Interfacing perovskite strontium molybdate to molybdenum disulfide nanoplatelts for boosting HER from water

Due to low hydrogen adsorption free energy at the edges of 2D-MoS₂ layered sheets, nanostructured MoS₂ materials recently are assigned to prospective electrocatalysts for hydrogen evolution reaction (HER) from water. However, the efficiency and stability of HER onto the MoS₂ designed on the conductive substrates are poor. To significantly increase the number of active sites and achieve a long-time working stability, the design of hybrid-type electrodes is crucial. Here, we report the synthesis of a new hybrid material composed of molybdenum disulfide and molybdenum oxides heterostructured with strontium molybdate. For this, a facile one-pot hydrothermal process was developed directly onto the TiO₂ nanotube carpet substrate. The interfacing of strontium molybdate at the electrode substrate verified by X-ray photoelectron spectroscopy and Time of flight secondary ions mass spectrometry (ToF SIMS) techniques. Considerable higher catalytic activity at the surface of this hybrid film, with the onset potential of 190 mV vs RHE and a Tafel slope of 66 mV dec^?1 attaining ~80 mA cm^?2 at 0.35 V overvoltage was ascertained. Exciting HER stability in comparison with the pure synthetic MoS₂ was verified by a prolonged potential cycling from 0.05 to ?0.35 V versus RHE potential and 45 h continuous HER processing at a constant current density.     

Stable and highly efficient MoS2/Si NWs hybrid heterostructure for photoelectrocatalytic hydrogen evolution reaction

We report, the fabrication of molybdenum disulphide (MoS₂) wrapped silicon nanowires (Si NWs) for visible light driven water splitting applications. The morphological and elemental studies ensure the vertical alignment of Si NWs wrapped with 2D layered MoS₂. The photoelectrocatalytic (PEC) results evidence the significant enhancement in performance of MoS₂/Si NWs based hybrid photocathode with ~300 mV (under reversible hydrogen electrode (RHE)) anodic shift in onset potential as that of pristine Si NWs (+0.194 V vs. RHE), and the current density of −26.5 mA/cm² was achieved at the applied bias of 0 V vs. RHE. Further, the electrochemical impedance studies ensure the interface resistance-free charge transfer between Si NWs and electrolyte via 2D MoS₂ layer which provokes rapid hydrogen production. The wrapping of Si NWs with MoS₂ protects the superlative photocathode from harsh acid electrolyte environment. The overgrown MoS₂ triangular particles with active sulphur edge sites are found to eventually augment the solar hydrogen evolution rate. Further, the PEC performance of our MoS₂/Si NWs is also comparable with stable Pt/Si NWs photoelectrode. It is note-worthy that, MoS₂/Si NWs hybrid heterostructure would be a potential candidate in future large scale, low cost and day-to-day solar water splitting applications.     

Efficient and long-term photocatalytic H2 evolution stability enabled by Cs2AgBiBr6/MoS2 in aqueous HBr solution

Lead-free Cs₂AgBiBr₆ (CABB) double perovskite as a new-type photocatalytic material alternative to lead halide perovskites holds promise to implement the solar-H₂ conversion, but the interior recombination of photo-generated carriers and thus low photocatalytic hydrogen evolution reaction (HER) rate of CABB restrict its further industrial applications. Herein, we report the composite fabrication of MoS₂/CABB heterostructure for high-efficiency and durable photocatalytic HER by anchoring non-noble MoS₂ onto CABB via a facile dissolution-recrystallization method. The optimized MoS₂/CABB performs a visible-light HER rate of 87.5 μmol h^?1 g^?1 in aqueous HBr solution, ca. 20-fold compared to that of pure CABB (4.3 μmol h^?1 g^?1), and presents a discontinuous 500-h photocatalytic HER stability with no evident loss. The superb performance of MoS₂/CABB can be ascribed to the kinetics-facilitated heterostructure consisting of stable CABB and MoS₂. This work proposes a facile and versatile tactic to construct a low-cost Cs₂AgBiBr₆-based heterostructure for efficient and long-term photocatalytic HER.     

