Direct fabrication of hierarchical porous carbonaceous microparticles by electron-beam irradiation and post-annealing of polystyrene colloidal crystals

A novel approach to fabricate hierarchical porous carbonaceous microparticles (HPCMs) by electron irradiation of polystyrene (PS) colloidal crystals followed by annealing is presented. Electron irradiation transforms PS spheres into hydrogenated amorphous carbon and post-annealing further graphitizes the irradiated PS. Colloidal crystals consist of regularly ordered mesopores and electron irradiation and post-annealing create new micropores on the surfaces of PS spheres. Consequently, PS colloidal crystals were transformed into carbonaceous materials comprising mesopores and micropores. Through mechanically grinding the colloidal crystals, HPCMs are fabricated. Due to comparatively high surface areas and graphitic structures, the HPCMs exhibit moderate adsorption properties for methyl orange in an aqueous solution. Hierarchical porous carbonaceous microparticles are fabricated by electron-beam irradiation and post-annealing of polystyrene colloidal crystals. By controlling the electron-beam irradiation and post-annealing conditions, microparticles with regularly ordered meso-pores and micro-pores on the surfaces of PS spheres are obtained. These microparticles exhibit high specific surface area which is applied as an adsorbent for aqueous methyl orange removal.