Bimetallic Oxides Nanocompositesas Peroxymonosulfate Activators For Pollutants Degradation In Water

It is reported that,the sustained deterioration of water resources caused by dyeing industry and pharmaceutical enterprise wastewater pollution.These become an important issue garnering public concern worldwide.Recently,the application of sulfate radicals（SO₄^-·）has gained popularity in degradation of hazardous and non-biodegradable pollutants.This study prepared Co Fe₂O₄/ordered mesoporous carbon（OMC）nanocomposites and Mn_xCo_3-xO₄ nanocages successfully.In addition,catalytic performance,influencing factors,degradation mechanisms and application prospects have also been studied comprehensively.（1）Co Fe₂O₄/ordered mesoporous carbon（OMC）nanocomposites were synthesized and tested as heterogeneous Peroxymonosulfate（PMS）activator for the removal of rhodamine B（Rh B）.Characterization confirmed that Co Fe₂O₄ nanoparticles were tightly bonded to OMC and the hybrid catalyst possessed high surface area,pore volume and superparamagnetism.Oxidationexperimentsdemonstratedthat Co Fe₂O₄/OMC nanocomposites displayed favorable catalytic activity in PMS solution and Rh B degradation could be well described by pseudo-first-order kinetic model.Sulfate radicals（SO₄^-·）were verified as the primary reactive species.Under optimum operational condition,Co Fe₂O₄/OMC activated PMS system could achieve almost complete decolorization of 100 mg/L Rh B within 60 min.The enhanced catalytic activity of Co Fe₂O₄/OMC nanocomposites compared to that of Co Fe₂O₄nanoparticles could be attributable to the increased adsorption capacity and accelerated redox cycles between Co（II）/Co（III）and Fe（II）/Fe（III）.（2）Mesoporous Mn_xCo_3-xO₄ nanocages with large surface area,high pore volume and high cobalt content were synthesized through a self-assembly method.The as-prepared Mn_xCo_3-xO₄ NCs displayed excellent catalytic activity toward PMS and the metal ions leaching concentration could be negligible.Sulfate radical was identified as the predominant active species through radical quenching experiments and electron spin resonance spin-trapping technique.The kinetics of the oxidation process was of pseudo-first order.The increasing cobalt content in Mn_xCo_3-xO₄ NCs was in favor of enhancing the decomposition of PMS.The operating parameters such as Mn_xCo_3-xO₄ NCs dosage,PMS concentration,p H,reaction temperature and CBZ concentration put the promoting effect on the degradation.XPS analys is confirmed the reversible valence equilibrium between metal ions and the recovery of surface adsorbed oxygen ensured the sustainable catalytic activity.During the experiment,the increment of toxicity can be ascribed to the formation of more toxic intermediates such as ACIN under the oxidation of carbamazepine.