Auteur/autrice : david

We designed the first nanocrystals of sodium carbaboride in molten salts, and unveiled the deviation to ideal stoichiometry that is made possible by a specific molten salt-derived synthesis route and by the nanoscale of the objects. The nanocrystals can act as precursors towards functional boron carbides. This work is part of a Forum of Inorganic Chemistry.

Electron Precise Sodium Carbaboride Nanocrystals from Molten Salts: Single Sources to Boron Carbides, S. Delacroix, F. Igoa, Y. Song, Y. Le Godec, C. Coelho-Diogo, C.  Gervais, G. Rousse, D. Portehault*, Inorganic Chemistry, 10.1021/acs.inorgchem.0c03501

We report herein new oxides and oxyfluorides built on the apatite crystal framework and hosting Mn⁵⁺, a rare oxidation state of manganese, very scarcely observed in oxides. We take the opportunity of isolating these new solids to provide the first spectroscopic characterization of Mn⁵⁺ by EELS and to show the significant ionic conductivity of these solids.

This work was hosted by the department of Solid State Chemistry of the Universidad Complutense de Madrid. A strongly collaborative work with the RMES group of LCMCP lab, the Solid-State Chemistry and Energy Lab at Collège de France, and ILL at Grenoble.

Hydroxyapatites as Versatile Inorganic Hosts of Unusual Pentavalent Manganese Cations, A. Varela, I. Gómez-Recio, L. Serrador, M. Hernando, E. Matesanz, A. Torres-Pardo, M. T. Fernández-Díaz, J. L. Martínez, F. Gonell, G. Rousse, C. Sanchez, C. Laberty-Robert, D. Portehault, J. M. González-Calbet, M. Parras, Chemistry of Materials, DOI: 10.1021/acs.chemmater.0c03673

Correlative Microscopy Insight on Electrodeposited Ultrathin Graphite Oxide Films, N. Ortiz Peña, D. Ihiawakrim, V. Ball, S. Stanescu, M. Rastei, C. Sanchez, D. Portehault, O. Ersen, Journal of Physical Chemistry Letters, DOI: 10.1021/acs.jpclett.0c02482

The team has issued two new articles in September and October dedicated to boron chemistry in nanomaterials!

One article published in Inorganic Chemistry is one of the core achievements of Simon Delacroix would received his doctoral title recently. We report nanoparticles of a lithium boride and provide the first in-depth solid-state nuclear magnetic resonance study, coupled to DFT calculations, in order to assign the ⁷Li and ¹¹B NMR signals in such alkali borides. Nice collaboration with the SMILES group within LCMCP lab.

Synthesis in Molten Salts and Characterization of Li₆B₁₈(Li₂O)_x Nanoparticles, S. Delacroix, Y. Le Godec, C. Coelho-diogo, C. Gervais, I. Génois, P. Le Griel, D. Portehault*, Inorganic Chemistry, DOI: 10.1021/acs.inorgchem.0c01694

A second article relates to a work performed through our long-term collaboration with the team of Dr. Weiwei Lei at Deakin University. We report boronnitride-based membranes as high performance heat conductors.

Nacre-bionic nanocomposite membrane for efficient in-plane dissipation heat harvest under high temperature, J. Wang, D. Liu, Q. Li, C. Chen, Z. Chen, M. Naebe, P. Song, D. Portehault, C. J. Garvey, D. Golberg, W. Lei, Journal of Materiomics, DOI: 10.1016/j.jmat.2020.08.006

The work of Francisco Gonell on the selective synthesis of nickel perovskites into molten salts is published in ACS Applied Nanomaterials! This work was performed jointly with the RMES group of the Lab. LCMCP and with our colleagues from the LISE lab.

Francisco has studied the mechanisms at stake in the formation of perovskite oxides in molten salts in order to drive reaction pathways towards selected crystal structures. We have then shown that we could use these controlled syntheses to tune the electrocatalytic properties of the materials for the reduction of dioxygen.

Experimental Descriptors for the Synthesis of Multicationic Nickel Perovskite Nanoparticles for Oxygen Reduction, F. Gonell, C. M. Sanchez Sanchez, V. Vivier, C. Laberty-Robert, D. Portehault*, ACS Applied Nanomaterials, DOI: 10.1021/acsanm.0c01094

The nice work of Ram Kumar has been accepted for publication in Nanoscale! In this paper, we tune molten salts synthesis pathways in order design nanoparticles of nickel silicides. We show that these nanoparticles undergo surface transformation upon exposure to water and oxidative electrochemical potential, so that a thin layer of nickel oxyhydroxide forms at their surface. This layer is an active electrocatalyst for water oxidation, while the silicide particles core remains intact and provides fast charge transfer. The material shows surprising long term stability under operation of water oxidation. A nice collaboration with the RMES team of LCMCP, the LRS lab at Sorbonne University, and University of Strasbourg.

Phase selective synthesis of nickel silicide nanocrystals in molten salts for electrocatalysis of the oxygen evolution reaction, R. Kumar, M. Bahri, Y. Song, F. Gonell, C. Thomas, O. Ersen, C. Sanchez, C. Laberty-Robert, D. Portehault*, Nanoscale, DOI: 10.1039/D0NR04284F