Graphene is a thin sheet formed by a layer of carbon atoms. A hexagonal ring is formed between the atoms. The rings are connected to form a honeycomb plane. Together, 200000 pieces of graphene are as thick as a hair. Previously, this two-dimensional structure of carbon has always existed in people's conjecture, but it has never been made. The key problem is how to layer the graphite into very thin sheets.

        In 2004, Heim and Novoselov of the University of Manchester, UK, repeatedly pasted and ripped a piece of graphite sheet with transparent adhesive, gradually reducing the thickness of the graphite sheet, and finally forming graphene with a thickness of only 0.335nm. This is the first time in the world that graphene is obtained in a single layer, and two scientists won the 2010 Nobel Prize in Physics for this reason. At present, the mechanical stripping method evolved from the adhesive tape paper pasting method has become a method for preparing graphene in the laboratory. However, the limitations of this method are obvious. The products obtained are mixtures of graphene with different layers, which makes it difficult to prepare single-layer graphene on a large scale.

        At present, there are many methods to prepare graphene. Physical methods are mainly mechanical stripping methods, while chemical methods are mainly divided into chemical deposition and chemical synthesis. Physical preparation methods include micromechanical peeling method, carbon nanotube cutting method, orientation regeneration method, etc; Chemical preparation methods include chemical vapor deposition, oxidation reduction, organic synthesis, SiC epitaxial growth, etc. This paper provides an idea and possibility for the large-scale preparation of graphene.

        The traditional production process of graphene is believed to have been well understood. The industry's expectation for graphene is to develop an extensible, cheap and reproducible method to produce them. Now, Italian scientists have proposed a new process that can meet all these requirements.

        Francesco Bonacorso and colleagues from the Italian Institute of Technology proposed their so-called high-pressure wet jet milling process, mainly to separate the layers of graphite and other materials. The hydraulic mechanism and piston generate a pressure of up to 250 MPa to push the mixture of bulk materials dispersed in the solvent through five different plates. These discs are connected to each other and are perforated with tiny adjustable holes (0.3-0.1mm in diameter), which produce a collision jet. Similar processes have been used in industry to crush drugs or paints.

        The main advantage here is that it only takes a few minutes to produce high-quality 2D crystalline graphene, while other methods often take hours to complete. It takes less than 3 minutes to make 1g graphene with the new process. The obtained 2D crystal dispersion, such as graphene, can be used for inkjet printing and battery anode without additional purification steps.