Electrochemical water splitting is a green strategy for
hydrogen
(H2) production but is severely hindered by the sluggish
anodic oxygen evolution reaction (OER). Therefore, replacing the sluggish
anodic OER with more favorable oxidation reactions is an energy-saving
approach for hydrogen production. Hydrazine borane (HB, N2H4BH3) is considered a potential hydrogen storage
material due to its easy preparation, nontoxicity, and high chemical
stability. Furthermore, the complete electrooxidation of HB has a
unique characteristic of a much lower potential compared to that of
OER. All these make it an ideal alternative for energy-saving electrochemical
hydrogen production, however, which has never been reported so far.
Herein, HB oxidation (HBOR)-assisted overall water splitting (OWS)
is proposed for the first time for energy-saving electrochemical hydrogen
production. The as-synthesized NiCoP@CoFeP nanoneedle array catalyst
exhibited superefficient OER, hydrogen evolution reaction (HER), and
HBOR performance. Impressively, NiCoP@CoFeP serves as both anodic
and cathodic electrocatalysts for HB-assisted OWS, only requires a
low cell voltage of only 0.078 V to achieve a current density of 10
mA cm–2, which was 1.4 V lower than that for HB-free
OWS, indicating the highly energy-saving H2 production.