PhD student new redox systems for efficient energy conversion (M/F)
- Orsay, Essonne
- CDD
- Temps-plein
The aim is to obtain robust liquid thermoelectric materials and devices that are better than the current state of the art and that are also cost-effective, non-toxic and scalable. The main application will be small-scale electricity generation (1~100 W) from an external heat stream. However, WH-RECOLTE's basic knowledge can be extended to applications outside renewable energy research, such as temperature and chemical pollutant sensors. Thermoelectricity, the ability of a material to convert heat into electrical energy, has been known to exist in liquids for many decades. Observed values of the Seebeck coefficient (Se = - ΔV/ΔT, the ratio of induced voltage (ΔV) to applied temperature difference (ΔT)) are generally an order of magnitude greater than those found in solid devices.However, due to the low ionic conductivity of the liquids, the conversion efficiency was very low, preventing the use of conventional solvent-containing thermogalvanic cells in low-temperature waste heat recovery applications. The prospects for this technology have brightened over the last decade with the development of ionic liquids (ILs) [1-3]. ILs are molten salts with melting points below 100°C. Compared with conventional liquids, they have many interesting physico-chemical properties, such as a high boiling point, low vapour pressure, high ionic conductivity and low thermal conductivity, together with higher Se values. More recently, an experimental study conducted by IJCLab and SPEC revealed that record Se values can be achieved through the competitive complexation of transition metals in ionic liquid media.Understanding the chemical speciation in solution and the redox properties of the medium is therefore a very important step towards the rational design of thermogalvanic cells. The aim of this thesis is to carry out a fundamental study of the chemical and redox behaviour of solutions of metal salts (Fe, Cu, Ce, etc.) in ionic liquids as a function of temperature and solution composition, as well as their thermogalvanic properties (open circuit Se coefficient and power measurements). The results obtained will reveal the link between certain physico-chemical parameters (redox potential, stability constants of metal complexes) and the thermogalvanic properties of the medium in order to develop new innovative devices for waste heat recovery. Detailed presentation of the research project (+cooperative aspect.The member of staff will carry out a fundamental study of the physicochemical, chemical, electrochemical and thermogalvanic properties of transition metal solutions in ionic liquids using a number of physicochemical and electrochemical methods. This work is to be carried out in close interaction with the other partners in charge of thermogalvanic measurements (SPHYNX/SPEC/CEA) and the formulation and study of complex liquids (liquid dispersion of nanoparticles in ionic liquid-based solvents, including a redox couple for electron transfer) (PHENIX) [4].The thesis programme consists of several parts: 1) Studies of metal ion speciation (with an initial focus on Ce, Fe and Cu) in ionic liquids and LI/organic solvent mixtures, as a function of temperature and ligand content, using spectroscopic methods at the IJCLab. In addition, the interaction of the metal ion with hydrophilic ligands could be studied by affinity capillary electrophoresis in aqueous solutions [5-6]; 2) Studies of the redox properties of metal complexes in ionic liquids by electrochemical methods (cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, numerical simulations) and electrolysis tests of the solutions at the IJCLab; 3) Studies of the thermogalvanic properties of the selected systems (open circuit Se coefficient and power measurements), optimisation of the thermogalvanic cells at SPHYNX/SPEC/CEA; 4) Studies of the compatibility of the redox couple with the colloidal dispersion (in collaboration with the PHENIX partner) at the IJCLab and SPHYNX/SPEC/CEA. Numerous tests of the complex liquids (redox couple/nanoparticle dispersion) for their chemical, electrochemical and thermal stability will be carried out.The physico-chemical properties of the medium (viscosity, density, ionic conductivity, residual water content) will also be determined. Scientific, material and financial conditions of the research project The thesis work will be fully funded by the ANR WH-RECOLTE project. All the necessary equipment will be available in the host laboratory or on the technical platforms of the Université Paris-Saclay. The PhD student will present his/her thesis work at international and national conferences. The results of the thesis will then be published in international peer-reviewed journals. Candidate profile The candidate must hold a Master's degree in Physics (thermodynamics or energy) or Chemistry (physical, analytical or inorganic). A dual chemistry/physics background will be highly appreciated. The position requires a sound knowledge of solution chemistry, physicochemical characterisation methods, thermodynamics and/or renewable energies, good oral and written communication skills (French and English required) and data analysis. We are looking for a young researcher who is committed to the project, curious, with a degree of autonomy and a strong motivation to work in a team on an interdisciplinary project.Références bibliographiques [1] V. Zinovyeva, S. Nakamae, M. Bonetti, M. Roger. Enhanced Thermoelectric Power in Ionic Liquids. ChemElectroChem, 1 (2014) 426-430. [2] M. Bonetti, S. Nakamae, B.T. Huang, T. J. Salez, C. Wiertel-Gasquet, M. Roger. Thermoelectric energy recovery at ionic-liquid/electrode interface. J. Chem. Phys., 142 (2015) 244708. [3] M.F. Dupont, D.R. MacFarlane, J.M. Pringle. Thermo-electrochemical cells for waste heat harvesting - progress and perspectives. Chem. Commun., 53 (2017) 6288-6302. [4] K. Bhattacharya, M. Sarkar, T. J. Salez, S. Nakamae, G. Demouchy, F. Cousin, E. Dubois, L. Michot, R. Perzynski, and V. Peyre. Structural Thermodiffusive and Thermoelectric Properties of Maghemite Nanoparticles Dispersed in Ethylammonium Nitrate. ChemEngineering, 4 (2020) 5. [5] Sladkov, V. Affinity capillary electrophoresis in studying the complex formation equilibria of radionuclides in aqueous solutions. ELECTROPHORESIS, 37 (2016) 2558-2566. [6] Sladkov, V., Roques, J. & Meyer, M. Assignment of complex species by affinity capillary electrophoresis: The case of Th(IV)-desferrioxamine B. ELECTROPHORESIS, 41 (2020) 1870-1877.RequirementsResearch Field Chemistry Education Level Master Degree or equivalentResearch Field Chemistry Education Level Master Degree or equivalentLanguages FRENCH Level BasicResearch Field Chemistry » Physical chemistry Years of Research Experience NoneResearch Field Chemistry » Computational chemistry Years of Research Experience NoneAdditional InformationWebsite for additional job detailsWork Location(s)Number of offers available 1 Company/Institute Laboratoire de physique des 2 infinis - Irène Joliot-Curie Country France City ORSAY GeofieldWhere to apply WebsiteContact CityORSAYSTATUS: EXPIRED
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