A process for producing monodispersed carbon spheres comprising the steps of mixing supercritical-carbon dioxide fluid under pressure with a solvent in an inert atmosphere; heating the mixture in to a temperature to carbonise the solvent; and modulating the pressure to the heated mixture to produce carbon spheres. Subsequent addition of an organometallic precursor can be used to induce the nucleation and growth of nanocrystals across the surface of the spheres.