Effective Hydrogen Evolution Reaction Research Articles

Enhanced electrocatalytic hydrogen evolution reaction by injection of photogenerated electrons in Ag/WS2 nanohybrids

In renewable energies devices, effective water splitting by electrocatalysis holds a lot of promise for generating hydrogen fuel. Typically, designing commercially feasible, effective, and stable electrocatalysts to reduce activation potential barriers is essential to applying high-performance water splitting. Herein, we report an active catalyst based on photosensitive Ag/WS2 hybrids for effective and rapid hydrogen evolution reaction. Ag/WS2 hybrids with optimised material proportions demonstrate the over potential as low as −170 mV vs RHE in acidic medium and −180 mV in basic medium at −10 mA/cm2 for hydrogen evolution reaction which is far lower than that of pristine materials. We demonstrate that the injection of photogenerated electrons under excitation of Ag localized surface plasmon resonance (LSPR) as well as owing to exciton generation in WS2 nanosheets can further reduce the over potential upto −140 mV vs RHE at −10 mA/cm2 in acidic medium and −150 mV vs RHE in basic medium and significantly enhances the current density. This research advocates the promising path for activation of intrinsic electrocatalytic activities of semiconducting materials to encourage use of renewable sources of energy.

Accelerate the alkaline hydrogen evolution reaction of the heterostructural Ni2P@Ni(OH)2/NF by dispersing a trifle of Ru on the surface

Electrocatalytic water splitting for hydrogen production plays a vital role in the development of new energy field, but there is still a lack of low-content precious metal or cost-effective non-noble metal catalysts for the hydrogen evolution reaction (HER). Therefore, how to develop the catalysts with a smaller amount of precious metal to achieve higher performance is still a major challenge. Herein, we have fabricated Ru–Ni2P@Ni(OH)2/NF-2 heterostructure by phosphating Ni(OH)2/NF and then anchoring Ru on the surface through wet chemical strategy. Benefiting from its optimal ΔGH∗ and synergistic effect, this Ru–Ni2P@Ni(OH)2/NF-2 catalyst shows superior electrocatalytic HER kinetics in alkaline electrolyte. A small overpotential of 31 mV is needed for this electrocatalyst to obtain the current densities of 10 mA cm−2 with remarkable durability over 24 h. This work provides a new strategy for the preparation of effective HER electrocatalyst with a low precious metal content.

Self-supporting Atmosphere-Assisted Synthesis of 1D Mo2 C-based Catalyst for Efficient Hydrogen Evolution.

One-dimensional materials exhibit fascinating properties in electrocatalytic applications but their fabrication faces the challenge of tedious and complicated operations. We have developed a bottom-up strategy to construct a 1D metal carbide catalyst (Mo2 C@NC) consisting of ultrafine Mo2 C nanoparticles embedded within nitrogen-doped carbon layers by simply calcining a mixture of ammonium molybdate, urea and melamine. Experimental results and thermodynamic calculations demonstrate that the retainable pyrolysis-generated self-supporting atmosphere plays a crucial role in the crystalline phase and morphology of materials. When functioned as an electrocatalyst for the hydrogen evolution reaction (HER), the achieved Mo2 C@NC presents an excellent catalytic activity as well as outstanding stability. This work could shed fresh light onto the facile synthesis of effective HER catalysts with 1D nanostructure.

Charge-Modulated VS2 Monolayer for Effective Hydrogen Evolution Reaction

Charge-Modulated VS₂ Monolayer for Effective Hydrogen Evolution Reaction

Controllable fabrication of abundant nickel-nitrogen doped CNT electrocatalyst for robust hydrogen evolution reaction

