Effective Hydrogen Evolution Reaction Research Articles

Controllable preparation of Cu2S@Ni3S2 grown on nickel foam as efficient seawater splitting electrocatalyst

Seawater is one of the richest hydrogen sources around our environment, so it has a lot of advantages to decompose and produce hydrogen. However, considering that chloride ions in seawater have a strong corrosive action on the electrode. Therefore, the design and exploration of highly effective and antiseptic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalysts were studied. It's worth noting that Cu2S@Ni3S2/NF is engaged as a difunctional electrode in this study, which drives a current density of 10 mA cm−2 with requiring overpotentials of only 78 mV and 170 mV, and highlights its significant selectivity of OER and HER. The results show that the increased activity of Cu2S@Ni3S2/NF electrode can be assigned to the synergistic catalysis of (211) and (110) crystal faces, as well as the transfer and the increase of the number of active sites caused by lattice defects. The results of density functional theory show that Cu2S material has optimal free energy of the adsorbed states for H, indicating that the introduction of Cu2S promotes the kinetics of the reaction. The introduction of Ni3S2 material greatly improves the conductivity of Cu2S@Ni3S2/NF electrode. This paper proposes novel insights into the exploration of environmentally friendly and corrosion resistant difunctional catalysts for seawater splitting.

Front Cover: A Series of Cobalt bis(Thiosemicarbazone) Catalysts for Effective Photocatalytic Hydrogen Evolution Reaction (Eur. J. Inorg. Chem. 35/2023)

Front Cover: A Series of Cobalt bis(Thiosemicarbazone) Catalysts for Effective Photocatalytic Hydrogen Evolution Reaction (Eur. J. Inorg. Chem. 35/2023)

Structural properties and hydrogen evolution reactions of predicted two-dimensional V n C n (n = 2, 3, 6) with first-principles calculations

Developing stable, conductive and effective nonprecious hydrogen evolution reaction (HER) catalysts is critical to the future of the hydrogen economy. The possible structures of the two dimensional V n C n were searched with the evolutionary algorithm associated with the density functional theory (DFT) calculations. V n C n (n = 2, 3, 6) were found stable and the structures were refined with the DFT-PBE approaches at higher computational accuracies. Their thermal, dynamical and mechanical stabilities were confirmed theoretically with the same method. The electronic and the HER catalytic properties of these structures were investigated. All the structures exhibit metallicity, which is favorable to support adsorbing hydrogen atoms and transferring charges during HER. The Gibbs free energy of HER reactions support that the 2D V n C n (n = 3, 6) possess the catalytic ability of HER.

A Series of Cobalt bis(Thiosemicarbazone) Catalysts for Effective Photocatalytic Hydrogen Evolution Reaction

AbstractIn order to diminish environmental issues such as global warming due to increased carbo dioxide (CO2) emissions, considerable efforts have been made in the research community. Photocatalytic hydrogen (H2) production is a very important way towards this goal, since sunlight is an abundant source of energy and H2 is a clean fuel, producing no greenhouse gases. Inexpensive, stable and non‐toxic carbon dots were easily synthesized and used as photosensitizers in water in the presence of a series of molecular cobalt catalysts (CoTSC). The catalysts were thiosemicarbazone‐based complexes able to transfer electrons for hydrogen evolution reaction. Under visible light irradiation, the nitrogen‐doped carbon dots (NCdots) transfer the photoexcited electrons to the catalyst, producing an activity of 358 μmol gNCdot−1 h−1 (TONCo=570) for CoTSC−N(CH3)2CN after 24 h of irradiation. These types of molecular catalysts display great activity and stability in combination with the easily synthesized and modified carbon dot materials.

Waste plastics derived nickel-palladium alloy filled carbon nanotubes for hydrogen evolution reaction

Carbon nanotubes (CNTs) composed of bimetallic nickel-palladium (NiPd) nanoparticles encapsulated in graphitic carbon shells (NdPd@CNT) are prepared by the chemical vapour deposition method using waste polyethylene terephthalate (PET) plastic carbon sources and NiPd-decorated carbon sheets (NiPd@C) catalyst. The characterization results reveal that the face-centered cubic crystalline (fcc)-structured NiPd bimetallic alloy nanoparticles are encased by thin carbon nanotubes. The bimetallic synergism of NiPd nanoparticles actuates the outer CNT layers and accelerates the electrical conductivity, stimulating the electrochemical activity toward an effective hydrogen evolution reaction (HER). By virtue of the collective individualities of highly conductive aligned carbon walls and bimetallic active sites, the NiPd@CNT-equipped HER delivers a minimum overpotential of 87 mV and a Tafel slope value of 95 mV dec−1. The existing intact contact between NiPd and CNT facilitates continuous electron and ion transportation and firm stability toward long-term hydrogen production in HER. Notably, the NiPd@CNT reported here produces excellent electrochemical activity with minimal charge transference resistance, substantiating the efficacy of NiPd@CNT for futuristic green hydrogen production.

