Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction (HER) performance of molybdenum sulfide (MoS₂) and unraveling its structure-activity relationship. By leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering. Here, we successfully designed and synthesized MoS_x nanowire networks derived from [Mo₃S₁₃]²⁻ clusters via evaporation-induced self-assembly, which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic potentials. MoS_x nanowire networks electrode yields a current density of 100 mA cm⁻² at 142 mV in 0.5 M H₂SO₄. This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.

The transition metal chalcogenides represented by MoS₂ are the ideal choice for non-precious metal-based hydrogen evolution catalysts. However, whether in acidic or alkaline environments, the catalytic activity of pure MoS₂ is still difficult to compete with Pt. Recent studies have shown that the electronic structure of materials can be adjusted by constructing lattice-matched heterojunctions, thus optimizing the adsorption free energy of intermediates in the catalytic hydrogen production process of materials, so as to effectively improve the electrocatalytic hydrogen production activity of catalysts. However, it is still a great challenge to prepare heterojunctions with lattice-matched structures as efficient electrocatalytic hydrogen production catalysts. Herein, we developed a one-step hydrothermal method to construct Ni-MoS₂@NiS₂@Ni₃S₂ (Ni-MoS₂ on behalf of Ni doping MoS₂) electrocatalyst with multiple heterogeneous interfaces which possesses rich catalytic reaction sites. The Ni-MoS₂@NiS₂@Ni₃S₂ electrocatalyst produced an extremely low overpotential of 69.4 mV with 10 mA·cm⁻² current density for hydrogen evolution reaction (HER) in 1.0 M KOH. This work provides valuable enlightenment for exploring the mechanism of HER enhancement to optimize the surface electronic structure of MoS₂, and provides an effective idea for constructing rare metal catalysts in HER and other fields.

Doping foreign metal atoms into the substrate of transition metal dichalcogenides (TMDs) enables the formation of diverse atomic structure configurations, including isolated atoms, chains, and clusters. Therefore, it is very important to reasonably control the atomic structure and determine the structure–activity relationship between the atomic configurations and the hydrogen evolution reaction (HER) performance. Although numerous studies have indicated that doping can yield diverse atomic structure configurations, there remains an incomplete understanding of the relationship between atomic configurations within the lattice of TMDs and their performance. Here, diverse atomic structure configurations of adsorptive doping, substitutional doping, and TMDs alloys are summarized. The structure–activity relationship between different atomic configurations and HER performance can be determined by micro-nanostructure devices and density functional theory (DFT) calculations. These diverse atomic structure configurations are of great significance for activating the inert basal plane of TMDs and improving the catalytic activity of HER. Finally, we have summarized the current challenges and future opportunities, offering new perspectives for the design of highly active and stable metal-doped TMDs catalysts.