Séminaire DSI présenté par Aram Yoon

Aram Yoon (Shell Energy Transition Center, Amsterdam)

Résumé : Electrocatalysis plays a pivotal role in various energy conversion and storage applications, including fuel cells, electrolyzers, and batteries. It facilitates the conversion of chemicals from one form to another, making it essential for clean and sustainable energy technologies. Transition metal oxides show great promise in this regard, as they are abundant on Earth and can modify their electrical and chemical properties by adjusting their oxidation state through surface and interface engineering. To effectively harness these materials in energy conversion devices, it is imperative to gain insights into how catalysts’ structures behave in working environments, as this significantly influences chemical conversions and the catalysts’ own chemical status. However, investigating the structure and chemistry of electrocatalysts under electrochemical reaction conditions is a challenging endeavor. Electrochemical systems involve reactions and transformations occurring at multiphase boundaries, including solid-solid and solid-liquid interfaces. This complexity necessitates the use of diverse techniques to probe these interfaces, further complicated by the need to maintain the electrolyte and applied potential.

In my presentation, I will delve into the behavior of Cu2O catalysts under dynamic reaction conditions, employing a multimodal approach centered on in situ Electrochemical Cell Transmission Electron Microscopy (EC-TEM). This approach will focus on two conversion reactions involving Cu2O catalysts: electrochemical CO2 reduction and nitrate reduction. Through this investigation, I will demonstrate structural changes of Cu2O catalysts during redox reactions. The primary emphasis will be on correlating various operando techniques, such as X-ray absorption microscopy and spectroscopy, with electrochemical characterization to gain a comprehensive understanding of how structural heterogeneity impacts catalysis.

Pour tout contact : Maria Letizia De Marco (0388107028 – maria-letizia.demarco@ipcms.unistra.fr)

Séminaire DMONS – DCMI – Axe 5 présenté par : Abhishake MONDAL

Abhishake MONDAL (Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore)

Abstract : 

The pursuit of smart multifunctional materials with stimuli-responsive magnetic and optical response has drawn escalating interest in both fundamental science and potential applications to switches, sensors, and intelligent devices.1 One of the appealing feature of such materials is the tunability of their physical property via chemistry, where the linking structure and physical properties can be modulated in practically infinite ways, which gives them an edge over the solid-state magnetic materials (Figure 1, a).2 The field of molecular bistable systems is rapidly budding towards utilizing these molecule-based magnetic materials in physics-driven and nanotechnology-driven fields (Figure 1, b).

Figure 1: a) Stimuli-responsive molecular bistable systems and b) Application areas where these systems are actively studied for developing devices

Here, I will briefly cover the exciting field of Molecular Magnetism and will specifically focus on three most important aspects of Molecular Magnetism being pursued in my laboratory i) Spin Crossover (SCO) materials3 ii) Metal-to-Metal Electron Transfer Systems (MMET)4 and iii) Single Molecule Magnets (SMM).5 Lastly, I shall discuss the application of these bistable systems in developing ring-resonator devices for Photonics Application, molecular break junctions and microelectromechanical systems.

Acknowledgments: I thank the Indian Institute of Science (IISc), Bangalore, India, and the Ministry of Human Resource Development (MHRD), Ministry of Education (MoE), Government of India, IISc-Start-up Research Grant, the Department of Science and Technology, Mission on Nano Science and Technology (Nano Mission), Scheme for Transformational and Advanced Research in Sciences (STARS, MHRD), Council of Scientific and Industrial Research (CSIR) for the research fundings.

References:

