Thèse Développement d'Électrodes Innovantes à Atomes Métalliques Isolés dans une Matrice Carbonée pour Capteurs Électrochimiques Performants H/F Doctorat.Gouv.Fr

Établissement : Université de Toulouse École doctorale : SDM - SCIENCES DE LA MATIERE - Toulouse Laboratoire de recherche : LCC - Laboratoire de Chimie de Coordination Direction de la thèse : Myrtil KAHN ORCID 0000000330795759 Début de la thèse : 2027-09-01 Date limite de candidature : 2026-11-23T23:59:59 Ce projet vise à développer une nouvelle génération d'électrodes pour capteurs électrochimiques, en exploitant un procédé innovant couplant chimie et plasma pour incorporer des atomes métalliques isolés dans une matrice carbonée. Cette approche permet de contrôler finement la structure et la réactivité des sites actifs, offrant ainsi des performances améliorées en termes de sensibilité, sélectivité et stabilité.
Le travail sera mené en collaboration avec Antonella Badia (Université de Montréal), experte en chimie des matériaux carbonés et en électrochimie. Les électrodes développées seront testées pour des applications dans des domaines clés tels que la détection environnementale, la surveillance de la santé ou l'analyse industrielle.
Ce projet s'inscrit dans une démarche de durabilité, avec des matériaux et procédés conçus pour minimiser l'impact environnemental tout en maximisant l'efficacité des capteurs. Electrochemical sensors play a critical role in various fields, from environmental monitoring to medical diagnostics, where their performance is often limited by the nature of the electrodes used.[1] While carbon-based nanomaterials such as graphene and carbon nanotubes provide excellent conductivity and high surface area,[2] their functionalization with metals to enhance reactivity remains a significant challenge.[3] Traditional methods like chemical vapor deposition or wet chemical reduction often lack precise control over metal particle distribution and size,[4] which can hinder sensor performance in terms of sensitivity, selectivity, and long-term stability.
Our team has developed an innovative chemistry-plasma coupled process that enables the formation of multifunctional thin films.[5] By injecting aerosol, the precise incorporation of isolated metal atoms into a carbon matrix can be envisioned. This approach will offer several advantages: atomic-level control over the distribution of active, enhanced reactivity due to the isolation of metal atoms (which prevents aggregation and leverages quantum effects), and improved stability provided by the carbon encapsulation. By fine-tuning the plasma and chemical parameters, this project proposes to synthesize electrodes with tailored properties for high-performance electrochemical applications, an application that we haven't explored yet.
This method not only pushes the boundaries of electrode design but also aligns with sustainability goals by reducing energy consumption and avoiding toxic. The project builds on existing literature in single-atom catalysis[6] and plasma-assisted nanomaterial synthesis,[7] while leveraging the expertise of Antonella Badia from the University of Montreal, whose work on carbon-based materials and electrochemistry[8] will provide valuable insights for optimizing and testing these advanced electrodes. The primary objective of this thesis project is to develop and optimize a chemistry-plasma coupled process for synthesizing electrodes based on isolated metal atoms embedded in a carbon matrix. The project aims to achieve precise control over the deposition and distribution of metallic atoms (such as Fe, Co, or Ni) to enhance the reactivity, sensitivity, and stability of electrochemical sensors.
To accomplish this, the work will focus on mastering the synthesis parameters, such as temperature, pressure, chemical ratios, and plasma conditions, to ensure a uniform and tailored distribution of active sites within the carbon structure. Advanced characterization techniques, including electron microscopy (SEM, TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, will be employed to analyze the structural and chemical properties of the electrodes.
Additionally, the project will evaluate the electrochemical performance of the synthesized electrodes, assessing their sensitivity, selectivity, and long-term stability for targeted applications, such as environmental pollutant detection or biomedical sensing. A key aspect will be optimizing the process to minimize the use of toxic reagents and reduce its environmental footprint, aligning with sustainability goals.
Collaboration with Antonella Badia from the University of Montreal will play a pivotal role in validating the performance of these electrodes in real-world applications and exploring their potential for industrial or environmental use. This partnership will also facilitate knowledge exchange and joint experimental efforts, strengthening the project's international outreach. The project will follow an iterative approach combining synthesis, characterization, and performance testing to develop high-performance electrodes with isolated metal atoms embedded in a carbon matrix. The process begins with the use of our chemistry-plasma coupled method to form the nanocomposite thin films consisting of metal atoms (such as Fe, Co, or Ni) embedded into DLC matrices. Key parameters, including temperature, pressure, plasma duration, and chemical ratios, will be systematically optimized to achieve precise control over the density and distribution of the metal atoms. In situ diagnostic tools, such as mass spectrometry and plasma diagnostics, will be employed to monitor and refine the synthesis process.
Following synthesis, the electrodes will undergo comprehensive structural and chemical characterization. Techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy will be utilized to analyze the morphology, chemical bonding, and crystallographic structure of the materials. These analyses will provide critical insights into the relationship between the synthesis conditions and the resulting properties of the electrodes.
The electrochemical properties of the developed electrodes will first be characterized using cyclic voltammetry and electrochemical impedance spectroscopy (EIS) to assess charge-transfer and interfacial properties, conductivity, and stability. Their voltammetric performance will then be evaluated for the detection of electroactive target analytes. A key application will be the monitoring of water quality in closed-loop water-recovery systems for manned spacecraft, where potable water is recycled from humidity condensate, urine distillate, and hygiene wastewater. Electrochemical sensing is particularly well suited to this application because it enables the development of compact, low-power, and reagent-efficient analytical devices. Representative analytes selected for this study span several classes relevant to spacecraft water recycling and include acetaminophen, a pharmaceutical residue; uric acid, a urinary metabolite whose presence in recycled water could indicate incomplete removal during treatment; caffeine, a marker of human consumption-derived wastewater; and silver ions (Ag), which are used as antimicrobial agents in some spacecraft potable-water systems. All four analytes are amenable to voltammetric detection. While acetaminophen, uric acid, and caffeine will be investigated as contaminants or indicators of treatment performance, Ag will be monitored as a water-treatment agent whose concentration must be controlled to ensure both effective microbial control and potable-water quality. These chemically distinct analytes will provide a relevant test set for evaluating the versatility of the developed electrode materials. Electrode stability will be evaluated under relevant operating conditions, including repeated electrochemical cycling and prolonged exposure to representative aqueous environments, to assess long-term durability.
Collaboration with Antonella Badia at the University of Montreal will be integral to this process, as her expertise will help validate the electrodes' performance in real-world applications, including environmental sensing or medical diagnostics.