High-performance Hydrogen Evolution Reaction Catalysts Research Articles

An Efficient and Stable MXene-Immobilized, Cobalt-Based Catalyst for Hydrogen Evolution Reaction

Hydrogen (H2) is considered to be the best carbon-free energy carrier that can replace fossil fuels because of its high energy density and the advantages of not producing greenhouse gases and air pollutants. As a green and sustainable method for hydrogen production, the electrochemical hydrogen evolution reaction (HER) has received widespread attention. Currently, it is a great challenge to prepare economically stable electrocatalysts for the HER using non-precious metals. In this study, a Co/Co3O4/Ti3C2Tx catalyst was synthesized by supporting Co/Co3O4 with Ti3C2Tx. The results show that Co/Co3O4/Ti3C2Tx has excellent HER activity and durability in 1 mol L−1 KOH, and the overpotential and Tafel slope at 10 mA·cm−2 were 87 mV and 61.90 mV dec−1, respectively. The excellent HER activity and stability of Co/Co3O4/Ti3C2Tx can be explained as follows: Ti3C2Tx provides a stable skeleton and a large number of attachment sites for Co/Co3O4, thus exposing more active sites; the unique two-dimensional structure of Ti3C2Tx provides an efficient conductive network for rapid electron transfer between the electrolyte and the catalyst during electrocatalysis; Co3O4 makes the Co/Co3O4/Ti3C2Tx catalyst more hydrophilic, which can accelerate the release rate of bubbles; Co/Co3O4 can accelerate the adsorption and deionization of H2O to synthesize H2. This study provides a new approach for the design and preparation of low-cost and high-performance HER catalysts.

Facile hydrothermal synthesis of ZnIn2S4/TiO2 nanosheets for promoted hydrogen evolution reaction

The current study was conducted by introducing a narrow bandgap semiconductor, ZnIn2S4, with the goal of addressing the inefficiency of hydrolysis dissociation and the limited visible light absorption capacity faced by TiO2 as a hydrogen evolution reaction (HER) catalyst due to its low conduction band position and wide bandgap. Using a one-step hydrothermal process, ZnIn2S4 nanosheet/TiO2 nanorod heterostructures were built on nickel foam substrates. The nanosheet structure of ZnIn2S4 is shaped like a flower, which greatly increased the roughness of the TiO2 surface and revealed additional active sites. The ZnIn2S4/TiO2 heterostructure demonstrates quick reaction kinetics and effective electron transport capability, as demonstrated by the electrochemical test results. An overpotential of just 195 mV is required to obtain a current density of 10 mA cm−2. In addition, the overpotential is further decreased to 160 mV under simulated solar radiation. Furthermore, ZnIn2S4 addition minimizes the free energy of hydrogen adsorption on the TiO2 surface and optimizes the position of its Fermi energy level, improving the usage of photogenerated carriers, according to density functional theory (DFT) calculations. This work validates the prospective use of ZnIn2S4/TiO2 heterostructures in photoelectrocatalysis and offers a fresh viewpoint for developing high-performance HER catalysts.

A highly efficient and self-supporting nanoporous FeMoC catalyst for enhanced hydrogen evolution reaction

Optimizing structure and surface morphologies in electrocatalyst design are important to enhance the intrinsic activity of the hydrogen evolution reaction (HER). Mo-based phosphides and carbides have been confirmed as the widely-reported catalysts for HER. However, the origin of their enhanced catalytic activity is not fully clarified. Herein, the np-FeMoC and np-FeMoP with a self-supporting nanoporous structure were prepared using the melt-spinning and dealloying methods. Benefiting from the self-supporting electrode, nanoporous structure, abundant active species, low charge-transfer resistance and electron synergy, the np-FeMoC exhibits good catalytic performance. The np-FeMoC performs a low overpotential of 50.8 mV at 10 mA cm−2 current density for HER in 1 M KOH. This value is 2.7 times lower than that of the np-FeMoP sample, indicating a synergistic effect between Mo2C and Fe. From XPS and in-situ Raman results, it was observed that the dissolution of Mo2C occurs accompanied by dynamic evolution during the HER process on the np-FeMoC surface. This work unveils the intrinsic activity of Mo-based carbide and phosphide, providing valuable guidance for reasonable exploit of high-performance HER catalysts.

