Techniques for making nanowires with a desired diameter are provided. The nanowires can be grown from catalytic nanoparticles, wherein the nanowires can have substantially same diameter as the catalytic nanoparticles. Since the size or the diameter of the catalytic nanoparticles can be controlled in production of the nanoparticles, the diameter of the nanowires can be subsequently controlled as well. The catalytic nanoparticles are melted and provided with a gaseous precursor of the nanowires. When supersaturation of the catalytic nanoparticles with the gaseous precursor is reached, the gaseous precursor starts to solidify and form nanowires. The nanowires are separate from each other and not bind with each other to form a plurality of nanowires having the substantially uniform diameter.