(397bg) Changing the Mesostructure of MOF-Derived Carbons By Doping MOF-5 With Ni2+ for Bulk Synthesis of Carbon Nanofibers

High quality production of carbon nanostructures has been an extensive area or research with a great emphasis placed on Chemical vapor deposition (CVD). Here we illustrate a novel concept in tailoring the architecture of Metal-Organic Framework-derived carbons (MDCs) by doping Metal-Organic Framework (MOF) crystals with transition metal ions prior to its use as a template in CVD growth of carbon nanofibers. MOF-5 was isomorphously doped with Ni²⁺ during its synthesis. The Ni-doped MOF-5 was then used as a template in the CVD process (at ~550 – 650 °C) and yielded a 3D hierarchy composed of a labyrinth of carbon nanofibers with electrical conductivity (~ 550 S/m) in sharp contrast to a ‘flake-like’ morphology and lack of electrical conductivity in MOF-5 derived carbons. The nanofibers were short, having variable diameters, (~ 10-40 nm) but possess a conical arrangement of graphene sheets as observed by HRTEM, while electrochemical measurements show good charge storage capability, suggesting their potential in double layer capacitor devices. This approach can be used for production of bulk quantities of carbon nanofibers. The uniformly distributed metals joined by aromatic carbon groups in the MOFs could provide a new method to develop carbons with tunable architecture.