The development of high-efficiency and multifunctional advanced new materials is the key to making breakthroughs in high-tech fields such as information,aerospace,energy chemistry and so on.Due to the heterogeneity of different materials,composites often face problems such as uniformity and stability in the formation process,especially at the micro level such as nano and molecular scale.Therefore,the development of effective methods to organically combine materials with different excellent properties is an urgent scientific problem in this field.
High performance nano carbon materials and ultra-thin two-dimensional silicate materials have attracted attention in the field of high-end materials because of their designability and wide performance adjustment space.It is undoubtedly an effective way to expand new materials to obtain new properties by controllable compounding of these two kinds of nano materials with different properties.Carbon materials are chemically inert,so previous attempts have mostly combined the two materials through physical composite to obtain composites with both properties.Although this method is relatively simple,it is difficult to ensure uniformity and composite degree at the micro scale,which limits its application prospect in high-end fields.How to realize the chemical combination of these two materials through stable chemical bonding has become the key to solve the above problems.Recently,researchers such as Qingdao Institute of bioenergy and process,Chinese Academy of Sciences,creatively prepared a new class of carbon and silicate two-dimensional ultra-thin composite materials driven by weak hydrogen production reaction,and named it carbosilicate(carbosilicate).The corresponding materials showed better effect than commercial IrOx in the process of hydrogen production from electrolytic water.Through synergy,three reactions that cannot occur continuously by themselves(iron reacts with water to produce hydrogen,carbon tubes form graphene bands,and bulk silicon oxide decomposes and rearranges to form a two-dimensional silicate layer)continue to occur and chemically bond under mild hydrothermal conditions,and finally form new composites.
In order to further explore the reaction mechanism,the researchers used AIMD simulation as the main means,combined with the corresponding static calculation,to study the"cracking"mechanism of carbon nanotubes in the solution containing iron ions.The results show that the presence of iron ions plays an important role in promoting the cracking of carbon nanotubes,especially in the initial process of carbon carbon bond cracking,the cracking energy of the first carbon carbon bond with iron ions(0.06 EV)is 5 times lower than that without iron ions(3.3 EV).At the same time,the calculation results also show that the participation of oxygen(or hydroxyl)in the solution plays a key role in the continuous cracking of carbon nanotubes.These calculated results are in good agreement with the experimental results,which provides a powerful verification for the experiment.
This new family of chemical composites combines the advantages of nano carbon and ultra-thin two-dimensional silicate,and has special properties that cannot be provided by the two alone.At the same time,the wide adjustability and economy provide a broad space for the application and expansion of the material family.This study reveals how three reactions that cannot be sustained by themselves can be sustained through synergetic promotion,and shows the new mechanism of synergetic chemistry.The proposal of synergy mechanism provides simpler ideas and broader possibilities for the development of relevant new materials and processes.
Relevant results were published in German Journal of Applied Chemistry.The research work has been supported by the National Natural Science Foundation of China,etc.
Paper link
Schematic diagram of possible"untie and connect"synthesis process of carbosilicate
Calculation of reaction mechanism by AIMD simulation