The intriguing bifunctional effect of strong metal support interaction (SMSI) and hydrogen spillover effect (HSPE) for effective hydrogen evolution reaction

The mechanistic insights behind the kinetics of Hydrogen evolution reaction are unraveled through the bifunctional effect - Strong Metal Support Interaction (SMSI) and Hydrogen Spillover Effect (HSPE) on the WO3 hexagonal nanorods decorated with gold clusters and supported on the reduced graphene layers. The investigation is extended to scaling the electrocatalyst in a flexible electrode-carbon fiber for robust hydrogen evolution reaction in broad pH spectra. The research found that the proposed electrocatalyst demonstrated a reduced overpotential of 20 mV at a current density of 10 mA cm2 in acidic conditions and the stability of the ternary catalyst was verified through the Pourbaix profile. The Tafel slope was also comparable to that of the noble metal electrocatalyst Pt/C, with values of 35 mV dec–1 in 0.5 M H2SO4. The study demonstrated the potential for large-scale application of the proposed catalyst with stable operation observed for 24 h.

Factors Effecting and Structural Engineering of Molybdenum Nitride‐Based Electrocatalyst for Overall Water Splitting: A Critical Review

The advancement of spotless hydrogen energy generation is being accelerated by the advancement in nonprecious electrocatalysts for effective hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting. In this review, the main focus is given to the most significant innovations in the surface topography, morphological shape, size distribution, and electrocatalytic functionality of highly engineered molybdenum nitride catalysts, equal to or even better than state‐of‐the‐art electrocatalyst for HER and OER. Different morphological or interfacial engineering techniques, such as in situ electrospinning, topochemical methods, and classic chemical methods for synthesizing nonprecious molybdenum nitride electrocatalysts, are extensively covered. Molybdenum nitrides are discovered the excellent electrocatalyst, and the factors that can improve its electrocatalytic properties, such as morphological tuning, controlled geometrical composition, pH effect, hybrid and electronic structures, the effect of temperature, and effects of active sites, are comprehensively discussed.

Facile synthesis of strongly coupled platinum-molybdenum/silicon carbide quantum-dots heterostructures as electrocatalyst for hydrogen evolution reaction

Strongly coupled platinum-based transition-metal oxide and the development of quantum-dot structures of hybrid catalysts are cost-effective and maximize accessible active sites. However, a significant obstacle still exists for the rational proposal and simple synthesis of hybrid quantum-dot material catalysts. Herein, novel PtxMo1-xSiC quantum dots (PtxMo1-xSiC QDs) for catalyzing the hydrogen evolution reaction (HER) were fabricated through a simple solution-induced impregnation method. The optimized Pt0.05Mo0.95SiC QDs catalyst only require overpotentials of 28 mV to deliver a current density of 10 mA cm−2 in acidic media, respectively. The synergistic effects of the PtxMo1-xSiC QDs networks that promote electron transfer are responsible for the outstanding HER performance. This work presents a novel method for producing an extremely effective HER catalyst for applications on large-scale.

One-step solution-induced impregnation synthesis of strongly coupled platinum–molybdenum/silicon carbide quantum dots heterostructures encapsulated on reduced graphene oxide sheet as electrocatalyst for hydrogen evolution reaction

Strongly coupled platinum-based transition-metal oxide/carbon hybrids and the development of quantum-dot structures of hybrid catalysts are cost-effective and maximize accessible active sites. However, a significant obstacle still exists for the rational proposal and simple synthesis of hybrid quantum-dot material catalysts. Herein, novel PtxMo1-xSiC quantum dots encapsulated in reduced graphene oxide (rGO) (PtxMo1-xSiC QDs @rGO) for catalyzing the hydrogen evolution reaction (HER) were fabricated through a simple solution-induced impregnation method. The optimized Pt5Mo95SiC QDs @rGO catalyst only require overpotentials of 18 mV and 25 mV to deliver current densities of 10 mA cm−2 and 250 mA cm−2 in acidic media, respectively. The synergistic effects of the inner PtxMo1-xSiC QDs networks and outer conductive rGO sheets that promote electron transfer are responsible for the outstanding HER performance. This work presents a novel method for producing an extremely effective HER catalyst for applications on large-scale.

