Efficient elimination of organic contaminants with novel and stable zeolite@MOF layer adsorbents

Abstract

Many metal–organic frameworks (MOFs) trapped in water exhibit instability and small-particle agglomeration issues, which unquestionably constrain their potential applications, such as the capture of organic contaminants (OCs). In this study, four types of micron-sized MOFs (Zn/Cu-BTC, MOF-5, ZIF-8, and UiO-66) were grown within a zeolite-13X support to form millimeter-sized zeolite-13X@MOF composites for the elimination of benzothiophene, methyl orange, and tetracycline from the liquid phase by dynamic adsorption in a column. We observed that the 13X@Zn/Cu-BTC exhibited extraordinarily high OC capture capacities as a result of the Zn2+ and Cu2+ combinative effects of the acid–base interaction. Remarkably, the 13X@UiO-66 preserved its structural integrity when immersed in water for 15 days, in contact with boiling water for 12h, and in both strong acidic and basic aqueous media. Moreover, the OC capture abilities of the 13X@UiO-66 only underwent a slight change after the fifth round. This work provides new method for the design of desirable millimeter-sized zeolite@MOFs, thereby advancing their practical application for OC capture.