Cation-mediated Synthesis Of Three-dimensional Noble Metal Nanochain Networks And Their Applications

Noble metal nanomaterials exhibit special properties due to their small size effect,surface and optical effect,which not only promote the research of basic science,but also play an important role in the application field of electron,photonics,catalysis,imaging,sensing,biomedicine and therapeutics.However,there are still many very important issues that need to be solved in the practical applications of noble metal nanomaterials.One of the most critical issues is the lack of synthesis methods of Recyclable noble metal nanocatalysts with controllable structural properties.On the other hand,the nanomaterials which synthesized in the absence of surfactants exhibit very excellent properties,among which very few studies use cations to modulate in the synthesis of noble metal nanomaterials.Based on the above points,this paper aims to design a rapid,clean universal method for the synthesis of noble metal nanomaterials,and successfully synthesized different components of three-dimensional nanochain networks(3D NCNs),combined with the characteristics of different materials,we explore the behavior of materials in monitoring the catalytic reaction in situ by Surface Enhanced Raman Scattering(SERS)and the electrocatalysis,the main research contents and results are as follows:1.A universal method for the one step synthesis of monometallic 3D NCNs using cation mediated without surfactants was designed,and Pd 3D NCNs and Au 3D NCNs were successfully synthesized.The role of cations in the synthesis of 3D NCNs was investigated.It was found that the cations can assemble nanowires into 3D NCNs by electrostatic adsorption.Different cations have different capacities for fabricating the network structure.higher valence cations have stronger abilities to fabricate the network structures.While the presence of anions can promote the anisotropic growth of nanoparticles into nanowires,The Au 3D NCNs prepared by this method can be used for monitoring the catalytic reaction in situ by SERS,and has an excellent catalytic performance of p-NTP reduction compared with Au nanoparticles.Moreover,due to the advantages of the network structure,it can be loaded on the filter membrane and recycled for catalytic degradation reaction.2.Three different metal ratios of PdAu 3D NCNs were successfully synthesized by cation-mediated,and its electrocatalytic performance for ethanol oxidation was explored.The electrocatalytic ability to ethanol oxidation was tested in alkaline medium.It was found that the optimal mass activities of PdAu 3D NCNs to ethanol oxidation was 3.78 A/mgpd,which was 3.34 times that of commercial Pd/C and exhibited Higher stability than commercial Pd/C,the results of this study indicate that they can be used as effective electrocatalysts for direct ethanol fuel cells.Because the synthesis method is simple and rapid,and without surfactant in the reaction,the surface of the material is clean,and it brings new possibilities for the large-scale production of various alloy 3D NCNs catalysts with excellent properties.Also,It can be used in formic acid oxidation,methanol oxidation,oxygen reduction and other reactions in fuel cells.