Preparation method and application of bimetal organic framework composite material

Abstract

The invention provides a preparation method of a bimetal organic framework composite material. According to the preparation method, the methanol solution of 2-methylimidazole is added into a zinc salt-containing solvent, and the methanol solution and the zinc salt-containing solvent are stirred uniformly, an obtained mixed solution stands still, so that ZIF-8 can be obtained; the methanol solutionof 2-methylimidazole is added into a solvent containing a proper amount of ZIF-8 and cobalt salt, and the methanol solution and the solvent are uniformly stirred, and an obtained mixed solution stands still, so that a bimetal organic framework precursor ZIF-8@ZIF-67 is obtained; the precursor is transferred into a tubular furnace so as to be subjected to high-temperature annealing, and porous carbon of a core-shell structure is obtained through derivation; the porous carbon material is mixed with PDDA, an obtained mixture is stirred, and the mixture is compounded with graphene oxide; and an obtained product is subjected to freeze-drying and high-temperature annealing sequentially, so that a porous carbon / graphene composite material is obtained. The porous carbon material prepared by the method disclosed by the invention is uniformly distributed on a graphene sheet layer; the composite material is good in stability and low in cost; and when the composite material is applied to an MFC cathode catalyst, the composite material shows good electrochemical catalytic performance.

Description

technical field [0001] The invention relates to a preparation method and application of a bimetallic organic framework composite material, in particular to a preparation method and application of a bimetallic organic framework derived porous carbon / graphene composite material, and belongs to the technical field of microbial dye batteries. Background technique [0002] Microbial fuel cell (MFC) is a new energy technology that converts organic matter in wastewater into electrical energy. MFC can process wastewater while generating electricity, and has broad application prospects. However, problems such as low power output, high internal resistance, and high cost of MFC limit its commercial application, in which the electron transfer and oxygen reduction reaction of the cathode become the bottleneck of battery performance improvement. Therefore, the development of low-cost, high-activity, and high-stability cathode non-platinum-based catalysts is the key to the application of ...

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Problems solved by technology

After searching, it was found that the patent with the publication number CN108834389A disclosed a bimetallic organic framework derived porous carbon / multi-walled carbon nanotube nanocomposite absorbing material. Although the method adopts a simple high-temperature pyrolysis method to prepare the nanocomposite material in one step, However, the carbon nanotubes in the composite material cannot effectively connect the dispersed porous carbon, and they are easy to fall off during the oxygen reduction reaction in the solution, which cannot guarantee the long-term stable operation of the fuel cell; the patent with the publication number of 109126885 discloses a copper-cobalt Bimetallic organic framework / nanofiber composite material, although the composite material prepared by this method has strong stability, the conductivity of the metal organic framework in the composite material is not very good, which is not conducive to the rapid transmission of electrons, which limits its performance in the electrical field. Application in the field of chemical catalysis; the patent publication No. 109546107A discloses a method for preparing a graphene / two-dimensional Co-Zn dual-core metal framework composite material. Although the method adopts a simple preparation process, the prepared composite material is The two-dimensional flake morphology is not conducive to the adsorption and desorption of oxygen, and does not contain Co-Nx active centers that are conducive to oxygen reduction, which limits its application in MFC cathode catalysts

[0005] In summary, currently synthesized metal-organic framework-derived porous carbon / graphene materials are not ideal for catalyzing the oxygen reduction reaction, which greatly limits their practical application in microbial fuel cells.

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