In situ construction of layered transition metal phosphides/sulfides heterostructures for efficient hydrogen evolution in acidic and alkaline media

Construction of electrocatalysts with exceptional intrinsic activity and rich active sites has proved to be an effective strategy for remarkably enhancing the activity of the hydrogen evolution reaction (HER). In this work, durable and highly efficient layered Re2P/ReS2 (RePS) heterostructures were successfully fabricated by an in-situ phosphating layered ReS2. Taking advantage of the unique layered structure can provide abundant reaction active sites and the strong electronic interaction between ReS2 and Re2P can enhance the intrinsic activity, the optimized RePS electrocatalysts show superior catalytic activities of 69 and 57 mV at 10 mA cm−2 for HER in alkaline and acidic media, respectively. The density functional theory results suggest that the formed heterostructures between ReS2 and Re2P play an important role in optimizing the catalytic kinetics of the electrocatalysts. This work not only demonstrates that modulation of the electronic structure of catalysts is an efficient way to improve the HER activity but also confirms that the layered RePS heterostructure is a promising candidate for robust and high performance HER catalysts.

Spin Polarization of 2D Weyl Semimetal Fe2Sn Enabling High Hydrogen Evolution Reaction Activity.

It is well known that magnetic field is one of the effective tools to improve the activity of hydrogen evolution reaction (HER), but considering the inconvenient application of an external magnetic field, it is essential to find a ferromagnetic material with high HER activity itself. Fortunately, recent study has shown that the two-dimmention (2D) Fe2Sn monolayer is a stable ferromagnetic topological Weyl semimetal material with high Tc of 433 K. Here, we report the Fe2Sn monolayer can be used as an alternative HER catalyst compared with expensive platinum (Pt). Our first-principles results show that the Gibbs free energy (ΔGH*) value of the spin polarized Fe2Sn monolayer is -0.06 eV, much better than that without considering spin polarization (-1.23 eV). Moreover, the kinetic analysis demonstrates that the HER occurs on the Fe2Sn monolayer according to the Volmer-Tafel mechanism with low energy barriers. Hence, our findings provide obvious evidence for spin-polarization-improved HER activity, paving a new way to design high-performance HER catalysts.

Universal electronic descriptors for optimizing hydrogen evolution in transition metal-doped MXenes

The integration of transition metal (TM) atoms into two-dimensional (2D) transition metal carbides and nitrides (MXenes) has been identified as a promising strategy for enhancing hydrogen evolution reaction (HER) performance. However, the vast combinatorial space presents challenges for rapid catalyst screening. In response, high-throughput calculations were conducted on Ti2CO2 and Zr2CO2 doped with a wide array of TM single atoms. The local structural and corresponding electronic structural changes were analyzed, with an emphasis on their implications for HER performance. Furthermore, universal electronic descriptors were developed using the Sure Independence Screening and Sparsifying Operator (SISSO) method, harmonizing the Gibbs free energy of hydrogen adsorption (ΔGH*) trends across different MXenes substrates doped with TM atoms. These descriptors enabled the prediction of Cr, Fe, Ru, Pd, Os, and Ir as effective dopants for optimizing the ΔGH* of Hf2CO2, resulting in a reduction of ΔGH* from 1.082 eV to within ±0.2 eV. Our work not only highlights the potential of these TM dopants in significantly enhancing the catalytic activity of MXenes but also underscores the value of universal electronic structure descriptors in rapidly identifying and developing high-performance HER catalysts.

Engineering heterostructured Mo2C/MoS2 catalyst with hydrophilicity/aerophobicity via carbothermal shock for efficient alkaline hydrogen evolution.

