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1.
The development of cheap, efficient, and active non-noble metal electrocatalysts for total hydrolysis of water (oxygen evolution reaction (OER) and hydrogen evolution reaction (HER)) is of great significance to promote the application of water splitting. Herein, a heterogeneous structured electrode based on FeAlCrMoV high-entropy alloy (HEA) was synthesized as a cost-effective electrocatalyst for hydrogen and oxygen evolution reactions in alkaline media. In combination of the interfacial synergistic effect and the high-entropy coordination environment, flower-like HEA/MoS2/MoP exhibited the excellent HER and OER electrocatalytic performance. It showed a low overpotential of 230 mV at the current density of 10 mA cm−2 for OER and 148 mV for HER in alkaline electrolyte, respectively. Furthermore, HEA/MoS2/MoP as both anode and cathode also exhibited an overpotential of 1.60 V for overall water splitting. This work provides a new strategy for heterogeneous structure construction and overall water splitting based on high-entropy alloys.  相似文献   

2.
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.  相似文献   

3.
The study of high efficiency and low cost catalysts is of great significance to the overall development of electrochemistry. In this paper, NiCoM (M = P, S, Se, O)–Ni3S2–MoS2 hybrid material was prepared by hydrothermal, calcination and hydrothermal three-step reaction method, and its hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline environment were studied and compared. The experimental results showed that at 10 mA cm?2, the overpotential of NiCoP–Ni3S2–MoS2 was only 140 mV for HER, while the overpotential of NiCoSe–Ni3S2–MoS2 was only 160 mV for OER. Compared with other catalysts, the activity of NiCoP–Ni3S2–MoS2 and NiCoSe–Ni3S2–MoS2 was higher, and the chemical reagents needed for preparation were cheap and low cost. What is noteworthy is that the morphology of NiCoP–Ni3S2–MoS2 material change after long time stability test for hydrogen evolution reaction, the change makes the performance of the samples toward a better direction. A series of characterization found that the surface of the NiCoP–Ni3S2–MoS2 samples increased more holes and more active site, and did not produce new material after other characterization. Density functional theory calculation shows that the presence of this MoS2 material accelerates the kinetics of hydrogen production and this Co2P material enhances the conductivity of the material. Their synergistic effect makes the NiCoP–Ni3S2–MoS2 catalyst exhibit enhanced hydrogen production activity. The bramble structure of NiCoSe–Ni3S2–MoS2 allows the sample to have more active sites and higher electrocatalytic activity during the OER process. This experiment provides new insights into the preparation of robust water splitting catalysts by simple methods.  相似文献   

4.
Molybdenum disulfide (MoS2), attracts great attention in hydrogen evolution reaction (HER) field, however, low catalytic activity sites and poor conductivity still limit its further application. In this study, an efficient hydrogen evolution electrode with nano-pom-pom multiphasic MoS2 uniformly grew on porous carbonized wood (NP MoS2/CW) was developed. Interestingly, the nano-pom-pom are stacked from sheets of MoS2. Fully exposed active edges of nano-pom-pom MoS2 and high excellent electrical conductivity of carbonized wood enhance collectively electrocatalytic performance for HER. Specifically, the NP MoS2/CW electrode requires an overpotential of 109.5 mV and 305 mV to achieve the current density of 10 mA cm−2 and 400 mA cm−2, respectively (0.5 M H2SO4). NP MoS2/CW has excellent electrocatalytic performance and stability in acidic and alkaline media due to the perfect combination of NP MoS2 unique nanostructure and the unique properties of CW. Therefore, the present work provides a promising strategy into the rational development and utilization of MoS2 for the development of hydrogen evolution.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
The development of highly active and low-cost catalysts for hydrogen evolution reaction (HER) is significant for the development of clean and renewable energy research. Owing to the low H adsorption free energy, molybdenum disulfide (MoS2) is regarded as a promising candidate for HER, but it shows low activity for oxygen evolution reaction (OER). Herein, graphene-supported cobalt-doped ultrathin molybdenum disulfide (Co–MoS2/rGO) was synthesized via a one-pot hydrothermal method. The obtained hybrids modified electrode exhibits a high HER catalytic activity with a low overpotential of 147 mV at the current density of 10 mA cm−2, a small Tafel slope of 49.5 mV dec−1, as well as good electrochemical stability in acidic electrolyte. Meanwhile, the catalyst shows remarkable OER activity with a low overpotential of 347 mV at 10 mA cm−2. The superior activity is ascribed not only to the high conductivity originated from the reduced graphene, but also to the synergistic effect between MoS2 and cobalt.  相似文献   

