Preparation And Performance Research Of Monodisperse L1₀FePt Nanoalloy

FePt composite nanoparticles owning face-centered tetragonal structure?L1₀ FePt?have a wide range of application prospects in the field of magnetic recording materials,electrochemical catalysts,biomedical and so on due to their high chemical stability and large magnetocrystalline anisotropy characteristics.In this work,the monodisperse L1₀ FePt,FeNi,FeCo,CoPt,NiPt nanoparticles were prepared by an approach“reverse microemulsion method”combined with azeotropic distillation process,and their magnetic,electrocatalytic and biological medicine properties were systematic studied.Firstly,FePt@NaCl nanoparticles were successfully synthesized by a facile“reverse microemulsion method”combined with azeotropic distillation process.And then monodispersed FePt nanoparticles with narrow size distribution were obtained after high temperature treatment,reduction of hydrogen and washed.Core/shell structure of FePt/NaCl exhibited high thermal stability,which can effectively prevent FePt nanoparticles from sintering and aggregation and give full play to chemical properties of FePt.The particle size and crystal structure of FePt nanoparticles have been characterized by Transmission Electron Microscopy?TEM?,High Resolution Transmission Electron Microscopy?HRTEM?and X-ray Diffraction?XRD?.These results showed that FePt nanoparticles with average particle size at about 3 nm had narrow particle size distribution and regular shape.FePt nanoparticles were fct L1₀ ordered strucure.And then monodisperse FeNi,FeCo,CoPt,NiPt nanoalloy were also successfully prepared by the same method.Their particle size and crystal structure were characterized by Transmission Electron Microscopy?TEM?and X-ray Diffraction?XRD?,which indicated these nanoalloys had good crystallinity,narrow size distribution as same as FePt nanoalloy.This novel approach brings forward a broad idea to synthesize other functional materials,even generating new metastable intermetallic alloys and a new opportunity to research and apply other fields.Finally,their magnetic,electrocatalytic,biological toxicity performances were tested.We found that L1₀ FePt nanoparticles exhibited better magnetic properties and higher coercivity at room temperature than FeNi and FeCo nanoparticles.L1₀ FePt nanoparticles also showed higher electrocatalytic activity and enhanced CO tolerance in methanol oxidation than CoPt and NiPt nanoparticles.And these alloys all have better electric catalytic effect than pure Pt.Additionally,L1₀ FePt nanoparticles exhibited better biocompatibility than FeNi and FeCo nanoparticles,which may be as excellent medical materials in the future.High performance of monodispersed FePt nanoparticles may result from the unique chemical properties and molecular structure of Fe and Pt.