Hydrothermal Synthesis Of Copper, Silver And Cu-Ag Alloy With Dendritic Strustures

IB Group metallic nanomaterials have been receiving great attention due to their excellentperformance in catalysis, electronics, magnetic s and optics; and they have the widespread applicationprospect in the fields of sensors, batteries, devices, catalysis and biology. It is of great importance toexplore synthesetic methods and formation mechanism of crystal with similar morphology for studying therelationship between the structure and nature of nanomaterials, developing new materials, loweringdevelopment costs, getting excellent materials at the lower price. Many researchers pursue developingsimpler methods with low cost to synthesis uniform nanomaterials. Dendritic nanomarerials are popularwith many researchers due to its hierarchical structure, large specific surface area, the good conductivityofelectricity and heat, and excellent catalytic performance. This thesis mainly focuses the followings:Copper dendrites and silver dendrites have been hydrothermally synthesized using CuSO₄and AgNO₃asprecursors, red phosphorus as reducing agent. The products obtained were characterized by powder x-raydiffraction, scanning electron.Microscopy transmission electron microscopy, and cyclic voltammetry. The various factors affectingthe formation and the morphology of the productss have also been studied. The results show that thesefactors such as chelating agent, temperature, PH of solution and SO₄^2-were crucial to the morphology ofthe products obtained. The suitable temperature, different chelating agent, and the pH of solution can makea nonequilibrium solution environment in favor of formation of dendrites. The SO₄^2-is the main factor forformation of dendrites in this iopsided conditions. Based on experimental observations, the probablegrowth mechanism of Copper dendrites and silver dendrites was initially discussed. Cyclic voltammetrywas used to study the property of copper dendrites.Dendritic Cu-Ag alloys with single morphology, uniform size have been hydrothermally synthesizedusing AgNO₃, Cu（NO₃）₂and ammonia as raw materials, the right amont of concentrated H₂SO₄as controlagent. The products obtained were characterized by powder x-ray diffraction, scanning electron microscopy,transmission electron microscopy. The results indicated that the products obtained were well crystallizeddendritic structure. By means of a series of contrast test, the probable formation mechanism was also proposed.The main innovations in this thesis are: Dendrites with controllable morphology, good dispersion,uniform size have been quickly synthesized using a simple hydrothermal methods. This synthetic methodcan be easily controlled and can effectively inhibit agglomerating of dendrites.