Catalysts For Hydrogen Evolution Research Articles

Noble metal-free ternary cobalt-nickel phosphides for enhanced photocatalytic dye-sensitized hydrogen evolution and catalytic mechanism investigation.

Transition metal phosphides have emerged as compelling alternatives to noble metal catalysts for photocatalytic hydrogen evolution, owing to their high efficiency, stability, ease of preparation, and low-cost-effectiveness. This study investigates a series of binary and ternary phosphides predominantly composed of cobalt and nickel employed for photocatalytic dye-sensitized hydrogen evolution. Under the optimal dye-to-catalyst mass ratio, CoNiP exhibited the highest hydrogen evolution activity (12.96 mmol g-1 h-1), demonstrating more significant and satisfactory performance than a variety of other reported materials. This can be attributed to the high conductivity and low hydrogen evolution overpotential of phosphides, which result from their metallic characteristics and the presence of free electrons, which promote efficient electron transfer between the catalyst and sensitizer. Density functional theory calculations revealed that the cobalt incorporation into the binary phosphides causes a negative shift in the average d-band center for CoNiP, weakening the adsorption affinity of the catalyst towards H2 molecules, thus effectively improving the hydrogen evolution rate compared to the pure binary phosphides. This work provides valuable insights for the development of low-cost and high-performance ternary phosphide photocatalysts.

Modulating surface electron density of Ni(OH)2 nanosheets with longitudinal Ti3C2Tx MXenenanosheets by Schottky effect toward enhanced hydrogen evolution reaction.

Due to their low cost and excellent electrocatalytic performance, nickel-based hydroxides are widely used as hydrogen evolution catalysts for large-scale hydrogen production by water electrolysis. In this study, a heterostructured composite with improved electron transport and modulated electron surface density was prepared by combining Ni(OH)2 with two-dimensional layered Ti3C2Tx (Ti3C2Tx-MXene). Ni(OH)2 nanosheets were formed on nickel foam (NF) substrates using acid etching, followed by the longitudinal growth of negatively charged Ti3C2Tx-MXene on positively charged Ni(OH)2/NF via electrophoretic deposition. The resulting structure facilitates spontaneous electron transfer from Ti3C2Tx-MXene to Ni(OH)2/NF by means of the Mott-Schottky heterostructure effect and establishes a continuous electron transport path which effectively increases the concentration of active sites, improving hydrogen evolution during water electrolysis. The obtained electrode is characterized by an HER overpotential of 66 mV (vs. RHE) and a Tafel slope of +105 mV dec-1 at a current density of 10 mA cm-2, combined with good electrochemical stability.

Is the doped MoS2 basal plane an efficient hydrogen evolution catalyst? Calculations of voltage-dependent activation energy.

Transition metal dichalcogenides are cheap and earth-abundant candidates for the replacement of precious metals as catalyst materials. Experimental measurements of the hydrogen evolution reaction (HER), for example, have demonstrated significant electrocatalytic activity of MoS2 but there is large variation depending on the preparation method. In order to gain information about the mechanism and active sites for the HER, we have carried out calculations of the reaction and activation energy for HER at the transition metal doped basal plane of MoS2 under electrochemical conditions, i.e. including applied electrode potential and solvent effects. The calculations are based on identifying the relevant saddle points on the energy surface obtained from density functional theory within the generalized gradient approximation, and the information on energetics is used to construct voltage-dependent volcano plots. Doping with 3d-metal atoms as well as Pt is found to enhance hydrogen adsorption onto the basal plane by introducing electronic states within the band gap, and in some cases (Co, Ni, Cu, Pt) significant local symmetry breaking. The Volmer-Heyrovsky mechanism is found to be most likely and the associated energetics show considerable dopant and voltage-dependence. While the binding free energy of hydrogen can be tuned to be seemingly favorable for HER, the calculated activation energy turns out to be significant, at least 0.7 eV at a voltage of -0.5 V vs. SHE, indicating low catalytic activity of the doped basal plane. This suggests that other sites are responsible for the experimental activity, possibly edges or basal plane defects.

