Adsorptive removal of ibuprofen and diclofenac from water using metal-organic framework-derived porous carbon

A metal-organic framework (MOF) (here, zeolitic-imidazolate framework-8) was pyrolyzed at different temperatures (800, 1000, and 1200 °C) in order to prepare porous carbons derived from MOF (PCDMs). Adsorption of ibuprofen (IBP) and diclofenac sodium (DCF) from aqueous solutions was carried out over the produced PCDMs and compared with that over pristine MOF and commercial activated carbon (AC). Among the tested adsorbents, the PCDM prepared at 1000 °C (PCDM-1000) was found to be the best candidate for both IBP and DCF. The maximum adsorption capacities of IBP (320 mg/g) and DCF (400 mg/g) over PCDM-1000 were ∼3 and ∼5 times, respectively, of that of AC. Interaction mechanisms such as H-bonding (H-donation from PCDM, H-acceptance from IBP or DCF) were suggested based on the effect of solution pH on the zeta potential of PCDM and the adsorbed quantity of IBP and DCF along with functional groups created on the surface of PCDM-1000. Finally, PCDM-1000 was confirmed to be as a highly efficient and recyclable adsorbent having potential applications in water purification.