Theme 1: Microsystems and multi-scale electrochemistry

Coordinator : V. Vivier (DR)

Participants : F. Huet (PR), M. Keddam (DR bénévole), P. Letellier (PR émérite), J. Mouton (enseignant-chercheur EPF), K. Ngo (MdC-HDR), C. Sánchez-Sánchez (CR-HDR), E. Sutter (PR bénévole), M. Tran (CR), H. Takenouti (DR bénévole), M. Turmine (MdC-HDR), B. Tribollet (DR émérite)

The main objective of our research is to characterize the electrochemical properties of materials in different environments and at different scales. It is based on the use of both time and space resolved electrochemical techniques by implementing a suited instrumentation to address, in an original way, the study of electron transfer and material ageing. Thus, our approach is based on the understanding of the reaction mechanisms at the electrode/solution interface, whether for model systems (development of the use of ionic liquids, manufacture and use of microfluidic systems in electrochemistry, etc.) or systems directly linked with industrial applications (characterization of materials for energy, study of corrosion processes, etc.). The examples presented below, some of which are the result of national or international collaborations, are representative of our research activity.


1. Corrosion and impedance spectroscopy

image 1
Comparison of the thickness of an electroformed oxide film on zirconium, obtained by impedance spectroscopy and XPS [8].

The oxide layers that spontaneously form on different metals such as stainless steels or aluminium and its alloys give these materials a natural protection against corrosion that can be reinforced by the application of a coating. In both cases, these layers, whose thickness varies from a few nanometers to a few tens of micrometers, act as a barrier that is very often characterized by electrochemical impedance spectroscopy measurements1.

The study of these protective layers as a function of time often reflects a distribution of time constants represented by a constant phase angle element (CPE) whose physical origin had not been explained until now. In collaboration with our colleagues in Toulouse, Padova (Italy) and Gainesville (United States), we have undertaken a detailed analysis of different systems in order to propose a resistivity distribution model, such as a power law, that induces a normal distribution of time constants within the film2. This model allowed to characterize the aging of paints on aluminum alloys that results in an inhomogeneous electrolyte ingress in the thickness of the coating3 and, more specifically, we showed that the behavior of the paint layer is then equivalent to a two-layer system with distinct physical properties whose characteristics are accessible over different frequency domains4. These studies on coating ageing were complemented by local electrochemical impedance spectroscopy studies to identify delamination zones5. In the case of oxide films on metals (steel6, aluminium7, zirconium8), we have shown that the resistivity distribution model of the power law type, either by combining the usual electrochemical measurements with reflectivity measurements1, XPS8, or by proposing different graphical representations of the results6-7, also allows us to explain the evolution of experimental impedance diagrams

image2
Evolution of the current as a function of time for 7 identical experiments of single pit formation on 316L stainless steel.

The use of electrochemical microscopy makes it possible to study localized corrosion without the random nature of the pitting initiation processes9-10. For instance, by using a microcapillary to inject locally an aggressive solution, it is possible to generate a single pit and monitor its evolution11-12. Measurements on 316L stainless steel in sulphuric acid solution have shown that a single pit is reproducible and that it is possible to maintain its propagation or to study repassivation conditions. In addition, from the analysis of currents as a function of time for different polarizations of the steel substrate and by making optical measurements of the radius and depth of the pits, it was possible to determine two distinct kinetics for the propagation of a pit: one corresponding to the propagation in depth, the other to the increase in radius. This approach allowed us to quantitatively describe the propagation of a pit in stainless steel11. 


2. Electrochemical noise in microfluidic

Droplet microfluidics, which appeared at the end of the 2000s, is a field of microfluidics that allows the manipulation of droplets via the generation of monodisperse microspheres (or droplets) resulting from the introduction of two immiscible liquids into a microfluidic channel of about ten to a hundred micrometers. Each droplet, with a volume between 1 nL and 1 fL, i. e. 103 à 109 times smaller than the volume of reagents present in a conventional test microbe  can be used as an individual microreactor for a precise handling and high throughput analysis. This is why droplet microfluidics has been used in the last ten years in various fields such as cellular analysis, drug delivery and diagnosis.  Up to now, optical techniques have mainly been used to characterize these droplets in microchannels. Although they are efficient and accurate, they nevertheless have two major disadvantages: their dependence on the opacity of the system and the difficulty of integrating them into the microsystem.

image3
Image of a 86 mm in diameter oil droplet circulating in a microchannel (a) and experimental (black curve) and theoretical (red curve) variations of the electrolyte resistance (b) - from [14].

