Synthesis And Property Studies Of Nobel Metals And Metal Sulfides Nanocrystals

Noble metals and metal sulfides nanomaterials have gained more and more attention from the researchers due to their excellent properties and potential applications in the fields of catalysis,new energy,biology et al.Nanomaterials with different sizes,morphologies and components have different physical and chemical properties.In order to obtain high quality nanomaterials with certain morphology,synthesis method,which is rational designed,facile to operate and environmentally benign is highly demanded.This thesis explored the liquid synthesis methods of noble metals and metal sulfides,developed three new methods and then explored the catalysis and electrochemical properties of the as-synthesized nanomaterials.We developed a facile method,within the system of ODA,synthesizing Pd nanodendrites with uniform size and morphology.The as-synthesized Pd nanodendrites,due to the special dendrite-morphology,showed excellent catalysis property for the reaction of phenylacetylene hydrogenation with high selectivity and long stability.Through characterizations in detail,we proposed that the formation of Pd nanodendrites followed the fast-growth mechanism,based on which we developed an one-pot method to synthesize Au@Pd core-shell nanodendrites.The as-synthesized core-shell nanodendrites showed excellent CO oxidation catalysis property due to the Au-Pd synergy effect.Our method provided guide for the synthesis of alloyed nanomaterials.We developed a new method using vulcanized polyisoprene to synthesize ultrathin Cu₂ S nanosheets with uniform size and morphology,and thickness of only 1.2 nm,which is the thinnest reported Cu₂ S nanosheets.Through characterizations in detail and comparison experiments,we proposed the growth mechanism and we succeeded in controlling the thickness of Cu₂ S nanosheets by adjusting the ratio between CTAB and CTAC.We found that as the thickness became smaller,the Uv-vis absorption of Cu₂ S nanosheets had a blue shift.Besides,the ultrathin Cu₂ S nanosheets showed good catalysis property toward HER when combined with TiO2 nanofibers.Our method provided guide for the synthesis of 2D nanomaterials.We developed a new method that released the sulfur powder slowly to synthesize the NiS nanoflowers.The as-synthesized nanomaterials consisted of 2D nanosheets,with uniform size and morphology.Through characterizations in detail and comparison experiments,we proposed the growth mechanism and pointed out that the slow release of sulfur into the reaction solution was vital for the synthesis of NiS nanoflowers.Due to the unique flower morphology and a larger specific surface,NiS nanoflowers showed excellent electrochemical property.This new method provided guide for the synthesis of metal sulfides and the as-synthesized nanomaterials had the potential of being applied in the field of super capacitor.