Study On The Preparation And Properties Of The Three Dimensional Graphene

Graphene, a single sheet of carbon atoms patterned in a honeycomb lattice form, is the basic unit to build other dimensional carbonaceous materials, it has many excellent unique properties. Such as high electron mobility, high transparency, high thermal conductivity, etc., make it have broad application prospects in many fields such as the transparent conductive film, semiconductor device, composite materials, sensors, etc. Three dimensional graphene is porous structure which is composed of two dimensional grapheme. Compared to two dimensional grapheme, it has more excellent performance such as higher mechanical strength, electrical conductivity, specific surface area etc.In our work, we first use the modified Hummers method to prepare the graphene oxide, and then prepared reduction graphene oxide by hydrothermal method, which is 3D graphene; We characterize the prepared graphene of the microstructure by using scanning electron microscopy, transmission electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray diffraction, while testing its conductive properties, oil properties and mechanical properties; In addition, taking into account the Ag nanoparticles having special electronic structure and huge surface area makes it have important applications in chemical reaction catalysis, surface-enhanced Raman scattering, sensing, biological markers, antibacterial etc. Compositing graphene and Ag nanoparticles can use their synergies to improve its sensing and catalytic properties further, In this paper, we prepared Ag nanoparticles with the polyol method and chemical reduction method, and by hydrothermal method, and prepared Ag nanoparticles/graphene composites to characterize and test its microstructure and properties.The main results were as follows:1、We prepared high quality graphene oxide with the modified Hummers method, the graphene oxide dispersed uniformly and stable in aqueous solution after the sonication.2、The graphene oxide solution which is different concentrations is prepared to the three-dimensional graphene by the hydrothermal method, this method can be mass produced without adding any reducing agent, binder, green pollution-free, easy to operate.3、Under optimal hydrothermal conditions:Three-dimensional graphene obtained by By hydrothermal method, high temperature which is 180℃, heating 24h, have good stable structure, after vacuum freeze-drying at -50℃, there can be obtained a stable three-dimensional structure of graphene aerogel.4、The prepared three dimensional graphene aerogel is heated at a high temperature under a nitrogen atmosphere at 400℃ for 2h, there still has good thermal stability, it has good adsorption properties, the adsorption rate can be up to 24 times of its own weight and can bear 50g without deformation)5、The silver nanoparticles’ shape is cube, and the particle size is about 50nm. By polyol method and chemical reduction methods, we prepared the silver nanoparticles. By Comparison, the silver nanoparticles obtained by polyol method has stable performance, the particles dispersed uniformly and without agglomeration.6、In the Ag nanoparticles/graphene composites prepared by hydrothermal method, three-dimensional graphene’s shape is more structured and the structure is more stable after compositing. Ag nanoparticles can uniformly distributed in the graphene.7、The Ag nanoparticles/graphene composites electrochemical performance test results show:in the pH= 7.0,0.2 M in the phosphate buffer as electrolyte, we can prove that the electrode for hydrogen peroxide is a response, and the minimum detectable concentration is 1.6μM.