Design and Epitaxial Growth of MoSe₂–NiSe Vertical Heteronanostructures with Electronic Modulation for Enhanced Hydrogen Evolution Reaction

Abstract

Transition metal dichalcogenides (MX2, where M = Mo or W and X = S or Se) have been regarded as some of the best alternatives for noble metal-free electrocatalysts for the hydrogen evolution reaction (HER). A tremendous number of attempts have mainly focused on the maximization of the number of active edge sites and the conductivity of MX2-based electrocatalysts to enhance HER performance. However, for MX2-based electrocatalysts, the acceleration of the kinetic process to improve HER performance has been neglected until now. Here we report a colloidal epitaxial growth strategy for synthesizing MoSe2–NiSe nanohybrids with well-defined heterointerfaces that are constructed by in situ growth of metallic NiSe nanocrystallites on the MoSe2 nanosheets. These high-quality vertical heteronanostructures with band alignment give rise to the electrons being transferred from the metallic NiSe nanocrystallites to the MoSe2 matrix, achieving the electronic modulation of the MoSe2–NiSe nanohybrids for efficient electrocatalytic activity. The MoSe2–NiSe nanohybrids exhibit excellent HER catalytic properties with a low onset potential of −150 mV, a large cathodic current density (10 mA cm–2 at an overpotential of 210 mV), and a small Tafel slope of 56 mV per decade. The greatly enhanced electrocatalytic properties were attributed to the electronic structure modulation from the synergetic interactions between NiSe nanocrystallites and MoSe2 nanosheets. We anticipate that the construction of hybrid structures will be a powerful tool for creating high-performance electrocatalysts in solids.

Active Site Identification and Evaluation Criteria of In Situ Grown CoTe and NiTe Nanoarrays for Hydrogen Evolution and Oxygen Evolution Reactions

“…The onset potential of CoTeNR/NF reaches −126 mV (vs RHE) and only requires the low overpotential of 202 mV to derive 10 mA cm −2 , while the NiTeNR/NF and bare NF need 248 and 371 mV overpotential to derive 10 mA cm −2 , respectively. Although the HER activity of CoTeNR/NF catalyst is still slightly inferior to commercial 20% Pt/C under alkaline conditions, it is among forefront of the most reported transitional metal‐based HER catalysts at current density of 10 mA cm −2 , e. g., Co 0.85 Se 2 /NiFe‐LDH/G (260 mV), MoSe‐NiSe (210 mV), Ni 2 P/NF (220 mV), NiCo 2 S 4 NW/NF(210 mV), Ni 3 S 2 (220 mV) and CoP nanowires (209 mV), etc (Table S2, Supporting Information) …”

NiSe2 as Co‐Catalyst with CdS: Nanocomposites for High‐Performance Photodriven Hydrogen Evolution under Visible‐Light Irradiation

“…From Figure d, one can see that both Ni 3d orbitals and Se 4p orbitals crossing the E F . This may be caused by the performance of metallic properties of NiSe 2 . Under the light irradiation, the photo‐induced electrons would transfer from the S 3p orbitals to the Cd 5s orbitals along the Ni 3d orbitals or Se 4p orbitals, which act as electron transport “high speed railways” to accelerate the migration of electrons.…”

Facile synthesis and promising application of iron‐doped nickel selenide nanoparticles as high‐efficiency counter electrodes of dye‐sensitized solar cells

“…Compared with the pure Ni 0.85 Se, we notably found that the diffraction peaks of iron-doped nickel selenides were shifted to higher angles, which may be owing to the substitution of Fe for Ni. 26,27 As exhibited in Figure 2c, the Fe 2p spectrum indicates that there are two binding energy peaks at 706.1 and 712.2 eV, which correspond to Fe 2+ 2p 3/2 and Fe 3+ 2p 3/2 , respectively. For the Ni 2p spectrum (Figure 2b), the peak located at 852.4 eV with its satellite peak at 855.5 and 861.1 eV originates from Ni 2p 3/2 , while the peak at 869.7 eV with its satellite peak at 873.2 and 879.1 eV is assigned to Ni 2p 1/2 .…”