Towards Functional Advanced Materials Using Ordered Anodic Oxides Supports and Templates

Abstract

Synthesis of highly-ordered nanostructures of valve metal oxides has recently attracted huge scientific and technological interest motivated by their possible use in many applications. The nanoporous Al2O3 – most established member of this group of materials – has been prepared by anodic oxidation of Al under suitable electrochemical conditions nearly two decades ago into perfectly ordered, honeycomb-like porous structures [1]. Owing to the flexibility of the pore diameter/length and the relative ease of the Al2O3 dissolution, its porous membranes have been since than widely used as templating material of the choice for a range of materials [2-4].It is the TiO2 [5] that has received the highest attention after Al2O3 motivated by its range of applications, including photocatalysis [6], water splitting [7], solar cells [8] and biomedical uses [9]. Very significant research efforts have led to reproducible synthesis of self-organized TiO2 nanotube layers by means of anodic oxidation [10-14], during which the starting Ti substrate is converted into highly-ordered nanotubular layer by anodization in suitable electrolyte.Although many applications of the nanoporous Al2O3 and nanotube TiO2 nanotube layers have been presented, their potential for the synthesis of advanced functional nanomaterials, in particular when considering all possible shapes and geometries, has not at all been exploited.In the presentation, we want to focus in detail on various filling routes of anodic templates and supports. We will show examples of various functional devices including some very recent results on chalcogenide-sensitized TiO2 nanotubes [15] and on the new design of resistive switching of memory switching cells using porous AAO templates [16]. References 1) H. Masuda, K. Fukuda, Science, 268 (1995) 1466.2) H. Masuda, H. Yamada, M. Satoh, H. Asoh, M. Nakao, and T. Tamamura, Appl. Phys. Lett. 71 (1997) 2770.3) K. Nielsch, F. Müller, A.-P. Li, U. Gösele, Adv. Mater. 12 (2000) 5824) H. Asoh et al., J. Electrochem.Soc. 148 (2001) B152.5) J.M. Macak et al., Curr. Opin. Solid State Mater. Sci. 1-2 (2007) 3.6) A. L. Linsebigler, G. Lu, J. T. Yates, Chem. Rev., 95 (1995) 735.7) A. Fujishima and K. Honda, Nature 238 (1972) 37.8) B.O´Regan and M.Grätzel, Nature 353 (1991) 737.9) Y.T. Sul et al., Biomaterials, 23 (2002) 491.10) V. Zwilling, M. Aucouturier and E. Darque-Ceretti, Electrochim. Acta 35, (1999) 921.11) J. M. Macak, H. Tsuchiya, P. Schmuki, Angew. Chem. Int. Ed. 44 (2005) 2100.12) J. M. Macak, et al., Angew. Chem. Int. Ed., 44, 7463 (2005).13) S. Albu, A. Ghicov, J M. Macak, P. Schmuki, Phys. Stat. Sol. (RRL), 1 (2007) R65.14) S.So, K. Lee, P.Schmuki, J.Am.Chem.Soc. 134 (2012) 11316.15)J.M. Macak, T. Kohoutek, L. Wang, R. Beranek, Nanoscale, 5 (2013), 9541. 16) J. Kolar, J.M. Macak, K. Terabe, T. Wagner, J.Mater. Chem.C, DOI:10.1039/C3TC31969E.