Mesoporous platinum hosts for electrode vertical bar liquid vertical bar liquid - Triple phase boundary redox systems

Mesoporous metal hosts are attractive electrode materials for complex electrode reactions, for example those involving a system of two immiscible liquids. Here we show that a solution of tetraohenylporphyrianto manganese (MnTPP) in 4-(3-phenylpropyl)-pyridine (PPP) organic liquid can be immobilized into mesoporous platinum thin films electrodeposited from a liquid crystalline template. When immersed in an aqueous solution, the organic liquid remains immobilized inside the mesoporous platinum framework. Well-defined, stable, and reproducible ion transfer voltammograms are recorded. The effects of mesoporous platinum membrane thickness (volume), scan rate, and the type of aqueous electrolyte anion (for Cl-, PF6-, ClO4- CN-, SCN- and NO3-) are investigated. Mesoporous platinum is proposed as a very effective electrode material for liquid/liquid anion sensing and for other applications of electrochemically driven liquid/liquid redox systems. (c) 2005 Elsevier B.V. All rights reserved.