부산대학교 도서관

The present study offers a novel recyclable Fe3O4/MnO2/ZIF-8 heterojunction photocatalyst for the degradationof reactive blue 19 (RB19) under visible light irradiation. The catalyst was facilely synthesized bydepositing Fe3O4/MnO2 nanocomposite onto the surface of ZIF-8 and characterized by field-emissionscanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy,X-ray diffraction, nitrogen adsorption–desorption isotherms and UV–vis spectroscopy. Morphology and structure characterization of the prepared photocatalyst indicated that polyhedralZIF-8 (ca. 500 nm) was coated by MnO2/Fe3O4 nanorods. The synergy effect of Fe3O4/MnO2/ZIF-8 compositeexhibited an excellent photocatalytic activity toward RB19 degradation of 99.5 % after 60 min of irradiationdue to high surface area and heterojunction formation. According to scavenger tests, thephotodegradation of RB19 dye over Fe3O4/MnO2/ZIF-8 was mainly contributed by OH and O2reactiveradicals. The kinetic study showed that the catalytic degradation of RB19 on Fe3O4/MnO2/ZIF-8 was betterdescribed by the first-order kinetic model. The new catalyst was easily recovered using an external magneticfield because of its magnetic properties. Besides, Fe3O4/MnO2/ZIF-8 showed high recyclability andstability, maintaining a high removal efficiency of 91.3 % even after ten repeated cycles. The overallresults indicated that the fabricated composite can be used as an efficient photocatalyst for treatingorganic dyes in wastewater.