Engineering catalytic sites at the atomic level provides an opportunity to understand the catalyst’s active sites, which is vital to the development of improved catalysts. Here we show a reliable and tunable polyoxometalate template-based synthetic strategy to atomically engineer metal doping sites onto metallic 1T-MoS 2 , using Anderson-type polyoxometalates as precursors. Benefiting from engineering nickel and oxygen atoms, the optimized electrocatalyst shows great enhancement in the hydrogen evolution reaction with a positive onset potential of ~ 0 V and a low overpotential of −46 mV in alkaline electrolyte, comparable to platinum-based catalysts. First-principles calculations reveal co-doping nickel and oxygen into 1T-MoS 2 assists the process of water dissociation and hydrogen generation from their intermediate states. This research will expand on the ability to improve the activities of various catalysts by precisely engineering atomic activation sites to achieve significant electronic modulations and improve atomic utilization efficiencies.

Crystalline high-entropy ceramics (CHC), a new class of solids that contain five or more elemental species, have attracted increasing interest because of their unique structure and potential applications. Up to now, only a couple of CHCs (e.g., high-entropy metal oxides and diborides) have been successfully synthesized. Here, a new strategy for preparing high-entropy metal nitride (HEMN-1) is proposed via a soft urea method assisted by mechanochemical synthesis. The as-prepared HEMN-1 possesses five highly dispersed metal components, including V, Cr, Nb, Mo, Zr, and simultaneously exhibits an interesting cubic crystal structure of metal nitrides. By taking advantage of these unique features, HEMN-1 can function as a promising candidate for supercapacitor applications. A specific capacitance of 78 F g is achieved at a scan rate of 100 mV s in 1 m KOH. In addition, such a facile synthetic strategy can be further extended to the fabrication of other types of HEMNs, paving the way for the synthesis of HEMNs with attractive properties for task-specific applications.

Platinum (Pt) is the most active and stable HER catalyst, but its high cost and low abundance hinder its widespread applications. [3][4][5][6] Recently, tremendous efforts have been devoted to the search for noble-metal-free catalysts to replace Pt-based catalysts in the generation of H 2 with a high current density at a low overpotential. [7][8][9][10] In particularly, molybdenum carbides and molybdenum phosphides have been demonstrated as active and robust HER catalysts due to their high conductivities, high catalytic activities, and excellent stabilities. [11][12][13][14][15] The high-performance catalytic activities of these materials may be related to the function of their heteroatoms, such as phosphorus, which possesses lone-pair electrons in 3p orbitals and vacant 3d orbitals and can thus accommodate the surface charge as well as induce local charge density. [16] Nitrides of transition metals have also been shown to have excellent catalytic activities in the HER. [17][18][19][20][21] Taking all the above works together, we predicted that nitrogen (N)-doped molybdenum carbide and phosphide hybrids, N@MoPCx, might be promising electrocatalysts for efficient hydrogen evolution. However, it remains a challenge to obtain a targeted N-doped molybdenum carbide and phosphide hybrid with a uniform distribution and desirable porosity that also exhibits high electrocatalytic activity, which requires (i) preventing the aggregation of nanoparticles; (ii) obtaining a desirable porosity; and (iii) achieving uniform carburization, phosphorization, and heteroatoms doping. To avoid the aggregation of nanoparticles and increase their electrical conductivities, substrates such as carbon cloth, carbon nanotubes, and graphene have been introduced into metal-based catalysts for use in multiple catalytic reactions. [22][23][24] However, the introduction of substrates creates additional cost and still cannot completely prevent aggregation.Polyoxometalates (POMs) are a special class of well-defined molecular metal oxide clusters with a wide range of applications in medicine, catalysis, materials sciences, etc. [25][26][27][28][29][30] It is well known that organoimido derivatives of POMs can be prepared by introducing exogenous N-containing ligands to replace the oxo groups in the POM clusters. [31][32][33][34][35] The controllable preparation of multifunctionalized derivatives of hexamolybdate has been achieved by the powerful N,N′-dicyclohexylcarbodiimide (DCC)-dehydrating protocol by Ruhlmann and our group. [36,37] P-containing organoimido derivatives of POMs could be The efficient evolution of hydrogen through electrocatalysis is considered a promising approach to the production of clean hydrogen fuel. Platinum (Pt)-based materials are regarded as the most active hydrogen evolution reaction (HER) catalysts. However, the low abundance and high cost of Pt hinders the large-scale application of these catalysts. Active, inexpensive, and earth-abundant electrocatalysts to replace Pt-based materials would be highly beneficial to the ...

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