The exploration of high-performance hydrogen evolution reaction (HER) catalysts is conducive to the development of clean hydrogen energy, yet still remains a challenge. Herein, we rapidly synthesize the Mo2C/MoS2 heterostructure on carbon paper (Mo2C/MoS2-CP) via carbothermal shock in only two seconds. The construction of the Mo2C/MoS2 heterostructure regulates the electronic structure of the Mo site and facilitates charge transfer during the HER process. Moreover, the catalyst exhibits enhanced hydrophilicity and aerophobicity, facilitating optimal electrolyte-catalyst interaction and efficient hydrogen bubble detachment for accelerated mass transfer. Consequently, Mo2C/MoS2-CP exhibits superior intrinsic alkaline HER activity, and excellent stability for 100 h. This finding provides a novel insight into the development of outstanding HER catalysts.

In Situ Construction of Built-In Opposite Electric Field Balanced Surface Adsorption for Hydrogen Evolution Reaction.

Achieving a balance between H-atom adsorption and binding with H2 desorption is crucial for catalyzing hydrogen evolution reaction (HER). In this study, the feasibility of designing and implementing built-in opposite electric fields (OEF) is demonstrated to enable optimal H atom adsorption and H2 desorption using the Ni3(BO3)2/Ni5P4 heterostructure as an example. Through density functional theory calculations of planar averaged potentials, it shows that opposite combinations of inward and outward electric fields can be achieved at the interface of Ni3(BO3)2/Ni5P4, leading to the optimization of the H adsorption free energy (ΔGH*) near electric neutrality (0.05eV). Based on this OEF concept, the study experimentally validated the Ni3(BO3)2/Ni5P4 system electrochemically forming Ni3(BO3)2 through cyclic voltammetry scanning of B-doped Ni5P4. The surface of Ni3(BO3)2 undergoes reconstruction, as characterized by Grazing Incidence Wide-Angle X-ray Scattering (GIWAXS) and in situ Raman spectroscopy. The resulting catalyst exhibits excellent HER activity in alkaline media, with a low overpotential of 33mV at 10mA cm-2 and stability maintained for over 360 h. Therefore, the design strategy of build-in opposite electric field enables the development of high-performance HER catalysts and presents a promising approach for electrocatalyst advancement.

Defect-rich MoS2/CoS2 on Mo2TiC2Tx MXene as an efficient catalyst for hydrogen evolution reaction in acidic media

Electrocatalytic hydrogen production is an effective way to produce hydrogen energy, and the key is to find inexpensive and effective catalysts. Loading transition metal sulfides onto two-dimensional transition metal carbide (MXene) is an effective method to prepare cheap and high-performance hydrogen evolution reaction (HER) catalysts. In this study, Mo2TiAlC2 was etched with hydrofluoric acid to prepare Mo2TiC2Tx MXene, which was then composited with MoS2 and CoS2 to prepare defect-rich MoS2/CoS2@Mo2TiC2Tx composite by a hydrothermal method. MoS2/CoS2 provides a large number of active sites for electrocatalysis, while Mo2TiC2Tx MXene as a carrier not only provides nucleation and growth sites for MoS2/CoS2, but also increases the rate of electron transfer in HER process, which achieves good synergy between MoS2/CoS2 and Mo2TiC2Tx MXene. Consequently, MoS2/CoS2-2@Mo2TiC2Tx exhibits an excellent HER performance. When the current density reaches 10 mA cm−2, the optimal MoS2/CoS2-2@Mo2TiC2Tx catalyst only requires an overpotential of 80 mV, and exhibits good cycling stability and durability. This work gives a new idea for the preparation of efficient HER catalysts using non-precious metal composites to replace the precious Pt/C.

High-Performance Hydrogen Evolution Reaction Catalysts in Two-Dimensional Nodal Line Semimetals.

