Preparation And Morphology Evolution Of Silver Nanosheets

The small size effect of silver nanosheets gives it unique physical and chemical properties,and has special applications in many fields such as electricity,optics,sensor technology,and biomedicine.By adjusting the morphology and size of the particles,silver nanoparticles with certain characteristics can be obtained and applied to related fields.So far,the methods for preparing silver nanosheets mainly include chemical reduction method,photo-induced chemical method,soft template method,ultrasound-assisted method,biological method,and so on.In this paper,the method of metal salt reduction was used to prepare silver nanosheets at room temperature.Glucose is added to the silver ammonia solution as a reducing agent,and a certain amount of aluminum nitrate solution is introduced to induce the generation of silver nanosheets.The synthesized silver flakes were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),transmission electron microscopy(TEM)and other testing methods.The influence of adding different reactants in the silver ammonia solution on the morphology of the prepared silver nanosheets was explored.The main work is as follows:(1)Metal salt reduction method was used to prepare silver nanosheets at room temperature.The silver ammonia solution is prepared first,and then glucose and aluminum nitrate solution are added to the silver ammonia solution,and finally silver nanosheets with stacking fault structure are generated.The microstructure of silver nanosheets was studied in detail by TEM,EDX,XRD and other analytical methods.The chemical reaction and the formation process of silver nanosheets are analyzed,and the growth mechanism of silver nanosheets is proposed.(2)A new method for preparing hexagonal silver nanosheets was explored.It also uses metal salt reduction method at room temperature,using silver ammonia solution as the silver source.The innovation is that hydrogen peroxide is used as the reducing agent,and the original aluminum nitrate solution is used as a reducing agent.The generated aluminum hydroxide is used to induce the formation of hexagonal silver nanosheets.The microstructure of hexagonal silver nanosheets was studied by SEM,EDX,XRD and other methods,and the growth mechanism was discussed.At the same time,through comparative experiments,the influence of different reducing agents on the morphology of silver nanosheets was explored.(3)The morphology evolution law of silver particles is obtained.The silver particles obtained when glucose is used as the reducing agent and aluminum nitrate is not added,the morphology is mainly equiaxed particles and irregular aggregates;and aluminum nitrate is involved.During the reaction,the morphology of the obtained silver particles is irregular nanoplates;when hydrogen peroxide is used as a reducing agent and aluminum nitrate participates in the reaction,the morphology of the obtained silver particles is mainly hexagonal.