Zirconium-Based Metal-Organic Framework Nanocomposites Containing Dimensionally Distinct Nanocarbons for Pseudocapacitors

Electrically conductive nanocomposites composed of a zirconium-based metal-organic framework (MOF) and nanocarbons are synthesized by in situ growth of MOF nanocrystals in the presence of graphene nanoribbons (GNRs) or graphene oxide (GO). The electrical conductivity and porosity of the obtained MOF-based nanocomposites are highly tunable by adjusting the MOF-to-carbon ratio as well as the type of nanocarbons used during the synthesis. Redox-active manganese sites are thereafter decorated in the MOF structure in these nanocomposites to render redox hopping in MOF under electrochemical conditions, and the pseudocapacitive behaviors of these MOF-GNR and MOF-GO nanocomposites are investigated in aqueous electrolytes. With the electrical conductivity provided by nanocarbons and the high-density redox-active manganese sites supported by the porous framework, the Mn-decorated nanocomposites exhibit better performances as the materials for pseudocapacitors than the pristine Mn-decorated MOF and nanocarbons.