Ru nanoclusters coupling with hierarchical phosphorus and oxygen dual-doped carbon nanotube architectures for effective hydrogen evolution reaction

The construction of an effective catalyst for hydrogen evolution reaction (HER) is a top priority. Herein, we demonstrate ruthenium (Ru) nanoclusters coupled with phosphorus and oxygen dual-doped carbon nanotube (CNT) architecture (Ru-POCA). The increased hydrophilicity and negatively charged surface of CNTs can strongly trap Ru ions. The hierarchical structure is favorable of providing abundant pathways and exposing more active sites for HER. Due to the synergistic effect of the hierarchical structure and modified surface chemistry, Ru-POCA exhibits excellent catalytic HER activity. The overpotential is 22 and 40 mV with a Tafel slope of 28.0 and 27.1 mV dec−1 in 1 M KOH and 0.5 M H2SO4 at 10 mA cm−2. Moreover, Ru-POCA processes good catalytic stability in both acidic and alkaline electrolytes, while the boosted catalytic HER activity is fundamentally studied by density functional theory calculation. This work provides a rational approach to constructing hierarchically structured Ru-CNTs-based catalysts for hydrogen evolution reaction.

WO3 Nanorods Decorated with Very Small Amount of Pt for Effective Hydrogen Evolution Reaction

The electrochemical hydrogen evolution reaction (HER) is one of the most promising green methods for the efficient production of renewable and sustainable H2, for which platinum possesses the highest catalytic activity. Cost-effective alternatives can be obtained by reducing the Pt amount and still preserving its activity. The Pt nanoparticle decoration of suitable current collectors can be effectively realized by using transition metal oxide (TMO) nanostructures. Among them, WO3 nanorods are the most eligible option, thanks to their high stability in acidic environments, and large availability. Herein, a simple and affordable hydrothermal route is used for the synthesis of hexagonal WO3 nanorods (average length and diameter of 400 and 50 nm, respectively), whose crystal structure is modified after annealing at 400 °C for 60 min, to obtain a mixed hexagonal/monoclinic crystal structure. These nanostructures were investigated as support for the ultra-low-Pt nanoparticles (0.2-1.13 μg/cm2): decoration occurs by drop casting some drops of a Pt nanoparticle aqueous solution and the electrodes were tested for the HER in acidic environment. Pt-decorated WO3 nanorods were characterized by performing scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Rutherford backscattering spectrometry (RBS), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and chronopotentiometry. HER catalytic activity is studied as a function of the total Pt nanoparticle loading, thus obtaining an outstanding overpotential of 32 mV at 10 mA/cm2, a Tafel slope of 31 mV/dec, a turn-over frequency of 5 Hz at -15 mV, and a mass activity of 9 A/mg at 10 mA/cm2 for the sample decorated with the highest Pt amount (1.13 μg/cm2). These data show that WO3 nanorods act as excellent supports for the development of an ultra-low-Pt-amount-based cathode for efficient and low-cost electrochemical HER.

Three-Dimensional Strawlike MoSe2-Ni(Fe)Se Electrocatalysts for Overall Water Splitting.

The development of efficient and low-cost transition-metal electrocatalysts is of great significance for hydrogen production from water splitting. Herein, we synthesized three-dimensional strawlike MoSe2-NiSe composed of microrods on nickel foam (NF) by a one-step hydrothermal reaction. The as-prepared MoSe2-NiSe/NF exhibited effective hydrogen evolution reaction (HER) activity (low overpotential of 79 mV at 10 mA cm-2 and stability of 21 h in 1 M KOH), benefiting from the large electrochemically active area provided by strawlike structures, proper Se content, and synergistic effect of active phases. The enhanced oxygen evolution reaction (OER) activity (the low overpotential of 217 mV at 10 mA cm-2 and maintaining stability for 47 h in 1 M KOH) was further observed for Fe-doped MoSe2-NiSe/NF (MoSe2-NiFeSe/NF) prepared by facile soaking, which can be mainly ascribed to optimized active phases formed on the OER process after Fe doping. The two-electrode system (MoSe2-NiSe/NF||MoSe2-NiFeSe/NF) requires a low cell voltage of 1.54 V to obtain a current density of 10 mA cm-2 in 1 M KOH, which provides an interesting idea for constructing an effective overall water splitting system.

