A preparation method of nitrogen and oxygen co-doped porous carbon materials based on bio-based benzoxazine

Abstract

The invention discloses a preparation method of a nitrogen-oxygen co-doped porous carbon material based on bio-based benzoxazine. The method comprises the steps of using vanillin, 4, 4'-diaminodiphenyl ether and paraformaldehyde as raw materials to synthesize a bio-based benzoxazine monomer, preparing a polybenzoxazine resin through a thermal ring-opening polymerization method, and using polybenzoxazine as a precursor to prepare the nitrogen-oxygen co-doped porous carbon materials through processes such as soft templates, KOH activation and the like. The porous carbon materials prepared by themethod are of a loose porous structure, the porous structure exhibits a multi-stage pore structure such as micropores, mesopores, macropores and the like, and the problems in the prior art that the pore size distribution of the porous carbon materials is single, the adjustability is insufficient and the like are solved. The above carbon materials are prepared into a supercapacitor electrode, goodcycle charge and discharge performance and high mass specific capacity are exhibited, the mass ratio capacity is as high as 167 F g-1, and the capacity retention rate can reach over 95% after 1000 cycles.

Description

technical field [0001] The invention relates to the field of preparation of new materials, in particular to a preparation method of nitrogen and oxygen co-doped porous carbon materials. Background technique [0002] Porous carbon material is a carbon functional material with developed pore structure. It has excellent properties such as high specific surface area, good chemical stability, strong mechanical properties, and high catalytic activity. It also has the advantages of electrical conductivity and thermal conductivity. It is widely used in Fuel cells, lithium-sulfur batteries, supercapacitors, water treatment and other fields. [0003] The known porous carbon materials mainly include activated carbon, activated carbon fibers, carbon molecular sieves and carbon nanotubes. The common synthesis methods of porous carbon materials include catalytic activation method, organogel carbonization method, self-assembly method and template method, etc. The catalytic activation meth...

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Problems solved by technology

However, subsequent hydrofluoric acid treatment is required to remove the hard template, and the template cannot be recycled. The operation steps are cumbersome, time-consuming, increase the cost, and are harmful to the environment. This greatly restricts the preparation of porous carbon materials and is not suitable for large-scale production.

[0005] In contrast, it is more effective to prepare porous carbon materials by the soft template method (Chemistry of Materials, 2008 (20), 932-945.), but although the polymer soft templates currently used can achieve effective control of the pore structure, However, it is difficult to maintain the original pore structure after being removed from the template, and there are problems such as low specific surface area, small pore volume, wide pore size distribution and many closed cells.

[0006] However, porous carbon materials have a strong dependence on pore size as electrode materials. However, most of the existing porous carbon materials have the problems of single pore size distribution and insufficient adjustability, and the resulting electrochemical performance problems often affect their application as electrode materials. : For example, although activated carbon has a large specific surface area, it has many micropores, and its electrochemical performance drops seriously under high current density conditions; the small specific surface area of ​​mesoporous carbon materials also limits the improvement of its electrochemical performance. Although single-walled carbon nanotubes and graphene materials have excellent electrochemical properties, their high prices also limit their applications.

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