The influence of sacrificial carbonaceous supports on the synthesis of anhydrous NiF2 nanoparticles.
Résumé
We report a multistep synthesis of anhydrous NiF2 nanoparticles using Single Walled Carbon Nanotubes (SWCNT), Multi Walled Carbon Nanotubes (MWCNT) and cellulose as sacrificial supports. The synthesis method includes precipitation at the surface of carbonaceous supports, followed by gas-solid treatments under air and pure molecular fluorine. The as-prepared nanoparticles exhibit different particle size distributions depending on the initial support from ∼20 nm with SWCNT up to ∼60 nm with cellulose. The carbonaceous matrices act as sacrificial supports and are totally removed under fluorine gas. The influence of carbonaceous supports on the as-obtained nanoparticles is reported and discussed. Since SWCNT, MWCNT and cellulose exhibit different surface chemistries (nature of chemical sites, size related reactivity, …), they drive the formation of nanoparticles with different characteristics. Moreover, intermediate materials Ni(OH)2/C and NiO/C have been also studied and the opportunity to obtain promising structures like NiO/graphene nanocomposites by this method has been demonstrated.