The Synthesis Of Carbon Nanomaterials And Their Application In The Reduction Of Carbon Dioxide Electrocatalysis

With the rapid development of human society and economy,the burning of large quantities of fossil fuels has caused the increasingly serious problem of global environment and caused the situation of increasing energy shortage,which restricts the further development of human economy and society,and even seriously threatens the survival of mankind.Due to environment and energy are closely related to human survival and development,the development and utilization of environmental governance and protection and new renewable clean energy are urgently needed to be solved.CO2 is widely recognized as the most significant contributor to climate change,reducing carbon emissions,making its impact on climate change becoming a more and more severe scientific challenge.Many methods can be used to reduce carbon emissions,such as carbon capture and sequestration,increase the use of carbon neutral energy sources such as wind and solar power.However,it is more attractive to convert CO2 directly into small organic molecules,which can produce valuable products.By contrast,the cost of wind and solar energy is much higher,because it still requires efficient energy storage.In the process of converting CO2 to organic small molecules,the different methods,such as the photocatalysis,the electriccatalytic method,the photoelectric catalysis method,etc.,using different methods can turn CO2 into valuable organic small molecules,however,because of the difference of the method itself,faraday efficiency has obvious different efficiency.Electrocatalysis is the most promising method in many catalytic reduction methods.However,there are two main problems with electrocatalytic reduction of carbon dioxide:(1)faraday efficiency is low;(2)poor selectivity of products.To improve the problem,scientists have done a lot of work on the synthesis of electrocatalytic materials.In order to further improve the performance of electrocatalytic reduction of carbon dioxide,we have done a series of work,and synthesized a variety of porous carbon materials with large specific surface area.The main contents of this paper are as follows:The first chapter:induction summarizes the main characteristics of electrocatalytic CO2 reduction and recent development.The second chapter:this thesis involves the experiment of the reagent and laboratory equipment,at the same time,this paper expounds the kinds of characterization methods needed for the experimental analysis.The third chapter:the design and synthesis of the nitrogen doped triazine structure with a large specific surface area of porous carbon nanomaterials(NCTF),using the method of in-situ doping,the successful doping of nitrogen elements into the porous carbon nanomaterials,and the synthesis of porous carbon materials with a large specific surface area than traditional elements doped with the top down structure.After graphitization of the NCTF at various temperatures,carbon dioxide reduction tests were carried out at different potentials,NCTF exhibited excellent electrochemical performance,and the faraday efficiency of CO was 74.98%.The fourth chapter:the design and synthesis of the nitrogen fluorine double-doped triazine structure with a large specific surface area of porous carbon nanomaterials(FCTF).Due to the unique microporous structure of FCTF,its adsorption effect on carbon dioxide gas is enhanced,at the same time;the product selectivity of the catalyst is further optimized due to the addition of fluorine elements.Because of the doping structure different from other elements,FTCF is more conducive to the generation of methane in the process of reducing CO2,and the farad efficiency of methane is as high as 99%.It shows excellent product selectivity and high Faraday efficiency.The fifth chapter:using the chlorine-based materials as a monomer,synthesizing the porous carbon nanomaterials of chlorine-nitrogen,which is a contrast between the elements of the first two chapters,and the elements of fluorine and nitrogen,to study the effects of the materials in the process of the electrocatalytic process of carbon dioxide.The results showed that nitrogen was beneficial to reducing carbon dioxide to carbon monoxide,while the addition of halogen was beneficial to reducing carbon monoxide to methane.