Since the beginning of the 21st century, the rapid development of new carbon nanomaterials, such as nano diamond, fullerene, carbon nanotubes and graphene, has attracted worldwide attention. When the scale of carbon materials is reduced to nano scale, some of their physical and chemical properties will change significantly, and show a series of unique properties caused by high specific surface area or quantum effect. The new type of carbon nanomaterials have the characteristics of good stability, high strength, high specific surface area and rich sources. They are the most potential frontier materials and also the strategic materials leading the future high-tech competition.
Although nano diamond and fullerene were discovered earlier, they are still in the laboratory stage due to the limitation of mass production technology and application field development. At present, graphene and carbon nanotubes have attracted the attention of governments, academics and industries all over the world.
Graphene is not only the strongest, hardest and thinnest material in the world, but also the material with the lowest resistivity and the highest thermal conductivity.
Graphene materials can be divided into two types: Micro flake (powder) and thin film according to their morphology and application. The preparation methods of graphene microsheets include redox method, intercalation stripping method, liquid phase stripping method and mechanical stripping method; the preparation methods of graphene thin films include chemical vapor deposition method and epitaxial growth method. Among them, a great breakthrough has been made in the preparation of graphene thin films by large area deposition and chemical vapor deposition.
The development of graphene materials in the application level will go through the following three stages: primary, intermediate and advanced. Primary application stage: due to cost factors, it is difficult to realize large-scale graphene application alone in a short time. Graphene is mainly used to improve the performance of other materials, and is expected to play an important role in the fields of lithium-ion batteries, thermal conductive materials, conductive inks, anticorrosive coatings, etc.; intermediate application stage: with the gradual maturity of high-quality graphene mass production technology, graphene application is expected By supporting all kinds of new devices, we will find new ways out in flexible display, solar cells, supercapacitors, membrane materials, sensors, transistors and prosthesis implants; in the advanced application stage, once the mass production of graphene is mature and the wafer level graphene single crystal has made a breakthrough, it will continuously challenge the technological breakthroughs through system integration, which will lead to a higher technical threshold In the fields of biomedicine, high-frequency devices and high-strength multifunctional composite materials, it is expected to play a potential role in subverting traditional industries.
Global R & D status
In 2004, Andre Haim (Andre Geim) and Konstantin Novoselov (Kostya Novoselov), physicists at the University of Manchester, UK, successfully separated the SP2 hybrid graphene from graphite for the first time. Especially in recent years, the United Kingdom, the United States, Germany, Japan, South Korea and the European Union have all raised the research and development of graphene to a strategic height. The academic and industrial circles have been making efforts to echo the national high-level layout, forming the climax of technology research and industrial investment, and striving to seize the opportunities of graphene technology revolution and industrial revolution.
As the birthplace of graphene, since 2011, the British government has designated graphene as an emerging technology and invested a lot of money. The key research fields include electronic information, sensors, composite materials, energy storage materials and structural materials. The research foundation of graphene in the UK is strong, with Manchester University and the University of Cambridge as the main academic research institutions. The research institutions are led by the national graphene Research Center (NGI) of the UK, and the second graphene technology innovation center, the GEIC, has also been built in 2018. At the industrial level, in addition to British enterprises, the UK National graphene Research Center has established cooperative relations with about 50 enterprises around the world, aiming to promote the industrialization of basic research on graphene.
In recent years, the German government, together with the European Union, has fully mobilized the enthusiasm of domestic scientific research institutions, enterprises and universities through policy encouragement and financial support, fully participated in graphene R & D projects, and formed a graphene R & D network integrating government, industry, education and research, which has strong advantages in the application of graphene in the field of Photonics and optoelectronic devices. In addition, the metal organic chemical vapor deposition equipment developed by aixtron marks a breakthrough in large-scale graphene preparation technology.
In 2013, the EU launched the graphene flagship project with a total investment of 1 billion euro, and released the graphene technology roadmap a year later. Up to now, the graphene flagship project has led the UK, Germany, France, Italy, the Netherlands, Denmark and other European countries to jointly promote the R & D and industrialization of graphene, and actively promote cooperation and exchanges with other regions of the world.
The U.S. government is highly targeted in the R & D and application of graphene. The Ministry of defense has launched a number of graphene research projects, focusing on the application of graphene in the field of lighter, smaller, faster and higher frequency electronic devices with the most potential to subvert traditional industries, as well as composite materials and sensors to improve military capabilities, so as to occupy the commanding height of military frontier technology. In recent years, universities and scientific research institutes have been actively engaged in the preparation and application of graphene materials. At the industrial level, the United States presents a diversified layout, including industrial giants such as IBM, Intel and Boeing, as well as a number of small and medium-sized graphene emerging enterprises.
With the rapid development of graphene preparation technology and device research in South Korea, the government has provided hundreds of millions of US dollars to support related research. The main research institutions include some universities, Samsung Electronics and LG company. They have rich application research results in film preparation, optoelectronic devices, transistors and OLEDs, and actively cooperate with the UK and European graphene flagship projects.
In recent years, the Japanese government has strongly supported the research on nano carbon materials including graphene, and the Ministry of economy and industry has invested 12 billion yen to encourage research and development. With the support of the government, Japan has made some achievements in the mass production technology and energy storage application of graphene, trying to consolidate its traditional advantages in the battery field with the excellent performance of graphene.
In recent years, China has carried out a lot of research in the field of graphene, ranking first in the field of graphene research in the world, and the total number of patents applied in the world. A number of innovative research results with international influence have been obtained in the preparation, physical properties and application of graphene. The scientific research force is mainly concentrated in Tsinghua University, Zhejiang University and Harbin Institute of technology, Chinese Academy of Sciences and some enterprises. In recent years, China's graphene industry has also shown a trend of vigorous development, but the quality of products is uneven, and the industrial development is booming. Our government has also given great support to graphene research and industrial development. Graphene is regarded as the frontier new material in the 12th Five Year Plan of new material industry. Graphene is definitely listed as an advanced functional material and subversive technology in the 13th five year plan of national science and technology innovation. "Made in China 2025" also clearly requires to do a good job in the layout and development of strategic frontier materials such as graphene in advance, and has prepared the technical roadmap of graphene industry. On the whole, there is a lack of original innovation and systematic innovation in graphene research field in China, and there is a lack of real killer level graphene application technology; the conversion rate of achievements is low, the level of industrialization technology needs to be improved, and the quality of industrial development needs to be strengthened.
Future development trend
In the future, graphene, as the hot spot of international high-tech industry competition, its development will be comprehensively improved from the aspects of preparation technology and industrial application. The preparation technology will further develop controllable, green, low-cost and large-scale industrialized preparation technology of high-quality graphene powder and graphene film; the industrial application will explore the development potential of extensive application fields, and strive to develop the "killer mace" and high cost-effective application of graphene. In addition, the international standardization of graphene is also in steady progress.