Facile green synthetic graphene-based Co-Fe Prussian blue analogues as an activator of peroxymonosulfate for the degradation of levofloxacin hydrochloride.

A kind of Co-Fe Prussian blue analogues (Co-Fe PBAs), cobalt hexacyanoferrate Co3[Fe(CN)6]2, and graphene oxide (GO) were combined to synthesize magnetically separable Co-Fe PBAs@rGO nanocomposites through a simple two-step hydrothermal method. The crystalline structure, morphology and textural properties of the Co-Fe PBAs@rGO nanocomposites were characterized. The catalytic performance of the nanocomposites was evaluated by PMS activation, with Levofloxacin Hydrochloride (LVF) as the target contaminant. Synergistic interactions between the Co-Fe PBAs and rGO prevented the aggregation of the Co-Fe PBAs nanoparticles, which resulted in enhanced degradation efficiencies. The influence of several critical parameters was investigated, including the reaction temperature, PMS and Co-Fe PBAs@rGO catalyst concentrations, solution pH and salt content. LVF degradation was favored at higher catalyst and PMS concentrations, high temperatures, and in neutral or weak acidic solutions. Sulphate radicals were the dominant active species in the Co-Fe PBAs@rGO/PMS system. In addition, the Co-Fe PBAs@rGO exhibited no significant decrease in LVF degradation efficiency following five catalytic cycles. Thus, the as-prepared Co-Fe PBAs@rGO nanocomposite catalyst might be applied to the removal of hard-to-degrade organics owing to its high catalytic ability to activate PMS, as well as its good reusability and recyclability.