Dominating Role of Aligned MoS₂/Ni₃S₂ Nanoarrays Supported on Three-Dimensional Ni Foam with Hydrophilic Interface for Highly Enhanced Hydrogen Evolution Reaction

Abstract

When using water splitting to achieve sustainable hydrogen production, low-cost, stable, and naturally abundant electrocatalysts are required to replace Pt-based ones for the hydrogen evolution reaction (HER). Herein, for the first time, a novel nanostructure with one-dimensional (1D) MoS/NiS nanoarrays directly grow on a three-dimensional (3D) Ni foam is developed for this purpose, showing excellent catalytic activity and stability. The as-prepared 3D MoS/NiS/Ni composite has an onset overpotential as low as 13 mV in 1 M KOH, which is comparable to Pt-based electrocatalyst for HER. According to the classical theory, the Tafel slope of the new composite is relatively low, as it goes through a combined Volmer-Heyrovsky mechanism during hydrogen evolution. All the results attribute the excellent electrocatalytic activity of the nanostructure to the electrical coupling among Ni, NiS, and MoS, the super hydrophilic interface, the synergistic catalytic effects produced by the MoS/NiS nanoarrays, and abundant exposed active edge sites. These unique and previously undeveloped characteristics of the 3D MoS/NiS/Ni composite make it a very promising earth-abundant electrocatalyst for HER.

A highly active and durable electrocatalyst for large current density hydrogen evolution reaction

“…Note that NF, Pt/C-NF, Ni 7 S 6 & Ni 3 S 2 -NF and MoS 2 /Ni 3 S 2 NW-NF show CAs of 137°, 126°, 98°a nd 0°, respectively. It has been reported that surface energy of MoS 2 increases with increasing number of layers and low crystalline can further increase the wettability [35][36][37]. Therefore, the super hydrophilicity of MoS 2 /Ni 3 S 2 NW-NF can be due to the multilayer and low-crystallinity structure of the outer MoS 2 nanosheets in MoS 2 /Ni 3 S 2 heterostructure, which have been proved by TEM and XRD results shown above.…”

Nitrogen‐Doped Cu2S/MoS2 Heterojunction Nanorod Arrays on Copper Foam for Efficient Hydrogen Evolution Reaction

“…The transformation of Cu(OH) 2 into Cu 2 S was verified in terms of these intense diffraction peaks at 24.0°, 27.1°, 28.2°, 29.3°, 33.0°, 33.7°, 35.6°, 37.6°, 38.8°, 46.1°,and 48.6°, corresponding to the respective (122), (032), (222), (132), (240), (012), (402), (034), (422), (630) and (106) planes of Cu 2 S (JCPDS No.83‐1462) . Compared to the diffraction peaks of Cu 2 S/CF, the bulges of Cu 2 S/MoS 2 /CF at 14.1° and 39.2° correspond to the (002) and (100) lattice planes of MoS 2 (JCPDS NO.75‐1539) . These results suggested that Cu 2 S and MoS 2 were successfully fabricated in light of the anticipated reaction.…”

“…[19b] Compared to the diffraction peaks of Cu 2 S/CF, the bulges of Cu 2 S/MoS 2 /CF at 14.1°and 39.2°c orrespond to the (002) and (100) NO.75-1539). [20] These results suggested that Cu 2 S and MoS 2 were successfully fabricated in light of the anticipated reaction.…”

“…Electrochemical impedance spectroscopy (EIS) analyses were researched in the frequency range of 10 kHz to 0.01 Hz with an amplitude of 5 mV. Electrochemical double layer capacitance (C dl ) of each synthesized material was measured by CV in non-faradaic region from 0.128 to 0.228 V versus RHE with different scan rates (20,40,60,80 and 100 mV s À 1 ) to estimate the effective electrode surface area. The C dl value is half of the linear slope.…”

Graphene-supported platinum/nickel phosphide electrocatalyst with improved activity and stability for methanol oxidation

“…8 Efforts to mitigate CO poisoning of Pt nanoparticles can be made through the addition of some metals, such as Ru, [9][10][11] Sn, 12 Ni. 13 Among them, nickel-based nano-materials not only have been proved to show electrocatalytic activity toward alcohols oxidation but also have been used in the hydrogen evolution reaction, 14,15 the hydrolytic dehydrogenation, 16 the electrolytic hydrogen generation, and the hydrogen peroxide reduction reaction, 17,18 as non-noble metal catalysts.…”