Ni/Mo Bimetallic‐Oxide‐Derived Heterointerface‐Rich Sulfide Nanosheets with Co‐Doping for Efficient Alkaline Hydrogen Evolution by Boosting Volmer Reaction

Abstract

Molybdenum disulfide (MoS2) is a promising alternative to Pt‐based catalysts for electrocatalytic hydrogen evolution reaction (HER) in an acidic environment. However, alkaline HER activity for molybdenum disulfide is limited by its slow water dissociation kinetics. Interface engineering is an effective strategy for the design of alkaline HER catalysts. However, the restricted heterointerfaces of current catalysts have significantly limited their alkaline HER performance. Herein, a novel assembly of cobalt‐doped interface‐ and defect‐rich MoS2/Ni3S2 hetero‐nanosheet anchoring on hierarchical carbon framework for alkaline HER is reported by directly vulcanizing NiMoO4 nanosheets. In the heterostructure nanosheet, Ni3S2 acts as a water dissociation promoter and MoS2 acts as a hydrogen acceptor. Density functional theory calculations find that redistribution of charges at the heterointerface can reduce hydrogen adsorption Gibbs free energy (∆GH*) and water decomposition energy barrier. The resulting hierarchical electrode with the synergistic effect of both hybrid components shows a low overpotential of 89 mV at −10 mA cm−2 in 1 m KOH, a Tafel slope as low as 62 mV dec−1, and can run at −100 mA cm−2 for at least 50 h without obvious voltage change. This study provides a potentially feasible strategy for the design of heterostructure‐based electrocatalysts with abundant active interfaces.

Synergistic Electrocatalysts for Alkaline Hydrogen Oxidation and Evolution Reactions

“…The slow kinetic process of alkaline HER could be ameliorated by heterostructure interface engineering through tune the adsorption energy between the catalyst and intermediate of the alkaline HER process. [102][103][104] The different components of the heterostructure catalyst play synergic roles in alkaline HER will be discussed in this section, including promoting the water dissociation in the Volmer process as well as the followed hydrogen generation process.…”

Heterogeneity in a metal–organic framework in situ guides engineering Co@CoO heterojunction for electrocatalytic H2 production in tandem with glucose oxidation

“…+ OH − . 49,50 As marked in blue, the water dissociation reaction (TS-1) on Co@CoO proceeded with much lower energy barrier (0.52 eV) than that on Co (0.88 eV). This suggested that the O-abundant surface CoO site was more favorable for cleavage of H–OH on Co site (TS-1 step in Fig.…”

Heterostructural MoS2/NiS nanoflowers via precise interface modification for enhancing electrocatalytic hydrogen evolution

“…[17][18][19] In order to overcome the above-mentioned problems, many methodologies have been proposed, such as increasing the exposure of active edge sites, 20,21 introducing vacancies or defects, [22][23][24] atomic doping, [25][26][27] crystalline phase regulation, [28][29][30] and construction of a heterostructure. [31][32][33][34] Among the above strategies, the construction of heterostructures has been proven to be a feasible strategy for improving the HER activity of MoS 2 . Bao et al synthesized a Co-Ni-P/MoS 2 heterostructure through the in situ growth of MoS 2 on MOFsderived Co-Ni-P spheres, which provided abundant active sites and showed an excellent overall water splitting performance under alkaline conditions.…”