Adsorption and photocatalytic degradation of pharmaceuticals in aqueous solutions by metal-organic-framework/activated carbon composite

Abstract

ZIF-8/Activated carbon (AC) composite was synthesized by heating plate method. Morphology and structural properties of the material were examined with Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorptive properties of ZIF-8/AC were evaluated by the adsorption isotherm and kinetics for removal of tetracycline hydrochloride (TCH) and diclofenac sodium (DCF). Effect of pH and point of zero charge of the composite were determined. Adsorption of tetracycline hydrochloride by ZIF-8/AC was fit with Freundlich adsorption model, while adsorption of DCF showed better fit with Langmuir isotherm model. Kinetics of adsorption followed pseudo-second-order kinetic model. Suggested mechanisms of adsorption are pi-pi interactions and hydrogen bond formation. Photocatalytic experiments showed that ZIF-8/AC performed photoactivity under visible light irradiation with 80% TCH degradation.

This work utilized the results obtained in European Regional Development Fund supported project “Uuden sukupolven katalyytit ympäristöterveyden edistämiseksi Etelä-Karjalassa” (A77605).