Preparation of dispersed hollow carbon spheres assisted by silica/carbon shell isolation for supercapacitors

Abstract

Nitrogen-doped mesoporous hollow carbon spheres are crucial in energy storage and the strategy of converting the inexpensive polymer polyacrylonitrile (PAN) into hollow carbon spheres needs to be improved. In this study, polystyrene/polyacrylonitrile (PSPAN) composite spheres were subjected to silica/carbon shell isolation to prepare nitrogen-doped hollow carbon spheres. In the carbonization process, the pyrolysis of PSPAN lead to the cavity due to the total decomposition behavior of PS. Due to the isolation of silica/carbon shells, the formation of a molten state during the pyrolysis process of PAN can be effectively prevented, thus avoiding the agglomeration of carbon spheres, and obtaining dispersed and regular hollow carbon spheres. The pore structure and specific surface area of the material were adjusted by hydrolyzing tetraethyl orthosilicate on the template surface and introducing dopamine for polymerization after different times. The hollow structure, nitrogen doping characteristics and abundant mesopores endow the NHCS with high performance in supercapacitor.