Method for preparing nano-structure single crystal silver

Abstract

The invention relates to a method for preparing nano-structure single crystal silver. The method comprises the following steps of: reducing high-conductivity forming porous activated carbon containing chloride ion, putting the activated carbon into a silver-containing precursor solution, growing nano-structure single crystal silver on the surface of the activated carbon, providing a crystal nucleus and slow and stable crystal growth environment required by growth of single crystal silver through the silver-containing precursor and proper chlorine content, and obtaining nano silver single crystal with multiple features by controlling the concentration of the solution containing the silver-containing precursor and the growth time. The method belongs to a green synthesis method, pollution is avoided, any additive is not required, and the nano-structure single crystal silver is grown on the surface of the forming porous activated carbon at room temperature; the nano-structure single crystal silver is high in productivity, high in purity and easily separated from the forming porous activated carbon, the silver is naturally stripped after growth, and the activated carbon is ultrasonically treated by absolute ethyl alcohol or alkaline liquor and can be regenerated; and the obtained single crystal silver has the characteristics of high mechanical strength, high conductivity and low crystal defect.

Description

technical field [0001] The invention belongs to the technical field of nanomaterial preparation, and in particular relates to a preparation method of nanostructured single crystal silver. Background technique [0002] Silver nanomaterials, especially single crystals, have become a current research hotspot because of their excellent electrical conductivity, heat transfer properties, specific properties in catalysis and antibacterial aspects. Nano-silver materials have broad application prospects in electronic components, optical fibers, conductive silver paste, chemical / biological sensors, chemical catalysis, conductive fillers and other fields. [0003] At present, the preparation methods of silver nanomaterials mainly include: ball milling method, template method, liquid phase reduction method, electrochemical reduction method and so on. The ball milling method can prepare flaky silver powder, and more additives need to be added during the ball milling process. The impurit...

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Problems solved by technology

The ball milling method can prepare flake silver powder. During the ball milling process, more additives need to be added. The impurities in the ball milling medium cannot be completely removed in the end, which affects the performance of the flake silver powder in electronic paste.

Although the template preparation method can obtain a high ratio of silver nanomaterials, the template agent needs to be eliminated during the preparation process, which increases the complexity of the process and reduces the yield of the product, which has certain limitations.

In the process of synthesizing silver nanomaterials by the liquid phase reaction method, there are disadvantages such as high reduction temperature, easy pollution of the environment, complicated preparation process, and low purity of the product. The obtained silver nanowires are not single crystals, so they are not suitable for popularization and utilization.

[0004] Found through literature search to prior art, in-situ reduction in linear chitosan membrane prepares silver nano-particle and silver single crystal, Acta Phys.Chim.Sin., 2003,19 (5): 464-468, this article adopts Spherical silver nanoparticles and silver single crystals with triangular and hexagonal appearances were prepared in the chitosan film by photoreduction and electrochemical methods, but the resulting silver single crystals had single morphology and low yield

In the inventor's existing work, the invention patent CN102418118A discloses a method for electrochemically assisting the preparation of nano-silver powder with a special shape. The working electrode and the counter electrode are respectively the cathode and the anode, and are immersed in a solution or sol containing silver ions. , nano-silver powders with various shapes are prepared by electrochemical reaction, but the prepared nano-silver is not a single crystal, and the silver ions are directly reduced to simple silver during the reaction process, and no new crystal seeds are introduced.

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