Smart Functional nano-materials synthesis from molecular engineering
Résumé
Chemical solution routes (i.e. Sol-gel, MOD) are usually coupled to the design of tunable molecular precursors (i.e. alkoxides) and the industrial development of such techniques is strongly dependent of and associated to the inorganic molecular engineering1. Indeed, they are usually the starting point of the processes and influence the micro-, nano-structure and finally the nature and the properties of the materials. Furthermore, the use of well defined precursors also allows establishing relationships between precursors and the final material and getting some insight in their transformation. The aim is then to design homo or heterometallic (single-source) precursors which will be converted into materials by bottom-up approaches by having (i) a formulation matching that of the materials, especially stoichiometry between metals for multimetallic materials, (ii) appropriate physicochemical properties (solubility, thermal stab ility), (iii) the required chemical functionalities (coordination sphere with an appropriate set of ligands), and (iv) a clean, low temperature conversion into materials and minimize undesired residues in them. Such concepts will be addressed in this presentation about well-defined metal-organic precursors for up-converting (NaYF4 co-doped Ln3+, Ln = Eu, Tb, Yb)2, thermoelectric (SnxTi1-xO2 doped with M5+, M = Nb, Ta)3 and catalytic (Au@Al4Ga2O9)4 colloids.