Ultra-sustainable Fe(78)Si(9)B(13) metallic glass as a catalyst for activation of persulfate on methylene blue degradation under UV-Vis light

Stability and reusability are important characteristics of advanced catalysts for wastewater treatment. In this work, for the first time, sulfate radicals (SO(4)∙(−)) with a high oxidative potential (E(o) = 2.5–3.1 V) were successfully activated from persulfate by a Fe(78)Si(9)B(13) metallic glass. This alloy exhibited a superior surface stability and reusability while activating persulfate as indicated by it being used for 30 times while maintaining an acceptable methylene blue (MB) degradation rate. The produced SiO(2) layer on the ribbon surface expanded strongly from the fresh use to the 20(th) use, providing stable protection of the buried Fe. MB degradation and kinetic study revealed 100% of the dye degradation with a kinetic rate k = 0.640 within 20 min under rational parameter control. The dominant reactive species for dye molecule decomposition in the first 10 min of the reaction was hydroxyl radicals (∙OH, E(o) = 2.7 V) and in the last 10 min was sulfate radicals (SO(4)∙(−)), respectively. Empirical operating variables for dye degradation in this work were under catalyst dosage 0.5 g/L, light irradiation 7.7 μW/cm(2), and persulfate concentration 1.0 mmol/L. The amorphous Fe(78)Si(9)B(13) alloy in this work will open a new gate for wastewater remediation.