Bimetal organic framework/graphene oxide derived magnetic porous composite catalyst for peroxymonosulfate activation in fast organic pollutant degradation

A magnetic nitrogen-doped porous carbon material (Co/CoO_x@NC) with large surface area was synthesized for peroxymonosulfate (PMS) activation. The addition of reduced graphene oxide (rGO) remarkably improved the catalytic performance of Co/CoO_x@NC due to its enhancement on graphitization degree and structural regulation. Co/CoOx@NC exhibited excellent PMS activation for phenol removal with almost 100% removal efficiency in 10 min, close to that of homogeneous Co²⁺. Simultaneously, good reusability and recyclability of Co/CoO_x@NC was achieved, demonstrating its feasibility for practical application. The PMS activation process in Co/CoO_x@NC/PMS system was dominant by efficient mediation of electron transfer from pollutants to PMS through the sp²-hybridized carbon and nitrogen network. Batch tests of various organic compounds removal revealed the specific selectivity related to the electron-donating ability in Co/CoO_x@NC/PMS system. As the negligible role of reactive radicals on pollutants degradation, the inhibition of interfering species (e.g., Cl^-, natural organic matters) was largely weakened. Present study not only provided a strategy for rationally designing highly efficient nanocarbon-based catalysts on PMS activation, but also presented new insight into the mechanism of PMS heterogeneous activation.