posted on 2024-02-28, 18:42authored byXupeng Zhang, Jiabo Wang, Yiyang Bi, Ying Wang, Qun Liu, Yu Zhang, Li Chen
Hydrogen (H2) stands as a clean energy alternative
to
fossil fuels, especially within the domain of the hydrogen evolution
reaction (HER), offering prospective solutions to mitigate both environmental
and energy-related challenges. In this work, we successfully synthesized
a sea-urchin-like catalyst, specifically a nickel–cobalt phosphide
nanoneedle array on N-doped carbon nanospheres (Ni0.5Co1.5P@NCSs), for efficient HER by a sequential hydrothermal
and low-temperature phosphating process. The catalyst exhibits sea-urchin-like
structures, offering a specific surface area of 298 m2 g–1 and consequently furnishing a greater abundance of
active sites. Comparing with non-sea-urchin-like Ni0.5Co1.5P@CN catalysts, the Ni0.5Co1.5P@NCSs
exhibit an overpotential of 163 mV at 10 mA cm–2, a Tafel slope of 60 mV dec–1, and a maintained
current density of approximately 90% during 50 h of continuous electrolysis.
Experiments demonstrate that the outstanding electrochemical properties
of the Ni0.5Co1.5P@NCSs originate from nitrogen
doping of carbon spheres, the distinctive morphology of sea-urchin-like
nanoneedle arrays, and simultaneous enhancements in intermediate adsorption
energy, charge transfer, and electrolyte diffusion channel shortening.
This work emphasizes a preparation strategy for synthesizing an attractive
electrocatalyst with a low cost and efficient HER performance.