Designing highly effective and durable non-noble metal based electrocatalysts for hydrogen evolution reaction (HER) is cardinal for the sustainability of clean energy technologies. This present work explores the fabrication of nickel-nitrogen doped CNT through a simplistic approach. The as-fabricated Ni-NCNT8.0 showcases a robust HER performance amongst the other catalysts (Ni-NCNT7.5, Ni-NCNT8.5, Ni-x, and Glu-x) with a small overpotential of 147 mV and Tafel slope of 57.6 mV dec-1 to approach a current density of 10 mA cm−2 in alkaline medium. It also exhibits an excellent stability for 20 h. The high HER performance originates from the abundant and well-formed N-doped CNT that serves as conductive support and the synergy between the nickel nanoparticles which suffice as the catalyst active sites and the N-doped CNT. Additionally, the optimized electronic structure of the nickel nitrogen-doped CNT provided by density functional theory calculations, revealed a low HOMO-LUMO energy gap and high ionization potential that enhanced the stability of the electrocatalyst and conveys an effective HER.

Hybrid Structure of Ionic Liquid and TiO2 Nanoclusters for Efficient Hydrogen Evolution Reaction.

Hydrogen energy has received significant attention in the renewable energy sector due to its high energy density and environmentally friendly nature. For the efficient hydrogen generation from water, the hydrogen evolution reaction (HER) has to be optimized, which requires a highly efficient electrocatalyst. In this work, a hybrid structure of the ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (C2mim TfO) and (TiO2)n nanoclusters with n = 2-12 has been investigated in the pursuit of new catalyst materials for effective HER. We have employed state-of-the-art density functional theory (DFT) computations to depict the HER catalytic performance of IL/(TiO2)n hybrid systems through Gibbs free energy (ΔG) and an exchange-current-based "volcano" plot. We have explored the effect of the TiO2 nanoclusters on the structural and electronic characteristics of the IL, calculating the adsorption energy, the energies of the highest occupied (HOMO) and lowest unoccupied molecular orbitals (LUMO), the HOMO-LUMO band gap Eg, and the work function ϕ. The variation in size of the TiO2 nanocluster in the IL/(TiO2)n hybrid system was found to have a significant influence on the electronic properties. The obtained results suggest that the ΔG of the hydrogen adsorption is remarkably close to the ideal value (0 eV) for the IL/(TiO2)5 system, which also reflects from the volcano plot, suggesting that this complex is the best HER catalyst among the studied systems; it might be even better than the traditional Pt-based catalyst. Thus, the present work suggests ways for the experimental realization of low-cost and multifunctional IL-based hybrid catalysts for clean and renewable hydrogen energy production.

One-Dimensional Multichannel g-C3N4.7 Nanostructure Realizing an Efficient Photocatalytic Hydrogen Evolution Reaction and Its Theoretical Investigations

The emerging metal-free carbon nitride (C3N4) offers prominent possibilities for realizing the highly effective hydrogen evolution reaction (HER). However, its poor surface conductivity and insuffi...

Ultra-thin CoS2 nanosheets synthesized by one-step hydrothermal process for hydrogen evolution

Rationally designing and synthesizing nanostructures with increased density of active sites are an effective route to enhance the hydrogen evolution reaction (HER) activity of electrocatalysts. In this work, a simple one-step hydrothermal method was used to synthesize cobalt disulfide (CoS2) nanosheets on the stainless-steel fiber (SSF) felt substrate, by which the thickness of CoS2 nanosheets can be sensitively tuned by thiourea concentration in reactant precursors. Especially, the CoS2 nanosheets synthesized under a thiourea concentration of 0.083 M present an ultra-thin thickness of about 10 nm with abundant gaps between the nanosheets. Such morphology with large effective surface area together with superhydrophilic property assures it an effective HER electrode, showing an overpotential of − 290.6 mV at 10 mA cm−2 and a Tafel slope of 74.21 mV dec−1 over other samples synthesized under higher thiourea concentrations. Chronoamperometric test also shows excellent HER durability by the assistance of chemical-stable SSF substrate.

Vanadium Cluster Neutrals Reacting with Water: Superatomic Features and Hydrogen Evolution in a Fishing Mode.

