ИСТИНА

International Workshop on Electrochemistry of Electroactive Materials June 16–21, 2019, Borovets, Bulgaria WEEM-2019 Synthesis of Polypyrrole Films Possessing an Extended Potential Range of Their Electroactivity O.I. Istakova1,2, T.O. Medvedeva3, O.A. Goncharova3, D.V. Konev1,2, M.A. Vorotyntsev1,2,3,4 1Institute for Problems of Chemical Physics of the Russian Academy of Sciences, Chernogolovka, Russia 2D. I. Mendeleev University of Chemical Technology of Russia, Moscow, Russia 3M. V. Lomonosov Moscow State University, Moscow, Russia 4ICMUB - UMR 6302 CNRS - Université de Bourgogne, Dijon, France е-mail: oistakova@gmail.com Polypyrrole (pPy) polymer materials attract much attention of researchers due to their original properties. Proposed methods for deposition of pPy coatings as well as for synthesis of various pPy-containing composite materials has opened prospects for their use in a wide range of practical applications, such as molecular electronics, electrochemical sensors, supercapacitors, etc. [1-3]. One of the main methods of polypyrrole synthesis is the electrochemical method, the essence of which consists in electro-oxidation of the dissolved monomer on the electrode surface with formation of a polymer film. The overwhelming majority of papers on electrodeposited polypyrrole arrives to the conclusion that the resulting conjugated polymer possesses an electrochemical activity potential region of about 1 V in width, the potential shift in the negative direction leads to the transition of this material into a neutral/insulator state while its shift in the positive direction results in "overoxidation" processes related to irreversible degradation. Such a narrow window of potentials of electroactivity is a disadvantage of this material, limiting its applicability, for example, as an active element of supercapacitors or a matrix for electrodeposition of most metals in the synthesis of composite metal-polymer catalysts / sensors. However, it was mentioned in [4] that using low deposition potentials and low monomer concentrations quite different polypyrrole films can be prepared, which exhibit electroactivity in a wider range of potentials. This change is irreversible and can occur either immediately after synthesis (electropolymerization) or during repeated cycling of the film in an extended range of potentials. The goal of this work is to study and to optimize the method of electrodeposition of polypyrrole under non-conventional conditions (ensuring a low 110044 International Workshop on Electrochemistry of Electroactive Materials June 16–21, 2019, Borovets, Bulgaria WEEM-2019 rate of polymer formation on the electrode surface), as well as to investigate the structure and properties of the obtained promising materials. To do this, we have studied the conditions in which there is an extension of the electroactivity region of polypyrrole for the subsequent purposeful enhancement of this effect (varied and measured parameters: concentration of pyrrole during electrodeposition within a submmol range, low oxidation potential small thickness of the polymer coating, multiscan parameters of the obtained polymer film). Resulting films have also been studied via cyclic voltammetry, UV and IR spectroscopies and SEM microscopy. Acknowledgments: This work was supported by the Russian Foundation for Basic Research (project no. 19-33-01303 mol_a). [1] B. Lakard, S. Carquigny, O. Segut, T. Patois, S. Lakard, Metals, 2015, 5, 1371-1386. [2] L.H.M. Krings, E.E. Havinga, J.J.T.M. Donkers, Synthetic metals, 1993, 54, 453-460. [3] R. Bittihn, G. Ely, F. Woeffer, H. Miinstedt, H. Naarmann, D. Naegele, Makromolekulare Chemie. Macromolecular Symposia, 1987, 8, 51-59. [4] M.A. Vorotyntsev, V.A. Zinovyeva, D.V. Konev, Mechanisms of electropolymerization and redox activity: fundamental aspects, S. Cosnier, A. Karyakin (ed.). Electropolymerization: concepts, materials and applications. John Wiley & Sons. 2011, 27-50. 11005