Synergistic adsorption and degradation of CBZ by an adenine-anchored porous iron-based catalyst

Developing porous iron-based catalysts with high metal loading for highly efficient removal of the organic pollutants has been a challenge in environmental catalysis. In this work, the preparation of porous iron–nitrogen-co-doped carbon catalyst (pNC-Fe) innovatively utilized zinc nitrate (Zn(NO 3 ) 2 ) as a pore-forming agent and adenine for metal anchoring. The resulting catalyst possessed a high Fe loading (18.49 wt%) and a high specific surface area (395.69 m 2 /g), which enhanced the adsorption and degradation of pNC-Fe. As a demonstration, the maximum adsorption capacity of pNC-Fe for CBZ (389.7 mg/g) surpassed nearly all recently reported CBZ adsorbents. Additionally, pNC-Fe possessed an excellent adsorption regeneration capability even after 5 cycles, enhancing its reusability. Surprisingly, pNC-Fe in PMS system removed almost 100 % of 50 μmol/L carbamazepine (CBZ) in 15 min and performed an excellent k obs (0.5895 min −1 ), outperforming the majority of metal-based catalysts. Interestingly, the adsorption of CBZ by pNC-Fe also remarkably facilitated the degradation of CBZ. Notably, different from the free radical mechanism of most reported work, the quenching experiments and EPR detection demonstrated that the main reactive oxygen species (ROS) of the pNC-Fe/PMS system was singlet oxygen ( 1 O 2 ), endowing pNC-Fe with potential environmental anti-interference capability (less affected by common anions and pH variations). This work provides a valuable insight for the design of porous iron-based catalysts for wastewater remediation.