Nickel
Nanoparticles Protruding from Molybdenum Carbide
Micropillars with Carbon Layer-Protected Biphasic 0D/1D Heterostructures
for Efficient Water Splitting
It
remains a tremendous challenge to achieve high-efficiency bifunctional
electrocatalysts for both the hydrogen evolution reaction (HER) and
the oxygen evolution reaction (OER) for hydrogen production by water
splitting. Herein, a novel hybrid of 0D nickel nanoparticles dispersed
on the one-dimensional (1D) molybdenum carbide micropillars embedded
in the carbon layers (Ni/Mo2C@C) was successfully prepared
on nickel foam by a facile pyrolysis strategy. During the synthesis
process, the nickel nanoparticles and molybdenum carbide were simultaneously
generated under H2 and C2H2 mixed
atmospheres and conformally encapsulated in the carbon layers. Benefiting
from the distinctive 0D/1D heterostructure and the synergistic effect
of the biphasic Mo2C and Ni together with the protective
effect of the carbon layer, the reduced activation energy barriers
and fast catalytic reaction kinetics can be achieved, resulting in
a small overpotential of 96 mV for the HER and 266 mV for the OER
at the current density of 10 mA cm–2 together with
excellent durability in 1.0 M KOH electrolyte. In addition, using
the developed Ni/Mo2C@C as both the cathode and anode,
the constructed electrolyzer exhibits a small voltage of 1.55 V for
the overall water splitting. The novel designed Ni/Mo2C@C
may give inspiration for the development of efficient bifunctional
catalysts with low-cost transition metal elements for water splitting.