatalytic performance to H₂O₂ with wider linear detection range and higher sensitivity. In addition, the catalytic mechanism of the electrodes was also discussed in the work. The research demonstrated that the PB which immol/Lobilized on the surface of electrode was the real catalyst for reduce H₂O₂.Second, based on the study of above-mentioned which the catalytic properties which the immol/Lobilized ferricyanide within Ionic Liquid founctionalized mesoporous silica for hydrogen peroxide. The MCF-IL-PB composites was successfully achieved by chemical synthesis, due to strong interaction between ferric ions and MCF-IL-Fe（CN）₆^3-. And we had studied the catalytic properties of the MCF-IL-PB composites atvarious p H conditions. MCF-IL-PB composites used for construction of modified glass carbon electrode fixed by PVA, Chit and Nafion respectively, which denoted as MCF-IL-PB/PVA,MCF-IL-PB/Chit and MCF-IL-PB/Nafion. The MCF-IL-PB/PVA electrode showed a better electrocatalytic performance to H₂O₂ with wider linear detection range and higher sensitivity in the acid solution rather than in the neutral solution. The MCF-IL-PB/Nafion had higher sensitivity for the electrocatalytic performance to H₂O₂ in the weak alkaline solution. The MCF-IL-PB Chit showed worse electrocatalytic performance to H₂O₂ with low sensitivity in the both acid and neutral solution.Moreover, we did the further study on the application of MCF-IL-Fe（CN）₆^3- composites. The MCF-IL- Fe（CN）₆^3-/PVA electrode showed a better electrocatalytic performance to AA with wider linear detection range and higher sensitivity in the neutral solution. This study essentially paves a new avenue to for explore the advantage of the MCF-IL-Fe（CN）₆^3- composites as a sensor.