Interfacial coupling effect of CoO/CoMoO4 promotes alkaline hydrogen electrode for hydrogen energy storage system

Herein, CoO and CoMoO4 heterostructure supported on nickel foam (CoO/CoMoO4@NF) are proposed as an effective bifunctional hydrogen evolution reaction (HER) and hydroxide reaction (HOR) electrocatalyst. The electron density distribution at the interface can be optimized by coupling CoO and CoMoO4, thereby improving conductivity and regulating the hydrogen binding energy (HBE) and hydroxyl binding energy (OHBE). CoO/CoMoO4@NF exhibits high stability and activity with an exchange current density of ∼3.67 mA cm−2. Co/CoMoO4@NF reaches the current density of −10 mA cm−2 at only −29 mV and the corresponding Tafel slope of 40.2 mV dec−1. This work provides a promising solution for non-precious metal catalyst for hydrogen reaction in energy storage.

Rational construction of efficient ZnS quantum dots-supported g-C3N4 with Co3O4 heterostructure composite for bifunctional electrocatalytic hydrogen evolution reaction and environmental pollutant degradation

Bifunctional heterostructure composite catalysts of ZnS quantum dots (QDs) are incorporated with Co3O4-coupled g-C3N4 (GCOZS) for enhanced electrocatalytic hydrogen evolution reaction (HER) and photocatalytic aqueous dye degradation performance. The phase purity, chemical composition, surface/deep morphology, and specific surface area of the as-obtained catalyst materials are determined using powder XRD, FT-IR, high-resolution XPS, FESEM with EDX mapping, HRTEM and BET analyses. The as-developed GCOZS composite catalysts exhibit an effective HER performance through a less Tafel slope of 71 mV dec−1 and low overpotential of − 304 mV at the current density of 10 mA/cm2. Moreover, the GCOZS composite catalysts exhibit excellent aqueous Rhodamine B (Rh B) dye degradation efficiency (∼93.05 %) within 180 min of light exposure. In addition, the catalytic performance of the ternary heterostructure composite is improved owing to the efficient charge transfer pathway among intimate interfacial contacts with a high specific surface area by incorporating functional ZnS QDs and Co3O4 to the g-C3N4 layer surface. As a result, providing an efficient bifunctional electro/photocatalyst system has been of great interest for realistic energy conversion in environmental applications, which may offer new designing possibilities for novel catalysts utilizing carbon-based materials.

Regulation of the electronic structure of a RuNi/MoC electrocatalyst for high-efficiency hydrogen evolution in alkaline seawater.

Alkaline seawater electrolysis offers a way to generate hydrogen without carbon emissions. However, developing highly efficient catalysts that can sustain high performance and stability for the hydrogen evolution reaction (HER) in alkaline seawater is a formidable challenge. Here, a nanowire (NW) of a RuNi/MoC heterojunction embedded in N-doped carbon (RuNi/MoC@NC) was developed as a potent HER catalyst. The catalyst required only 21 mV at 10 mA cm-2 for HER in alkaline seawater, which surpasses 20% Pt/C. Moreover, using nickel foam (NF) as a catalyst carrier, an electrolyzer composed of RuNi/MoC@NC and nickel-iron layered double hydroxide (NiFe LDH) needed only 1.81 V at 500 mA cm-2 for full water splitting and showed long-term stability (over 500 h). Theoretical calculation revealed that the Ru and Ni sites in the catalyst had the optimal adsorption energy for hydrogen and water, respectively, which synergistically lowered the energy barrier for HER. This work offered an efficient method to design a highly effective HER catalyst for alkaline seawater splitting.

Redrawing HER Volcano with Interfacial Processes—The Role of Hydrogen Spillover in Boosting H2 Evolution in Alkaline Media

The requirements for the efficient replacement of fossil fuel, combined with the growing energy crisis, places focus on hydrogen production. Efficient and cost-effective electrocatalysts are needed for H2 production, and novel strategies for their discovery must be developed. Here, we utilized Kinetic Monte Carlo (KMC) simulations to demonstrate that hydrogen evolution reaction (HER) can be boosted via hydrogen spillover to the support when the catalyst surface is largely covered by adsorbed hydrogen under operating conditions. Based on the insights from KMC, we synthesized a series of reduced graphene-oxide-supported catalysts and compared their activities towards HER in alkaline media with that of corresponding pure metals. For Ag, Au, and Zn, the support effect is negative, but for Pt, Pd, Fe, Co, and Ni, the presence of the support enhances HER activity. The HER volcano, constructed using calculated hydrogen binding energies and measured HER activities, shows a positive shift of the strong binding branch. This work demonstrates the possibilities of metal–support interface engineering for producing effective HER catalysts and provides general guidelines for choosing novel catalyst–support combinations for electrocatalytic hydrogen production.

