Polyethyleneimine-loaded bimodal porous silica as low-cost and high-capacity sorbent for CO2 capture

► PEI-impregnated bimodal porous silica as low-cost sorbent for CO2 capture. ► Macropores enhances the accessibility of PEI inside the mesopores. ► PEI-loaded bimodal porous silica proved to provide higher effective amine density to adsorb CO2. ► PEI-loaded bimodal porous silica exhibits a high CO2 uptake with excellent regeneration efficiency.