Enhanced photocatalytic activity of MOF-derived ZnO nanoparticles for dye degradation

Abstract

In this study, the photocatalytic performance of Metal-Organic Framework (MOF) derived ZnO has been shown to be more efficient than the pure ZnO for Malachite Green (MG) dye degradation, a commonly used organic dye having considerable environmental influence. ZnO in pure form was prepared by chemical coprecipitation method and MOF-derived ZnO was prepared by self-assembly process. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Field emission scanning electron microscope (FESEM), Fourier-transform infrared spectroscopy (FTIR), and UV-visible spectroscopy (UV-vis) were utilized to characterize the materials. XRD established that the two materials crystallize in the hexagonal wurtzite form, and FESEM established that pure ZnO was made up of both spherical and spindle-like particles, and MOF-derived ZnO consisted of mostly spherical particles. The UV-visible absorption spectra showed that both samples had bandgap energies of 3.32 eV. The photocatalytic performance (under UV light irradiation) of MOF-derived ZnO was excellent, as it was able to degrade MG dye by 98\% in 3 hours. Such enhancement may be ascribed to the increased effective surface area and increased porosity of the MOF-derived structure which allows more effective photocatalysis.