8.
Electrocatalytic hydrogen evolution reaction (HER) is one of the green and effective method to produce clean hydrogen energy. However, the development of non-Pt HER catalysts with excellent catalytic activity and long-term stability still remains a great challenge. Herein, a vertically aligned core-shell structure material with hollow polypyrrole (PPy) nanowire as a core and Ru-doped MoS2 (Ru–MoS2) nanosheets as a shell is firstly reported as a highly efficient and ultra-stable catalyst for HER in alkaline solutions. Results indicate that Ru–MoS2@PPy catalyst demands a low overpotential of 37 mV at 10 mA cm?2. In addition, the overpotential at 100 mA cm?2 is 157 mV and it is almost unchanged after 40,000 cyclic voltammetry cycles. The existence of PPy core not only ensures the vertical growth of MoS2 nanosheets to expose more edge sites, but also promotes the rapid transfer of electrons, contributing to the improvement of catalytic activity. More importantly, the strong interface interaction between MoS2 and PPy prevents the collapse of the vertical structure of MoS2 sheets in the electrocatalytic process and greatly enhances the stability of catalysts, which offers an effective strategy to design and synthesize the HER catalysts with superior catalytic stability.  相似文献   

9.
Self-standing and hybrid MoS2/Ni3S2 foam is fabricated as electrocatalyst for hydrogen evolution reaction (HER) in alkaline medium. The Ni3S2 foam with a unique surface morphology results from the sulfurization of Ni foam showing a truncated-hexagonal stacked sheets morphology. A simple dip coating of MoS2 on the sulfurized Ni foam results in the formation of self-standing and hybrid electrocatalyst. The electrocatalytic HER performance was evaluated using the standard three-electrode setup in the de-aerated 1 M KOH solution. The electrocatalyst shows an overpotential of 190 mV at ?10 mA/cm2 with a Tafel slope of 65.6 mV/dec. An increased surface roughness originated from the unique morphology enhances the HER performance of the electrocatalyst. A density functional approach shows that, the hybrid MoS2/Ni3S2 heterostructure synergistically favors the hydrogen adsorption-desorption steps. The hybrid electrocatalyst shows an excellent stability under the HER condition for 12 h without any performance degradation.  相似文献   

10.
--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.  相似文献   

11.
Developing cost-effective and remarkable electrocatalysts toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performs excelling role in boosting the hydrogen energy application. Herein, a novel in-situ one-pot strategy is developed for the first time to synthesize molybdenum carbide nanoparticles (Mo2C NPs) incorporated on nitrogen (N) and phosphorous (P) co-doped stereotaxically carbon (SC). The optimized Mo2C NPs/N, P–SC–800 electrocatalyst exhibits lower overpotentials of 131 and 287 mV for HER and OER to deliver a current density of 10 mA cm?2 in 1.0 M KOH medium with smaller Tafel slopes of 58.9 and 74.4 mV/dec, respectively. In addition, an electrolyzer using Mo2C NPs/N, P–SC–800 electrode as cathode and anode delivers a current density of 10 mA cm?2 at a small voltage of 1.64 V for overall water splitting. The excellent water splitting performance could be ascribed to optimum Mo2C NPs for more accessible active sites, highly active N, P-SC networks for accelerated electron transfers, and synergetic effect between Mo2C NPs and N, P-SC networks. The N, P-SC network not only enhances the overall dispersion of Mo2C NPs but also contributes numerous electroactive edges to enhance the performance of HER, OER, and overall water splitting activity. This research work explores the in-situ one-step strategies of advanced, cost-effective, and non-precious metal electrocatalysts for efficient water splitting and motivates the consideration of a novel class of heteroatom doped stereotaxically carbon nanocomposites for sustainable energy production.  相似文献   

12.
Molybdenum sulfide (MoS2) as a graphene-like sheet material has attracted wide attention owing to the potential for hydrogen evolution reaction (HER). However, the large-scale application of MoS2 is still difficult due to the inherent poor conductivity and insufficient active edge sites. Herein, we develop a simple method to grow P-doped MoS2 nanosheets on carbon cloth for high efficiency HER. The 2D carbon cloth can prevent the stacking of MoS2 nanosheets and improve the conductivity with the doping of P atoms. As a result, the P–MoS2/CC-300 shows the excellent electrocatalytic activity with an overpotential of 81 mV at 10 mA cm?2 and the lower Tafel slope of 98 mV/dec. Furthermore, it also shows the good electrocatalytic durability for 15 h. This work provides an opportunity for the design of excellent and robust MoS2-based catalyst via structural engineering and doping method.  相似文献   

