Abstract
We use fiber-paper-supported carbon nanofoams as the basis for "multifunctional electrode nanoarchitectures" in which
the nanofoams serve as conductive, ultraporous scaffoldings for subsequent incorporation of electroactive functionalities
such as metal oxides, metal nanoparticles, and ultrathin polymers. The resulting functionalized carbon nanofoam papers
are designed to serve as "plug-and-play" electrode structures in electrochemical devices ranging from high-rate Li-ion
batteries and electrochemical capacitors to metal-air batteries and fuel cells. Electroless deposition is an attractive
approach to functionalize structurally complex substrates, such as carbon nanofoams, and we have recently demonstrated
that conformal nanoscopic coatings of manganese oxide (MnOx) can be generated on the exterior and interior surfaces of
pre-formed carbon nanofoam papers via redox reaction with aqueous permanganate (MnO4-). The resulting nanoscale
MnOx coatings provide not only faradaic charge-storage functionality to the nanofoam structure, but also enhanced
electrocatalytic activity for molecular oxygen reduction. The electrocatalytic functionality of MnOx can now be
combined with the desirable structural characteristics of carbon nanofoams (through-connected and size-tunable pore
structures, high specific surface areas, and good electrical conductivity) to produce high-performance air-breathing
cathodes for metal-air batteries. Herein, we report preliminary results for a particular series of native and
MnOx-functionalized carbon nanofoams as examined for their O2-reduction activity in a three-electrode testing
configuration.