1. Kamilya, S.; Dey, B.; Kaushik, K.; Shukla, S.; Mehta, S.; Mondal, A. Chem. Mater. 2024, 36, 4889, Kaushik, K.; Mehta, S.; Das, M.; Ghosh, S.; Kamilya, S.; Mondal, A., Chem. Commun., 2023, 59, 13107, Coronado, E., Nat. Rev. Mater. 2020, 5, 87. 2. Minguez Espallargas, G.; Coronado, E., Chem. Soc. Rev. 2018, 47, 533. 3. Ghosh, S.; Kamilya, S.; Pramanik, T.; Rouzieres, M.; Herchel, R.; Mehta, S.; Mondal, A., Inorg. Chem. 2020, 59, 13009, Ghosh, S.; Ghosh, S.; Kamilya, S.; Mandal, S.; Mehta, S.; Mondal, A., Inorg. Chem. 2022, 61, 17080, Bagchi, S.; Kamilya, S.; Mehta, S.; Mandal, S.; Bandyopadhyay, A.; Narayan, A.; Ghosh, S.; Mondal, A., Dalton Trans., 2023, 52, 11335, Ghosh, S.; Bagchi, S.; Kamilya, S.; Mehta, S.; Sarkar, D.; Herchel R.; Mondal, A., Dalton Trans., 2022, 51, 7681. 4. Kamilya, S.; Ghosh, S.; Li, Y.; Dechambenoit, P.; Rouzières, M.; Lescouëzec, R.; Mehta, S.; Mondal, A., Inorg. Chem., 2020, 59, 11879, Kamilya, S.; Ghosh, S.; Mehta, S.; Mondal, A., J. Phys. Chem. A 2021, 125, 4775. 5. Hossain, S. M.; Kamilya, S.; Ghosh, S.; Herchel, R.; Kiskin, M. A.; Mehta, S.; Mondal, A., Cryst. Growth Des. 2023, 23, 1656.

Séminaire DCMI présenté par Paul ROBINEAU 

Paul ROBINEAU (Institut pluridisciplinaire Hubert Curien)

Pour votre information, Paul Robineau sera candidat auprès de la commission interdisciplinaire (CID) 52 du CNRS intitulée «  Environnements sociétés: du savoir à l’action ».

Séminaire présenté par Philippe POULIGUEN

Philippe POULIGUEN (Agence Innovation Defense (AID)

L’exposé comportera les présentations :

  • de l’AID
  • du domaine Ondes Acoustiques et Radioélectriques (en focalisant sur la partie radioélectrique)
  • des outils de soutien à la recherche

Séminaire DON / Axe 2 présenté par Pr. Keiichi INOUE

Orateur : Pr. Keiichi INOUE (Functional Materials Group, The Inst. for Solid State Physics, University of Tokyo)

Rhodopsins, or retinal proteins, are light-sensitive membrane proteins, with very important biological functions. In vertebrates, rhodopsins are the sensors for vision. 

Pr. Inoue is a world-leading expert in the photochemical studies of microbial retinal proteins (https://www.icpworldcongress.com/keiichi-inoue). His research aims at a detailed molecular understanding of how the different biological functions of these rhodopsins are encoded in the structural and spectroscopic properties. The abstract can be found : here

Contact: Stefan Haacke (stefan.haacke@ipcms.unistra.fr)

Séminaire DCMI – Axes 3 et 5 présenté par: Raquel UTRARA MELERO

Abstract : Materials exhibiting luminescence stimuli-responsive properties, present potential application as detection systems. Among these materials, copper (I) iodide molecular clusters coordinated by phosphine ligands, exhibit thermochromic and mechanochromic luminescence properties. These compounds are characterized by a change of their emission wavelength in response to temperature or mechanical stress. The establishment of structure- properties relationships permit to study the mechanisms responsible for their properties. The main characterization techniques used are solid-state NMR, X-ray diffraction, Infrared and Raman spectroscopies. In addition to the thermo and mechanochromic properties, these compounds have the particularity of exhibiting aggregation-induced emission (AIE) properties. The understanding of properties is crucial for applications. Therefore, DFT (Density Functional Theory) calculations are also carried out to rationalize the different results and in particular the optical properties. In the last years, copper has been proposed as a substituent in lead perovskite-based devices due to its non-toxic nature. We are currently investigating the use of copper perovskites for solar cells.

Séminaire IPCMS présenté par : prof. Ifor D.W. Samuel

Résumé :

Organic semiconductors  are remarkable carbon-based materials that combine novel  semiconducting optoelectronic properties with simple processing.  They can be used to make printed and flexible electronics,  and their properties (e.g.  colour) can be tuned  by changing their chemical structure.  Organic light-emitting diodes (OLEDs) are compact visible light sources that are now found across the world in mobile phone displays and televisions.  This talk will give an introduction to organic semiconductors and optoelectronic devices made from them.

It will then explore two emerging fields of application. The first is photodynamic therapy (PDT).  In PDT light in combination with a light-activated chemical leads to the generation of reactive oxygen species.  OLEDs are very attractive light sources for PDT because they emit over an area, are thin and potentially flexible.   We have shown that PDT with OLEDs can kill skin cancer, parasites and bacteria.   Another emerging application is in visible light communication (or Li-Fi) in which light is modulated to encode information to supplement Wi-Fi.  Finally a new organic optoelectronic device – a laser electrically driven by an OLED will be presented.