Pore size control of monodispersed starburst carbon spheres

We describe the synthesis of highly monodispersed starburst carbon spheres (MSCS) with pore size of 1.9–3.8 nm by using monodispersed mesoporous silica spheres (MMSS) which is modified with aminopropyl group, as a starting material. The wall thickness of the MMSS could be thickened by solvothermal treatment with increasing the ratio of aminopropyl group. The thickened silica wall of solvothermally treated MMSS (MS) prevented the shrinkage of the mesoporous silica template during carbonization, causing the formation of nanospaces between carbon and the silica. Furthermore, the thicker carbon nanorods obtained from pore-expanded MS would prevent the starburst structure from collapsing. As a result, MSCS with large mesopores could be obtained after removing the silica template by hydrofluoric acid etching.