Structural and electrical studies of a sol–gel derived nanocomposite ionic liquid based on positively charged polysilsesquioxane and iodide

• Published in: Electrochemistry communications Vol. 7; no. 7; pp. 692 - 696
• Main Authors: Orel, Boris, Šurca Vuk, Angela, Jovanovski, Vasko, Ješe, Robi, Perše, Lidija Slemenik, Hočevar, Samo B., Hutton, Emily A., Ogorevc, Božidar, Jesih, Adolf
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.07.2005; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Conductivity; Energy; Exact sciences and technology; Ionic liquid; IR spectroscopy; Nanocomposite; Natural energy; Photovoltaic conversion; Raman; Solar cells. Photoelectrochemical cells; Solar energy; Sol–gel; Voltammetry; Conductivity; Voltammetry; Nanocomposite; Raman; Sol–gel; IR spectroscopy; Ionic liquid; Performance evaluation; Ionic solution; Sol-gel; Infrared spectrometry; Energetic efficiency; Colloid electrolyte; Photoelectrochemical cell; Electrodiffusion
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2005.04.025

A new sol–gel precursor, based on 1-methyl-3-[3-(trimethoxy-λ 4-silyl)propyl]imidazolium iodide (MTMSPI +I −), was synthesized and investigated as a potential novel quasi-solid-state ionic liquid redox electrolyte for dye-sensitized photoelectrochemical cells of the Graetzel type. MTMSPI +I − was hydrolyzed with acidified water and the reaction products of the sol–gel condensation reactions were assessed with the help of 29Si NMR and infrared spectroscopic techniques, which revealed that the aged MTMSPI +I − sols consisted of a positively charged polyhedral cube-like silsesquioxane and iodide/triiodide species. The addition of iodine increased the specific conductivity of the non-hydrolyzed and hydrolyzed MTMSPI +I −, which was attributed to the formation of triiodide ions and demonstrated from Raman spectra measurements. Steady-state voltammetric measurements at a Pt disc microelectrode, performed for the hydrolyzed MTMSPI +I − and MTMSPI +I − + I 2 sols, revealed changes in the apparent diffusion coefficients ( D app) during the course of transformation of the ionic liquid from a liquid to a quasi-solid-state.