Synthesis of MOF derived porous cobalt/N-doped carbon polyhedrons for enhancing the electrochemical hydrogen storage properties of Co–P material

Abstract

Employing metal-organic framework ZIF-67 as the precursor, the porous cobalt/N-doped carbon polyhedron (Co–CN) was synthesized via a facile high temperature carbonization process. Co–P material was synthesized through mechanical alloying. By adjusting the content of Co–CN and milling time, a series of Co–P + Co–CN composite electrodes were prepared to enhance the electrochemical hydrogen storage performance of Co–P. Ultimately, the electrode of 5 wt% Co–CN modified Co–P milling for 5 min attained the best discharge capacity of 590.4 mAh/g. The special porous structure and high specific surface area (SSA) of Co–CN derived from ZIF-67 could provide more electrochemical active sites. The nitrogen-doped carbon could further improve the conductivity of Co–P. After Co–CN polyhedrons modification, the HRD, capacity retention and kinetics properties were also enhanced. The Co–CN porous framework can serve as the active additive for designing the high-performance hydrogen storage materials.