ic9b03516_si_001.pdf (1.12 MB)
MOF Derived Co3O4@Co/NCNT Nanocomposite for Electrochemical Hydrogen Evolution, Flexible Zinc-Air Batteries, and Overall Water Splitting
journal contribution
posted on 2020-02-13, 14:42 authored by Tarandeep Singh, Chayanika Das, Neha Bothra, Nivedita Sikdar, Shubhajit Das, Swapan K. Pati, Tapas Kumar MajiToward the goal of
clean and sustainable energy source, the development
of a trifunctional electrocatalyst is a boon for energy storage and
conversion devices such as regenerative fuel cells and metal-air batteries.
MOF-derived semiconducting-metallic core–shell electrocatalyst Co3O4@Co/NCNT (NCNT = nitrogen-doped carbon nanotube),
which was shown to catalyze oxygen reduction reaction (ORR) and oxygen
evolution reaction (OER), is also found to be an active electrocatalyst
for hydrogen evolution reaction (HER) with a low overpotential of
171 mV. Here, the HER activity of Co3O4@Co/NCNT is presented and is shown as highly efficient and robust trifunctional
electrocatalyst. The detailed theoretical calculation has found N-center
of Co–N4 moiety to be the H+ binding
active site and thus proves Co3O4@Co/NCNT to be
active for HER. Further, the ORR and OER bifunctionality of Co3O4@Co/NCNT helped in fabricating secondary Zn-air
battery with high power density of 135 mW/cm2. Also, an
all-solid-state flexible and wearable battery with Co3O4@Co/NCNT as cathode and electrodeposited Zn on carbon fiber
cloth as anode was shown to withstand its performance even under stressed
conditions. Finally, the material being trifunctional in nature was
used both as an anode and cathode material for the electrolysis of
water, which was powered by the Zn-air batteries with Co3O4@Co/NCNT as the cathode material. It is believed that the
development of a trifunctional catalyst would help in wide commercialization
of regenerative fuel cells.