China University of Science and Technology Realizes the Preparation of Ultrafine Carbon Nanofiber A
2018-06-28 18:13:17 From: Tradematt-Aerogel
Carbon nanofiber aerogel materials have attracted wide attention because of their high specific surface area, excellent mechanical properties, and high electrical conductivity. They have broad application prospects in the fields of energy, catalysis, environment, and polymers. At present, rational design, synthesis and performance optimization of functionalized carbon nanofiber aerogel materials for specific applications are still the bottleneck restricting their practical application. In particular, inexpensive, macroscopic, sustainable production of carbon nanofiber aerogels has not yet been achieved.
Recently, the Yu Shuhong research team of the University of Science and Technology of China proposed a method of catalytic pyrolysis to change the pyrolysis process of woody nano-cellulose. For the first time, high-quality ultra-fine carbon nanofiber aerogel materials were prepared using cheap wood as raw materials. The result is "Wood-Derived Ultrathin Carbon Nanofiber Aerogels", published in the journal "German Application Chemistry" (Angew. Chem. Int. Ed. 2018, 57, 7085-7090). The first author of the dissertation was Ph.D. student Li Sicheng.
Preparation of Ultrafine Carbon Nanofiber Aerogel Material Based on Wood Nanocellulose
Cellulosic materials are widely found in natural plants. Due to its wide range of sources, low cost, and environmental friendliness, lignocellulosic materials are an ideal precursor for the preparation of carbon nanofiber aerogels. However, because of the extremely small size of lignocellulose nanofibers, it shrinks violently in the process of pyrolysis to prepare carbon fibers and cannot maintain the morphology of the fibers. So far, there is no precedent for the successful preparation of carbon nanofiber aerogels using wood as a raw material. To this end, the researchers proposed a catalytic pyrolysis method that uses p-toluenesulfonic acid to catalyze the rapid dehydration of woody nanocellulose in the early stage of pyrolysis, and changes its pyrolysis process and intermediates, resulting in the pyrolysis of nanocellulose. After having a high carbon yield, it can also maintain a good three-dimensional network structure. The catalytic pyrolysis conversion method can convert inexpensive and abundant natural precursor materials into high value-added carbon nanofiber aerogel materials, which has guiding significance for the development of green chemistry synthesis of renewable materials.
The ultrafine carbon nanofibers aerogel prepared by this method have an average diameter of only 6 nm, a high electrical conductivity (710.9 S m-1) and a specific surface area (553-689 m2 g-1). Due to its unique three-dimensional network structure characteristics, excellent electrical conductivity, and high specific surface area, the carbon nanofiber aerogels prepared by the team developed by the research team can be directly used to assemble a supercapacitor without a binder, and The performance of pure carbon supercapacitors shows excellent capacitance. This new type of carbon nanofiber aerogel can also be used in water purification, electrocatalyst carriers and battery electrode materials. After the paper was published, it was reported by the academic media ScienceDaily, Phys.org, Wiley NewsRoom, etc. with the theme of "Wood to supercapacitors" as a highlight of the research.
In recent years, the team has continued to conduct a series of researches around the synthesis, functionalization and application of carbon nanofiber materials, and developed a template-guided hydrothermal carbonization method and a method for direct carbonization of biomass bacterial cellulose. Macro-preparation of carbon nanofibers Aerogel materials, based on such materials, have been prepared through a series of rational chemical modification functionalization methods for a series of functional nanomaterials, and applications of these materials in the fields of environment, energy, catalysis, and polymer composites have been explored (Acc. Chem. Res. 2013, 46, 1450-1461; Acc. Chem. Res. 2016, 49, 96-105).
Recently, the research team was invited to write a review paper titled "Emerging Carbon Nanofiber Aerogels: Chemosynthesis versus Biosynthesis" for "German Applied Chemistry" (Angew. Chem. Int. Ed. 2018, DOI: 10.1002/anie.201802663). The advantages and disadvantages of the carbon nanofibers aerogel prepared by the chemical conversion method and biological method developed by the team were compared, and the series of the physical and chemical properties, functional methods, and applications of the carbon nanofiber materials prepared by these two synthetic routes were summarized. Progress has been made, and suggestions for future research on carbon nanofiber aerogel materials and scientific issues worthy of attention in the future have been put forward.
The above work was supported by the National Natural Science Foundation of China's Innovation Research Group, the National Natural Science Foundation of China, the National Major Scientific Research Project, the Frontier Science Research Project of the Chinese Academy of Sciences, the Nanoscience Innovation Center of the Chinese Academy of Sciences, the Suzhou Nanotechnology Collaborative Innovation Center, Hefei University. Science Center Funding for Excellent User Funding.