Since the beginning of the 21st century, the rapid development of new nano-carbon materials such as nano-diamonds, fullerenes, carbon nanotubes, and graphene has attracted widespread attention worldwide. When the scale of carbon materials is reduced to the nanometer range, some of their physical and chemical properties will change significantly, and they will exhibit a series of unique properties caused by high specific surface area or quantum effects. The new type of nano-carbon material has the characteristics of good stability, high strength, high specific surface area and abundant sources. It is a cutting-edge material with the most development potential and a strategic material that will lead future high-tech competition.
Although nanodiamonds and fullerenes were discovered earlier, they are still in the laboratory stage due to mass production technology and application development restrictions. At present, graphene and carbon nanotubes are the key new type of nano-carbon materials that have attracted the attention of governments, academics, and industries from all countries, and have a certain scale of industrial foundation.
Graphene
Graphene is not only the strongest, hardest, and thinnest material known in the world, but also the smallest resistivity and highest thermal conductivity material among the known materials.
Graphene materials can be divided into microplates (powders) and thin films according to their morphology and applications. The preparation methods of graphene microplates include redox method, intercalation peeling method, liquid phase peeling method, mechanical peeling method, etc .; the preparation methods of graphene thin film include chemical vapor deposition method and epitaxial growth method. Among them, graphene microchip preparation technology has been widely industrialized, and the technology of growing and transferring large-area graphene films by chemical vapor deposition and roll-to-roll technology has also achieved major breakthroughs.
The development of graphene materials at the application level will go through the following three stages: primary, intermediate, and advanced. Primary application stage: subject to cost factors, it is difficult to achieve large-scale graphene application alone in a short time. Graphene is mainly used to improve the performance of other materials, and is expected to be used in lithium-ion batteries, thermally conductive materials, conductive inks, anticorrosive coatings Play an important role; Intermediate application stage: As the high-quality graphene mass production technology gradually matures, graphene applications are expected to support various new devices in flexible displays, solar cells, supercapacitors, film materials, sensors, transistors and prostheses. Find new ways for implants and other aspects; advanced application stage: once the mass production of graphene is mature and wafer-level graphene single crystal has achieved a breakthrough, it will continue to challenge technological breakthroughs through system integration and have a higher technical threshold in the future The fields of biomedicine, high-frequency devices and high-strength multifunctional composite materials are expected to exert their potential to subvert traditional industries.
Global R & D Status
In 2004, the physicists Andre Geim and Kostya Novoselov of the University of Manchester in the UK successfully separated sp2 hybrid graphene from graphite for the first time Since then, graphene research has set off a boom. Especially in recent years, Britain, the United States, Germany, Japan, South Korea and the European Union have all increased graphene R & D to a strategic height. Various academics and industries have made efforts to echo the national high-level layout, and are forming technology R & D and industrial investment. The climax, strive to seize the opportunities of graphene technology revolution and industrial revolution.
As the birth country of graphene, the British government has designated graphene as a key emerging technology since 2011 and has invested huge amounts of money. The key research areas involve electronic information, sensors, composite materials, energy storage materials and structural materials. The graphene research foundation in the UK is strong, and the academic aspects are dominated by the University of Manchester and the University of Cambridge. The scientific research institution is led by the National Graphene Research Center (NGI), and the second graphene technology innovation center, the British Graphite, was built in 2018. Engineering Innovation Center (GEIC). On the industrial level, in addition to the British local companies, the National Graphene Research Center has established cooperative relations with about 50 companies around the world, aiming to promote the basic research of graphene to industrialization.
In recent years, the German government and the European Union have fully mobilized the enthusiasm of domestic scientific research institutions, enterprises and universities through policy encouragement and financial support, fully participated in graphene research and development projects, and formed a graphene research and development network integrating government, industry, education and research. He has strong advantages in the field of optoelectronic devices. In addition, the metal organic chemical vapor deposition equipment developed by AIXTRON (Germany) marks a breakthrough in large-scale graphene preparation technology.
In 2013, the European Union launched the Graphene Flagship (Graphene Flagship), with a total investment of up to 1 billion euros, and released a graphene technology roadmap one year later. Since its inception, the graphene flagship plan has led European countries such as Britain, Germany, France, Italy, the Netherlands, and Denmark to jointly promote the development and industrialization of graphene, and actively promote cooperation and exchanges with other regions of the world.
The US government is extremely targeted when it comes to the deployment of graphene research and development. The Ministry of Defense has carried out a number of graphene research projects, with the focus on applying them to lighter, smaller, faster, and higher-frequency electronic devices that have the most potential to disrupt traditional industries, as well as composite materials and sensors that improve military capabilities Field, with a view to occupying the commanding heights of frontier military technology. In recent years, universities and research institutes have actively engaged in extensive research in the field of graphene material preparation and application. At the industrial level, the United States has a diversified layout, including IBM, Intel, Boeing and other industry giants, as well as a group of small and medium-sized graphene emerging companies.
South Korea's graphene preparation technology and device research are developing rapidly. The government has provided hundreds of millions of dollars in funding to support related research. The main research institutions include some universities and Samsung Electronics and LG companies. They already have thin film preparation, optoelectronic devices, transistors and OLEDs. Rich application research results, and actively cooperate with the British and European graphene flagship plan.
In recent years, the Japanese government has strongly supported research on nano-carbon materials including graphene, and the Ministry of Economy, Trade and Industry has invested 12 billion yen to encourage research and development. With the support of the government, Japan has achieved certain results in graphene mass production technology and energy storage applications, trying to use graphene's excellent performance to consolidate its traditional advantages in the field of batteries.
In recent years, China has carried out a lot of research in the field of graphene, ranking among the world's first echelon of graphene research, the world's first total number of patent applications, and has obtained a batch of innovative research with international influence in the exploration of graphene preparation, physical properties and application foundation. Results. Research strength is mainly concentrated in universities and colleges such as Tsinghua University, Zhejiang University and Harbin Institute of Technology, scientific research institutions such as the Chinese Academy of Sciences, and some enterprises. In recent years, China's graphene industry has also shown a vigorous development trend, but product quality is uneven. The Chinese government has also given great support to graphene research and industrial development. In the "Twelfth Five-Year Development Plan of the New Materials Industry", graphene is regarded as a frontier new material for key development. In the "Thirteenth Five-Year Plan for National Science and Technology Innovation", graphene is clearly listed as an advanced functional material and disruptive technology for key development. "Made in China 2025" also clearly requires the advance layout and development of graphene and other strategic frontier materials, and has prepared a technical roadmap for the graphene industry. Overall, China's research leadership in graphene lacks original innovation and system innovation, and lacks a real killer level of graphene application technology; the conversion rate of results is low, the level of industrialization technology needs to be improved, and the quality of industrial development needs to be strengthened.
Future trends
In the future, graphene, as a hotspot in the international high-tech industry competition, its development will mainly be comprehensively upgraded from the aspects of preparation technology and industrial application. The preparation technology will further develop the controllable, green, low-cost and large-scale industrial preparation technology of high-quality graphene powder and graphene film; industrial application will explore the development potential of a wide range of applications, and strive to develop graphene "killer "And cost-effective applications. In addition, the international standardization of graphene is also steadily in progress.