Toward Metal–Organic‐Framework‐Based Supercapacitors: Room‐Temperature Synthesis of Electrically Conducting MOF‐Based Nanocomposites Decorated with Redox‐Active Manganese

Abstract

Nanocrystals of a zirconium‐based metal–organic framework (Zr‐MOF) were grown on carboxylate‐functionalized carbon nanotubes (CNT) at room temperature to synthesize electrically conducting Zr‐MOF‐CNT nanocomposites. To further enable charge transport within the Zr‐MOF phase via redox hopping under electrochemical conditions, redox‐active manganese sites were then installed in the Zr‐MOF and nanocomposites at room temperature by means of the solvothermal deposition in MOFs (SIM) technique. The redox hopping behavior of the Mn‐decorated Zr‐MOF nanocrystals was investigated. With the high electrical conductivity provided by the one‐dimensional CNT bridges interconnecting multiple MOF nanocrystals, as well as the high‐density accessible redox‐active Mn sites supported by the Zr‐MOF, the Mn‐decorated Zr‐MOF‐CNT nanocomposites show more electrochemically addressable manganese sites and thus much higher pseudocapacitive performance compared to those of both the Mn‐decorated Zr‐MOF and the Mn‐decorated CNT.