Zinc/Cobalt-Based Zeolite Imidazolate Frameworks for Simultaneously Degrading Dye and Inhibiting Bacteria

Abstract

In this work, the zinc/cobalt-based zeolite imidazolate frameworks ((Co/Zn)ZIFs) were synthesized with the solvothermal method. The obtained material was characterized by utilizing scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis diffusive reflectance spectroscopy, and nitrogen adsorption-desorption isotherms. XRD and SEM analyses show that (Co/Zn)ZIFs are composed of nanocrystals with polyhedral shapes of around 50100nm and belong to the I-43m space group as those of ZIF-8 and ZIF-67. Optical studies demonstrate a red shift in the absorbance spectrum of (Co/Zn)ZIFs compared with individual components of ZIF-67 or ZIF-8. (Co/Zn)ZIF composite was utilized as photocatalytic material to treat a model aqueous solution containing rhodamine B and bacteria. It was found that (Co/Zn)ZIFs could simultaneously degrade rhodamine B and inhibit bacteria (E. coli and S. aureus). The manufactured composite could catalyze the mineralization of rhodamine B and also exhibited good antibacterial activity against Gram-negative E. coli (93.32 inhibition rate) and Gram-positive S. aureus (90.86 inhibition rate) in the visible-light region within four hours of irradiation. Gram-negative bacteria were more resistant to (Co/Zn)ZIFs than Gram-positive bacteria. (Co/Zn)ZIFs can be used as light-driven catalysts for water and environmental detoxification from organic compounds like dyes and bacteria.