Synthesis Of Electrospun Iron-based Composite Nanofibers And The Study Of Their Peroxidase-like Catalytic Properties

Scientists have found that when the size of materials reduced to nanoscale,the enhanced performance can be achieved,which is attributed to their large surface area,small-size effect as well as surface/interface effect.The excellent properties render them great chances to make contributions in all aspects and possess promising prospects in various fields.With the rapid development of nanotechnology,a large variety of synthetic methods have been continuous emerged.Among numerous techniques,electrospinning has been aroused intensive interests in recent years,which served as a simple and quick way to generate nanofibers.Electrospun nanofibers have acquired extrusive achievements in the fields of photoelectricity,catalysis,energy,biochemistry,etc.Owing to the outstanding magnetism property,iron-based materials have caused increasing attention of researchers because the products can be recycled from the reaction system by a magnet conveniently.Varied iron-based materials have been synthesized and applied in many fields.Electrospun iron-based nanofibers are one type of terrific catalyst carriers,their high surface area as well as stability is beneficial for the loading of other functional components.Natural enzymes have played dominant role in plenty of fields attributed to their prominent performance and unique specificity.However,low stability as well as high cost of natural enzymes has led researchers to shift their sights in artificial enzymes.Acting as alternative to natural enzymes,they possess similar enzyme activity as natural enzymes with high stability and low cost.A great many of nanomaterials have been used for mimicking natural enzymes,such as noble metals and metal sulfides.Nevertheless,single materials always have some inevitable limitations,like ease of agglomeration and poor dispersity,which dramatically restrict their practical applications.In order to avoid aforementioned defects,composite materials have been developed.In addition,composite materials are able to integrate the characteristics of individual components,and the interactions among different components are tend to form synergistic effects,facilitating the enhanced properties of materials further.Nanocomposite artificial enzymes inherit the advantages of nanomaterials,and maintain the superiority of composite materials as well,which can maximum exert the activities.Consequently,in this thesis,we developed an electrospinning technique combined with calcination and other methods to prepare two series of electrospinning iron-based composite nanofibers.By means of the combination of electrospun nanofibers with metal nanoparticles or metal sulfides,the enhanced peroxidase-like catalytic activity can be obtained,and the synergistic effect among components has been investigated.Furthermore,when applied in biosensor field,the as-prepared materials can realize the determination of H2O2,dopamine,L-cysteine,AA with a high sensitivity as well as excellent selectivity.Our thesis mainly includes two sections: 1.We have successfully combined two kinds of metal nanoparticles with nanofibers through electrospinning with post treatments,the samples can remain excellent morphology,and the metal nanoparticles distributed uniformly,which is in favor of the improvement of catalytic properties.When acted as peroxidase mimics,it has been observed that the excellent catalytic performance of these two materials is corresponding to the synergistic effect among components.In addition,we have established a simple approach for the colorimetric detection of H2O2 and L-cysteine,and the fantastic detection abilities of our samples have been demonstrated.2.By means of electrospinning as well as hydrothermal method,we have successfully fabricated iron-based nanofibers with metal sulfides,and we have studied the peroxidase-like catalytic properties of the products and investigated the synergistic effect between components.Subsequently,we introduced conducting polymer or another type of metal sulfide to further tune the catalytic activity of composite materials.These as-prepared composite nanofibers presented prominent peroxidase-like properties owing to the outstanding synergistic effects among components.On the basis of the excellent catalytic performance,the sensing of H2O2,dopamine and AA with a high sensitivity as well as excellent selectivity has been realized.