MoS2/NiFeS2 heterostructure as a highly efficient electrocatalyst for overall water splitting at high current densities

Searching for efficient, stable and low-cost nonprecious catalysts for oxygen and hydrogen evolution reactions (OER and HER) is highly desired in overall water splitting (OWS). Herein, presented is a nickel foam (NF)-supported MoS₂/NiFeS₂ heterostructure, as an efficient electrocatalyst for OER, HER and OWS. The MoS₂/NiFeS₂/NF catalyst achieves a 500 mA cm⁻² current density at a small overpotential of 303 mV for OER, and 228 mV for HER. Assembled as an electrolyzer for OWS, such a MoS₂/NiFeS₂/NF heterostructure catalyst shows a quite low cell voltage (≈1.79 V) at 500 mA cm⁻², which is among the best values of current non-noble metal electrocatalysts. Even at the extremely large current density of 1000 mA cm⁻², the MoS₂/NiFeS₂/NF catalyst presents low overpotentials of 314 and 253 mV for OER and HER, respectively. Furthermore, MoS₂/NiFeS₂/NF shows a ceaseless durability over 25 h with almost no change in the cell voltage. The superior catalytic activity and stability at large current densities (>500 mA cm⁻²) far exceed the benchmark RuO₂ and Pt/C catalysts. This work sheds a new light on the development of highly active and stable nonprecious electrocatalysts for industrial water electrolysis.     

Advanced catalysts for hydrogen evolution reaction based on MoS2/NiCo2S4 heterostructures in Alkaline Media

There are great challenges to develop and fabricate a high performance, low-cost and stable non-platinum catalyst for hydrogen evolution reaction (HER). In our study, we firstly developed a simple method to successfully fabricate a new MoS₂/NiCo₂S₄ heterostructure by a two-step hydrothermal method, and studied the HER property of MoS₂/NiCo₂S₄, where the as-prepared NiCo-layered double hydroxide (NiCo-LDH) was used as the precursor of NiCo₂S₄. Benefitting from the prominent synergistic effect between NiCo₂S₄ and MoS₂, MoS₂ provided massive catalytic active edge sites, and NiCo₂S₄ enhanced the conductivity of the composite. As a result, the MoS₂/NiCo₂S₄ showed excellent HER catalytic activity, with a current of 10 mA cm⁻² at overpotential of 94 mV for HER and a low Tafel slope of 46 mV dec⁻¹, and good cycling stability in Alkaline Media. As well as, our work offered one promising high active and stable non-platinum catalyst for overall water splitting.     

Molybdenum disulfide/silver/p-silicon nanowire heterostructure with enhanced photoelectrocatalytic activity for hydrogen evolution

Suitable semiconductor and its efficient coupling with catalysts is vital to hydrogen evolution reaction (HER). Herein, Ternary heterostructured MoS₂/Ag/p-type silicon nanowires (SiNWs) array photocathode are constructed by a simple two-step method, where Ag is self-reduced on SiNWs via Galvanic Displacement method and MoS₂ is subsequently loaded by direct thermal decomposition. Ag interfacial layer is introduced between Si and MoS₂ to facilitate the charge transfer and suppress the recombination of photo-generated electron-hole pairs. MoS₂/Ag/SiNWs exhibits an onset potential of 62 mV and photocurrent density of 50 mA cm^?2 at ?1.0 V_RHE, as well as good stability. Besides, MoS₂/Ag/SiNWs is capable of generating 325.9 μL hydrogen per minute. The superior HER catalytic activity of MoS₂/Ag/SiNWs is contributed to the improved charge transport at the solid–solid interfaces by virtue of Ag layer, allowing more electrons flow from SiNWs to MoS₂ and thus effectively separating the photoelectrons and holes. This work demonstrates the potential of novel heterostructure for robust and efficient photoelectrochemical HER.     

Heterostructure and phase engineering synergistically activated highly efficient alkaline hydrogen evolution in Mo2C/MoS2-rGO hybrids

Heterostructure and phase engineering are effective method to tune the electronic structure of MoS₂, which can activate and boost its intrinsic catalytic activity. Herein, the theoretical calculations reveal that the free energy of H1 adsorption (ΔG_H1) for Mo₂C (−0.65 eV) is lower than MoS₂ (2.05 eV), which is favorable for hydrogen adsorption. Inspired by the theoretical predictions, we develop a facile strategy to prepare nanostructured Mo₂C/MoS₂ dispersed on reduced graphene oxide (rGO) via a hydrothermal preparation and carburization reaction. Since the Mo₂C/MoS₂-rGO nanostructures with great deal of both MoS₂ and Mo₂C edges by heterostructure and phase engineering, which can induce massive active sites for HER on the surface of rGO, the intimate interfacial coupling effect between Mo₂C and MoS₂ can effectively improve the charge transfer rate. The Mo₂C/MoS₂-rGO catalyst exhibits exceptional HER properties, delivering a high turnover frequency (TOF) of 0.209 s⁻¹ at an overpotential of 200 mV in 0.1 M KOH. This work may open a new window for designing NPM electrocatalysts with highly efficient HER property based on earth-abundant materials.     