Hydrogen evolution reaction (HER) is known as the heart of various energy storage and conversation systems of renewable energy sources. Here we observe the cluster reactions of a light transition metal, vanadium, with water in a gas-phase flow tube reactor. While HER products of V1 and V2 were not observed, the effective HER of water on neutral Vn (n ≥ 3) clusters reveals reasonable and size-dependent reactivity of the vanadium clusters. Superatomic features and reaction dynamics of V10, V13, and V16 are highlighted. Among the three typical superatoms, V10 and V16 exhibit an abnormal superatomic orbital energy level order, 1S|2S|1P|1D..., where the energy-reduced 2S orbital helps to accommodate the geometric structure and hence reinforce the cluster stability. In comparison, V13 bears a less symmetrical structure and reacts readily with water, allowing for recombination of a hydroxyl atom with an adsorbed hydrogen atom, akin to a fishing-mode HER process. The joint experimental and theoretical study on neutral Vn clusters clarifies the availability of superatom chemistry for transition metals and appeals further development of cluster theory based on electronic cloud/orbital analysis instead of simply counting the valence electrons. Also, we provide insights into the HER mechanism of metal clusters and propose a strategy to design new materials for portable fuel cells of hydrogen energy.

Ultrafine multi-metallic carbide nanocrystals encased in a carbon matrix as durable electrocatalysts towards effective alkaline hydrogen evolution reaction

A general route to synthesize a series of ultrafine Mo-based HER-active bi-/tri-metallic carbide electrocatalysts by direct carbonization of multi-metal molybdate precursors.

DNA-based low resistance palladium nano-spheres for effective hydrogen evolution reaction

Highly stable and less resistance Pd/DNA NSs are designed for HER in acidic medium and require a low overpotential (η10) of 79 mV. DNA plays multiple roles such as stabilizer, structure-directing agent and binder in the fabrication of electrodes.

Multifunctional Hierarchically Architectured ZnO for Luminescence, Photocatalytic, Electrocatalytic, and Energy Storage Applications

Hierarchically ZnO nanoarchitecture synthesized through coprecipitation technique. Growth process has been analyzed by varying pH from 5.5 to 13 along with post heat treatment process through the observation of surface morphology from 2D plates, triangular, hexagonal rods, needles, and finally to hierarchical. X-ray diffraction (XRD) reveals many intermediate phases along with ZnO which has been eliminated through the proper pH and temperature. The native defects have been discussed by using Raman and positron annihilation spectroscopy. Further, multifunctional properties of synthesized material have been discussed by candle-like warm white luminescence, photocatalysis, electrocatalysis and energy storage applications. Specially hierarchically nanoarchitecture found suitable for warm white lighting along with effective for waste water treatment by visible light. The highly porous property of the same material made itself appropriate for effective oxygen evaluation reaction and hydrogen evolution reaction together with reduced overpotential and Tafel slope. The application for supercapacitor electrode (~780 F/g) also has been revealed which opened new dimension for hierarchical ZnO.

Amorphous‐crystalline Co−B−P Catalyst for Synergistically Enhanced Hydrogen Evolution Reaction

AbstractThe development of highly practical and stable catalysts for hydrogen evolution reaction (HER) remains challenging to accomplish continuous H2 production through water electrolysis. In this work, the porous network Co−B−P amorphous‐crystalline catalyst was synthesized through a hydrothermal‐alternating immersion boronization‐phosphidation pathway. The Co−B−P nanocomposite consists of the amorphous Co−B−O and crystalline Co2P2O7 compositions. The Co−B−P catalyst shows highly effective HER electrochemical performance with low overpotential of 51 mV at current density of 10 mA cm−2 and Tafel slope of 44 mV dec−1 in alkaline solution (pH=14). After 1000 cycles of CV scanning, the catalyst shows no significant reduction in HER performance. Such superior HER performance can be ascribed to (1) the amorphous Co−B−O structure accelerating charge transfer between active sites and intermediates and (2) the formed P−O bonds of crystalline Co2P2O7 promoting the dissociation course of water molecules. The combination of crystalline and amorphous substances provides prospects for the design of HER catalyst structures in the future.