13.
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.  相似文献   

14.
Herein, a highly active, and stable copper phosphide/nickel-copper phosphide (CuP2/NiCuP) nanosheet supported by a g-C3N4 is constructed via phosphorization for hydrogen and oxygen evolution reactions (HER and OER, respectively). Strong coupling between CuP2/NiCuP heteronanosheets and the structured g-C3N4 provides CuP2/NiCuP/g-C3N4 with a regulated electronic state, sufficient anchored active sites, reduced mass transport distance, and improved structural stability. Consequently, the obtained CuP2/(NiCu)1:1P/g-C3N4 electrocatalyst manifests excellent performance in HER and OER, with overpotentials of 96 and 280 mV at 10 mA cm−2, respectively, as well as stability. The excellent HER and OER activities are mainly ascribed to the collective effects of electronic structure engineering, strong interaction between CuP2 and NiCuP in the heteronanojunction, abundant catalytic active sites, and highly conductive g-C3N4 support. This study provides novel insights for designing cost-effective bimetallic alloy-phosphide HER/OER electrocatalysts for various sustainable energy-conversion applications.  相似文献   

15.
The layered MoS2 nanostructures have been widely used in the electrochemical hydrogen evolution reaction (HER), but rarely applied in overall water splitting application for their ignorable oxygen evolution reaction (OER) activity. To address this issue, a novel self-standing and bifunctional electrocatalyst, consisting of Co-doped MoS2 nanosheets anchored on carbon fiber paper, has been prepared via hydrothermal method. Taking advantage of conductive substrate of carbon fiber paper, sufficient-exposed active edges of MoS2 sheets, and metallic character caused by Co-doping, our electrode exhibits high-efficient bifunctional activities for the overall water splitting in alkaline electrolyte (1 M KOH), which can produce a current density of 20 mA cm−2 at an overpotential of 197 mV for HER and 235 mV for OER.  相似文献   

16.
In order to solve the problem of large overpotential in water electrolysis for hydrogen production, transition metal sulfides are promising bifunctional electrocatalysts for hydrogen evolution reaction/oxygen evolution reaction that can significantly reduce overpotential. In this work, Ni3S2 and amorphous MoSx nanorods directly grown on Ni foam (Ni3S2-MoSx/NF) were prepared via one-step solvothermal process, which were used as a high-efficient electrocatalyst for overall water splitting. The Ni3S2-MoSx/NF composite exhibits very low overpotentials of 65 and 312 mV to reach 10 mA cm−2 and 50 mA cm−2 in 1.0 M KOH for HER and OER, respectively. Besides, it exhibits a low Tafel slope (81 mV dec−1 for HER, 103 mV dec−1 for OER), high exchange current density (1.51 mA cm−2 for HER, 0.26 mA cm−2 for OER), and remarkable long-term cycle stability. This work provides new perspective for further the development of highly effective non-noble-metal materials in the energy field.  相似文献   

17.
Water splitting is an appealing way of producing hydrogen fuel, which requires efficient and affordable electrode materials to make the overall process viable. In the last couple years, abundant transition metals (and their compounds and hybrids) attracted ever-growing attention as the alternatives of noble metals. Particularly the layered transition metal dichalcogenide (TMDs) are interesting with their stability and promising electrocatalytic performance for hydrogen evolution reaction (HER). However, the neat TMDs are often poor in terms of the abundance of catalytically active sites and electrical conductivity, which limit their application potential significantly. Herein, as a proof-of-concept, we report on the design of a high-performance electrocatalyst system formed by the decoration of ultrasmall molybdenum sulfide (MoS2) nanosheets on carbon nanotubes (CNTs). The ultrasmall MoS2 nanosheets provide distorted lattice, confined size and rich defects, which endows the resulting electrocatalysts (MoS2/CNT) with abundant active sites. The CNTs, on the other hand, serve as the conductive net for ensuring electrocatalytic performance. As a result, the hybrid electrocatalyst exhibits excellent electrocatalytic performance for HER, achieving a large current density of 100 mA cm−2 at overpotential of only 281 mV and a small Tafel slope of 43.6 mV dec−1 along with a decent stability. Our results are of high interest for electrocatalyst technologists as well as hydrogen fuel researchers.  相似文献   

