Nanoparticles of lanthanide and transition metal oxysulfides : from colloidal synthesis to structure, surface, optical and magnetic properties Clement Larquet To cite this version: Clement Larquet. Nanoparticles of lanthanide and transition metal oxysulfides : from colloidal synthe- sis to structure, surface, optical and magnetic properties. Material chemistry. Sorbonne Université, 2018. English. NNT : 2018SORUS432. tel-02950055 HAL Id: tel-02950055 https://tel.archives-ouvertes.fr/tel-02950055 Submitted on 27 Sep 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Sorbonne Université Ecole doctorale 397 : Physique et chimie des matériaux Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP) Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) Nanoparticles of lanthanide and transition metal oxysulfides: from colloidal synthesis to structure, surface, optical and magnetic properties Par M. Clément Larquet Thèse de doctorat de Sorbonne Université Dirigée par Clément Sanchez et Andrea Gauzzi Présentée et soutenue publiquement le 25 septembre 2018 Devant un jury composé de : Mme. Elsje Alessandra Quadrelli Directrice de recherches - CPE Lyon Rapporteur M. Stéphane Jobic Directeur de recherches - IEMN Rapporteur Mme. Catherine Louis Directrice de recherches - SU Examinatrice Mme. Asma Tougerti Chargée de recherches – Univ. Lille Examinatrice M. Patrick Maestro Directeur scientifique - Solvay Examinateur Mme. Sophie Carenco Chargée de recherches - SU Encadrant principal M. Andrea Gauzzi Professeur - SU Directeur de thèse M. Clément Sanchez Professeur - Collège de France Directeur de thèse Introduction Among the various combinations of metal with chalcogens, the association of a metal with oxygen and sulfur anions is peculiar. It was given the name of metal oxysulfide. Because these two anions present dissimilar sizes and electronic properties, associating them with a metal in a single compound is a synthetic challenge. Notably, metal oxysulfides are scarcer in nature than their oxide or sulfide cousins despite the abundance of the two chalcogens. From a synthetic point of view, even if the first oxysulfides were described in the XIXth century, their preparation was developed only at the beginning of the 1950’s with the advent of the first lanthanide- and actinide-based chalcogenides. Remarkably, the d-block transition metal oxysulfides are rarely involved in monometallic oxysulfide compounds. However, the formation of bimetallic oxysulfides enriched the number of elements that could crystallize in oxysulfide structures. Since 1967, bimetallic oxysulfides are regularly reported and more complex compositions (quinary oxysulfides and more) started to emerge at the beginning of the 1980’s. Since 2000, the hype for nanoparticles has reached the oxysulfides. Twenty years later, Ln2O2S crystalline phase and the other oxysulfides are now studied within two segregated chemists communities. Great efforts were made on the development of various syntheses of Ln2O2S nanoparticles whose applications in luminescence are diverse and were previously identified in the bulk phases. On the contrary, few works on other nanoscaled oxysulfides were reported in the same period. In the Laboratory of the Chemistry of Condensed Matter of Paris (LCMCP) was noted that lanthanide oxysulfide nanoparticles were almost exclusively studied for luminescence despite their intriguing bichalcogenide nature. At the beginning of the project, the works of Ishikawa et al. on the photocatalytic properties of Sm2Ti2S2O5 and He et al. on the magnetic properties of Eu2-xO2S nanoparticles were already reported since a few years. Building from the know-how the LCMCP developed on the synthesis of complex nanostructures, collaboration started with the Institute of Mineralogy, Physics of Materials and Cosmochemistry (IMPMC) whose expertise on the electronic, optical and magnetic properties of complex materials was extremely valuable and complementary. 3 The strategy of the project was first to acquire some know-how from the Ln2O2S nanoparticles synthesis and then switch to the d-block oxysulfide nanoparticles, for which novel structures and properties were expected. We did not expect that lanthanide oxysulfide nanoparticles would be such a complex and surprising system despite the dozens of reported works on the subject. Following this strategy, the manuscript is divided in two independent parts. The first one is dedicated to the lanthanide oxysulfide nanoparticles. We will see from a detailed bibliographic study that the synthesis of Ln2O2S nanoparticles is now well controlled both in aqueous and organic solvents, with various morphologies, surfaces, and applications (Chapter I). Then, the challenging case of cerium oxysulfide nanoparticles is handled (Chapter II). For the first time, unsupported Ce2O2S nanoparticles are obtained via a colloidal synthesis in organic surfactants, using Ce(acac)3, elemental sulfur and a sodium complex. The peculiar reactivity of the entire series of the oxysulfide solid solution of (Gd,Ce)2O2S nanoparticles is evaluated with in situ X-ray absorption near edge spectroscopy (XANES) and near ambient pressure X-ray photoemission spectroscopy (NAP-XPS). Following this work, an investigation on the structure and the surface of the Ln2O2S nano-objects is conducted through the case study of Gd2O2S (Chapter III). The sulfur amount, the ligands quantity and coordination mode, the sodium localization and role in the synthesis are discussed, leading to a more precise vision of the final nanoparticles contradictory on several points with previous works on the subject. Also, the study of colloidal solution samples during the nanoparticles nucleation and growth allow us to propose a detail formation mechanism for Ln2O2S nanoparticles. This work on the description of the structure is a milestone for the quantification of the magnetic and optical properties of the (Gd,Ce)2O2S nanocrystals. The electronic properties of cerium in the oxysulfide structure leads to significant evolutions of these properties (Chapter IV). In the second part, transition metal oxysulfides were investigated. The bibliographic study underlines the lack of monometallic structures and reviews the several syntheses of transition metal oxysulfides syntheses (Chapter V). An exploratory approach is conducted to reach monometallic and bimetallic oxysulfides with d-block transition metals at the nanoscale (Chapter VI). Confronted with mitigated results, a new strategy is developed to obtain at mild temperatures the concomitant oxidation and sulfidation of a metal (0) complex, leading to an unprecedented synthesis of amorphous nickel oxysulfide (Chapter VII). 4 Note: Part of this manuscript was written using the manuscripts of several journal articles (published, submitted or to be submitted) for which I wrote the first draft. Whenever an extract of an article was used, the corresponding sections are clearly delimited in the text. At the end of the manuscript, an experimental section references details on the various conducted syntheses and techniques throughout the project. Now is the time to dive in the fascinating world of the metal oxysulfides. 5 6 Table of contents Introduction ..............................................................................................................................3 Table of contents ......................................................................................................................7 Part I: Lanthanide oxysulfide nanoparticles ..........................................................................9 Chapter I - Lanthanide oxysulfide syntheses: from bulk to nanoparticles .............................11 Chapter II - Synthesizing and storing Ln2O2S nanoparticles: from Gd2O2S to Ce2O2S ..................................................................................................................................63 Chapter III - Unveiling the structure of Ln2O2S nanoplates in high boiling point organic solvents with an alkaline source: Gd2O2S as a case study ..................................93 Chapter IV - Benefits of bimetallic composition: the tunable optical and magnetic properties of Gd2(1-y)Ce2yO2S nanoparticles ............................................................137 Part II: d-Block transition metal oxysulfide nanoparticles...............................................159 Chapter V - The synthesis of bulk and nanoscaled transition metal oxysulfides: a burgeoning challenge.......................................................................................161 Chapter VI - Attempts at transposing Ln2O2S synthesis to nanoscaled transition metal oxysulfides ....................................................................................................195 Chapter VII - Towards nickel oxysulfide nanoparticles .......................................................217 Conclusion and perspectives ................................................................................................245