Quasi zero-dimensional MoS2 quantum dots decorated 2D Ti3C2Tx MXene as advanced electrocatalysts for hydrogen evolution reaction

Developing advanced noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER) is still a great challenge. Herein, a novel HER catalyst with quasi zero-dimensional (0D) MoS₂ quantum dots (QDs) supported on two-dimensional (2D) Ti₃C₂T_x MXene nanosheets is facilely synthesized. The MoS₂ QDs/Ti₃C₂T_x nanohybrid retains the unique layer structure, and the MoS₂ QDs are in situ formed and distributed uniformly. The obtained MoS₂ QDs/Ti₃C₂T_x catalyst exhibits superior electrocatalytic activity due to its excellent conductivity, abundant of active sites exposed and a high percentage of 1T metallic phase (～76%) of MoS₂ QDs. Remarkably, an early HER overpotential of 220 mV at 10 mA cm^?2 and a small Tafel slope of 72 mV dec^?1 of MoS₂ QDs/Ti₃C₂T_x are achieved in 0.5 M H₂SO₄ solution. In addition, the exchange current density of MoS₂ QDs/Ti₃C₂T_x is ～5 times larger compared with pure MoS₂, thus demonstrating an accelerated charge transfer during the electrocatalytic process.     

Directly growth of highly uniform MnS–MoS2 on carbon cloth for advanced H2 evolution electrocatalyst in different pH electrolytes

The activation energy barrier of the H–O bond of water molecules is high, and thus the rate of H₂ evolution reaction (HER) via water splitting is very slow. Hence, chemists are committed to finding high-performance, cheap and stable catalysts for realizing efficient H₂ production. The molybdenum disulfide (MoS₂)-based bimetallic sulfide electrocatalysts are favored by researchers because of their particular structures and properties. Herein, the Waugh type polyoxometalate (POM) is used as raw materials. A series of MnS–MoS₂ electrocatalysts are in-situ coupled on carbon cloth (CC) substrate by a hydrothermal sulfidation method. The catalyst MnS-MoS₂-CC possesses high catalytic activity for HER in a alkaline electrolyte, showing a low overpotential of 54 mV at a current density of 10 mA cm^?2, which is very close to 35 mV of the 20% Pt/C electrode. Meanwhile, under a current density of over 50 mA cm^?2, the overpotential of MnS-MoS₂-CC is less than that of the 20% Pt/C electrode. Moreover, the electrocatalysts show overpotentials of 141 mV and 201 mV at a current density of 10 mA cm^?2 in 0.5 M H₂SO₄ and 1.0 M phosphate buffer solution (PBS), respectively. Besides the high catalytic activity, the MnS-MoS₂-CC electrode shows long-term durability in a wide pH range, which is confirmed by several methods including the tests of linear sweep voltammetry (LSV) curve, current density vs. time (I-t) curve, and scanning electron microscopy (SEM). This work provides a feasible route for the preparation of HER electrocatalysts applied in broad pH conditions, especially for alkaline solutions.     

Ethylenediamine-assisted phase engineering of 1T/2H–MoS2/graphene for efficient and stable electrocatalytic hydrogen evolution

1T-MoS₂ exhibits superior eletroconductivity and electrocatalytic activity in hydrogen evolution reaction (HER) over 2H–MoS₂. But its thermodynamic instability severely hinders its practical application. This paper develops a highly active and stable triphasic 1T/2H–MoS₂/graphene heterostructure through a facile one-step hydrothermal route with the assistance of a small organic molecule, ethylenediamine, as the structure-directing reagent. The novel triphasic heterostructure is fabricated by vertically stacking lateral 1T/2H–MoS₂ heterojuctions on graphene. The stability of the 1T phase is associated with the strain effects in the lateral 1T/2H–MoS₂ heterojunctioned nanosheets and the electron coupling effects in the vertical 1T/2H–MoS₂/graphene 2D/2D heterostructure. The content of 1T phase in 1T/2H–MoS₂/graphene can be regulated by adjusting the preparation temperature. The optimized 1T/2H–MoS₂/graphene hybrid contains 40.5% 1T phase and exhibits outstanding HER performance with a low overpotential of 143 mV at current density of 10 mA cm^-2, a small Tafel slope of 64 mV dec^-1 and excellent durability in acid electrolyte. This work highlights a new strategy to utilize structure-directing reagents for fabricating highly efficient MoS₂-based electrocatalysts.     

