Ultrafast activation efficiency of three peroxides by Fe78Si9B13 metallic glass under photo-enhanced catalytic oxidation: A comparative study

Metallic glasses with long-range disordered atomic structure have recently been attracted a great deal of research attention in catalytic field. Compared to crystalline materials, the metallic glasses present many advanced catalytic properties, yet the catalytic mechanism is not sufficiently understood. In this work, an Fe78Si9B13 glassy ribbon manufactured by melt-spinning method was applied for the first time to compare its activation behavior on three peroxides, including hydrogen peroxide (H2O2), persulfate (PS) and peroxymonosulfate (PMS). It was shown that Fe78Si9B13 metallic glass had exceptionally high capability for activating these three common peroxides to produce reactive radicals (center dot OH and/or SO4 center dot(-)). The dominant species of H2O2 in this work was demonstrated as hydroxyl radical (center dot OH) while the PS and PMS activation mainly generated sulfate radical (SO4 center dot(-)). The order of predominant radical generation rate by Fe78Si9B13 activation under UV - vis irradiation was PS > H2O2 > PMS. The relative contribution of sulfate radical (SO4 center dot(-)) in PS' activation was 78% compared to 61% in PMS. All the peroxides activated by Fe78Si9B13 metallic glass presented a radical generation rate at least similar to 2 times higher than other iron-containing materials. Crystal violet (CV) dye was used to investigate the catalytic performance of Fe78Si9B13 metallic glass for peroxides, which showed an ultrafast dye degradation rate with completely color removal within 15 min. The radical evolution mechanisms for H2O2, PS and PMS activation were also investigated. The change in surface morphology of ribbon after 5th run reused indicated that the inclusions of Si leading to formation of SiO2 layer played an important role in the surface stability of ribbons.