Synthesis Of Nitrogen-doped Hierarchically Porous Carbon For Catalytic Oxidation And Supercapacitors Applications

Nowadays,with the rapid de velopment of industry and the acceleration of human urbanization,the discharge of industrial waste water and urban domestic sewage is increasing,and the environmental pollution brought by this has become one of the most serious problems of the world today.In addition,the energy crisis caused by the depletion of fossil fuels is also one of the serious problems.The development of new energy is the key to solve the energy crisis.And the de velopment of efficient energy storage device is one of the important links in the development of new energy.In this paper,a series of nitrogen-doped hierarchically porous carbon materials were synthesized and used in the catalytic oxidation process with persulfate as the oxidant and the construction of supercapacitor.In the synthesis process of this material,we selected polyaniline as the carbon and nitrogen source and added nano-scale silicon dioxide and zinc chloride as the template and activated pore making agent.We synthesized nitrogen-doped hierarchically porous carbon material by calcination in a pot,and optimized its structure through adjusting the mass ratio of silicon dioxide and polyaniline.When the mass ratio of silica to polyaniline is 0.5,the specific surface area is the largest,which can reach to 1641 m²/g.At the same time,it has the best catalytic oxidation activity in the catalytic activation of persulfate in the degradation of phenol;the degradation rate constant can reach 1.3 min^–1.Based on the results of the experiment and DFT calculation,we believe that the enhancement of phenol degradation activity of hierarchically porous carbon materials is due to the rich hierarchically porous structure and the synergistic effect between nitrogen doping and structural defects.In the following research study,we prepared a variety of nitrogen-doped hierarchically porous carbon materials by adjusting the particle size of the template,and used them in the construction of supercapacitors.The experimental results show that when the size of the template is 15 nm,the obtained material has large specific surface area,optimized porous structure and strong electrical conductivity,exhibiting good performance and long-term stability in the supercapacitor electrode material.The specific capacitance can reach 170 F g^–1 even at a high current density of 30 A g^–1,which is 54.0%of the capacity at 1 A g^–1.After characterization analysis and experiments,we found that the improvement of its performance was due to the increase of specific surface area and the decrease of impedance caused by reasonable regulation of pore structure.The micropore-mesoporous hierarchical structure is more conducive to the rapid electron transmission and better conductivity.Based on the above two work,we successfully prepared nitrogen-doped hierarchically porous carbon materials with large specific surface area,pore structure using the template and activate the pore system.It can be used as a sulphate efficient catalyst for the degradation of pollutants in water,also can be a super capacitor electrode materials to build large capacity.In addition,the relationship between its microstructure and catalytic and energy storage properties is also analyzed,which provides an important theoretical basis for the further optimization of the material.