Magnetic Fe–Co crystal doped hierarchical porous carbon fibers for removal of organic pollutants

Abstract

Porous carbonaceous materials are widely used as catalyst carriers to activate peroxymonosulfate (PMS) for catalytic oxidative degradation of organic pollutants. Herein, hierarchical structured ferro-cobalt alloyed crystals supported on nitrogen doped activated porous carbon fibers (FeCo₂@APCFs) were prepared by a combination of multicomponent electrospinning, activation, and carbonization. Benefiting from the precursor design and activation process, the carbon fibers derived from a PAN/PBZ (polyacrylonitrile/polybenzoxazine) precursor exhibited a tunable porous structure with an ultrahigh specific surface area (SSA) and pore volume of 2085 m² g⁻¹ and 1.12 cm³ g⁻¹, respectively. Most importantly, the FeCo₂ crystals can be directly synthesized by carbonization at high temperature in a N₂ flow with no other reducing gases. The as-prepared FeCo₂@APCFs exhibited robust activation of PMS with reactive oxygen radicals (SO₄˙⁻, ˙OH, and ¹O₂) for ultrafast removal of organic pollutants, as well as good stability and recyclability with high total organic carbon (TOC) removal. The catalyst suspended in aqueous solution after catalysis can be easily separated with an external magnet without tedious separation processes. This study is meaningful for the development of novel catalyst carriers or a fascinating strategy for wastewater treatment.