The discipline of topological quantum catalysts (TQCs) is developing due to the emergence of exotic quantum materials and their corresponding catalysts. Although a series of 3D TQCs with different topological signatures are proposed, the emergence of 2D TQCs in 2D topological semimetals is still rarely touched by others. As a typical example, we proposed that the 2D nodal line semimetal Cu2Si monolayer is a superior TQC for hydrogen evolution reaction (HER). Using first-principles calculations, we find that the Cu2Si monolayer exhibits two Γ-centered nodal lines (L1 and L2) in the kz = 0 plane. The Gibbs free energy (ΔGH*) of Cu2Si is as low as 0.195 eV, comparable to that of Pt, and better than other conventional catalysts. Moreover, it is found that changing the position of nodal lines (relative to the Fermi level) under different electron/hole conditions can effectively affect the catalytic activity of HER. Besides Cu2Si, the emergence of high HER performance in other 2D nodal line semimetals, Ti3C2, Cr2S3, ScCl, and CuSe, is also theoretically determined. These results highlight the critical role of nodal lines in studying electrocatalytic mechanisms for TQCs and benefit the seeking of high-performance HER catalysts without noble metals on a 2D scale.

High temperature shock synthesis of superfine Ru nanoparticles anchored on TiO2 @nitrogen-doped carbon for pH-universal hydrogen evolution reaction

Due to energy crisis and environmental pollution, it is urgent to develop efficient and cheap catalysts for hydrogen production from water electrolysis. As a cheaper platinum group metal, Ru, a cheaper platinum group metal, is a highly competitive candidate to Pt because of the similar bond energy of M-H. Herein, TiO2 @nitrogen-doped carbon composite supported superfine Ru nanoparticles was synthesized by high temperature shock in a Joule furnace using Ti-MOF support (Ru/TiO2 @NC-J). In the extremely rapid process, MOF was quickly converted into highly conductive nitrogen-doped carbon with tiny TiO2 dispersed in it, and superfine Ru nanoparticles were generated simultaneously in less than 0.5 s. The obtained Ru/TiO2 @NC-J displays wonderful HER performance in the wide pH range. In 1.0 M KOH solution, the overpotential was as low as 11 mV at 10 mA cm−2 and a Tafel slope was 39.2 mV dec−1, which far exceeded the activity of Pt/C and conventional calcined samples as well as most of the recently reported catalysts. The as-developed electrocatalysts also showed excellent stability to accommodate large working current for long term test without obvious activity loss in universal pH range. Experimental investigations suggest that the strong metal-support interaction dominantly facilitate the activity of electrocatalytic hydrogen evolution reaction (HER), and stability of Ru/TiO2 @NC-J. This strategy provides a new and super-fast methodology to prepare low-budget and high-performance HER catalysts for practical applications.

Activating MoO4 tetrahedrons to MoOx species in MoNi alloy for boosting performance in alkaline hydrogen evolution reaction

MoNi alloys as excellent alkaline hydrogen evolution reaction (HER) electrocatalysts benefit from activated Mo-based polymerides for optimizing hydrogen desorption of Ni site. Mo-based polymerides are transformed from adsorbed MoO42−, which is formed by dissolved Mo. However, the dissolution behavior of Mo is uncontrollable and adsorbed MoO42− is limited, resulting in reduced activity of the MoNi alloys. Herein, we reported a unit cell activation strategy to prepare activated MoOx species in MoNi (MoOx/MoNi) alloy for boosting performance in alkaline HER. Characterization by Raman spectroscopy shows that activated MoOx species in MoNi alloy are mainly derived from MoO4 tetrahedrons of the β-NiMoO4 under HER, which have strong correlation with the HER performance of the catalyst. The obtained MoOx/MoNi performs a brilliant HER activity with a low overpotential and Tafel slope of 35 mV@10 mA cm−2 and 58 mV dec−1, respectively, even surpassing commercial Pt/C. As revealed by a series of characterization techniques and theoretical methods, the brilliant HER activity can be ascribed to both the capacity of MoOx on adjusting the hydrogen desorption of Ni site and the intrinsic property of the MoNi alloy. Significantly, activating MoO4 tetrahedrons to MoOx species is an efficient way to replace the self-dissolution and restructure of Mo in MoNi alloy, which could effectively minimize the adverse effect of dissolved Mo on the catalytic activity of MoNi alloy. This work demonstrates the activation process of MoO4 tetrahedrons to MoOx species, providing a new insight into designing and fabricating high-performance HER catalysts by unit cell activation instead of self-dissolution and restructure.

