Preparation method of cobalt-nitrogen co-doped carbon nanocage

Abstract

The invention designs a preparation method of a cobalt-nitrogen co-doped carbon nanocage, which specifically comprises the following steps: by using a ZIF-8 structure as an inner core, coating a ZIF-67 shell on the outer layer of the ZIF-8 structure by a seed-mediated growth method; in the process, after Co < 2 + > and 2-methylimidazole are added, taking ZIF-8 spontaneously as an inner core to wrap ZIF-67 to obtain a ZIF-8@ZIF-67 bimetallic core-shell structure; further, in a flowing nitrogen atmosphere at 800 DEG C, carbonizing the organic ligand to form a porous N-doped material, and preliminarily obtaining a cobalt-nitrogen co-doped carbon nanocage material; and performing HCl etching to finally obtain the cobalt-nitrogen co-doped carbon nanocage material. The cobalt-nitrogen co-doped carbon nanocage nanoparticles prepared by the method are good in morphology, uniform in particle, simple in synthesis method step and high in repeatability, have higher activity through morphology and size adjustment, and have a wide application prospect in the fields of electrochemistry, catalysis, biomedicine, virus resistance and the like.

Description

Technical field: [0001] The present invention designs a method for preparing cobalt-nitrogen co-doped carbon nanocages (Co / NCNC for short), specifically using the ZIF-8 structure as the core, and wrapping the ZIF-67 shell on its outer layer by a seed-mediated growth method . During this process, when ZIF-8 is dispersed in methanol solution, its core is gradually hydrolyzed. Since ZIF-67 and ZIF-8 are MOF materials with similar structures, the addition of Co 2+ And 2-methylimidazole will spontaneously wrap ZIF-67 on the outside with ZIF-8 as the inner core, resulting in a bimetallic core-shell structure of ZIF-8@ZIF-67. Further, in a flowing nitrogen atmosphere at 800 °C, Zn 2+ 、Co 2+ The derivatized carbon is reduced to Zn and Co atoms, carbon nanotubes are gradually produced at high temperature, organic ligands are carbonized to form porous N-doped materials, and cobalt-nitrogen co-doped carbon nanocage materials are initially obtained; after HCl etching for 12-24 hours, ...

AI Technical Summary

Problems solved by technology

[0006]However, the existing methods for preparing cobalt-nitrogen co-doped carbon nanocages are usually obtained by pyrolysis and nitriding of ZIF-8@ZIF-67, There is no specific research on the ZIF-8@ZIF-67 precursor synthesis method involved in the synthesis process and the subsequent high-temperature process, so that the final polyhedron has shortcomings such as unclear structure, variable size, and unstable performance.

Therefore, there are certain shortcomings and many challenges in the synthesis of Co / NCNC at present.

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