A Novel Prussian Blue-magnetite Composite Synthesized By Self-template Method And Its Catalytic Performance

Using Prussian blue?PB?as the iron source,a PB-Fe₃O₄ magnetic composite material with catalytic activity was synthesized by the self-template method.The effect of NaAc/PB concentration ratio on the synthesis of PB-Fe₃O₄ magnetic composite from the template method was investigated.Its catalytic activity for the oxidation of methylene blue,and to explore the catalytic mechanism of PB-Fe₃O₄magnetic composite.The main research contents were:Firstly,PB-Fe₃O₄ magnetic composite was prepared by the self-template method.Prussian blue was not only used as a template for the synthesis of magnetic composite,but also provided iron source(Fe³⁺and Fe²⁺).Under the action of NaAc,Fe²⁺-CN-Fe³⁺bonds on the 2?m Prussian blue surface were broken,and then self-assembled to form 50 nm Fe₃O₄ spherical particles.In PB-Fe₃O₄ magnetic composite,Fe₃O₄ particles were uniformly distributed on the surface of Prussian blue cube,and PB-Fe₃O₄ magnetic composite was non-hollow structure.The specific surface area of the PB-Fe₃O₄ magnetic composite was 42.32 m²/g,the pore volume was 0.168 cm³/g,and the average pore size was 15.86 nm.At the same time,PB-Fe₃O₄ magnetic composite had good thermal stability at 350°C.Secondly,PB-Fe₃O₄-0,PB-Fe₃O₄-1,PB-Fe₃O₄-2,and PB-Fe₃O₄-3 magnetic composites were prepared by adjusting the NaAc/PB concentration ratios to 0,400,700,and 1000,respectively.The samples with different NaAc/PB concentration ratios were detected.The results showed that the NaAc/PB concentration ratio had an important influence on the morphology,magnetic properties and electrochemical properties of the PB-Fe₃O₄ magnetic composite synthesized by the template method.When the NaAc/PB concentration ratio is 700,the Fe₃O₄ nanoparticles have an optimal crystal structure and have a maximum Ms(22 emug^-1).Finally,a heterogeneous Fenton reaction system was established using PB-Fe₃O₄ magnetic composite synthesized by the template method,and its catalytic mechanism for the oxidation of methylene blue was explored.The results showed that the catalytic oxidation capacity of PB-Fe₃O₄ magnetic composite decreased with the increased of NaAc/PB concentration ratio,and there were two kinds of strong oxidizing substances generated in this system,which were hydroxyl radicals and reactive oxygen species.But hydroxyl radicals played a major role in this reaction system.