An underlying nickel difluoride material as bifunctional electrode for energy storage and hydrogen evolution reaction

Supercapacitors (SC) with high power density and long cycle life and hydrogen evolution reactions (HER) with green and environment-friendly act a significant role in the field of electrochemical storage and conversion. It is very important to develop low-cost and high-performance positive materials and hydrogen evolution catalysts for the application of SCs and HER devices. At the same time, it is very significant to develop multifunctional electrode materials that can be used for both energy storage and energy conversion devices. Nickel-based materials are widely used in the field of SCs because of their high specific capacitance and abundant reserves. In addition, the transition metal nickel element is located near the top of the volcanic curve, that is, nickel-based materials have obvious advantages as hydrogen evolution catalysts. Therefore, it is of great significance to develop nickel-based bifunctional electrode materials. In this work, NiF2 material with rutile phase structure was prepared by a simple solvothermal method. Electrochemical tests in different electrolytes of three-electrode system show that NiF2 has electrochemical activity only in alkaline electrolyte. Surprisingly, the bifunctional electrode material NiF2 has an excellent specific capacitance of 889.2F/g at 0.5 A/g in 6 M KOH electrolyte. Even at 10 A/g, the specific capacitance remains at 617.1F/g, and the retention rate is 69.8 %, which has excellent rate performance. At the same time, the capacity retention rate is 80 % after 10,000 cycles. Furthermore, the HER based on NiF2 electrode shows that 10 mA cm−2 can be reached at an overpotential of 176 mV, and the Tafel slope is 125 mV dec−1 in 1 M KOH, which has excellent cycle stability. Therefore, its excellent electrochemical performance indicates that NiF2 will be a very hopeful electrode material in the future in fields of SC and HER.

Efficient Visible Light Hydrogen Evolution Catalyst Composed of Non-noble Metal Nitride (Ni3N) Cocatalyst and Zn0.5Cd0.5S Solid Solution

Efficient Visible Light Hydrogen Evolution Catalyst Composed of Non-noble Metal Nitride (Ni3N) Cocatalyst and Zn0.5Cd0.5S Solid Solution

Giant polyoxomolybdate clusters -derived bimetallic Ni/Mo2C catalyst for electrochemical hydrogen evolution

Developing stable and efficient electrocatalysts to produce clean energy sources is an impressive way to solve energy crisis problems. Herein, electrocatalysts of nickel and Mo2C nanoparticles painted with N-doped carbon layers (Ni/Mo2C@NC) were prepared based on the giant polyoxomolybdate clusters of ((NH4)42[Mo132O372(CH3COO)30(H2O)72]·10CH3COONH4·300H2O) (Mo132). Ni/Mo2C@NC shows outstanding electrocatalytic hydrogen generation activity and stability with overpotentials of 107 and 125 mV at 10 mA cm−2 in 1 M KOH and 0.5 M H2SO4. This article offers a general way for preparing transition metal combined molybdenum carbide electrocatalysts applied in sustainable energy generation and conversion fields.

Pt-Doped Biomass Carbon Decorated with MoS2 Nanosheets as an Electrocatalyst for Hydrogen Evolution

It is necessary to develop an efficient hydrogen evolution catalyst to improve the efficiency of the hydrogen evolution reaction (HER). Herein, a MoS2 nanosheet is decorated on the Pt-doping biomass yeast cells (MoS2@Pt/YC) via a simple hydrothermal process. Reducing the noble metal loading without compromising its performance is a challenging task. The smooth surface of YCs is conducive to the growth of MoS2 nanosheets, and its functional groups provide attachment sites for metal Pt. The Pt/YC is covered with MoS2 nanosheets, thus improving the exposed active sites for HER. The obtained MoS2@Pt/YC delivers a competitive overpotential of 118 mV at the benchmark current density of 10 mA cm-2 and achieves a small Tafel slope of 74 mV dec-1, indicating the great HER performance of MoS2@Pt/YC. Moreover, MoS2@Pt/YC shows robust stability after 24 h of continuous operation toward HER in acidic solution. By introducing transition metal sulfides with high specific surface area, the loading of precious metals can be reduced without compromising properties. This work provides a method to design Pt-doping HER electrocatalysts through a simple method. The facile preparation process for MoS2@Pt/YC and its outstanding performance allow it to be a promising electrocatalyst for practical HER application.