Data-Driven Discovery of Graphene-Based Dual-Atom Catalysts for Hydrogen Evolution Reaction with Graph Neural Network and DFT Calculations.

The flexible tuning ability of dual-atom catalysts (DACs) makes them an ideal system for a wide range of electrochemical applications. However, the large design space of DACs and the complexity in the binding motif of electrochemical intermediates hinder the efficient determination of DAC combinations for desirable catalytic properties. A crystal graph convolutional neural network (CGCNN) was adopted for DACs to accelerate the high-throughput screening of hydrogen evolution reaction (HER) catalysts. From a pool of 435 dual-atom combinations in N-doped graphene (N6Gr), we screened out two high-performance HER catalysts (AuCo@N6Gr and NiNi@N6Gr) with excellent HER, electronic conductivity, and stability using the combination of CGCNN and density functional theory (DFT). Furthermore, comprehensive DFT studies were conducted on these two catalysts to confirm their outstanding reaction kinetics and to understand the cooperative effect between the metal pair for HER. To obtain ideal hydrogen binding in AuCo, the inert Au weakens the strong hydrogen binding of Co, while for NiNi, the two weakly binding Ni cooperate. The present protocol was able to select the two catalysts with different physical origins for HER and can be applied to other DAC catalysts, which should hasten catalyst discovery.

Dual roles of sub-nanometer NiO in alkaline hydrogen evolution reaction: breaking the Volmer limitation and optimizing d-orbital electronic configuration.

Pt-based nanoclusters toward the hydrogen evolution reaction (HER) remain the most promising electrocatalysts. However, the sluggish alkaline Volmer-step kinetics and the high-cost have hampered progress in developing high-performance HER catalysts. Herein, we propose to construct sub-nanometer NiO to tune the d-orbital electronic structure of nanocluster-level Pt for breaking the Volmer-step limitation and reducing the Pt-loading. Theoretical simulations firstly suggest that electron transfer from NiO to Pt nanoclusters could downshift the Ed-band of Pt and result in the well-optimized adsorption/desorption strength of the hydrogen intermediate (H*), therefore accelerating the hydrogen generation rate. NiO and Pt nanoclusters confined into the inherent pores of N-doped carbon derived from ZIF-8 (Pt/NiO/NPC) were designed to realize the structure of computational prediction and boost the alkaline hydrogen evolution. The optimal 1.5%Pt/NiO/NPC exhibited an excellent HER performance and stability with a low Tafel slope (only 22.5 mv dec-1) and an overpotential of 25.2 mV at 10 mA cm-2. Importantly, the 1.5%Pt/NiO/NPC possesses a mass activity of 17.37 A mg-1 at the overpotential of 20 mV, over 54 times higher than the benchmark 20 wt% Pt/C. Furthermore, DFT calculations illustrate that the Volmer-step could be accelerated owing to the high OH- attraction of NiO nanoclusters, leading to the Pt nanoclusters exhibiting a balance of H* adsorption and desorption (ΔGH* = -0.082 eV). Our findings provide new insights into breaking the water dissociation limit of Pt-based catalysts by coupling with a metal oxide.

Stabilization of Ru NPs over 3D LaCrO3 Nanostructures for High-Performance HER Catalysts in Acidic Media.

