Anodic Oxidation of Bismuth in Halide Containing Electrolytes

The 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 two most established members of this group of materials are nanoporous Al 2 O 3 and TiO 2 nanotubes [1,2]. While Al2O3 membranes have been since than widely used as template material of choice for a range of materials [2-4] due to the flexibility of the pore diameter/length and the relative ease of the Al 2 O 3 dissolution, TiO2 nanotubes received high attention because of their applications in e.g. photocatalysis, water splitting, solar cells and biomedical uses [5]. Bismuth oxide is another interesting material and its nanostructures show an enhanced photoelectrochemical performance [6,7]. However, the formation of bismuth nanostructures, such as bismuth oxide nanopores [6,7] or bismuth phosphate nanorods [8], by anodization is not well explored by now. Similar to the formation of nanoporous Al 2 O 3 nanoporous Bi 2 O 3 was produced in acidic, F - -free electrolytes. In this presentation, we demonstrate the anodization of bismuth in halide containing electrolytes similar to the electrolytes classically used for the formation of TiO 2 nanotubes. References 1. H. Masuda, K. Fukuda, Science, 268 (1995) 1466. 2. J.M. Macak et al., Curr. Opin. Solid State Mater. Sci. 1-2 (2007) 3. 2. K. Nielsch, F. Müller, A.-P. Li, U. Gösele, Adv. Mater. 12 (2000) 582. 3. H. Asoh et al., J. Electrochem. Soc. 148 (2001) B152. 4. J. Kolar, J. M. Macak, K. Terabe, T. Wagner, J. Mater. Chem. C, 2 (2014) 349. 5. K. Lee, A. Mazare, P. Schmuki, Chem. Rev. 114 (2014) 9385. 6. X. Lv, J. Zhao, X. Wang, X. Xu, L. Bai, B. Wang, J. Solid. Stat Electrochem. 17 (2013) 1215. 7. K.C. Chitrada, K. S. Raja, R. Gakhar, D. Chidambaram, J. Electrochem. Soc. 162 (2015) H380. 8. M. Yang, N. K. Shrestha, R. Hahn, P. Schmuki, Electrochem. Solid-State Lett. 13 (2010) C5.