Stable uranium sols as precursors for the elaboration of nanostructured nc-UO2 materials

•A colloidal sol-gel and templating method was used to elaborate sols as precursors for nanostructured and nanocrystallized nc-UO2 materials.•The UO2 nanoparticles formation was controlled either by their complexation by either by their diffusion limitation.•With AKYPO used as template, stable sols and promising partially nanostructured nc-UO2 materials is obtained.•The high concentration of Glucopon in the sol, has led to a carbon enriched material with few nc-UO2 zones.