Micro-nano Structural Design And Application Of IB Group Silver And Copper Functional Materials

Metallic nanomaterials have attracted much attention due to their unique physical and chemical properties which are different from traditional bulk materials.Among them,IB group silver and copper nanomaterials have excellent surface plasmon resonance effect(SPR)and catalytic performance.As a result,they have been widely used in sensing detection,photocatalysis and electrocatalysis.Silver have excellent SPR effect,and the resonances depend on their morphologh and size.However,the face-centered cubic structure of silver nanomaterials promotes the symmetry of crystal growth to form symmetric structure,which makes it difficult to study the sensing and photocatalytic performance of its asymmetric structure.Copper nanomaterials have good catalytic activity,and low cost of production.Furthermore,copper materials are the only efficient catalysts in the field of electrocatalytic CO₂redcution reaction(CO₂RR)to generate C₂ products.However,the selectivity of C₂products and catalytic stability are still low.In view of above problems,this thesis focuses on the investigation of controlled synthesis of silver nanocones and copper nanocatalysts and their corresponding applications in plasmonic sensing and photocatalytsis and electrochemical CO₂RR.In the study,optical spectra,electrochemical measuments and Scanning Electron Microscope,Transmission Electron Microscope as well as other characterization methods were used to study the properties of the two metallic nanomaterials.The detailed results are listed as follows:(1)Using wet chemical methods,asymmetric silver nanocones with unique plasmonic features were prepared.Experimental and theoretical studies on different sizes of silver nanocones showed that their refractive index(RI)sensitivity is significantly affected by their size,and the maximum RI sensitivity is 910 nm/RIU with a length of 133±7 nm.In the study of photocatalytic applications,the synthesized silver nanocones showed good performance due to their plasmonic features.(2)Through sol-gel process,copper nanoparticles were synthesized by reducing precursors Cu Cl₂·2H₂O.After adding K₂B₄O₇·4H₂O,the B doped Cu nanoparticles show significantly improved surface areas.As a result,their catalytic performances in CO₂RR were imporved with the highest selectivity and Faradaic efficiency to the C₂products.When the potential is-1.6 V(vs.RHE),the Faradaic efficiency of the C₂product is as high as 62.9%(Faradaic efficiency of C₂H₄ is 54.9%,the Faradaic efficiency of C₂H₅OH is 8.0%).The current density is about 52.1 m A/cm²,and the stability is 10 hours.