Core-shell FeMn@NG derived from cellulose supported Prussian blue analogs for peroxymonosulfate activation: Non-radical mechanism and ultra-low metal leaching

Abstract

FeMn bimetallic nanoparticles coated with nitrogen-doped graphene shells (FeMn@NG) were prepared by calcination of cellulose supported Prussian blue analogs under N2 flow, and used as catalysts to activate peroxymonosulfate (PMS) for the degradation of 2,4,6-trichlorophenol (2,4,6-TCP). The addition of cellulose during the formation of Prussian blue analogs reduced the agglomeration of metal particles in the subsequent carbonization process, thus increasing the specific surface area and enhancing the catalytic efficiency of the obtained catalyst. 1O2 and the electron transfer pathway were proved to be the main mechanisms by radical quenching experiment, electron paramagnetic resonance and chronoamperometry analysis. The metal leaching of lower than 0.1 mg L−1 and high catalytic stability were attributed to the stable core-shell structure that the metals were encapsulated and protected by graphene shells. The XPS analysis implied that a Fe/Mn redox cycle existed and played a role in balancing electrons during the PMS activation. This study shows that the PMS activator with high catalytic activity can be obtained for the degradation of pollutants by combining Prussian blue analogs with cellulose.