Preparation Of Penolic Resin Carbon Materials And Their Performances

In recent years,carbon materials prepared with phenolic resin as the precursor have become one of the research hotspots due to their advantages of low production cost,high carbon residue rate and stable chemical structure.However,its single morphology and small specific surface area limit its further development and application.In this paper,a systematic study on the preparation and application of phenolic resin-based carbon materials was carried out,and three-dimensional composite carbon,bulk carbon and spherical carbon materials were obtained.The effects of reaction components on the structure,morphology and surface properties of polymer-based carbon materials were studied,and their applications in the fields of adsorption and energy were explored.The main research contents of this paper are as follows:1.Compared with two-dimensional carbon sheets,three-dimensional composites usually contain more active sites,which can improve the electrochemical properties of the materials.Using C₃N₄ as self-sacrificial template and gradient temperature rising carbonization pyrolysis method,we controlled the ratio of melamine to glucose in the reaction material and adjusted the content of SiO₂@RF to obtain two-dimensional porous carbon nanosheets（1.0-CNS）and hollow carbon nanospheres three-dimensional composites（0.20-CHSs@CNS）.When it’s used as an electrode material,the specific capacitance of 1.0-CNS is 216.5 F g^-1 at the current density of 0.5A g^-1,and can be maintained to 99.3 F g^-1 at the current density of 10 A g^-1.Compared with the two-dimensional carbon nanosheets 1.0-CNS,0.20-CHSs@CNS with the three-dimensional structure of hollow carbon nanospheres showed excellent electrochemical performance and good rate capability.The improvement of performance is attributed to the fact that the three-dimensional structure of hollow carbon nanospheres makes the material have a higher comparative area,which provides a convenient path for electron migration,reduces the mass transfer path of electrolyte ions,and makes the material exhibit a higher specific capacitance value.2.The pore structure and specific surface area size are one of the main factors affecting the properties of materials.In this paper,resorcinol and furfural are used as raw materials,and melamine is used as dopant.A simple two-step method of hydrothermal reaction and high-temperature carbonization activation is designed to prepare N-doped copolymer-based derivative carbon materials.The S_BETtest results show that the surface area of RMFC-3.6 can be as high as 2572.3 m² g^-1.This higher surface area can produce many well-distributed pore structures.Through elemental analysis test,the nitrogen content is as high as 1.4 wt%.This result shows that the higher N-doping amount and porous characteristics provide the structural basis for the excellent adsorption and electrochemical performance of the material.When RMFC-3.6 is used as an electrode material,its specific capacitance can reach 408F g^-1at 0.5 A g^-1,and it can still maintain 264 F g^-1 at 10 A g^-1,with excellent rate performance.Furthermore,we performed adsorption tests on the obtained nitrogen-doped porous copolymer resin-based carbon materials,and the results showed that RMFC-3.6 has the largest adsorption of Congo Red（CR）,Rhodamine B（Rh B）and Malachite Green（MG）The capacities reached 3207.6,2947.4,and 5769 mg g^-1,respectively,which were much higher than the reported values in the literature.These two excellent properties can be attributed to the large specific surface area,hierarchical pores and the doping effect of N,because it provides active sites in this interconnected network structure and provides suitable transport for molecules and ions channel.3.The bimetal-coated hollow carbon spheres were prepared by the sacrificial template method.Using resorcinol as raw material,SiO₂@RF was prepared by polycondensation with formaldehyde at room temperature.By combining the pseudocapacitance of the metal element itself with the electric double layer capacitor of the carbon material with better reversibility.The influence of the addition amount of Ni（NO₃）₂·6H₂O and the addition amount of SiO₂@RF on the electrochemical performance was investigated in detail.It can be proved in the electrochemical performance graph that the obvious redox peak can be attributed to the pseudocapacitance generated by the synergistic effect of bimetallic ions,which further indicated that the redox reaction of the metal atoms occurred in the alkaline electrolyte.The as-prepared sample 0.5-CHS@Co@Ni showed good electrochemical performance,which showed that the specific capacitance value at the current density of 1 A g^-1 could be as high as 2387 F g^-1,much higher than that of the pure phenolic resin-based carbon material.