Graphene encapsulated FexCoy nanocages derived from metal-organic frameworks as efficient activators for peroxymonosulfate

A series of nitrogen-doped graphene encapsulated FexCoy bimetallic (FexCoy@C) nanocages were newly fabricated via a one-step thermal decomposition of Prussian blue analogue FeyCo1-y[Co(CN)(6)](0.67)center dot nH(2)O nanospheres at different temperatures. The as-synthesized FexCoy@C nanocages were systematically characterized and applied as effective catalysts to activate peroxymonosulfate (PMS) for the removal of bisphenol A (BPA). The catalytic activity of Fe3Co7@C-650 obtained at 650 degrees C was found to be the highest and also much higher than that of metallic cobalt, cobalt oxide and cobalt-iron spinels. The nitrogen-doped graphene shells were demonstrated to be effective in preventing the release of metal ions, thus resulting in a better stability. Furthermore, the BPA degradation pathway was proposed based on GC-MS and LC-MS results. The involved radicals were identified through electron paramagnetic resonance and radical scavenger experiments. Based on the systematic characterization of the catalyst before and after the catalytic oxidation reaction, the overall mechanism of PMS activation over FexCoy@C nanocages was proposed. Results indicate that FexCoy@C nanocages are available to serve as promising materials for environmental remediation by activation of PMS.