Inorganic nano-materials are intensively developed for the creation of new advanced devices and equipments and for improving process performances. Indeed, structures at the nano-dimensional regime display new physical (optics, magnetism, spin crossover, conductivity, etc.) and chemical (e.g. catalysis, sensing, gas storage) properties absent in bulk matter of the same composition. In inorganic nano-materials, these specific functionalities are the consequence of a complex multi-level organization (chemical, structural, textural) of their architecture. The global properties and functional performances largely depend on the extent to which these levels are mastered during the synthesis process.