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Interface engineering is verified as an efficient strategy for enhancing the intrinsic activity of transition metal-based electrocatalysts in alkaline hydrogen evolution reaction (HER). Here, the heterostructural MoO 2 /Ni 3 S 2 nanorod arrays fabricated on nickel foam (MoO 2 /Ni 3 S 2 /NF) are produced by a straightforward and effective hydrothermal approach. Benefiting from interfacial effect and self-supported structure, MoO 2 /Ni 3 S 2 /NF electrocatalyst exhibits remarkable HER catalytic properties and durability with a low overpotential of 74.0 mV for achieving a current density of 10 mA cm−2 in 1.0 M KOH, as well as a long-term stability without obvious attenuation. Density functional theory (DFT) calculations reveal electron transfer at the interface domain reduces the energy barrier of the water dissociation step and optimizes H adsorption capability, thereby expediting HER kinetics in alkaline media. This work provides a viable strategy based on interfacial engineering for designing high-efficient HER electrocatalysts. [Display omitted] ● The self-supported heterostructure MoO 2 /Ni 3 S 2 /NF nanorod arrays were synthesized. ● Interface engineering modulate the electronic structure within interface region. ● Electronic effect reduces water dissociation barrier and optimizes H adsorption. ● The MoO 2 /Ni 3 S 2 /NF exhibits excellent HER catalytic performance and stability. [ABSTRACT FROM AUTHOR]

The electronic metal-support interaction (EMSI) of heterogenous catalysts has attracted much attention for its enhancing electrocatalytic efficiency by impacting adsorption and desorption energy of reaction intermediates. Herein, we synthesize the monodispersed single-crystal Pt nanoparticles (~3 nm) decorated on MoS 2 nanosheets with 2 H phase (Pt-MoS 2) by a universal wet chemical method. The morphology and structure characterizations show that the loaded Pt single-crystals are approximately half truncated octahedral shapes enclosed by {1 1 1} and {2 0 0} facets. Benefitting from interfacial electronic structure modulation, the Pt-MoS 2 exhibits a lower overpotential (67.4 mV at the current desity of 10 mA·cm−2), smaller Tafel slope (76.2 mV·dec−1), and robuster HER durability than those of pristine MoS 2 nanosheets and prepared Pt NPs. The theoretical simulations further reveal that the Pt atom at the interface, which belong to {2 0 0} facets and adjoin S atoms, own the smallest hydrogen adsorption free energy by manipulating the d -band center of the Pt metal surface. This work provides crystalline structure and electronic configuration engineering strategy towards to design and develop of metal-support heterostructure with high HER activity and stability. A heterostructure of Pt nanoparticles supported by MoS 2 nanosheets (Pt-MoS 2) is fabricated as a hydrogen evolution reaction (HER) electrocatalyst with high HER activity and stability. The enhanced performance is proved to be ascribed to the interfacial electronic structure modulation. [Display omitted] • HER performance of Pt-MoS 2 heterostructure is significantly enhanced. • Atomic-level structure characterization of Pt-MoS 2 is investigated. • The enhanced catalysis activity is attributed to the interfacial electronic structure modulation. [ABSTRACT FROM AUTHOR]

Two-dimensional transition metal carbides and nitrides (MXenes) hold promise as electrode materials for alkali metal ion batteries on account of some fascinating peculiarities. However, the high temperature required in the synthesis of the MAX phase severely hinders its further development. Herein, MAX phase (Ti 2 AlC) is first grown on carbon cloth (CC) by molten salt method at a milder temperature, then the hierarchical structure that Ti 2 C sheets arrayed on the carbon fibers can be obtained after HF treatment, demonstrating 269 mA h g−1 after 400 cycles at 1 mA cm−2 for lithium-ion storage and 206 mA h g−1 after 100 cycles at 0.1 mA cm−2 for sodium-ion storage when served as freestanding anode. Meanwhile, in-situ and ex-situ characterization techniques are employed to monitor the possible phase transitions in the electrochemical process. In addition, the kinetics for carrier diffusion in the electrochemical process is also studied. This work endows edification for configuration of MXene-based freestanding electrode. [Display omitted] • MAX phase would be grown directly on the carbon cloth by molten-salt method. • Neoteric MXene-based freestanding anode can be structured. • The electrode without binder shows distinguished electrochemical performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • An exquisite externally layered and internally hollow CoP@MoS 2 electrocatalyst was successfully prepared. • CoP can effectively enhance the catalytic ability of MoS 2 on hydrogen evolution reaction. • The externally layered and internally hollow nanostructure can accelerate the transfer of charge and mass. As the star material among nonprecious electrocatalysts, molybdenum disulfide (MoS 2) has received much attention. However, the catalytic inertness of the basal plane, low conductivity of its steady state (2H phase), and the agglomeration of lamellar structures have seriously hindered its catalytic performance. It is very essential to design and modulate the morphology and phase of MoS 2 to improve the above issues by synergistic regulation of electrical structure and defect engineering. Herein, MoS 2 was delicately composited on CoP nanoframe derived from a typical metal–organic frame nanostructure (ZIF-67), forming the hollow CoP@MoS 2 hetero-nanoframe. This exquisite externally layered and internally hollow CoP@MoS 2 electrocatalyst demonstrated excellent catalytic performance for the hydrogen evolution reaction, with a low overpotential of 119 mV at 10 mA cm−2, a small Tafel slope of 49 mV dec−1, a large electric double-layer capacitance of 10.28 mF cm−2, and prominent long-term stability. The remarkable catalytic performance of hollow CoP@MoS 2 hetero-nanoframe can be attributed to the unique architecture of the hetero-nanostructures, appropriate component ratios, strong interaction between CoP and MoS 2 , and large-scale defects and disorder. First-principles density-functional theory calculations can prove the above arguments adequately, the hydrogen adsorption free energy of CoP@MoS 2 is close to zero. [ABSTRACT FROM AUTHOR]