Preparation Of Graphene-based Nanosilver/gold Composites And Application Of Conductive Inks

Due to its unique quantum size effect,surface effect,volume effect and macroscopic quantum tunneling effect,nanomaterials have unique optical properties,electrical properties,thermal properties,mechanical properties,magnetic properties and catalytic performances,which have great application potential in various fields.Based on gold,silver and graphene nanomaterials,this paper studied the preparation of the graphene-based silver and gold nanomaterials under different sonochemical methods.Its application in conductive ink was also studied,which may play an important role in the printed electronic technology with its excellent conductivity,storage stability and flexibility.Graphene based silver nanocomposites were in situ prepared by reduction of silver nitrate with sodium citrate by a cyclic cooling sonochemical method in the absence of any stabilizers.The effects of reaction time,temperature,concentration of reactant and reducing agent on the properties of the nanocomposites were also studied.The composites were characterized by UV-vis absorption spectra,X-ray diffraction,atomic force microscopy,transmission electron microscopy and Raman spectroscopy.The results showed that the prepared silver nanoparticles which had small sizes about 10 nm and uniform particle size distribution were evenly distributed on the surface of graphene sheets,and the graphene had a good binding relationship with silver nanoparticles.It can be also found that sodium citrate can not only reduce silver nitrate,but also prevent the agglomeration of silver nanoparticles.Appropriate amount of graphene oxide can not only provide adsorption sites for silver nanoparticles,but also improve the stability of colloid.The graphene based gold nanocomposites were also in situ prepared by reduction of gold chloride with sodium citrate by a homothermal sonochemical method without any stabilizers.The composites were characterized by UV-vis absorption spectra to investigate the effects of reaction time,concentration,ultrasonication and graphene oxide on the properties of the nanocomposites.The composites ware also characterized by atomic force microscopy,and found that the prepared nanoparticles with about 20 nm diameter also have good morphology and good bonding relation with graphene oxide.The sonochemical method has unique advantages in the preparation of spherical metal nanoparticles.Conductive ink with 10%mass fraction was prepared with the graphene based silver nanocomposites used as conductive phase,ultrapure water used as solvent,trace ethanol,ethylene glycol,glycerol and acrylic resin used as additions.The conductive ink's writing performance was tested using the ordinary pen to draw conductive lines on Kodak photo paper.The conductive line was treated with washing,ultrasonic treatment,sintering and other post-processing techniques to enhance its conductivity.The results show that the resistivity of the conductive line after proper treatment is 15.4??·cm,which is about the 9.6 times of bulk silver.The prepared graphene based silver nanocomposites can be used in practice.In this paper,graphene based silver and gold nanocomposites were prepared by sonochemical method,and the preparation and application of the complex conductive ink were also studied.This graphene based silver and gold nanocomposites is expected to be applied in the catalyst,sensor and other fields.