Boosting electrochemical hydrogen evolution activity of MoS2 nanosheets via facile decoration of Au overlayer

--Owing to its unique physicochemical properties, two-dimensional (2D) layered MoS₂ has been proposed as a potential catalyst for efficient hydrogen evolution reaction (HER). However, their large-scale application is still hindered due to limited active sites, poor conductivity, and restacking during synthesis. Herein, we report a one-step hydrothermal route to grow MoS₂ nanosheets on molybdenum (Mo) foil substrate followed by Au decoration as an active cocatalyst to enhance the HER performance of MoS₂ nanosheets. A facile, quick, and controlled decoration of stable Au overlayer with different mass loadings was performed using a sputtering Au coating unit for different deposition times (10s, 30s, and 50s), thus paving the way for producing efficient and inexpensive HER electrocatalysts. Electrochemical studies of different Au–MoS₂/Mo hybrids demonstrate that the optimized Au–MoS₂/Mo-30s sample exhibits ultralow onset potential (52 ± 2 mV vs. RHE), small overpotentials of 136 ± 6 and 318 ± 3 mV (vs. RHE) at current densities of 10 and 100 mA cm^?2, a small Tafel slope (46.23 ± 6 mV/dec), along with an outstanding electrochemical stability over a couple of days. Presence of metallic 1T-phase of MoS₂, as well as the synergistic effect between MoS₂ and Au, result in enhanced electrical conductivity, high density of active sites, large electrochemically accessible surface area, and fast charge transfer at the catalyst-electrolyte interface for boosting HER activity of the hybrid catalyst.     

Nanostructural Co–MoS2/NiCoS supported on reduced Graphene oxide as a high activity electrocatalyst for hydrogen evolution in alkaline media

There are many tremendous challenges to enhance the hydrogen evolution reaction (HER) activity of MoS₂. In this study, nanoflower-like Co–MoS₂/NiCoS structure supported on reduced Graphene Oxide (rGO) was rationally developed via a simple hydrothermal route, where the synergistic regulations of both interface structural and electronic conductivity were successfully presented by using controllable interface engineering and Co metal ions doped into MoS₂ nanosheets. Ascribed to the 3D flower-like nanostructure with massive active sites, the interface coupling effect between MoS₂ and Ni–Co–S phase, and Co-doped MoS₂ can modulate its surface electronic density. The optimal Co–MoS₂/NiCoS/rGO hybrid exhibits excellent HER activity in 1.0 M KOH, with a small overpotential (η₁₀, 84 mV) at 10 mA cm^?2 and a low Tafel slope (46 mV dec^?1), accompanied by good stability. This work provides an effective route to produce other electrocatalysts based on interface structure and electronic conductivity engineering for HER in the future.     

Functionalized 2D materials F–MoS2 and F-g-C3N4 with TiO2 as Composite Electrocatalysts for Electrochemical Hydrogen Evolution

Electrochemical hydrogen evolution is an important research field to produce renewable energy. Nanostructured two dimensional (2D) materials such as g-C₃N₄ and MoS₂ are potential electrocatalysts for hydrogen evolution reaction (HER). The incorporation of semiconducting material into 2D material enhances the hydrogen evolution. Here in, we have developed composite of acid functionalized MoS₂ and g-C₃N₄ with TiO₂ (F–MoS₂/TiO₂, F-g-C₃N₄/TiO₂). The F–MoS₂/TiO₂ composite exhibited excellent electrochemical HER activity with an overpotential of 103 mV Vs RHE at 20 mA/cm² compared to pristine F–MoS₂ of 232 mV, TiO₂ of 455 mV Vs RHE. In addition F-g-C₃N₄/TiO₂ showed high overpotential of 322 mV at 5 mA/cm² than pristine F-g-C₃N₄ and TiO₂ of 433 mV and 448 mV Vs RHE at 2.7 mA/cm² respectively.     

