Enhanced adsorption and synergistic photocatalytic degradation of tetracycline by MOF-801/GO composites via solvothermal synthesis

Abstract

The widespread use of antibiotics seriously affects environmental safety and human health. The adsorption and degradation of antibiotics in water resources are particularly important for environmental protection and human health. In this work, we synthesized a new composite material with a metal–organic framework (MOF) and graphene oxide (GO) via one-pot solvothermal synthesis using zirconium oxychloride octahydrate, fumaric acid and GO. The structural characterizations and electrochemical tests of MOF-801/GO composites were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and electrochemical impedance spectroscopy (EIS). Compared with MOF-801, the MOF-801/GO has a smaller electrochemical impedance, a narrower bandgap, and a nearly hundred times improvement in the transient photoresponse to visible light. In addition, the average pore size becomes larger and thermal stability is improved. This indicates that GO provided a good electron transport channel, suppressed the recombination rate of photogenerated electrons and photogenerated holes in MOF-801, and successfully improved the photocatalytic activity of MOF-801. The MOF-801/GO composites were used for the adsorption photocatalytic removal of tetracycline, and the removal efficiency was as high as 97% at 60 min, nearly 30% improvement over MOF-801, and the efficiency remained above 90% after three cycles. This work provides a new approach for the adsorption and photocatalytic degradation of tetracycline in water resources and a new idea for utilizing the good electrical conductivity of GO to enhance the photoelectric activity of MOF.