Nitrogen-doped hierarchical porous carbon with enhanced interfacial affinity for the efficient adsorption of antibiotic micropollutants from water

Hierarchical porous carbon presents great application potentials for water purification, but its structure–property relationship during the adsorption removal of antibiotic micropollutants remains unclear due to the complex interactions between them. Herein, we demonstrate a nitrogen doping strategy to simultaneously modulate the pore structure and affinity sites of hierarchical porous carbons. By fitting the pore structure of nitrogen-doped hierarchical porous carbon with typical antibiotics, we improve the initial adsorption rate of carbonaceous adsorbents by orders of magnitude. Experimental characterizations and theoretical calculations reveal the formation of electron-deficient/rich centers in the sp2 hybridization plane of carbon caused by nitrogen doping, significantly strengthening the π-π interaction between the adsorbents and antibiotics, with 7.28-times and 2.2-times higher equilibrium adsorption capacity under the optimal conditions compared to the pristine carbon and commercial activated carbon, respectively. A versatile apparatus is elaborately designed for water purification by combining high-efficiency adsorption and microfiltration, realizing nearly 100% and over 92% removal of micropollutants from tap water and real pharmaceutical wastewater, respectively via single-pass treatment. This research provides a solution for the high-efficiency treatment of micropollutants by using hierarchical porous carbon with modulated pore structure and interfacial affinity.