Transition metal doped MoS2 nanosheets for electrocatalytic hydrogen evolution reaction

In the present work, the effect of transition metals (Ni, Fe, Co) doping on 2-dimensional (2D) molybdenum disulfide (MoS₂) nanosheets for electrocatalytic hydrogen evolution reaction (HER) was explored. A simple and cost-effective hydrothermal method was adopted to synthesis transition metals doped MoS₂ nanosheets. The morphological and spectroscopic studies evidence the formation of high-quality MoS₂ nanosheets with the randomly doped metal ions. Notably, the Ni–MoS₂ displayed superior HER performance with an overpotential of ?0.302 V vs. reversible hydrogen electrode (RHE) (to attain the current density of 10 mA cm^?2) as compared to the other transition metals doped MoS₂ (Co–MoS₂, Fe–MoS₂). From the Nyquist plot, superior charge transport from the electrocatalyst to the electrolyte in Ni–MoS₂ was realized and confirmed that Ni doping provides the necessary catalytic active sites for rapid hydrogen production. The stable performance was confirmed with the cyclic test and chronoamperometry measurement and envisaged that hydrothermally synthesized Ni–MoS₂ is a highly desirable cost-effective approach for electrocatalytic hydrogen generation.     

Tunably fabricated nanotremella-like Bi2S3/MoS2: An excellent and highly stable electrocatalyst for alkaline hydrogen evolution reaction

Reasonable design of efficient and stable catalysts with low cost and abundant natural reserves is vital for electrocatalytic water splitting. Herein, novel nanotremella-like Bi₂S₃/MoS₂ composites with different mass ratios between Bi₂S₃ and MoS₂ have been successfully prepared through a hydrothermal approach and further applied to hydrogen evolution reaction (HER) in 1.0 M KOH electrolyte for the first time. When the mass ratio of Bi₂S₃ and MoS₂ is 5:5, as-prepared nanotremella-like Bi₂S₃/MoS₂ (marked as BMS-5) manifests favorable HER catalytic activity with overpotential of 124 mV at current density of 10 mA cm⁻² and relatively low Tafel slope of 123 mV dec⁻¹. Moreover, it exhibits an extraordinary durability for uninterrupted hydrogen generation. The enhanced HER performances are ascribed to the synergistic effects between Bi₂S₃ and MoS₂, giving rise to large electrocatalytic active area and fast HER kinetics. The results pave a new path to design and construct excellent Bi₂S₃/MoS₂ nanomaterials for electrocatalytic hydrogen generation.     

Amorphous MoS2 nanosheets on MoO2 films/Mo foil as free-standing electrode for synergetic electrocatalytic hydrogen evolution reaction

A facile oxidation-sulfidation strategy is proposed to fabricate the vertically aligned amorphous MoS₂ nanosheets on MoO₂ films/Mo foil (MF) as free-standing electrode, which features as the integration of three merits (high conductivity, abundant exposures of active sites, and enhanced mass transfer) into one electrode for hydrogen evolution reaction (HER). Density functional theory (DFT) calculations reveal the strong interaction between MoS₂ and MoO₂, which can enhance the intrinsic conductivity with narrow bandgap, and decreases hydrogen adsorption free energy (ΔG_H1 = ~0.06 eV) to facilitate the HER process. Benefiting from the unique hierarchical structure with amorphous MoS₂ nanosheets on conductive MoO₂ films/MF to facilitate the electron/mass transfer by eliminate contact resistance, controllable number of stacking layers and size of MoS₂ slabs to expose more edge sites, the optimal MoS₂/MoO₂/MF exhibits outstanding activity with overpotential of 154 mV at the current density of 10 mA cm⁻², Tafel slope of 52.1 mV dec⁻¹, and robust stability. Furthermore, the intrinsic HER activity (vs. ECSA) on MoS₂/MoO₂/MF is significantly enhanced, which shows 4.5 and 18.6 times higher than those of MoS₂/MF and MoO₂/MF at overpotential of 200 mV, respectively.     

