Preparation method and application of a bimetallic organic framework composite material

Abstract

The present invention proposes a kind of preparation method of bimetallic organic framework composite material, originally the methanol solution of 2-methylimidazole is added in the solvent containing zinc salt, after stirring evenly, stand still, obtain ZIF-8; The methanol solution of imidazole is added to a solvent containing an appropriate amount of ZIF‑8 and cobalt salt, stirred evenly and then left to stand to obtain a bimetallic organic framework precursor ZIF‑8@ZIF‑67; placed in a tube furnace for high temperature annealing, derived Porous carbon with a core-shell structure; the porous carbon material is mixed with PDDA, stirred, compounded with graphene oxide, freeze-dried and then annealed at high temperature to obtain a porous carbon / graphene composite material. The porous carbon material prepared by the method of the invention is evenly distributed on the graphene sheet, the composite material has good stability and low cost, and when it is applied to an MFC cathode catalyst, it 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 ...

AI Technical Summary

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.

Images