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Creating Faradaic Carbon Nanotube Electrodes with Mild Chemical Oxidation
Author(s) -
Emmett Robert K.,
Kowalske Michael J.,
Mou Hansen,
Grady Mikaela,
Jiang Han,
Roberts Mark E.
Publication year - 2019
Publication title -
batteries and supercaps
Language(s) - English
Resource type - Journals
ISSN - 2566-6223
DOI - 10.1002/batt.201900049
Subject(s) - carbon nanotube , redox , materials science , nanocomposite , electrolyte , electrode , electrochemistry , chemical engineering , faraday efficiency , catalysis , inert , nanotechnology , nanoparticle , carbon fibers , energy storage , nanotube , chemistry , composite material , organic chemistry , composite number , metallurgy , power (physics) , physics , quantum mechanics , engineering
The development of new materials to improve interfacial charge transfer characteristics will drastically improve energy storage, heterogeneous catalysis, and many other electrochemical applications. Here, we report a simple procedure that can harness the Faradaic nature of residual iron nanoparticle catalysts that endure within multi‐walled carbon nanotubes (MWNT) post‐synthesis, thereby alleviating the challenges associated with forging hybrid nanocomposite electrodes. Non‐purified MWNTs, undergo a chemical oxidation process in acidic conditions with KMnO 4 to partially “unzip” the MWNTs and expose the redox‐active iron nanoparticles to the electrolyte. A stable redox peak associated with the Fe 2+/3+ transition is achieved during the MWNT oxidation process yielding a ∼350 % increase in capacitance (>300 F g −1 ) relative to purified MWNT electrodes (70 F g −1 ). While these materials solely may be pragmatic as energy storage electrodes, the integration of redox species within an inert carbon electrode will also provide new opportunities to accelerate heterogeneous charge transfer reactions.