Hierarchically Porous Nickel Sulfide Nanosheet Networks Derived From a Nickel‐Based Metal–Organic Framework

Hierarchically porous metal sulfide films are highly attractive for catalytic applications due to their large accessible surface area and interconnected charge transport pathways. Here, we synthesized a nickel‐based metal–organic framework incorporating 2‐methylimidazole (Ni‐MeIM‐MOF) via a solvothermal method. The Ni‐MOF was then employed as a structural and chemical precursor for the preparation of hierarchically porous nickel sulfide films. A solvent‐free sulfurization of the Ni‐MeIM‐MOF films at 400°C enabled their conversion into nickel sulfides. Short sulfurization yielded phase‐pure NiS 2 , whereas prolonged thermal treatment led to conversion to NiS. While additional porosity developed during sulfurization, the nanosheet‐network morphology of the MOF films was largely preserved, leading to a hierarchically porous nickel sulfide network. Scanning electron microscopy‐energy‐dispersive X‐ray spectroscopy (SEM‐EDX) analysis confirmed the expected stoichiometric nickel sulfide compositions for the respective phases. These results demonstrate the suitability of Ni‐MOF thin films as solid‐state precursors for the controlled fabrication of hierarchically structured nickel sulfide layers for catalytic and energy storage‐related applications.