Observation of a robust and active catalyst for hydrogen evolution under high current densities

Despite the fruitful achievements in the development of hydrogen production catalysts with record-breaking performances, there is still a lack of durable catalysts that could work under large current densities (>1000 mA cm−2). Here, we investigated the catalytic behaviors of Sr2RuO4 bulk single crystals. This crystal has demonstrated remarkable activities under the current density of 1000 mA cm−2, which require overpotentials of 182 and 278 mV in 0.5 M H2SO4 and 1 M KOH electrolytes, respectively. These materials are stable for 56 days of continuous testing at a high current density of above 1000 mA cm−2 and then under operating temperatures of 70 °C. The in-situ formation of ferromagnetic Ru clusters at the crystal surface is observed, endowing the single-crystal catalyst with low charge transfer resistance and high wettability for rapid gas bubble removal. These experiments exemplify the potential of designing HER catalysts that work under industrial-scale current density.

Platinum nanoparticles decorated Nb2CTx MXene as an efficient dual functional catalyst for hydrogen evolution and oxygen reduction reaction

Here, a dual functional Nb2CTx@Pt nanocomposite has been synthesized by in situ reduction method. The Pt loading in the composite has been optimized to get minimum overpotential (141 mV at 10 mA/cm2) for hydrogen evolution reaction (HER) along with a promising Tafel slope of 46.3 mV/dec, while Pt/C shows an overpotential and Tafel slope of 104 mV and 32.4 mV/dec, respectively. The Pt mass activity for Nb2CTx@Pt3.8 composite at 100 mV overpotential was 3.44 A g−1 while the Pt mass activity for conventional Pt/C was 0.7 A g−1, which shows that the activity of Nb2CTx@Pt3.8 composite is approximately 5 times higher than Pt/C. In addition, the catalyst was found to be stable for continuous 500 cycles without any binder molecules. The oxygen reduction reaction (ORR) capability of the material was also evaluated and found that the catalyst exhibited a current density of −4.28 mA/cm2 in the diffusion limiting region in comparison with the current density of −5.82 mA/cm2 for Pt/C at 2600 revolutions per minute (RPM). The Pt mass activity of Nb2CTx@Pt3.8 composite for ORR is approximately 10 times higher than Pt/C. The Nb2CTx@Pt3.8 composite was able to reduce O2 completely using the 4-electron pathway with very little peroxide production. From these results, the dual functionality of the Nb2CTx@Pt3.8 composite for both HER and ORR has been established.

Electrosynthesis of Low Pt‐Loaded High Entropy Catalysts for Effective Hydrogen Evolution with Improved Acidic Durability

The synergistic effect in multi‐metal electrocatalysts has gained attention as an efficient strategy for enhancing intrinsic electrocatalytic activities. In this study, a facile electrodeposition technique is used to synthesize a multi‐metal high entropy catalyst (HEC) for efficient electrocatalytic hydrogen production. To boost the synergistic effect between noble metals and transition metals, the Pt ratio is controlled in a multi‐metal electrocatalyst system. The prepared Pt‐involved HEC (Pt‐HEC) exhibits a bamboo‐like morphology with uniformly distributed elements. The 2.5 mM Pt‐HEC has outstanding electrocatalytic activity toward hydrogen evolution reaction (HER) among other Pt‐HECs, with a low overpotential of 70 mV and a Tafel slope value of 47 mV dec−1. Additionally, the Pt mass activity of the 2.5 mM Pt‐HEC is 5.6 times higher than commercial Pt/C electrocatalyst owing to the improved synergistic effect with an optimized Pt ratio. According to the electrochemical impedance spectroscopy (EIS) analysis, the proton‐coupled electron transfer (PCET) process occurs more quickly in the 2.5 mM Pt‐HEC electrocatalyst, confirming its smaller charge transfer resistance properties compared to those of the 5 and 1 mM Pt‐HEC. Therefore, HEC systems can be extensively encouraged as a platform for improving synergistic effects and enhancing electrocatalytic activities for a highly efficient HER electrocatalyst.

