Efficient degradation of drug ibuprofen through catalytic activation of peroxymonosulfate by Fe3C embedded on carbon.

Ibuprofen (IBU), a nonsteroidal anti-inflammatory drug, is becoming an important member of pharmaceuticals and personal care products (PPCPs) as emerging pollutants. To degrade IBU, magnetic Fe3C nanoparticles embedded on N-doped carbon (Fe3C/NC) were prepared as a catalyst by a sol-gel combustion method. As characterized, the Fe3C/NC nanoparticles were composed of a NC nano-sheet and capsulated Fe3C particles on the sheet. The Fe3C/NC nanoparticles were confirmed an efficient catalyst for peroxymonosulfate (PMS) activation to generate sulfate radicals (SO4•-), single oxygen (1O2) and hydroxyl radicals (•OH) toward the degradation of IBU. The added IBU (10 mg/L) was almost completely removed in 30 min by using 0.1 g/L Fe3C/NC and 2 g/L PMS. The catalyst was confirmed to have good ability and excellent reusability through leaching measurements and cycle experiments. A catalytic mechanism was proposed for the catalytic activation of PMS on Fe3C/NC, which involves both Fe3C reactive sites and N-doped carbon matrix as reactive sites in Fe3C/NC. Moreover, the degradation pathway of IBU in the Fe3C/NC-PMS system was proposed according to the detections of degradation intermediates.

Highly efficient catalysis of chalcopyrite with surface bonded ferrous species for activation of peroxymonosulfate toward degradation of bisphenol A: A mechanism study.

Chalcopyrite nanoparticles (CuFeS2 NPs) with abundant surface bonded ferrous were successfully prepared, characterized and used as a catalyst for peroxymonosulfate (PMS) activation and BPA degradation. The effect of reaction parameters such as initial pH, catalyst load, PMS concentration, initial BPA concentration and reaction temperature on BPA degradation in CuFeS2-PMS system was systematically investigated. As a bimetallic sulfide, CuFeS2 exhibits ultra-high activity for PMS activation compared with Cu2S, FeS2, CuFeO2 and Co3O4. It was found that by co-use of 0.1 g L-1 CuFeS2 and 0.3 mmol L-1 PMS, 20 mg L-1 of BPA was almost completely degraded (99.7%) and reached a mineralization rate of 75% within 20 min. The highly catalytic activity of CuFeS2 is closely related to two aspects: one is that S2- in the catalysts promotes the cycling of Fe3+/Fe2+ and Cu2+/Cu+ cycles on the surface, and the other is the synergistic effect of Fe3+/Fe2+ and Cu2+/Cu+ cycles in the PMS activation. These interesting findings shed some new insight on the development of metal sulfides for the oxidative treatment of organic contaminants.