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

Abstract

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.

Keywords: Catalytic degradation; Ibuprofen; Iron carbide; N-doped carbon; Peroxymonosulfate.