Keywords: Electrolysis, hydrogen production, materials synthesis, material characterization
One of the main challenges raised by global warming and climate change is the reduction of greenhouse gas emissions, particularly CO2. To achieve it, it is essential to decrease our use of fossil fuels and to turn to new energy vectors. Dihydrogen, for instance, could constitute a very promising “carbon-free” alternative but only if it is produced by electrolysis with renewable electricity. In particular, the emerging Anion Exchange membrane Water Electrolysis technology (AEMWE), based on the use of alkaline solid electrolytes, has gained interest in the field of electrolysis because it could lower significantly the cost of the produced H2 from water. 1
In order to make this technology commercially available, some challenges remain and in particular the development of very active and cheap electrocatalysts for the reduction of water in alkaline medium.
This PhD project aims at synthesizing and characterizing new electrocatalysts for this reaction, based on earth-abundant transition metals (TMs), for instance TM oxides or sulphides. The strategy consists in obtaining heterofunctionnal porous nanoparticles, with a hierarchical architecture, starting from bi or trimetallic alloys. These architectures will be synthesized by combining solutions routes2 and different thermal treatments. The PhD candidate will have access to a large range of (nano)materials characterizations techniques such as XRD, X-ray fluorescence, XPS, electronic microscopies (TEM and SEM). This work will be conducted in the framework of the ANR project HYKALIN so the PhD candidate will collaborate with other partners for electrochemical characterizations (Ecole Polytechnique), for material characterizations (LCMCP, Sorbonne Université) and for computational chemistry (ENS Lyon). He/she may also join X-ray Absorption experiments at synchrotron SOLEIL.
En science et ingénierie des nanomatériaux, les virus de plantes sont souvent envisagés comme échafaudages tridimensionnels pour fabriquer par biomimétisme, des nanostructures fonctionnelles complexes présentant des propriétés physico-chimiques remarquables à fort potentiel applicatif : nanomédecine, catalyse, conversion d'énergie, etc. Dans ce projet nous envisageons de fabriquer des objets hybrides solubles et stables dans l’eau pour l’imagerie biomédicale à partir de virus de plantes. Des fluorophores émettant dans le proche infra-rouge seront encapsulés dans la capside et leur fluorescence sera exaltée par les nanostructures anisotropes d’or greffées à la surface du virus.
La thèse se déroulera en plusieurs étapes (figure ci-dessous). Les deux premières pourront être réalisées en parallèle.
1) Etudes physico-chimiques du relargage de l’ARN et encapsulation de molécules fluorescentes. Cette étude est indispensable pour déterminer les paramètres physicochimiques pour relarguer l’ARN et obtenir des capsides vides et stables.
2) Fonctionnalisation de la surface externe de la capside soit par biominéralisation, soit par greffage de NPs d’or préformées.
3) Synthèse et caractérisation des matériaux bifonctionnels. Applications en fluorescence exaltée par le plasmon pour la bio-imagerie, SERS (spectroscopie Raman exaltée de surface) ou photothermie.
Profil et compétences recherchées : Physico-chimie, sciences de matériaux. Un intérêt pour la biochimie sera apprécié.
The deadline for application is 1st of June 2022.
The problem of environmental degradation is pushing researchers towards the quest for efficient and environmentally friendly energy sources or conversion technologies. Thermoelectric materials (TEMs) have attracted considerable attention in the last twenty years, as heat is a readily available energy source because of solar radiation and is also the inevitable “side product” of almost any industrial activity. Our PhD project focuses on energy harvesting from industrial activity by designing and printing large-area thermoelectric generator (TEG) flexible devices able to harvest energy from low but continuous temperature gradients. The utilisation of printing method allows the fabrication of very large TEG devices able to counterbalance low heat gradients while flexibility allows the TEG device to conform to the most frequently encountered elements of production chains (pipes, serpentines…). Organic semiconductors (OSCs) seem promising candidates for the fabrication of thermoelectric systems because of their processability at room temperature in liquid phase and their excellent mechanical robustness and flexibility.
The goal of this thesis is the development of all-printed, organic thermoelectric generators (OTEGs) fabricated on flexible substrates. The first part of the thesis project will consist in developing organic semiconducting inks necessary for the fabrication of the thermoelectric devices and in defining a process-flow for the fabrication of such all-printed devices on flexible foils. Later on, a protocol to test the stability of the printed OTEGs when subjected to mechanical stresses will be defined, the main objective being the description of the relationships existing between the mechanical and thermoelectric properties of printed organic semiconducting layers. The final aim of the thesis project is to obtain low-cost, flexible, high-power conversion, all-printed OTEGs suitable for non-planar and large-area applications.
Most of the PhD student’s experimental activities will be carried out at the ITODYS Laboratory of Université Paris Cité in France (https://www.itodys.univ-paris-diderot.fr/fr/) but this project is developed within an international collaboration with the Institut National de la Recherche Scientifique of Canada (INRS - https://inrs.ca/en/).
In addition to carrying out the experiments necessary to achieve the aforementioned scientific objectives, in collaboration with the supervisors, the PhD student will regularly present his/her activities at group and laboratory meetings. He/she will also contribute to the preparation of the manuscripts of scientific publications and present his/her project at local and national conferences, in order to engage with the wider scientific community.
Supervisors: Prof. Benoît PIRO, Dr. Giorgio MATTANA
Duration of the contract: 36 months
Gross salary: 1975 €/month (taxable, social security contribution to be applied)
Keywords: printed electronics, organic electronics, flexible electronics, thermoelectricity
Essential skills and qualifications: the ideal candidate graduated with an MSc in Chemistry, Physical Chemistry or Physics; he/she is naturally curious and meticulous, possesses a taste for careful experimental work and data analysis, and is ready to join a multidisciplinary and international team project. He/she has a good command of English (at least a B2 level). Previous experience in printed and/or organic electronics would be a plus but it is not a strict requirement.