An original approach consists in using the electrochemical noise technique13 as an alternative to detect and characterize droplets circulating in a microfluidic channel. Based on the know-how developed in our laboratory, this technique consists in measuring the fluctuations in electrolyte resistance between two electrodes immersed in a conductive electrolyte and the necessary methodological developments have been set up to adapt this technique to the micrometer scale. A theoretical model based on the finite element method was devised to study the influence of the various parameters on electrolyte resistance and in particular to determine a relationship between fluctuations in electrolyte resistance and droplet diameter. The excellent agreement obtained between the theoretical and experimental results made it possible to validate the theoretical model and also the measurement technique on droplets with a diameter greater than 25 µm with an error of a few percent using a microfluidic system with a characteristic size of 100 µm with integrated microelectrodes14-15. This approach has been developed to characterize droplets up to 100 µm in diameter and ongoing developments concern the miniaturization of the current microsystem to be able to characterize droplets in the order of a few micrometers, that is a characteristic size of biological cells.


3. Nanoparticles and electrocatalysis, nanotubes and photocatalysis: kinetic and thermodynamic approach

image 4
Exemple d’utilisation de la SECM utilisant une pipette pour apporter une espèce à un substrat jouant le rôle de collecteur pour étudier la réaction de réduction de CHCl3 en milieu aqueux – d’après [16].

Metal nanoparticles, due to their size, have a very interesting exalted reactivity, especially for electrocatalytic reactions. We have shown in the case of pollutant degradation16 or electro-oxidation of formic acid that the size and shape of nanoparticles play an important role17-18. Here again, the local approach is a key focus since the use of electrochemical microscopy and techniques derived from it allow a rapid and quantitative characterization of catalysts.

In order to better understand and predict the reactivity of nanoparticles, a thermodynamic approach was undertaken. SEM imaging shows that these nanoparticles are rarely uniform and spherical. The physicochemical behaviour of this divided material can therefore hardly be formalized from classical thermodynamics. For several years, we have been developing a non-extensive approach to thermodynamics (NET)19 that allows us to describe the physicochemical behavior of species in dispersed form or with poorly defined interfaces using a power law. These concepts can be applied to the electrochemical kinetics of nanoparticles20-21, which has allowed us to propose a generalization of the Plieth relationship (derived from that of Gibbs-Thompson) to non-spherical aggregates. NET relationships can quantitatively account for the movements of the electro-oxidation potentials of metal nanoparticles deposited on an electrode, depending on the measured dimension (length, diameter, etc.), thus offering a new approach for the study of nanomaterials, regardless of their field of application.

Finally, as part of a collaboration with Theme 2, photoelectrochemistry was used to study the transfer rate of photogenerated charges in TiO222-25 nanotubes. It was determined on the one hand by the competition between transfer and recombination rates, and on the other hand by the duration of storage of charges in energy traps located in the gap (surface state). Electrochemical impedance spectroscopy allows to quantify these states and estimate their storage capacity as a function of the geometry of the nanotubes. Charge transfer and recombination rates are measured by photocurrent spectroscopy obtained by the modulation of the light (IMPS) and by the development of a suitable model26.


4. Collaborations

National level : Dr. Olivier Devos (I2M – Bordeaux) ; Dr. Cédric Boissiere (LCMCP - Paris) ; Dr. Olivier Buriez (ENS – Paris) ; Dr. Thomas Cottineau (ICPEES- Strasbourg) ; Pr. Sophie Cribier (UPMC – Paris) ; Pr. Françoise Feugeas (INSA- Strasbourg) ; Dr. Benoit Gwinner (CEA – Saclay) ; Pr. Hamid Kokabi (UPMC - Paris) ; Pr. Christel Laberty (LCMCP – Paris) ; Dr. Michel Latroche (ICMPE – Thiais) ; Dr. Lionel Nicole (LCMCP - Paris) ; Dr. Nadine Pébère (CIRIMAT – Toulouse) ; Dr. David Portehault (LCMCP – Paris) ; Dr. Fabien Rouillard (CEA – Saclay).

