Tailoring ZIF-8-derived carbons through surface modifications for enhanced pharmaceutical removal

A series of porous carbons were prepared from the metal–organic framework ZIF-8 by tuning the calcination temperature and applying post-synthetic chemical treatments aimed at controlling porosity, surface chemistry and hydrophobicity. The resulting materials were thoroughly characterized by XRD, nitrogen adsorption–desorption, electron microscopy, XPS, Boehm titration and contact angle measurements. Their adsorption performance was evaluated using ibuprofen as a model pharmaceutical pollutant. Among the prepared materials, the carbon obtained by direct calcination at 1000 °C (C1000ZIF-8) exhibited the highest surface area (951 m 2 g -1 ), the lowest heteroatom content and the most hydrophobic surface (contact angle 127°), leading to superior adsorption behaviour. Ibuprofen adsorption followed the Langmuir model with a maximum capacity of 62.6 mg g -1 and showed fast kinetics, with more than 50 % removal within the first 15 min and an excellent fit to the pseudo-second-order model (R 2 = 0.998). The material retained over 93 % of its initial adsorption capacity after ten adsorption–desorption cycles, demonstrating high stability and reusability. Finally, C1000ZIF-8 achieved removal efficiencies above 88 % for several pharmaceuticals in real water matrices, including seawater, tap water and groundwater, highlighting the key role of hydrophobic interactions and pore filling and confirming the strong potential of this material for practical water remediation applications.