Template-free fabrication of hierarchical porous carbon by constructing carbonyl crosslinking bridges between polystyrene chains

A simple and effective template-free method to fabricate hierarchical porous carbon (HPC) has been successfully developed by adopting linear polystyrene resin as raw material, anhydrous aluminium chloride as Friedel-Crafts catalyst, and carbon tetrachloride as crosslinker and solvent. Experimental results show that the as-constructed carbonyl (-CO-) crosslinking bridges between polystyrene chains provide simultaneously to its hierarchical porous polystyrene precursor, both a high crosslinking density and a proper amount of oxygen atoms, and thus achieve good framework carbonizability and nanostructure inheritability during carbonization. The as-prepared HPC’s hierarchical porous structure exhibits interesting uniqueness: micropores (<2 nm) are from the network inside crosslinking polystyrene-based carbon nanoparticles of 10-30 nm in size, and mesopores (2-50 nm) and macropores (50-400 nm) result from the compact and loose aggregation of these network nanoparticles, respectively; and these micro-, meso- and macropores are three-dimensionally interconnected to each other. Its Brunauer-Emmett-Teller surface area and total pore volume are 679 m²g^-1 and 0.66 cm³g^-1, respectively.