Hierarchical porous carbon with tunable apertures and nitrogen/oxygen heteroatoms for efficient adsorption and separation of VOCs

•The pore size of BICs is controllable.•BICs have a maximum total pore volume of 2.42 cm3/g.•The adsorption capacity for benzene and methanol reaches 22.19 and 52.56 mmol/g.•BICs exhibit excellent benzene/methanol separation performance (∼30.13).•Surface heterogeneity induced by heteroatoms is revealed through DFT and GCMC simulation.