Inorganic fluorine-based compounds are found today as nano-components in many applications, including energy storage and conversion, photonics, electronics, medicinal chemistry, and more [1]. The strategic importance of nano-fluorinated materials can be illustrated by several examples drawn from various scientific fields. In the field of energy storage, fluorinated carbon nanoparticles (F-CNPs) are tested as active materials in primary lithium batteries, while 3d-transition metal fluorides and oxyfluorides, mainly iron-, cobalt- and titanium- based have been proposed as electrodes in secondary batterie(reversible) s. In all-solid-state batteries, materials derived from fluorite- (CaF₂) or tysonite- (LaF₃) structural types can be used as solid electrolytes, provided the F- anions are highly mobile. Nanocrystalline rare-earth fluorides are currently used for their photoluminescent properties at the micro- or nanoscale.

Functionalized nanoparticles and nanostructured compounds based on solid-state inorganic fluorides are used in many other advanced fields, including fluorinated graphene quantum dots (FGQDs), solar cells (DSSC, QDSSC), transparent conducting films (TCF), solid state lasers, nonlinear optics (NLO), UV absorbers, etc.
Their role is also decisive in medicine and biotechnologies [2], where doped rare-earth fluoride nanocrystals serve as luminescent biomarkers thanks to their up- and down-conversion properties, allow fluorine labeling of nanoparticles and in-vivo 19F NMR. Relevant nanotherapeutics include photodynamic therapy (PDT), luminescent thermometry, radiotracers for positron emission tomography (PET), theranostic nano-agents that incorporate both imaging probes and therapeutic media, and are therefore capable of carrying out both diagnosis and therapy within the same nano-object.