Green Chemistry: research team Ding Guqiao and he Peng from Shanghai Institute of Microsystems, Chinese Academy of Sciences made progress in the preparation of water-soluble graphene

Graphene materials are widely used in many fields, such as lithium-ion batteries, sensors, energy storage materials, biomedicine and so on, because of their excellent physical and chemical properties At present, using cheap graphite as raw material, through intercalation and stripping of graphite layers, graphene materials can be prepared in batches, but there are still some problems, such as low yield, environmental protection and poor safety At the same time, due to the effect of van der Waals force, the product graphene is prone to lamination and agglomeration In addition, the surface energy does not match, which makes it difficult to disperse graphene in aqueous solution or other low boiling organic solvents, which greatly affects the practical application of graphene materials Therefore, it is an important research topic in the field of graphene materials to develop new green, efficient and low-cost methods to make graphene better dispersed in aqueous solutions or other low boiling point organic solutions Recently, the academic journal green chemistry published online the preparation of water-soluble graphene materials by Ding Guqiao, he Peng and other researchers from the graphene powder materials research team of Shanghai Institute of micro systems, Chinese Academy of Sciences Important progress (DOI: 10.1039 / c7gc03345a): Based on the innovative electrochemical technology and ultrasonic assisted dispersion mechanism, the preparation of water-soluble graphene with few layers and high concentration was realized in the mixed electrolyte system of NaOH and PTA In this system, by controlling the electrochemical process, PTA was precipitated and adsorbed on the graphite electrode, which promoted the graphite to fully oxidize and peel off layer by layer Then, with the aid of ultrasonic treatment, the yield was further improved, and a small layer of water-soluble graphene with high yield (87.3%), high solid content (8.2g / L) and high stability (more than 8 months) was achieved Compared with the existing research reports, the preparation of At the same time, due to the mechanism of electrochemical anode molecular adsorption protection, the product layer SP 2 structure can be retained After the film is prepared, the higher conductivity (9517 s / M) can be obtained by thermal reduction at a lower temperature, and the application potential is huge Further mechanism research has clarified the electrochemical mechanism different from the previous intercalation, oxidation, expansion and stripping The new electrochemical mechanism of layer by layer stripping and in-depth oxidation overcomes the problems such as too many layers, low quality and poor dispersion caused by incomplete stripping of traditional electrochemical methods At the same time, further study confirmed the effect of ultrasound in different environment, different processing time and different precursor conditions, which has important guiding significance for the process improvement in the follow-up study The prepared water-soluble graphene is easy to form film, which has the advantages of low voltage, high temperature rise and good temperature consistency in the field of electric heating, and is expected to be used as a new type of electric heating material Corresponding author: Ding Guqiao and he Peng