posted on 2021-12-09, 19:08authored byPeng Wang, Fengtao Zhang, Cailing Wu, Jianji Wang, Buxing Han, Zhimin Liu
Herein,
we report CoCO3-coated nitrogen-doped carbon
nanotubes (NCNTs) with a sea cucumber-like morphology for water splitting.
The sample with a CoCO3 content of 26.8 wt % (CoCO3/NCNT-1) exhibits excellent performance for the hydrogen evolution
reaction in 1.0 M KOH electrolyte with an overpotential of 58 mV to
reach 10 mA cm–2, better than the most non-noble
metal catalysts reported; meanwhile, it exhibits superior electrocatalytic
activity for the oxygen evolution reaction. The excellent performance
of the catalyst is attributed to the nanotip effect caused by the
sea-cucumber-like morphology. Notably, CoCO3/NCNT-1 can
attain turnover frequencies of 2.7 s–1 at an overpotential
of 50 mV, higher than that of Pt/C (1.5 s–1). A
cell constructed using CoCO3/NCNT-1 as the catalyst of
the electrode pair needs a low cell voltage of 1.54 V at 10 mA cm–2, superior to most reported cells. In addition, CoCO3/NCNT-1 can maintain 10 mA cm–2 for overall
water splitting for 100 h without activity loss.