Two dimensional MAX supported copper oxide/nickel Oxide/MAX as an efficient and novel photocatalyst for hydrogen evolution

An innovative 2D MAX structure comprising of Ti3AlC2 multilayers and copper oxide (CuO)/nickel oxide (NiO) (CN) composite was fabricated via a facile chemical route for improving photocatalytic hydrogen evolution activity. The physicochemical properties of the synthesized nanocomposites were analyzed through various structural, morphological, and elemental techniques. The 2D Ti3AlC2/CuO/NiO composite showed a maximum H2 generation rate of 20.7 mmol g−1 h−1, which is greater than that of the CN nanocomposite. This improved activity can be attributed to the presence of Ti3AlC2 multilayers on CuO/NiO, which showed excellent photoinduced charge carrier separation via the s-scheme mechanism. As an electron-bridge, CN NC can support the photoelectrons to transfer from the CB of CN to the CB of MAX, from where the photoelectrons respond with hydrogen ion to release hydrogen. The time-resolved photoluminescence measurement results showed that the CuO/NiO/MAX (CNM) composite had a charge carrier lifetime of 3 ns. The outcomes of this study will be beneficial in realizing the industrial applications of Ti3AlC2 MAX-based structured catalysts for hydrogen evolution and other ecological energy systems.

Microwave induced rapid surface amorphization of metal oxide nanowire into sulfides shell for electronically modulated efficient hydrogen evolution catalyst

Order/dis-order atomic arrangements in crystalline/amorphous structure possess a complementing effect in electro-catalysis as the former one can offer a long-range electronic conducting path, whereas the latter is rich with active sites. However, atomic level interfacing of crystalline and amorphous structures is extremely challenging and thus often end-up with uncontrolled secondary deposition one above another. Here, we are reporting second-scale atomic rearrangement of crystalline oxide nanowire surface into amorphous molybdenum sulfide shell that displayed excellent hydrogen evolution activity. Employing transient heating by microwave-activated graphene filament, surface atoms of molybdenum tungsten oxide (MoWO) nanowire can be arrested in either an amorphous or crystalline state during their sulfidation. Such a nanowire structure consisting of crystalline oxide core-amorphous sulfide shell shows excellent catalytic activity for hydrogen evolution reaction (HER) and exhibits an overpotential of 136 mV at 10 mA cm−2 in the acid electrolyte, which is much lower than the overpotential of parent oxide nanowire (356 mV) and its fully sulfurized crystalline counterpart (163 mV). As-developed catalyst also shows competitive HER performance with excellent alkaline and neutral electrolytes stability, thereby qualifying it as a pH universal catalyst. A detailed density functional theory calculation reveals oxide core promoted activation of multiple sites of amorphous sulfide phase, which provide key insights of electronic modulation via crystalline/amorphous interfacial structure for HER catalysis. This rapid and highly facile technique can lay the platform for the development of generic crystalline/amorphous core-shell nanostructure and their possible use as cost-effective and efficient catalysts.

Rethinking Electronic Effects in Photochemical Hydrogen Evolution Using CuInS2@ZnS Quantum Dots Sensitizers

Molecular catalysts based on coordination complexes for the generation of hydrogen via photochemical water splitting exhibit a large versatility and tunability of the catalytic properties through chemical functionalization. In the present work, we report on light-driven hydrogen production in an aqueous solution using a series of cobalt polypyridine complexes as hydrogen evolving catalysts (HECs) in combination with CuInS2@ZnS quantum dots (QDs) as sensitizers, and ascorbate as the electron donor. A peculiar trend in activity has been observed depending on the substituents present on the polypyridine ligand. This trend markedly differs from that previously recorded using [Ru(bpy)3]2+ (where bpy = 2,2'-bipyridine) as the sensitizer and can be ascribed to different kinetically limiting pathways in the photochemical reaction (viz. protonation kinetics with the ruthenium chromophore, catalyst activation via electron transfer from the QDs in the present system). Hence, this work shows how the electronic effects on light-triggered molecular catalysis are not exclusive features of the catalyst unit but depend on the whole photochemical system.

Carbon fiber supported Co/Co3O4-embedded N-doped carbon microparticles for efficient overall seawater splitting and oxygen reduction

Due to low cost and abundance, direct seawater splitting to produce hydrogen is an encouraging strategy to alleviate the consumption of fossil energy, while also avoiding freshwater stress. However, when natural seawater is utilized as the electrolyte, the catalysts on the cathode and anode of water splitting should not only have high activity to promote energy efficiency, but also have good stability and durability to resist the corrosion of chloride ions. Herein, a hierarchical carbon-based catalyst for hydrogen and oxygen evolution, ZIF-67/CF-1, was prepared by annealing a composite of ZIF-67 and carbon fiber (CF). It exhibits good electrocatalytic activity and stability for overall splitting in natural seawater and neutral PBS solution. Impressively, when an electrolyzer consisting of ZIF-67/CF-1||ZIF-67/CF-1 is applied to overall seawater splitting, the current density of 10 mA/cm2 is achieved with a drive voltage of 2.46 V, which is only 0.28 V higher than precious metal-based electrolyzer (Pt/C||IrO2). Meanwhile, ZIF-67/CF-1 shows outstanding catalytic ability for oxygen reduction (E1/2 = 0.84 V, Tafel slope = 66.9 mV/dec), also demonstrating its application potential in rechargeable batteries and fuel cells.