International level : Pr. Hercílio Gomes de Melo (Université de São Paulo – Brésil) ; Pr. Hans-Joachim Krause (Forschungszentrum Jülich, Allemagne) ; Dr. Marco Musiani (EINI CNR – Padoue, Italie) ; Pr. Ramón Novoa (Université de Vigo – Espagne) ; Pr. Mark Orazem (Université de Floride – États-unis).

Industrial partners : ANDRA (Chatenay Malabry), Areva (La Défense), Chassis Brakes International (Drancy), IFPEN (Solaize), Institut de la Corrosion, Renault (Technocentre), SAFT (Bordeaux), Saint-Gobain (Gennevilliers), Total (La Défense).


5. Selected references

  1. Orazem, M. E.; Frateur, I.; Tribollet, B.; Vivier, V.; Marcelin, S.; Pebere, N.; Bunge, A. L.; White, E. A.; Riemer, D. P.; Musiani, M., Dielectric properties of materials showing constant-phase-element (CPE) impedance response. J. Electrochem. Soc. 2013, 160 (6), C215-C225.
  2. Amand, S.; Musiani, M.; Orazem, M. E.; Pebere, N.; Tribollet, B.; Vivier, V., Constant-phase-element behavior caused by inhomogeneous water uptake in anti-corrosion coatings. Electrochim. Acta 2013, 87, 693-700.
  3. Nguyen, A. S.; Musiani, M.; Orazem, M. E.; Pébère, N.; Tribollet, B.; Vivier, V., Impedance analysis of the distributed resistivity of coatings in dry and wet conditions. Electrochim. Acta 2015, 179, 452-459.
  4. Nguyen, A. S.; Musiani, M.; Orazem, M. E.; Pébère, N.; Tribollet, B.; Vivier, V., Impedance study of the influence of chromates on the properties of waterborne coatings deposited on 2024 aluminium alloy. Corros. Sci. 2016, 109, 174-181.
  5. Shkirskiy, V.; Volovitch, P.; Vivier, V., Development of quantitative Local Electrochemical Impedance Mapping: an efficient tool for the evaluation of delamination kinetics. Electrochim. Acta 2017, 235, 442-452.
  6. Chakri, S.; Patel, A. N.; Frateur, I.; Kanoufi, F.; Sutter, E. M. M.; Tran, T. T. M.; Tribollet, B.; Vivier, V., Imaging of a Thin Oxide Film Formation from the Combination of Surface Reflectivity and Electrochemical Methods. Anal Chem 2017, 89 (10), 5303-5310.
  7. Tran, T. T. M.; Tribollet, B.; Sutter, E. M. M., New insights into the cathodic dissolution of aluminium using electrochemical methods. Electrochim. Acta 2016, 216, 58-67.
  8. Benoit, M.; Bataillon, C.; Gwinner, B.; Miserque, F.; Orazem, M. E.; Sánchez-Sánchez, C. M.; Tribollet, B.; Vivier, V., Comparison of different methods for measuring the passive film thickness on metals. Electrochim. Acta 2016, 201, 340-347.
  9. Aouina, N.; Balbaud-Celerier, F.; Huet, F.; Joiret, S.; Perrot, H.; Rouillard, F.; Vivier, V., A flow microdevice for studying the initiation and propagation of a single pit. Corros. Sci. 2012, 62, 1-4.
  10. Aouina, N.; Balbaud-Celerier, F.; Huet, F.; Joiret, S.; Perrot, H.; Rouillard, F.; Vivier, V., Initiation and growth of a single pit on 316L stainless steel: Influence of SO42- and ClO4- anions. Electrochim. Acta 2013, 104, 274-281.
  11. Heurtault, S.; Robin, R.; Rouillard, F.; Vivier, V., Initiation and propagation of a single pit on stainless steel using a local probe technique. Faraday Discuss. 2015, 180, 267-282.
  12. Heurtault, S.; Robin, R.; Rouillard, F.; Vivier, V., On the Propagation of Open and Covered Pit in 316l Stainless Steel. Electrochim. Acta 2016, 203, 316-325.
