Peroxymonosulfate activation by CuFe-prussian blue analogues for the degradation of bisphenol S: Effect, mechanism, and pathway

The fenton-like process based on peroxymonosulfate (PMS) activation is considered as a promising strategy for the removal of organic pollutants. However, the development of efficient photocatalysts for PMS activation remains challenging. Herein, copper-iron prussian blue analogue (CunFe1-PBA, n = 1, 2, 3, 4) nanomaterials were first fabricated through a simple combination of co-precipitation and calcination processes. The as-synthesized CunFe1-PBA composite catalyst was used to activate PMS for the degradation of endocrine disruptor bisphenol S (BPS). As the result, Cu3Fe1-PBA calcined at 300 °C (Cu3Fe1-PBA*300 °C) mainly composed of CuFe2O4 and CuO showed a higher catalytic activity for activating PMS for BPS degradation than those of CunFe1-PBA composite. Additionally, Cu3Fe1-PBA*300 °C/PMS system was suitable for degradation of BPS at 400 mg/L catalyst or PMS and wide pH ranges from 3 to 11 while coexisting inorganic anions (SO42-, NO3-, and HCO3-) and humic acid all inhibited the reaction. Radical trapping experiment, electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS) proved that Cu and Fe could regulate the charge balance through changes of valence state, and active PMS to produce free radicals effectively, especially the production of 1O2. Furthermore, the analysis of the BPS intermediates of degradation was carried out by ultra-performance liquid chromatography-mass spectrometry, and two degradation pathways of BPS were proposed. In summary, this work provides a facile avenue to design efficient catalysts to activate PMS for the degradation of emerging organic pollutants in water remediation.