IrPt Alloy Nanoparticles with Controllable Compositions as Catalysts for Electrochemical Oxygen and Hydrogen Evolution

When two metal precursors are reduced to form alloy nanoparticles (NPs), the final size usually varies by the composition because the reduction rate is different for each precursor. In this study, we report that the composition of IrPt alloy NPs can be easily controlled without affecting the size using an antisolvent crystallization-based method owing to the separation of the particle growth and precursor reduction steps. The synthesized IrPt alloy NPs displayed low overpotentials in both hydrogen evolution reaction (65 mV with a Tafel slope of 32.2 mV dec–1) and oxygen evolution reaction (240 mV with a Tafel slope of 77.9 mV dec–1) to deliver a current density of 10 mA cm–2 in H2SO4 (0.5 M), showing their enhanced electrocatalytic activities compared with the pure Pt and Ir catalysts.

A noble metal-free candle soot derived carbon electrocatalyst for simultaneous H2 generation and wastewater treatment

Electrocatalytic water splitting to produce green hydrogen is a promising approach for clean energy generation. However, the commercial aspect of this approach is limited due to catalysts cost and feedstock. Thus design of an inexpensive and noble metal-free (Pt, Rh, Ir etc.) catalyst is desirable. Moreover, wastewater as a feedstock for hydrogen generation is not explored to its full potential for green hydrogen generation, which otherwise is also a problem to be managed especially in developing countries. In the present work, we have investigated an inexpensive catalyst i.e. candle soot-derived carbon as an electrocatalyst for H2 generation from textile wastewater utilizing methylene blue as a model pollutant. The carbon catalyst is synthesized from the candle soot and is characterized for its structural and morphological properties. Carbon soot coated onto the nickel foam (CS@NF) proves as an efficient hydrogen evolution catalyst due to its excellent electrical conductivity and large active surface area. CS2.5@NF (with the loading of 2.5 mg cm−2) shows an overpotential and Tafel slope of 117 mV and 43.85 mV/dec, respectively in an acidic medium containing textile pollutants. Under optimal condition, ∼62% degradation is achieved within ∼90 min, along with the stable hydrogen production of ∼0.158 mmol per hour. These preliminary findings demonstrate the potential usage of an inexpensive non-noble metal free catalyst for simultaneous wastewater treatment as well as hydrogen generation.

MOF-derived bimetallic NiMo-based sulfide electrocatalysts for efficient hydrogen evolution reaction in alkaline media

Hydrogen energy is regarded as one of the candidates for renewable and green energy because of its high energy density and zero pollution. Two dimensional MXene-based heterostructures combine advantages and synergistic properties of the constituents, attracting great interest as a kind of low-cost hydrogen evolution catalyst. Herein, we present an in-situ sulfidation method to form a MoS2/Mo2TiC2Tx nanohybrid so as to circumvent adventitious oxidation in Mo2TiC2Tx MXenes. On this basis, MoNiS/Mo2TiC2Tx electrocatalyst is synthesized by vulcanizing the precursor MOF self-assembled with MoS2/Mo2TiC2Tx. Benefiting from the synergistic coupling of Mo2TiC2Tx MXene, Ni2S and MoS2, the hydrogen evolution reaction (HER) test on MoNiS/Mo2TiC2Tx catalyst in 1 M KOH solution shows a significant HER activity with a low overpotential (153 mV) to produce a current density of 10 mA cm−2 and small Tafel slope (92 mV·dec−1). In addition, the catalyst is highly stable for at least 12 h with no drastically reduced activity. This design has important guiding significance for the preparation of hydrogen evolution materials by constructing the strategy of two-dimensional MXene and transition metal sulfide heterojunction.

