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Directionally solidified MnTiO3 –TiO2 eutectic as a potential material for photoelectrochemistry

Katarzyna B. Kołodziejak 1Piotr Barczuk 3Bruce Alexander 2Dorota A. Pawlak 1

1. Institute of Electronic Materials Technology (ITME), Wólczyńska 133, Warszawa 01-919, Poland
2. University of Greenwitch, School of Science, Central Avenue, Kent ME4 4TB, United Kingdom
3. University of Warsaw, Department of Chemistry, Pasteura 1, Warsaw, Warszawa 02-093, Poland


Eutectic materials are two or multiphase materials formed during cooling of a mixable melt with a eutectic composition. The possibility of considering versatile combinations of various component materials in eutectics provides a broad palette for many applications.[1],[2],[3] Eutectics also seem to be very attractive as energy-generating materials. This possible application of eutectics has been preliminarily studied, including solid-oxide fuel cells[4],[5],[6], thermoelectric materials[7],[8], and recently photoelectrochemical cells (using an SrTiO3-TiO2 eutectic system).[9] In the case of photoelectrochemical cells, eutectics made of photoactive phases could be very attractive due to their multiphase character and  potential broadband absorption, high crystallinity, and high fraction of interfaces (clean and atomically sharp) which may enable better charge transport.

A manganese titanate-titanium dioxide, MnTiO3–TiO2, eutectic is a new composite material obtained by the self-organization mechanism, which is easily available in millimeter-scale pieces. The TiO2 phase forms the interconnected precipitate-pattern and the MnTiO3 is the matrix phase. The microstructure is in the form of 3D-oval TiO2 inclusions/particles interconnected with each other by thin TiO2 layers/plates and this interconnected structure is embedded in the MnTiO3 phase (Fig.1).

Such mixed materials made of two semiconducting phases with bandgaps enabling absorption of UV-Vis wavelengths and with both phases extending in a connected way across the whole sample may be promising for photoelectrochemical applications. For this application, materials including such phases as TiO2 – a photoactive material under UV-light and, after proper doping, under visible light – would be particularly interesting.[10] TiO2 is a wide band gap semiconductor thus enabling UV absorption. On the other hand, MnTiO3 has not been considered as material for photoelectrochemical applications yet, though the recently-reported band gap for this material of 2.4 eV [11], or 1.8 eV [12] should provide absorption in the visible range of the solar spectrum. So such a mixed composite could potentially be interesting for photoelectrochemical applications.
The growth and characterization of the eutectic microstructure from a TiO2-MnO (57% - 43%) system, via directional solidification by the micro-pulling down method will be presented. The preliminary results of the measurements performed with manufactured by us MnTiO3-TiO2 photo anode will be also discussed.

Acknowledgements:  The research has been supported by a grant from Switzerland through the Swiss Contribution to the enlarged European Union.
(1) D. A. Pawlak, K. Kolodziejak, S. Turczynski, J. Kisielewski, K. Rozniatowski, R. Diduszko, M. Kaczkan,  M. Malinowski, Chem. Mater., 2006, 18, 2450-2457.
(2) D. A. Pawlak, Self-organized structures for metamaterials in Applications of Metamaterials (Metamaterials Handbook), 2009, Capolino F., Ed.; CRC Press, Vol II, Chapter 31.
(3) D. A. Pawlak, S. Turczynski, M. Gajc, K. Kolodziejak, R. Diduszko, K. Rozniatowski, J. Smalc and I. Vendik, Adv.Funct. Mat., 2010, 20, 116-1124.
(4) M. A. Laguna-Bercero, A. Larrea, R. I. Merino, J. I. Pen and V. M. Orera,  J. Am. Ceram. Soc., 2005, 88, 3215-3217.
(5) M. A. Laguna-Bercero, A. Larrea, J. I. Peña, R. I. Merino, V. M. Orera,  J. Europ. Ceram. Soc. 2005, 25, 1455-1462.
(6)R. I. Merino, J. I. Pena and V. M. Orera, J. Europ. Ceram. Soc., 2010, 30, 147-152.
(7) G. J. Snyder and E. S. Toberer, Nature Materials, 2008, 7, 105-114.
(8) M. I. Aliev, A. A. Khalilova, D. G. Arsaly, R. N. Ragimov and M. Tanogly, Inorg. Mater., 2004, 40, 331– 335.
(9) K. Bienkowski, S. Turczynski, R. Diduszko, M. Gajc, E. Gorecka, D. A. Pawlak, Cryst. Growth & Design, 2011, 11, 3935–3940.
(10) Grimes C. A.; Varghese, O. K.; Ranjan, S. In Light, water, hydrogen; Springer 2007, Chapter 4.
(11) Agui, A.; Mizumaki, M. J. Electr. Spectr. Rel. Phenom. 2011, 184, 463– 467.
(12)Szubka, M.; Talik, E.; Kołodziejak, K.; Pawlak, D. A. Journal of Physics: Conference Series 2011, 200, 072097-072100.

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Presentation: Poster at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, Topical Session 9, by Katarzyna B. Kołodziejak
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17

Submitted: 2013-06-04 14:56
Revised:   2013-07-26 12:44