NaN3 Assisting Synthesis of Hierarchical constructed Transition (Co/Ni) Metal Organic Framework (MOF)

Abstract

NaN3, as a kind of rich-nitrogen energetic material, engaged in the synthesis of hierarchical transition metal (Co/Ni) organic framework materials (MOFs) through a facile hydrothermal reaction, during which aqueous N3 − function groups being as an unique ligand in preparation of novel coordination polymer with the existence of Co2+ (or Ni2+) salts and dicyandiamide. The obtained compounds (Co-eMOF, Ni-eMOF, NiCo-eMOF) were characterized by structure and composition analysis, specific surface area, thermogravimetric analysis (TGA) and crystal X-ray diffraction. The prepared products regardless of the metal cautions (Co, Ni, or coexist Co and Ni), perform a well three-dimensions (3D) nanostructures with spherical shaped monoliths, known as organic framework materials. The as-prepared products with developed porosity demonstrate a high surface area in range of 80∼130 m2/g. XRD patterns for these three examples show similar lattice crystalline, which to an extent matches well with the simulated MOF-74 materials, suggesting profound formation of oriented crystal growth. XPS reveals the compounds all equipped with high nitrogen content (54∼60 at%), which is largely hinging on the contribution from N3 − function groups, suggesting the superiority of NaN3 serving as the rich nitrogen precursor. Accounting for extensive application, we will apply this as-prepared (Co/Ni) MOF materials as one kind of nitrogen-rich precursor and conduct them for further calcination treatment for preparation of graphite-based transition metal carbides (TMC), and it is highly anticipated to achieve efficient activity towards electrocatalysis in our follow-up actions.