First virtual Bilateral Conference on Functional Materials (BiC-FM). Сборник статей

meritorious thesis published awarded by The Finnish Chemists Society

      1996 The Elvings prize for the best thesis published at the Åbo Akademi University

      1997 Representative for Finland at Scientia Europea 2. Organized by Académie des Sciences (French Academy of Sciences) France.

      2006 The Pehr Brahe prize for meritorious research work awarded by the Foundation of Åbo Akademi University.

      2020 Member of Finnish Academy of Science and Letters

      Research Interests

      Conjugated polymers, composite materials, graphene and graphene oxide, ionic liquids, CO₂ conversion, in situ spectroelectrochemistry, electrochemistry

      Publications; 137 peer reviewed international scientific journals, 3 patent applications

      Positronium emission from materials for Li-ion batteries

      Bernardo Barbiellini^1,2*, Jan Kuriplach³

      ¹School of Engineering Science, LUT university, Lappeenranta 53851, Finland

      ²Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA

      ³Department of Low Temperature Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, CZ-180 00 Prague, Czech Republic

      [email protected]

      A positron and an electron annihilate into gamma-ray photons but before this annihilation, the positron and an electron can bind together to form a positronium (Ps). Mono-energetic positron beams can be used to bombard materials and to probe their atomistic properties. In particular, the implanted positron can diffuse back to the surface of a solid and be emitted as Ps with a range of kinetic energies that provides key information regarding the energy levels of the electrons in the material. These energies can be measured by time of flight (TOF) experiments, but the Ps lifetime before annihilation has been too short for precise measurements. Recently, Jones et al. [1], by exciting the emitted Ps with a laser to greatly increase its lifetime, obtained TOF measurements with an ultimate precision of the order of 5 meV that will allow materials simulations in systems pertinent for Li-ion batteries cathodes [2,3].

      References:

      [1] A. C. L. Jones, H. J. Rutbeck-Goldman, T. H. Hisakado, A. M. Piñeiro, H. W. K. Tom, A. P. Mills, Jr. B. Barbiellini, J. Kuriplach, Phys. Rev. Lett. 117, 216402 (2016)

      [2] B. Barbiellini, J. Kuriplach, Journal of Physics: Conf. Series 791, 012016 (2017)

      [3] J. Kuriplach, A. Pulkkinen, B. Barbiellini, Condensed Matter 4, 80 (2019)

      The role of nitrogen and oxygen in the formation capacity of carbon materials

      Evlashin S.A.^1,*, Fedorov F.S.¹, Dyakonov P.V. ^1,2, Maksimov Yu.M.², Pilevsky A.A.², Maslakov K.I.², Akhatov I.Sh.¹

      1 – Skolkovo Institute of Science and Technology, Moscow, Russia

      2 – Lomonosov Moscow State University, Moscow, Russia

      [email protected]

      Carbon materials are attracting increasing attention as a material for supercapcitor fabrication due to availability and high specific surface area. However, the initial capacitance of raw carbon is quite low, so the N and O heteroatoms are introduced in order to increase their specific capacitance. Despite the vast amount of studies on carbon materials, a lot of grey areas in mechanisms that lead to the increase in the specific capacitance remain. We demonstrate an effective method for modification of the surface of Carbon NanoWalls (CNWs) using DC plasma in atmospheres of O₂, N₂, and their mixture. Processing in the plasma leads to the incorporation of ∼4 atom % nitrogen and ∼10 atom % oxygen atoms. Electrochemical measurements reveal that CNWs functionalized with oxygen groups are characterized by higher capacitance. The specific capacitance for samples with oxygen reaches 8.9 F cm^-3 at a scan rate of 20 mV s^-1. In contrast, the nitrogen-doped samples demonstrate a specific capacitance of 4.4 F cm^-3 at the same scan rate. The mechanism of heteroatom incorporation into the carbon lattice is explained using density functional theory calculations.

      Acknowledgement.This work was supported by the Russian Science Foundation, grant 17-19-01787.

      References:

      [1] S.A. Evlashin, F.S. Fedorov, P.V. Dyakonov, Y.M. Maksimov, A.A. Pilevsky, K.I. Maslakov, Y.O. Kuzminova, Y.A. Mankelevich, E.N. Voronina, S.A. Dagesyan, V.A. Pletneva, A.A. Pavlov, M.A. Tarkhov, I.V. Trofimov, V.L. Zhdanov, N.V. Suetin, I.S. Akhatov, I. S., Role of Nitrogen and Oxygen in Capacitance Formation of Carbon Nanowalls. The Journal of Physical Chemistry Letters, 11(12), (2020).

      Nickel-Nitrogen active sites towards selective High-rate CO₂-to-formate electroreduction

      Cristina Flox¹, Fatemeh Davodi¹, Davide Pavesi^2,3 and Tanja Kallio¹

      1 – Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, FI-00076, Espoo, Finland

      2 – Avantium Chemicals BV, Zekeringstraat 29 1014 BV Amsterdam, The Netherlands

      3 – Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands

      [email protected]

      Electrochemical CO₂ reduction reaction is a key technology for the mitigation of the climate change. However, CO₂ reduction is highly energetic and unfavourable electrochemical reaction, requiring catalyst to achieve economically appealing performance. In this scenario, Nickel-Nitrogen (Ni-N)-active sites within porous carbon are attracting increasing interest as inexpensive and efficient electrocatalyst of CO₂ reduction. In fact, the Ni-N- active sites anchored to the carbon structures have been proposed as excellent solution for the conversion CO₂-to-CO, exceeding selectivity and partial current density values of the commercial electrocatalyst. Herein, the in-situ creation of Ni-N-active sites using Nickel Carbide nanoparticles-wrapped in a graphene shell (Ni₃C@graphene NPs) and Emeraldine as precursors in combination with the thermal treatments is evaluated. As a result, the Ni-N- active sites in combination with Ni₃C@graphene NPs provide a new paradigm, where the formate production is dominated leading a complete deactivation of CO route. Surprisingly, the unprecedent key performance indicators of the CO₂ reduction showed a Faradaic Efficiency up to 90 % at 0.55V vs. RHE at 25ºC. Additionally, the CO₂-to-formate conversion showed a temperature sensitive- dependence, increasing the selectivity (up to 96 %) in the voltage range tested (0.45 to 0.7V vs. RHE), when the electrolysis was performed at 40ºC. The apparent Energy Activation values were calculated, attaining values up to 45 kJ mol^-1 at -0.55 V vs. RHE@40ºC, which agrees well with previous reports. Therefore, the creation of Ni-N- active sites in the Ni₃C@graphene NPs can effectively reduce the energy barrier towards the CO₂-to formate conversion, providing new mechanism insight for the CO₂ reduction.

      Cristina Flox received her PhD in Electrochemistry applied to flow reactors from Universitat de Barcelona in 2008, followed by postdoctoral fellowships in LEITAT and Catalonia Institute for Energy Research, Spain (2008–2017). Subsequently, she joined Aalto University in 2017, working on the design of innovative nanomaterials for energy applications. Particularly, she is focused on the development of electrodes for CO₂ reduction and solid-electrolytes for lithium-ion batteries. Additionally, her research interest are fundamental aspects on energy storage systems, especially redox/semi-solid flow batteries, supercapacitors and Na-ion batteries. She published more than 47 refereed articles (h index 23, 2025 citations), 3 book chapters and 1 patent application.

      Development of