Synthesized Of Cu/Ag Core-Shell Ultrafine Powder By Hydrothermal Method And Its Crystallization Behavior

Ultrafine Cu/Ag core-shell powder is a functional material with high catalytic and high conductivity,and is widely used in aviation,aerospace,electronics,military,and other fields.In this paper,copper-containing wastewater was used as raw material to prepare Cu/Ag core-shell ultrafine powder by hydrothermal method,and the influence of different process parameters on the material was explored.The crystallization mechanism of Cu crystal and the growth mechanism of Ag coating were explored by means of SEM,XRD and other characterizations.the result shows:?1?The copper-containing wastewater can be effectively treat by the hydrothermal method,the ultrafine Cu and Cu/Ag core-shell particles can be synthesized from the wastewater.Comparing with the Cu particles,the Cu/Ag core-shell particles has higher anti-oxidation and anti-corrosion properties.?2?The “dissolution-crystallization” mechanism are used to explain the reduction process of the Cu particles.During the reduction process,the the intermediate Cu₁₀ clusters will be formed,and the addition of excess alkali can effectively inhibit the formation of the intermediate product Cu₂O.PVP in the system undergoes a coordination reaction on the surface of Cu crystals to form an adsorption system,thereby regulating the morphology of Cu.?3?The growth of Ag plating conforms to the Stranski-Krastanow?SK?mode.At the same time,there are chemical bonds,hydrogen bonds,van der Waals forces and other forces in the Cu / Ag interface,which causes the strain energy in the interface to be released to the outside and the surface morphology of the material to be unstable.