Preparation of Water Soluble Graphene Based on Electro - chemical Peeling with Molecular Adsorption Protection and Full Oxidation
Graphene materials due to its excellent physical and chemical properties (carrier mobility at room temperature up to 15000 cm 2/ V • s, high thermal conductivity: 5000 W / m • K, Young's modulus: 350 N / m, etc.) are widely used in many fields such as lithium ion batteries, sensing, energy storage materials and biomedicine , Low-cost large-scale preparation and effective dispersion of graphene materials are the preconditions to realize these applications and become an important issue in scientific research.Currently, low-cost graphite is used as a raw material and can be batch-prepared by intercalation and delamination of graphite layers Graphene materials, there are still some problems such as low yield, non-environmental protection and poor safety of the preparation system.At the same time, due to the van der Waals forces between products, graphene is prone to sheet lamination and condensation, and the surface can not match, Resulting in graphene is difficult to disperse in aqueous solution or other low boiling point organic solvents, greatly affecting the practical application of graphene materials.Therefore, the development of new methods of green, high efficiency, low cost, better graphene dispersed in aqueous solution or other Low boiling point organic solution, is an important research topic in the field of graphene materials.
Recent progress has been made in the preparation of water-soluble graphene materials by researchers such as Ding Gu-Qiao and He Peng, a research team of graphene powder materials at the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences. Based on innovative electrochemical techniques and ultrasonic assisted dispersion Mechanism in the NaOH and PTA mixed electrolyte system to achieve a small layer of high concentration of water-soluble graphene preparation, the relevant research results published online in Green Chemistry.In this system, the researchers through the control of electrochemical processes, PTA Precipitation and adsorption on the graphite electrode promoted graphite to be fully oxidized and layer-by-layer exfoliated, followed by sonication to further increase the yield, achieving high yield (87.3%), high solid content (8.2 g / L) and high stability Months), the preparation of low-layer micron-sized water-soluble graphene has obvious advantages compared with the previous studies.At the same time, the sp2 structure of the product layer is preserved due to the adsorption and protection mechanism of the electrochemical anode molecule, , The higher conductivity (9517 S / m) can be obtained by thermal reduction at a lower temperature, which has great potential for application.Further mechanistic studies have shown that different from Electrochemical mechanisms such as intercalation, oxidation, swelling, and delamination, and new electrochemical mechanism of layer-by-layer delamination and deep oxidation overcomes the problems of poorly dispersed, poorly dispersed product layers due to incomplete delamination by traditional electrochemical methods, , Further studies confirmed the effect of ultrasound in different environments, different treatment time and different precursors conditions, which have important guiding significance for the process improvement in the following research.It is easy to form water-soluble graphene, In terms of low voltage, high temperature and temperature consistency and good, is expected as a new type of electric materials to promote the use of.
The research team is committed to the innovative preparation and application of graphene materials, to develop original production technology to obtain high-quality graphene, water-soluble graphene and graphene quantum dots and other high-end graphene materials, the relevant research has won the national major science and technology Special projects, the National Natural Science Foundation projects and the Chinese Academy of Sciences strategic pilot science and technology special support.
