Chemistry and morphology of nanoalloys for growth catalysis of carbon nanotubes by CVD

Chemistry and morphology of nanoalloys for growth catalysis of carbon nanotubes by CVD

The proposed internship topic is part of a cooperative project on the development of new bimetallic catalysts in the solid solution state for the growth of carbon nanotubes, aiming at controlling their electronic properties during their synthesis.

Although several techniques are available for the synthesis of transition metal-based bimetallic catalysts, they generally lead to nanoparticles with a core/shell or janus morphology. Nevertheless, our previous studies have shown that it is possible to synthesize bimetallic particles in solid solution state, that is with no elemental segregation within the nanoparticle by combining surface chemistry and coordination chemistry under particular temperature conditions.

However, studying the thermodynamic behavior of these bimetallic catalysts often requires the implementation of complicated experimental techniques that often need to be coupled with theoretical approaches, even if the latter are still far from being able to reach such a level of complexity while remaining predictive. In collaboration with the partnering group of numerical simulations at the Institute of Molecular Chemistry and Orsay Materials (ICCMO) (Jérôme Creuze and Fabienne Berthier), we will undertake theoretical study to better characterize the behavior of these nanoparticles, in equilibrium and under ultra-vacuum first. Indeed, it is necessary to know the thermodynamics of nanoalloys as isolated systems before studying the influence of external perturbations. We will also study the kinetics of return to equilibrium in order to determine the stability and the lifetime of metastable configurations that will have been identified during the first step of the study.

The internship will thus identify and quantify the key thermodynamic parameters involved in the distribution of constituents within the bimetallic nanoparticles and understand how the thermodynamic variables influence the equilibrium configuration using these parameters. The candidate will be able to compare his results with experiences when possible.

Job: Internship (4-6 months)

Academic level : Master degree

Location: LEM, Châtillon

Expertise: Good training in condensed matter physics and chemistry with a major focus on nanoscience, thermodynamics. Strong interest for numerical calculations

Contacts: Armelle Girard, Annick.Loiseau