  13. Tran, A. T.; Huet, F.; Ngo, K.; Rousseau, P., Influence on the electrolyte resistance of the contact angle of a bubble attached to a disk electrode. J. Electroanal. Chem. 2015, 737, 114-122.
  14. Yakdi, N. E.; Huet, F.; Ngo, K., Detection and sizing of single droplets flowing in a lab-on-a-chip device by measuring impedance fluctuations. Sensors and Actuators B: Chemical 2016, 236, 794-804.
  15. Yakdi, N.; Huet, F.; Ngo, K., In-situ particle sizing at millimeter scale from electrochemical noise: simulation and experiments. Electrochim. Acta 2015, 180, 1050-1058.
  16. Lugaresi, O.; Perales-Rondón, J. V.; Minguzzi, A.; Solla-Gullón, J.; Rondinini, S.; Feliu, J. M.; Sánchez-Sánchez, C. M., Rapid screening of silver nanoparticles for the catalytic degradation of chlorinated pollutants in water. Applied Catalysis B: Environmental 2015, 163, 554-563.
  17. Perales-Rondón, J. V.; Herrero, E.; Solla-Gullón, J.; Sánchez-Sánchez, C. M.; Vivier, V., Oxygen crossover effect on palladium and platinum based electrocatalysts during formic acid oxidation studied by scanning electrochemical microscopy. J. Electroanal. Chem. 2017, 793, 218-225.
  18. Perales-Rondón, J. V.; Solla-Gullón, J.; Herrero, E.; Sánchez-Sánchez, C. M., Enhanced catalytic activity and stability for the electrooxidation of formic acid on lead modified shape controlled platinum nanoparticles. Applied Catalysis B: Environmental 2017, 201, 48-57.
  19. Letellier, P.; Turmine, M., Solubility of gas in confined systems. Nonextensive thermodynamics approach. Journal of Colloid and Interface Science 2013, 392, 382-387.
  20. Letellier, P.; Turmine, M., Displacement of voltammetric peaks with nanoparticles size: a nonextensive thermodynamic approach. Electrochim. Acta 2014, 127, 384-389.
  21. Letellier, P.; Turmine, M., Non-Applicability of the Gibbs-Duhem Relation in Nonextensive Thermodynamics. Case of Micellar Solutions. Journal of Physical Chemistry B 2015, 119 (10), 4143-4154.
  22. Pu, P.; Cachet, H.; Laidani, N.; Sutter, E. M. M., Influence of pH on Surface States Behavior in TiO2Nanotubes. J. Phys. Chem. C 2012, 116 (42), 22139-22148.
  23. Ngaboyamahina, E.; Debiemme-Chouvy, C.; Pailleret, A.; Sutter, E. M. M., Electrodeposition of Polypyrrole in TiONanotube Arrays by Pulsed-Light and Pulsed-Potential Methods. J. Phys. Chem. C 2014, 118 (45), 26341-26350.
  24. Atyaoui, A.; Cachet, H.; Sutter, E. M. M.; Bousselmi, L., Effect of the anodization voltage on the dimensions and photoactivity of titania nanotubes arrays. Surface and Interface Analysis 2013, 45 (11-12), 1751-1759.
  25. Fakhouri, H.; Pulpytel, J.; Smith, W.; Zolfaghari, A.; Mortaheb, H. R.; Meshkini, F.; Jafari, R.; Sutter, E.; Arefi-Khonsari, F., Control of the visible and UV light water splitting and photocatalysis of nitrogen doped TiOthin films deposited by reactive magnetron sputtering. Applied Catalysis B: Environmental 2014, 144, 12-21.
  26. Cachet, H.; Sutter, E. M. M., Kinetics of Water Oxidation at TiO2 Nanotube Arrays at Different pH Domains Investigated by Electrochemical and Light-Modulated Impedance Spectroscopy. J. Phys. Chem. C 2015, 119 (45), 25548-25558.