Hydrogen is considered as one of the best alternatives to carbon-based fossil fuels as energy sources. Electrocatalytic water splitting is one of the finest and eco-friendly methods for the production of hydrogen as compared to all other methods such as stream reforming carbon, hydrolysis of metal hydrides, etc. However, the sluggish kinetics on both the half-cell reactions limits the large-scale production of hydrogen. Hence, to overcome such kind of kinetic issues, designing a catalyst with characteristics of low overpotential and high stability is a matter of prime importance for the research community. Perovskite oxides are one of the well-documented materials for their excellent electrocatalytic water oxidation activity. But because of the lack of a proper proton adsorption site, these materials are unable to show proper hydrogen evolution reaction (HER) activity. Several strategies have been adopted for improving the HER activity of perovskite materials like cation doping, nanostructuring, etc. Here in this work, we prepared a shape-selective LaCrO3 (LCO) material. To enhance the electrocatalytic activity, we decorated the LCO with Ru nanoparticles via a hydrothermal method with different concentrations of Ru (Ru@LaCrO3), coined LCOn (n = 1-2.5). The as-synthesized RLCO2.5 showed the highest HER activity by demanding a low overpotential of 150 mV, whereas bare LCO demanded a higher overpotential of 364 mV to reach the benchmark current density of 10 mA/cm2. Also, RLCO2.5 showed a very low Rct value of 15.8 Ω and followed the facile kinetics with a lower Tafel value of 101 mV/dec. It also showed excellent stability over 55 h at a current density of 10 mA/cm2 in chronoamperometry studies. Acceleration degradation studies of RLCO2.5 showed comparably good activity with a small hike in overpotential toward HER. Hence, RLCO-based materials are highly helpful to develop efficient electrocatalysts to produce hydrogen in a large scale.

Co(OH)2 promoting the catalytic activity of CoP/Ni2P heterojunction for hydrogen evolution in both alkaline and acid media

Developing non-precious metal catalysts to replace commercial Pt for hydrogen evolution reaction (HER) is extremely significant for practical application of water splitting. Here, we synthesized a composite CoP/Ni2P@Co(OH)2 catalyst via the sequential phase growth strategy. Owing to the cooperative effect between CoP/Ni2P and Co(OH)2, the CoP/Ni2P@Co(OH)2 catalyst presents excellent HER catalytic performance with 39 mV overpotential in 1 M KOH and 68 mV overpotential in 0.5 M H2SO4 to deliver the current density of 10 mA cm−2. By designing a control experiment, we found that the Co(OH)2 may promote water dissociation effectively in alkaline media and accelerate the generation of M-H∗ in acidic media, while CoP/Ni2P can serve as the active sites for the adsorption and desorption of hydrogen. The synergistic effects of CoP/Ni2P and Co(OH)2 greatly boost its HER catalytic performance in both alkaline and acid media. In short, the new finding of introducing Co(OH)2 into the CoP/Ni2P can accelerate the development of high-performance HER catalysts.

Carbon dots modified molybdenum disulfide as a high-efficiency hydrogen evolution electrocatalyst

Molybdenum disulfide (MoS2) is considered a low-cost material that may replace platinum-based electrocatalysts towards hydrogen evolution reaction (HER). However, the catalytic activity of MoS2 is limited by the low conductivity and lack of active sites. Here, a biomass carbon dots-molybdenum disulfide (BCDs-MoS2) composite was synthesized as a HER catalyst by a simple hydrothermal method. The BCDs-MoS2 catalyst displayed excellent electrocatalytic performance for HER with lower onset overpotential (115 mV), smaller Tafel slope (56.57 mV dec−1) as well as high cycling stability, which superior to those of homemade MoS2, commercial MoS2, and most of the reported MoS2-based catalysts. According to the characterization results of morphology, surface properties, and valence states of elements, the outstanding catalytic activity of BCDs-MoS2 is ascribed to its loose structure with a large specific surface area along with abundant edges and defects, and the increase in the amount of S22− and S2− which possess higher activity due to the addition of the BCDs. This study can afford a new strategy to design high performance HER catalysts.

