The
generation of green hydrogen via electrocatalytic water splitting
is an emerging strategy in the prospect of developing future energy
devices. Herein, we designed water-soluble atomically precise Ni nanoclusters
(NCs) on MoSe2 nanosheets (NSs) to enhance the hydrogen
evolution reaction (HER) performance. The strong UV–vis absorption
band and matrix-assisted laser deposition ionization (MALDI) time-of-flight
mass spectra confirm the formation of Ni7 NCs. The energy-dispersive
X-ray spectroscopy mapping confirms the homogeneous distribution of
Ni, Mo, and Se throughout the surface of the ultrathin NS. X-ray photoelectron
spectroscopy study reveals the strong interfacial interaction between
Ni NCs and MoSe2 in the nanocomposite by substantial electron
density transferring from Ni NCs to the MoSe2 NSs. It is
seen that the 5 wt % Ni/MoSe2 composite structure exhibits
the most notable HER efficiency with an overpotential of 170 mV vs
reversible hydrogen electrode @ 10 mA/cm2 which is significantly
lower than that of bare MoSe2 NSs (350 mV). The significantly
lower Tafel slope of the Ni/MoSe2 nanocomposite indicates
that the HER kinetics of MoSe2 is accelerated in the presence
of Ni NCs. The charge-transfer resistance of the nanocomposite is
significantly low compared to pristine MoSe2, confirming
the enhanced interfacial charge transfer. This work opens up further
opportunities to design efficient and low-cost electrocatalysts for
improving the HER performance by incorporating the advantages of both
non-precious atomically precise metal NCs and transition-metal dichalcogenides
in one system.