Defect-rich Co/N-doped hierarchically porous carbons for rapid and highly efficient adsorption of organophosphorus pesticides from environmental water

Organophosphorus pesticides (OPPs) severely pollute various environmental water due to their excessive use, and it is extremely urgent to develop novel adsorbents with high adsorption capacities, rapid removal rate and easily recovery for the removal of OPPs. In this study, defect-rich Co/N-doped hierarchically porous carbons (Co/N-DHPCs) were constructed by pyrolyzing acid-etched ZIF-67 precursor. The developed Co/N-DHPCs possessed rich defects, well-developed hierarchical porous structure, high specific surface area and excellent magnetic property, and exhibited large adsorption capacities of 103.81∼126.10 mg g^-1 and high removal efficiencies of 94.06 %∼100.00 % for fenitrothion, fenthion and phosalone within 15 min. The exceptional adsorption performance of Co/N-DHPCs could be attributed to the pore-filling effect, hydrophobic and π-π interactions, as well as the new active sites formed by rich defects and N heteroatoms doping. In addition, the magnetic property of Co/N-DHPCs enabled rapid and straightforward separation from aqueous solution. The Co/N-DHPCs also showed good reusability with removal efficiencies of 85.24 % after five consecutive recycles. Furthermore, the developed Co/N-DHPCs demonstrated remarkable removal efficiencies of OPPs in seven environmental water samples, particularly in high-salt seawater. This work provides a kind of reliable adsorbents for removing pollutants in environmental water.