Synthesis of magnetic FeCo/BC composite by one-step pyrolysis for degradation of bisphenol A through peroxymonosulfate/peroxydisulfate activization

Abstract

In this study, biomass carbon supported with iron and cobalt bimetal (FeCo/BC) was synthesized by a one-pot calcination method to activate peroxymonosulfate (PMS) and peroxydisulfate (PDS) for bisphenol A (BPA) degradation. Characterization with X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy showed that Fe0, Fe3O4, Co0 and CoO nanocrystals were included in FeCo/BC materials. The degradation results showed Fe0.6Co0.4/BC had excellent catalytic activation performance for PMS or PDS. The Fe0.6Co0.4/BC (0.0050 g) combined with 0.25 g·L−1 of PMS could completely degrade 20 mg·L−1 BPA within 8 min, and the same amount of BPA could be removed with 0.020 g Fe0.6Co0.4/BC in the presence of 0.25 g·L−1 PDS within 20 min. The corresponding total organic carbon removal rates reached 83.49% and 77.5% respectively after 2 h. The Fe0.6Co0.4/BC also had good adaptability to solution pH and practical water body. After five cycles, the degradation rates of BPA in the two systems were all over 90%, and excellent magnetism was beneficial to the reuse of catalysts. Electron paramagnetic resonance and free radical quenching tests indicated that SO4•-, •OH, and 1O2 were the main active species involved in the BPA degradation. This work not only provided a promising catalyst for the degradation of organic pollutants, but also elucidated the synergistic effect between Fe-Co bimetal alloys during PMS and PDS activation, which would facilitate the design, synthesis, and application of catalytic materials with high efficiency.