Adsorptive removal of anti-inflammatory drugs from water using graphene oxide/metal-organic framework composites

Highly porous metal-organic framework (MOF) composites were synthesized by combining MIL-101(Cr) with graphene oxide (GnO). The porosity of the GnO/MIL-101 composite was increased by composing GnO onto the MOF up to a certain ratio. The GnO/MIL-101 composites were utilized to adsorb anti-inflammatory drugs (AIDs) such as naproxen (NAP) and ketoprofen (KTP) from water. It was observed that GnO/MIL-101 composites displayed highly improved adsorption toward both NAP and KTP relative to pristine MIL-101 and commercial AC. MIL-101_ GnO(3%) had a NAP adsorption capacity 2.1 and 1.4 times those of commercial AC and pristine MIL-101, respectively; its adsorption performance was also very competitive with other reported adsorbents. The improved adsorption performance of the composites for NAP was credited to H-bonding because of the presence of several functional groups in the composites. MIL-101_ GnO(3%) and NAP act as a H-bond donor and acceptor, respectively. Moreover, MIL-101_GnO(3%) can be regenerated without severe deterioration by simple ethanol washing and can be reused for successive adsorption. Therefore, the GnO/MIL-101 composite is suggested as an efficient adsorbent for the removal of AIDs from water.