18.
The development of highly efficient binary heterostructures with enhanced electrocatalytic activities is vital for reducing the energy consumed by the hydrogen evolution reaction (HER). Herein, we successfully design and synthesize an eco-friendly Ag3PO4/1T-2H MoS2 heterostructure to catalyze the HER process. Micromorphology and microstructure studies show that the Ag3PO4 nanoclusters are well dispersed with abundant catalytically active sites on the surface of the 1T-2H MoS2 nanoflowers. X-ray photoelectron spectroscopy confirms the stable oxidation state and electronic interactions in the 2 wt% Ag3PO4/1T-2H MoS2 nanostructure. Benefitting from the strong electronic interactions and advantages of abundant heterogeneous interfaces and catalytically active sites, the 2 wt% Ag3PO4/1T-2H MoS2 heterostructure delivers excellent and durable electrochemical HER activity in alkaline solution, with a low overpotential of 149 mV for the HER at 10 mA cm−2, in clear improvement over 1T-2H MoS2. The enhanced electrocatalytic activity is ascribed to the abundant catalytically active sites, rapid charge transport, and Ag3PO4/1T-2H MoS2 synergism. This study provides a novel strategy for exploring and synthesizing low-cost binary electrocatalysts that enhance the electrochemical HER performance in energy-conversion applications.  相似文献   

19.
Electrochemical water splitting is considered as a promising strategy for the efficient hydrogen production, yet it is hindered by the sluggish oxygen evolution reaction (OER). Herein, heterostructure OER catalyst is fabricated by combining MoS2 nanosheets with NiCo2O4 hollow sphere on Ti mesh. Benefiting from the heterogeneous nanointerface between NiCo2O4 and MoS2, this electrocatalyst demonstrates excellent OER activity in basic environment with overpotentials of 313 and 380 mV achieving 10 and 100 mA cm−2. The superb catalytic performance stems from hollow the nanostructure and interfacial engineering strategy that enhance intrinsic activity and provide faster charge transfer. Hence, this work provides a feasible path for exploiting the high-efficient catalysts.  相似文献   

20.
The mixed metal dichalcogenides combination of WS2–MoS2 was coated onto Cu substrate by electroless NiMoP plating technique and the electrocatalytic hydrogen evolution reaction (HER) performance was investigated. The enhanced structural, morphological parameters and boosted electrocatalytic performance of the various metal-metal molar ratio of WS2–MoS2 onto NiMoP plate were identified under variable operating conditions and it was successfully evaluated by various characterization techniques. The well-defined crystalline nature, phase, particle size, structure, elemental analysis and surface morphology of prepared coatings were analyzed by FESEM, XRD, AFM and EDS mapping. The electrochemical analysis was performed using open circuit potential (OCP) analysis, chronoamperometry (CA), electrochemical impedance spectroscopy (EIS), Tafel curves, linear sweep voltammetry (LSV), cyclic voltammetry (CV) and polarization studies to find the activity of prepared electrocatalyst towards electrochemical hydrogen evolution reactions. The performance of bare NiMoP and WS2–MoS2/NiMoP plates were compared and found that the HER activity of NiMoP can be reinforced by composite incorporation through the synergic effect arises with in the catalytic system, which improves surface roughness and enhances the magnitude of electrocatalyst toward HER. The achievement of enhanced catalytic performance of coatings was authenticate by the kinetic parameters such as decreases in Tafel slope (98 mV dec?1), enhanced exchange current densities (9.32 × 10?4 A cm?2), and a lower overpotential. The consistent performance and durability of the catalyst were also investigated. The enhanced electrocatalytic activity of WS2–MoS2/NiMoP coatings increased with respect to the surface-active sites associated with combination of mixed dichalcogenides and the synergic effect arises in between different components present in the coating system. This work envisages the progressive strategies for the economical exploration of a novel WS2–MoS2/NiMoP water splitting catalyst used for large scale H2 generation. The prepared WS2–MoS2/NiMoP embedded Cu substrate possess high catalytic activity due to its least overpotential of 101 mV at a benchmark current density of 10 mA cm?2, which demonstrated the sustainable, efficient and promising electrocatalytic property of prepared catalyst towards HER under alkaline conditions.  相似文献   

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