CO2-induced architectural transition of hierarchically porous carbon in reverse microemulsion system

Abstract A novel approach is provided to control the morphology and the structure of hierarchically porous carbon (HPC) materials with well-ordered mesoporous structure. A water-in-oil reverse microemulsion (F127/MMA) was employed as the reactive system and resorcinol and p-phthalaldehyde as the reactant with one-pot method by using compressed CO 2 . Specially, the morphology of the as-made HPC can be transformed from nanosphere to 3D network by simply increasing the pressure of CO 2 . Meanwhile, the porous structure of the obtained sample can be turned from mesopores/micropores to macropores/mesopores/micropores. The obtained HPC exhibits excellent performance in the CO 2 adsorption, drug delivery, and supercapacitor electrode. Furthermore, the mechanism of the transformation of HPC was discussed via investigating the solution. The results imply that CO 2 plays a decisive role to change the state of solution from the reserve microemulsion to Winsor type I microemulsion, leading to morphological and porous structural transformation of the as-prepared HPC. Different from conventional acid/base or inorganic additives as catalyst, CO 2 can not only be employed as an acid catalyst in the crosslinking of the precursors, but also be a controller of the structure transformation of HPC. This strategy can provide a novel route to develop architectural design of HPC in green processes.