Graphitization-mediated selective and rapid adsorption of bisphenol a by Fe-N-C derived from ZIF-8

Current adsorbents for bisphenol A (BPA) require complex preparation and relatively low adsorption capacities. Here, a high-performance adsorbent (Fe-N-C) was synthesized from iron-modified zeolite imidazole frameworks-8 (ZIF-8) via pyrolysis. With an exceptionally high specific surface area of 1565.15 m²·g⁻¹, Fe-N-C removed 90% of BPA within 10 min and achieved adsorption equilibrium within 3 h. Furthermore, Fe-N-C exhibited a maximum BPA theoretical adsorption capacity of 877.45 mg·g⁻¹ (288 K). The adsorption kinetics and isotherms conform to pseudo-second-order kinetics and the Langmuir model. Fe-N-C also demonstrated excellent performance across a wide pH range (4–10) and in complex water matrix. The high adsorption capacity was primarily attributed to π-π interactions, along with hydrogen bonding, electrostatic interactions, and hydrophobic interactions. Notably, in addition to efficiently adsorbing BPA, Fe-N-C exhibited a high selectivity toward organic compounds with two benzene rings by π-π interactions, such as bisphenol B (BPB), 2,2-bis (4-aminophenyl) propane (BAPP) and diclofenac (DCF) due to the mediation of graphitized microdomains. This study provides a simple route to prepare high-capacity N-doped carbon adsorbents for the selective and rapid adsorption of specific structural pollutants.