Synthesis And Characterization Of One-dimensional Semiconduchve-magnetic Functional Composite Nanoniaterials

Optical, electric and magnetic properties of nanomaterials could be largelyenhanced or changed by the functional-assembly of different nanostructures, whichhas opened new opportunities for nanomaterials. In this dissertation, we used highquality cadmium sulfide as the main raw mateial, which were synthesised by a mixedsolvothermal progress, to successfully prepare one-dimensional Ni@CdS andCo@CdS fuctional composite nanomaterials by a oil-bath method.(1) Three kinds of cadmium sulfide nanomaterials were prepared by a mixedsolvothermal method under differen growth conditions, using cadmium nitrate andL-cysteine as the main raw materials, and the water and ethylene diamine as solvent.It was found that, in this reaction system, a higher temperrature, as less as possiblewater and higher concentrations of reactants are more conducive to gain nanowires.The optical properties of the as-prepared CdS nano-materials with differentmorphologies shows that all the nano-materials exhibit obvious quantum size effects,indicating that they may find wide applications in optical, electricaland catalyticdevices.(2) One-dimensional Ni@CdS fuctional composite nanomaterials wereuccessfully gained by an oil-bath method using high quality CdS nanowires as themain raw material. It was found that, it is difficult to make all CdS nanowiresassemble with nickel nanoparticles when the addition of nickel is less than0.02mmol,and the average diameter of nickel nanoparticles on preformed CdS nanowiresbecome shorter with the decrease of the addition amount of Ni2+. With the increase oftemperature (from140to150°C), the proportion of one-dimensional Ni@CdSfuctional composite nanomaterials becomes more small, because the small nickelnanoparticles are easy dissolved to form bigger nickel nanoparticles when the reactiontemperature higher than140°C.(3) By using the as-prepared high quality cadmium sulfide as the main raw mateial, one-dimensional Co@CdS fuctional composite nanomaterials can besuccessfully prepared. It was found that, with the increase of temperature (from130to150°C), the proportion of one-dimensional Co@CdS fuctional compositenanomaterials becomes higher, and almostly all CdS nanowires have been assembledwith Co nanoparticles when the reaction temperature reached to150°C. One cannotgain Co@CdS fuctional composite nanomaterials by only using water or glycol assolvent. When Vglycol:Vwaterwas smaller than5:1, only CdS nanowires were resultedin which were covered by a coat of floccule; but when Vglycol:Vwaterequals to5:1, ahigh yield of Co@CdS fuctional composite nanomaterials was obtained.