Thermally-enhanced sono-photo-catalysis by defect and facet modulation of Pt-TiO2 catalyst for high-efficient hydrogen evolution

Sono-photo-catalysis (SPC) has been regarded as a promising route for hydrogen evolution from water splitting due to the sono-photo-synergism, whereas its current performance (∼μmol g−1 h−1) is yet far from expectation. Herein, we give the first demonstration that the intrinsically coupled thermal effects of light and ultrasound, which is normally underestimated or neglected, can simultaneously reshape the photo- and sono-catalytic activities for hydrogen evolution and establish a higher degree of synergy between light and ultrasound in SPC even on the traditional Pt-TiO2 catalyst. A high-efficient hydrogen evolution rate of 225.04 mmol g−1 h−1 with light-to‑hydrogen efficiency of 0.89% has been achieved in thermally-enhanced SPC, which is an order of magnitude higher than that without thermal effects. More impressively, the increase of synergy index up to 53% has been achieved. Through experiments and theoretical calculations, the thermally-enhanced sono-photo-synergism is attributed to the sono-photo-thermo-modulated structural optimization of defect-rich TiO2 support and deaggregated Pt species with functional complementary lattice facets, which optimizes not only the thermodynamic properties by enhancing light harvesting and the charge redox power, but also the kinetic properties by accelerating the net efficiency of charge separation and the whole processes of water splitting, including the dissociation of water molecules on high-index (200) Pt facets and production of H∗ intermediates on defect-rich TiO2-x support and low-index (111) Pt facets. This study exemplifies that coupling light- and ultrasonic-induced thermal effects in SPC system could enhance the synergy between light and ultrasound by modulating catalyst structure to achieve double optimization of thermodynamic and kinetic properties of SPC hydrogen evolution.

Self-supporting sandwich-structured Co–Pt–Co/CC electrocatalysts for high effective hydrogen production by electrolysis of water in alkaline solution

Trace precious metal modifying inexpensive transition metal catalyst is an effective method to optimize the activity, stability and cost of hydrogen evolution catalysts. In this feature work, self-supporting sandwich structured Co–Pt–Co/CC sheets were assembled on a carbon cloth (CC) by a simple electrodeposition/chemical displacement alternate growth method. Surprisingly, only 2.1 wt % Pt sandwich layer greatly improved the electrochemical activity of Co–Pt–Co/CC, which delivered a current density of 10 mA cm −2 at an overpotential as low as 46 mV. Importantly, its overpotential is almost 6 times lower than that of Co/CC, and is comparable to that of Pt–Co/CC. After well-tuning the sandwich layer, the optimized Co–Pt–Co/CC exhibited a higher current density and better long-term durability compared with Pt–Co/CC and Co/CC, which can be attributed to the unique tissue-structure and electronic structure optimization of the Co–Pt–Co/CC by the Pt sandwich layer.

Enhanced hydrogen evolution performance by nanoarchitectonics of Fe/Co alloy electrode beyond Fe/Co/Ni alloy electrode

With the increasing global energy demand, hydrogen production from electrolytic water became the main way to prepare efficient and clean hydrogen energy. Transition metal catalyst were promising hydrogen evolution catalyst for low cost, stable performance and high catalytic activity. In this study, Fe–Co–Ni, Co–Fe, Ni–Fe and Co–Ni alloy electrodes were prepared by electrodeposition. Among the four alloys, Co–Fe showed the best hydrogen evolution performance. The surface of Co–Fe alloy electrode coating was composed of round small particles of different sizes closely combined to form a large complex. In the alloy, Co was accounted for 62.2% and Fe was accounted for 37.8%. The increase of Co content increased the specific surface area of the electrode, provided a large number of catalytic active sites, and improved the hydrogen evolution performance. In the Co–Fe alloy electrode, Fe was existed in the form of Fe2+ and Fe3+, Co was existed in the form of Co2+. The electrochemical test results showed that Co–Fe alloy electrode had the highest electrocatalytic activity. Since the conductivity of cobalt hydroxide and iron hydroxide generated in the strong alkali environment, which was stronger than that of nickel hydroxide, the internal resistance of the Co–Fe alloy electrode in the hydrogen evolution process was reduced. Under the same conditions, the Co–Fe alloy electrode needed only 1483 mV overpotential to drive a current density of 0.1 A/cm2. The Tafel slope of Co–Fe alloy electrode was the smallest, only 144.04 mV/dec, and the electron transmission efficiency was the highest. Co–Fe alloy electrode had the lower electron conduction resistance and better electrochemical hydrogen evolution performance.