Hollow-structured amorphous Cu(OH)x nanowires doped with Ru for wide pH electrocatalytic hydrogen production

Developing efficient and stable catalysts for electrocatalytic hydrogen evolution reaction (HER) with low overpotential is the key point to realizing large-scale hydrogen commercialization. Herein, Ru doped amorphous hollow copper hydroxide nanowires on copper foam (Ru-Cu(OH)x/CF) is prepared by surface chemical oxidization and following solvothermal process. The hollow 3D nanowire structure can provide abundant accessibility active sites, promote electrolyte in filtration and facilitate gas diffusion in the process of the electrochemical reaction. Then, the as-synthesized Ru-Cu(OH)x/CF electrocatalyst exhibits impressive electrocatalytic performance for HER with 45, 80 and 50 mV to drive 10 mA cm−2 in 1.0 M KOH, 1.0 M phosphate-buffered saline (PBS) and 0.5 M H2SO4, respectively, with remarkable long-term stability. Moreover, sustainable energies can power the two-electrode setup with amounts of hydrogen generation. The strategy may be particularly beneficial to explore simple synthesis and high-performance catalysts for HER.

Boosting Hydrogen Evolution Reaction Activity of Amorphous Molybdenum Sulfide Under High Currents Via Preferential Electron Filling Induced by Tungsten Doping.

The lack of highly efficient, durable, and cost‐effective electrocatalysts for the hydrogen evolution reaction (HER) working at high current densities poses a significant challenge for the large‐scale implementation of hydrogen production from renewable energy. Herein, amorphous molybdenum tungsten sulfide/nitrogen‐doped reduced graphene oxide nanocomposites (a‐MoWSx/N‐RGO) are synthesized by plasma treatment for use as high‐performance HER catalysts. By adjusting the plasma treatment duration and chemical composition, an optimal a‐MoWSx/N‐RGO catalyst is obtained, which exhibits a low overpotential of 348 mV at a current density of 1000 mA cm−2 and almost no decay after 24 h of working at this current density, outperforming commercial platinum/carbon (Pt/C) and previously reported heteroatom‐doped MoS2‐based catalysts. Based on density functional theory (DFT) calculations, it is found that with a reasonable tungsten doping level, the catalytic active site (2S2 − ) shows excellent catalytic performance working at high current densities because extra electrons preferentially fill at 2S2 − . The introduction of tungsten tends to lower the electronic structure energy, resulting in a closer‐to‐zero positive ΔGH∗. Excessive tungsten introduction, however, can lead to structural damage and a worse HER performance under high current densities. The work provides a route towards rationally designing high‐performance catalysts for the HER at industrial‐level currents using earth‐abundant elements.

Edge terminated and interlayer expanded pristine MoS2 nanostructures with 1T on 2H phase, for enhanced hydrogen evolution reaction

Pristine molybdenum disulfide (MoS 2 ) nanostructures with 1T on 2H phase have been prepared by tuning the growth time in hydrothermal synthesis. The optimized sample has an expanded interlayer and it exhibits striking kinetic metrics with an onset potential of - 0.13 V, Tafel slope of 49 mV/decade, and an exchange current density of 3.98 × 10 −3 mA, performing best among the pristine MoS 2 based hydrogen evolution reaction (HER) catalysts reported so far. The edge terminated structure, together with the expanded interlayer, is believed to modify the electronic structure to enhance the conductivity of the compound. The Mott-Schottky analysis of the optimized sample indicated a decrease in band bending and an enhancement in the charge transfer. The promising HER response obtained with sufficiently low growth time and growth temperature for the pristine MoS 2 nanostructures suggests a potential way to design high-performance HER catalysts based on the compound. • Fabricated edge terminated, interlayer expanded 1T on 2H MoS 2 nanostructures. • 1T phase with HER active (001) plane obtained without the addition of any dopant. • Optimized sample has lower onset potential of −0.13 V and Tafel slope of 49 mV/dec. • High exchange current density of 3.98 × 10 −3 mA for the optimized sample. • Durable HER catalyst with high stability using MoS 2 nanostructures.