Solution-Solid-Solid Growth Of One-dimensional Sulfide Nanowires And Their Photoluminescence Properties

Controllable synthesis of nanomaterials is the precondition for studying their performances and popularizing their applications.Deep insight into the growth mechanism(effective controling product composition,morphology,crystal structure and growth direction)is very important.Solution-solid-solid growth(SSS)mechanism is a novel and efficient method for nanowires preparation,especially for the preparation of one-dimensional sulfide,selenide semiconductor nanomaterials.In the SSS mechanism,superionic conductor catalyst is the key,whose size determines the diameter of the nanowire product,hence the preparation of superionic conductor nanoparticles with uniform size is very crucial.In this thesis,we investigated the preparation conditions of superionic conductor catalysts,synthesized several sulfide nanostructures based on the SSS growth and characterized their PL properties.The results are summarized as follows:1.The Ag2S nanocrystals were synthesized by decomposing single-source precursor under different temperatures,which presented spherical shape and temperature-dependent size distribution,much different from the counterparts by double-source reaction method.2.Based on the SSS growth,we synthesized ZnS,CdS nanowires and ZnS-CdS multisection heterojunctions under the assistance of Ag2S catalyst,and characterized their PL properties.Compared with the PL spectrum of CdS nanowires,a shoulder peak of lower energy appears for Ag2S-ZnS-CdS heterostructure nanowires,while a shoulder peak of higher energy appears for the partially alloyed sample.3.The Au@Ag core-shell nanoparticles were synthesized,which were easily converted into Au@Ag2S nanoparticles by reacting with S.