Defective-MoS2/rGO heterostructures with conductive 1T phase MoS2 for efficient hydrogen evolution reaction

As a two-dimensional material, molybdenum disulfide (MoS₂) exhibits great potential to replace metal platinum-based catalysts for hydrogen evolution reaction (HER). However, poor electrical conductivity and low intrinsic activity of MoS₂ limit its application in electrocatalysis. Herein, we prepare a defective-MoS₂/rGO heterostructures material containing 1T phase MoS₂ and evaluate its HER performance. The experimental results shown that defective-MoS₂/rGO heterostructures exhibits outstanding HER performance with a low overpotential at 154.77 mV affording the current density of 10 mA cm^?2 and small Tafel slope of 56.17 mV dec^?1. The unique HER performance of as-prepared catalyst can be attributed to the presence of 1T phase MoS₂, which has more active sites and higher intrinsic conductivity. While the defects of as-prepared catalyst fully expose the active sites and further improve catalytic activity. Furthermore, the interaction between MoS₂ and rGO heterostructures can accelerate electron transfer kinetics, and effectively ensure that the obtained catalyst displays excellent conductivity and structural stability, so the as-prepared catalyst also exhibits outstanding electrochemical cycling stability. This work provides a feasible and effective method for preparation of defective-MoS₂/rGO heterostructures, which also supplies a new strategy for designing of highly active and conductive catalysts for HER.     

Three-dimensional ZnCo/MoS2–Co3S4/NF heterostructure supported on nickel foam as highly efficient catalyst for hydrogen evolution reaction

Exploring inexpensive and earth-abundant electrocatalysts for hydrogen evolution reactions is crucial in electrochemical sustainable chemistry field. In this work, a high-efficiency and inexpensive non-noble metal catalysts as alternatives to hydrogen evolution reaction (HER) was designed by one-step hydrothermal and two-step electrodeposition method. The as-prepared catalyst is composed of the synergistic MoS₂–Co₃S₄ layer decorated by ZnCo layered double hydroxides (ZnCo-LDH), which forms a multi-layer heterostructure (ZnCo/MoS₂–Co₃S₄/NF). The synthesized ZnCo/MoS₂–Co₃S₄/NF exhibits a small overpotential of 31 mV and a low Tafel plot of 53.13 mV dec^?1 at a current density of 10 mA cm^?2, which is close to the HER performance of the overpotential (26 mV) of Pt/C/NF. The synthesized ZnCo/MoS₂–Co₃S₄/NF also has good stability in alkaline solution. The excellent electrochemical performance of ZnCo/MoS₂–Co₃S₄/NF electrode originates from its abundant active sites and good electronic conductivity brought by the multilayer heterostructure. This work provides a simple and feasible way to design alkaline HER electrocatalysts by growing heterostructures on macroscopic substrates.     

MoS2/NiS heterostructure grown on Nickel Foam as highly efficient bifunctional electrocatalyst for overall water splitting

It is great important to develop and explore a non-precious bifunctional electrocatalyst with high efficiency and good stability for Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) in alkaline electrolyte. Herein, a three-dimensional (3D) needle-like MoS₂/NiS heterostructure supported on Nickel Foam (NF) (MoS₂/NiS/NF) is synthesized by a simple hydrothermal method for the first time, which can act as a good bifunctional electrocatalyst for overall water splitting. As expected, the optimal MoS₂/NiS/NF exhibits excellent catalytic performance with a low overpotential of 87 and 216 mV at 10 mA cm⁻² for HER and OER in 1 M KOH electrolyte, respectively, accompanied by good cycle stability. Furthermore, the MoS₂/NiS/NF as bifunctional electrocatalyst in an electrolyzer shows high efficiency with a cell voltage of 1.5 V at 10 mA cm⁻², as well as superior durability. The present work may open a new direction to design and develop a non-precious bifunctional electrocatalyst with excellent catalytic activity for water splitting in the future.     

Synthesis and electrocatalytic activity of Ni0.85Se/MoS2 for hydrogen evolution reaction

Recently, the replacement of expensive platinum-based catalytic materials with non-precious metal materials to electrolyze water for hydrogen separation has attracted much attention. In this work, Ni_0.85Se, MoS₂ and their composite Ni_0.85Se/MoS₂ with different mole ratios are prepared successfully, as electrocatalysts to catalyze the hydrogen evolution reaction (HER) in water splitting. The result shows that MoS₂/Ni_0.85Se with a molar ratio of Mo/Ni = 30 (denoted as M30) has the best catalytic performance towards HER, with the lowest overpotential of 118 mV at 10 mA cm⁻², smallest Tafel slope of 49 mV·dec⁻¹ among all the synthesized materials. Long-term electrochemical testing shows that M30 has good stability for HER over at least 30 h. These results maybe due to the large electrochemical active surface area and high conductivity. This work shows that transition metal selenides and sulfides can form effective electrocatalyst for HER.