Hierarchical heterostructured nickle foam–supported Co3S4 nanorod arrays embellished with edge-exposed MoS2 nanoflakes for enhanced alkaline hydrogen evolution reaction

Transition metal chalcogenides with abundant active edge sites and suitable structures for large-scale water splitting in alkaline hydrogen evolution reaction (HER) are challenging but promising. Herein, hierarchical heterostructured nickel foam–supported Co3S4 nanorod arrays embellished with edge-exposed MoS2 nanoflakes (Edge-MoS2/Co3S4@NFs) as an effective HER catalyst are designed. There into, porous nickel foam and moderately distributed nanorod arrays of Edge-MoS2/Co3S4@NFs provide multiscale pathways for efficient charge and mass transport and significantly enlarge the surfaces for the deposition of MoS2 flakes. The superhydrophilic/aerophobic surface improves the electrolyte transport and facilitates the detachment of hydrogen bubbles from the surface of the catalyst. The MoS2 flakes anchored on nanorods are well dispersed with plentiful active sites exposed which enhance the intrinsic activity of active sites owing to the adequate intersection of charge and mass. In addition, there is a synergetic effect of bimetal sulfides, evidenced by increasing the turnover frequency. Therefore, the Edge-MoS2/Co3S4@NF affords a low overpotential (η10 = 90.3 mV and η1000 = 502.0 mV) and small Tafel slope (61.69 mV dec−1). This study provides a facile strategy to develop electrocatalysts through the synergy of enhanced thermodynamic and kinetic processes, shedding lights on the advanced design of functional materials for energy chemistry.

Fabrication of Co(Ni)-P surface bonding states on core–shell Co(OH)2@P-NiCo-LDH towards electrocatalytic hydrogen evolution reaction

The application of NiCo-LDHs in the hydrogen evolution reaction (HER) is rarely reported because it is usually served as an effective electrocatalyst for oxygen evolution reaction (OER) owing to the essential chemical and electric structure features. It still is a challenge to realize the effective HER over NiCo-LDHs unless modified with noble metals. In this work, the noble-metal-free core–shell Co(OH)2@P-NiCo-LDH hybrid with dodecahedral hierarchical structure is prepared by the sacrificial template method along with subsequent phosphating process, which is available for the electrocatalytic HER. The fabricated Co(Ni)δ+-Pδ- bonding states on the surface of outer shell NiCo-LDH not only provide the abundant active centers but also reduce interfacial charge transfer resistance to enhance the HER activity. Meanwhile, the unique core–shell dodecahedral structure effectively avoids the agglomeration and restacking of NiCo-LDH nanosheets to improve the electrochemical stability. This work exploits a novel noble-metal-free modification strategy to expand the application of NiCo-LDH in HER.

Hydrophilic/Aerophobic Hydrogen-Evolving Electrode: NiRu-Based Metal-Organic Framework Nanosheets In Situ Grown on Conductive Substrates.

Electrocatalytic reduction of water via hydrogen evolution reaction (HER) is considered one of the most ideal avenues to produce high-purity hydrogen (H2) in large quantities, which always requires active electrocatalysts to overcome the high energy barrier. It is of significance yet challenging to design and construct effective HER electrocatalysts of an acceptable cost. In this study, a highly efficient metal-organic framework (MOF)-based electrochemical HER system based on NiRu-based binary MOF (Ru-doped Ni2(BDC)2TED MOF, BDC = 1,4-benzenedicarboxylic acid; TED = triethylenediamine) nanosheets grown on conductive substrates (e.g., Ni foam, carbon cloth) is fabricated by a facile solvothermal method. The resultant NiRu-MOF-based composites possess enhanced electron transport ability and water stability, accompanied by increased electrochemically active areas and hydrophilic/aerophobic properties. With these advantages, the optimized NiRu-MOF nanosheet arrays on Ni foam substrate (NiRu-MOF/NF) with a Ru/Ni molar ratio of 6/94 in the MOF structure could exhibit efficient catalytic performance for HER in alkaline conditions, requiring a small overpotential of 51 mV at -10 mA cm-2. This study could provide a feasible way for the design and synthesis of two-dimensional (2D) MOF-based materials with controllable interface properties for energy catalysis and beyond.