Template-assisted preparation of imbricate N–MoxC nanotubes for the effective electrocatalytic hydrogen evolution reaction

Imbricate N–MoxC nanotubes with enlarged specific surface area achieve an excellent electrocatalytic performance for the alkaline hydrogen evolution reaction.

Self-standing Co decorated Cu2O/CuS-based porous electrocatalyst for effective hydrogen evolution reaction in basic media

The self-standing Co decorated Cu2O/CuS-based porous electrocatalyst was prepared with the help of simple electrodeposition and hydrothermal method. The structural characterizations of fabricated samples were performed with X-Ray diffraction spectroscopy and X-Ray photoelectron spectroscopy, while the morphology of catalysts was studied with the help of Field-Emission Spectroscopy and Transmission Electron Spectroscopy. The electrochemical performance of the hydrogen evolution reaction was checked in a basic electrolyte. The gradual increment in the electrochemical performance of Cu2O was observed when it underwent sulfurization without and with Co precursor respectively. The best electrochemical performance for hydrogen evolution reaction with an overpotential of 150.29 mV to achieve a geometric current density of 10 mA/cm2 was observed for the Cu2O sample sulfurized with Co precursor. The results of different characterizations suggested that the improved electrochemical performance could be attributed to the increased intrinsic activity and surface porosity of the electrocatalyst after sulfurization.

Study on Nickel-induced 1T/2H MoS2 nanostructures in realizing efficient electrocatalysts for hydrogen evolution reaction

• Rational design and successfully prepared Ni-induced 1T/2H MoS 2 . • Ni-induced 1T/2H MoS 2 exhibits efficient HER catalytic performance. • The Ni-ions are favorable for enhancing the HER performance. Two-dimensional (2D) molybdenum disulfide (MoS 2 ) catalysts have gained great attention in several applications due to their unique properties as well as their tunable electronic structures. Fabrication of cost-effective and highly efficient electrocatalysts is vital for water splitting. Herein, we have synthesized nickel (Ni) induced mixed-phase (1T/2H) MoS 2 by solvothermal method and have studied its characteristics to be used for hydrogen evolution reaction (HER). The doping of Ni in MoS 2 is aimed at increasing the efficiency of HER performance and it has been proved to be a highly effective HER catalyst in an acidic medium. Ni-doped (9%) MoS 2 achieved the lowest overpotential of 127 mV for the HER at 10 mA cm −2 and a Tafel slope of 86 mV dec -1 among the other concentrations of Ni-doping studied. This work demonstrates the constructive outcome of doping the catalyst for HER and provides a pragmatic way for obtaining earth-abundant electrocatalysts.

Engineering the Coordination Interface of Isolated Co Atomic Sites Anchored on N-Doped Carbon for Effective Hydrogen Evolution Reaction.

The regulation of the coordination environment of the central metal atom is considered as an alternative way to enhance the performance of single-atom catalysts (SACs). Herein, we design an electrocatalyst with active sites of isolated Co atoms coordinated with four sulfur atoms supported on N-doped carbon frameworks (Co1-S4/NC), confirmed by high-angle annular dark-field scanning transmission electron microscope (HADDF-STEM) and synchrotron-radiation-based X-ray absorption fine structure (XAFS) spectroscopy. The Co1-S4/NC possesses higher hydrogen evolution reaction (HER) catalytic activity than other Co species and exceptional stability, which exhibits a small Tafel slope of 60 mV dec-1 and a low overpotential of 114 mV at 10 mA cm-2 during the HER in 0.5 M H2SO4 solution. Furthermore, through in situ X-ray absorption spectrum tests and density functional theory (DFT) calculations, we reveal the catalytic mechanism of Co1-S4 moieties and find that the increasing number of sulfur atoms in the Co coordination environment leads to a substantial reduction of the theoretical HER overpotential. This work may point a new direction for the synthesis, performance regulation, and practical application of single-metal-atom catalysts.