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XV. International Symposium on Relations Between Homogeneous and Heterogeneous Catalysis, Berlin, Germany, 11 - 16 September 2011, pp.13, (Full Text)
The preparation of mesoporous, i.e. high surface area thin film electrodes from transparent conduct- ing oxides (TCO) is a valuable goal in materials chemistry as such electrodes can enable further develop- ment of optoelectronic, electrocatalytic or bioelectronic devices. In particular such mesoporous TCO thin film electrodes, with well defined pore sizes and pore architectures in the nanometer range are of high interest for the immobilization of high amounts of electrochemically active enzymes [1]. In this context, the synthesis, through nanocasting techniques using block-co-polymers as pore directing agents of two types of mesoporous TCO thin film electrodes, based either on tin rich indium tin oxide (ITBO) or on anti- mony doped tin oxide (ATO), is presented. As those materials should represent a versatile platform for the immobilization of different enzymes, differing in size and shape, a particular focus was put on the control of the size of the obtained spherical pores, which could be tuned from 5 to 17 nm. The synthesis of the mesoporous ITBO thin film electrodes is based on a single source molecular precursor approach [2,3], whereas the mesoporous ATO thin film electrodes are based on the polymer assisted self-assembly of preformed crystalline ATO nanoparticles [4]. The as prepared mp-TCO films show a high and durable electrical conductivity and transparency combined with high surface area. Both types of mesoporous TCO thin films showed excellent performances as electrode materials on a broad potential range (-0.7 to 0.7 V vs Ag/AgCl). This makes them ideal candidates for hosting electroactive biomolecules for bioelectrocataly- sis, as demonstrated with successful immobilization of native cytochrome c and human sulfite oxidase for example. References: [1] S. Frasca, T. Graberg, J. Feng, A. Thomas, B. Smarly, I.Weidinger, F. Scheller, P. Hildebrandt, U. Wollenberger, ChemCatChem, 2 (2010) 839-845. [2] Y. Aksu., M. Driess, Angew. Chem. Int. Ed, 48 (2009) 7778-7782. [3] Y. Aksu, S. Frasca, U. Wollenberger, M. Driess, A. Thomas, Chem. Mat. 2011, 23(7), 1798-1804. [4] V. Müller, M. Rasp, J. Rathousky, B. Schütz, M. Niederberger, D.Fattakhova-Rohlfing, Small, 6, 5 (2010) 633- 637.