Adsorption And Catalytic Oxidation Of Hollow Nano-Fe₃O₄-Mn

Nanoscale hollow transition metal oxide have been widely used in catalyst,magnetic resonance imaging?MRI?,drug delivery,lithium-ion batteries and contamination separation due to their low density,high surface-to-volume ratio,good permeation and unique surface properties.However,the high cost and tedious syntheses have impeded the scaling-up for large scale application.In this paper,3DOM manganese oxide were synthesized by impregnation-dissol ution-baking method in alcohol solution using manganese salt as precursor and PM MA as template.The formation mechanism of 3DOM manganese oxide was explor ed by TEM.the hollow Fe₃O₄-Mn material were prepared via a water phase replac ement method by using Two kinds of Mn₃O₄ as raw material.All the materials be fore and after the replacement reaction were characterized by XRD,TEM and BET technologies.By optimizing Fe²⁺concentration,reaction temperature and replaceme nt time,we successfully obtained a series of nanosize hollow Fe3O4-Mn materials.In addition,Fe₃O₄-Mn nanomaterials were used to adsorb???ions in water.By changing the reaction conditions,it was concluded that the performance of hollow Fe3O4-Mn nanomaterials was better than that of Mn3O4.The adsorption ability of hollow octahedral Fe₃O₄-Mn is better than that of hollow rice type Fe₃O₄-Mn.The two hollow Fe₃O₄-Mn nanomaterials have the best adsorption effect when the concentration of???ions is 5mg·L^-1,and the removal rate can reach 90%.The adsorption ability is best under neutral conditions,and the lower or higher pH all lead to a decreasing in the performance.The optimum saturated adsorption amount was 1300?g·g^-1.The amount of adsorption increased by 1.27 times with hollow octahedral Fe₃O₄-Mn the than that of Mn₃O_4..Finally,Fe₃O₄-Mn was used to catalytically oxidation of phenol wastewater,and the effect of reaction conditions was investigated.It is concluded that the removal rate of phenol in wastewater by Fe₃O₄-Mn is 2.7 times that of Mn₃O₄.Temperature?20?,40?,50??,pH?2,3,4?had little effect on the removal of phenol by Fe₃O₄-Mn.The optimum dosage of hydrogen peroxide was 2.5 mL,and the corresponding removal rate was 95.5%.The optimum dosage of catalyst was 0.15 g.