Synthesis Of Low-dimensional Metal Nanomaterials With Special Packing Mode And Study Of Their Electrocatalytic Performance

In order to solve the growing environmental pollution and energy shortage,the research on high efficiency,clean,environmental protection and sustainable energy has attracted wide attention from researchers.Low-dimensional metal nanomaterials have unique structural characteristics such as large specific surface area,highly exposed surface atoms,and high charge transfer efficiency,so they are widely used in many fields such as catalysis,separation,and energy storage.In this paper,low-dimensional metal nanomaterials have been synthesized.Then the morphology and structural characteristics were characterized by HRTEM and XRD.Electro-catalytic performance of nanomaterials were explored.The specific research content mainly includes the following three aspects:1.The Au-Pd multi-block nanowires grown on the substrate were synthesized by wet chemical method.Firstly,the seeds were synthesized by wet chemical method on silicon wafers.Then Au nanowires were synthesized by template method,and Au-Pd heterostructure nanowires were synthesized by ligand induction method.On this basis,by increasing the number of growth by alternately using Au and Pd precursors,multi-block Au-Pd heterostructure nanowires were synthesized.The nanowire has a Boerdijk-Coxeter-Bernal?BCB?spiral structure and was constructed by linear stacking of regular tetrahedra.Thus there are a large number of highly active twin interfaces in BCB structures.The nanowires have catalytic activities in the formic acid oxidation reaction.As the number of blocks increases,the catalytic activity of the nanowires shows volcano shape.2.The crystal phase of the Co nanosheets were converted between the hcp phase and the fcc phase.Firstly,the?-Co?OH?₂ nanosheets were synthesized by wet chemical method and used as the precursor materials.Then Co nanosheets with a thickness of about 8 nm were synthesized by hydrothermal method.The stable structure of Co nanomaterials is the hcp phase.The p H of the reaction solution,which determines the crystal phase of Co nanosheet,is controlled by changing the amount of added KOH.The catalytic performance of OER were compared between hcp and fcc Co nanosheets.3.Pt-Zn nanocrystals were synthesized by hydrothermal method,and composition were controlled by changing the feed ratio of Pt and Zn.TEM characterization shows that the size of the nanocrystals is about 50 nm,and surface has a dendritic structure.At the same time,the catalytic activities of a series of Pt-Zn nanocrystals in the electro-catalytic oxidation reaction of formic acid were investigated.As a result,when the ratio of Pt and Zn is 1:2,the specific activity of the Pt-Zn(3.51 m A·cm^-2)is twice as high as commercial platinum black(1.76 m A·cm^-2)while mass activity(2030 m A·mg^-1)is9.2 times as high as commercial platinum black(220 m A·mg^-1).