2D Transition Metal Dichalcogenides: Design, Modulation, and Challenges in Electrocatalysis.

Hydrogen has been deemed as an ideal substitute fuel to fossil energy because of its renewability and the highest energy density among all chemical fuels. One of the most economical, ecofriendly, and high-performance ways of hydrogen production is electrochemical water splitting. Recently, 2D transition metal dichalcogenides (also known as 2D TMDs) showed their utilization potentiality as cost-effective hydrogen evolution reaction (HER) catalysts in water electrolysis. Herein, recent representative research efforts and systematic progress made in 2D TMDs are reviewed, and future opportunities and challenges are discussed. Furthermore, general methods of synthesizing 2D TMDs materials are introduced in detail and the advantages and disadvantages for some specific methods are provided. This explanation includes several important regulation strategies of creating more active sites, heteroatoms doping, phase engineering, construction of heterostructures, and synergistic modulation which are capable of optimizing the electrical conductivity, exposure to the catalytic active sites, and reaction energy barrier of the electrode material to boost the HER kinetics. In the last section, the current obstacles and future chances for the development of 2D TMDs electrocatalysts are proposed to provide insight into and valuable guidelines for fabricating effective HER electrocatalysts.

Facile fabrication of activated NiFe bimetallic NPs anchored N-doped CNTs arrays as reliable self-standing electrocatalyst for HER and OER

Hydrogen generation by water splitting in alkaline solution is a key candidate to product sustainable alternative energy in the 21st century. In this article, we fabricated the self-standing N-doped carbon nanotubes (CNTs) array encapsulated NiFe alloy nanoparticles (NPs) via facile solid-diffusion method as effective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts (NiFe/CNTs composites). As-prepared NiFe/CNTs-900 exhibited great electrocatalysis activity, with overpotentials of 149 ​mV for HER and 257 ​mV for OER to drive current density of 10 ​mA/cm2, and also displayed superior electrochemical stability, which are mainly due to the synergistic effect between the bimetallic transition metals and N-doped carbon and the large number of active sites generated during the products preparation process.

Dopant-Induced Edge and Basal Plane Catalytic Sites on Ultrathin C3N4 Nanosheets for Photocatalytic Water Reduction

The emerging carbon nitride (C3N4) offers a serious possibility for realizing a highly effective hydrogen evolution reaction (HER). However, their insufficient catalytic sites and poor conductivity...

Highly Active and Durable Nanostructured Ni-CNTs-HG Composite Electrocatalyst for Hydrogen Production

Background: World energy crisis has triggered more attention to energy developing of clean energy carrier. To find simple, economical and effective hydrogen evolution reaction catalysts is one of the major challenges. Rational design and modification of electrocatalysts materials are of great importance for the development of low-cost and effective catalysts. Methods: Herein, we report a Ni-CNTs-HG/NF electrode catalyst, which is fabricated on the surface of Ni foam by electrodeposition technique. The fabrication strategy allows the construction of a composite architecture with the Ni foam morphology at the macro level, and the Ni nanoparticles supported by carbon nanotubes and Hydrophilic graphene nanosheets at the nanoscopic level. Results: Compared to NF electrocatalyst, the Ni-CNTs-HG/NF, the CNTs and HG sheets possess the largest electrocatalytic active surface area, providing Ni nanoparticles with catalytically active sites. The Ni-CNTs-HG/NF electrocatalyst exhibits better HER performance in alkaline electrolytes. Conclusion: The Ni-CNTs-HG cathode performs its activity under alkaline conditions with an overpotential i.e 56 and 227 mV at a current density of 10 and 100mAcm-2, which is much lower than that of Ni foam electrode (423 and 278 mV). The secret of the enhanced electrochemical activity lies in its interior structure by coupling metal nanoparticles with carbon materials.