Stable Electrocatalyst For Hydrogen Evolution Reaction Research Articles

Charge Redistribution of Lattice-Mismatched Co─Cu3P Boosting pH-Universal Water/Seawater Hydrogen Evolution.

Practical applications of the hydrogen evolution reaction (HER) rely on the development of highly efficient, stable, and low-cost catalysts. Tuning the electronic structure, morphology, and architecture of catalysts is an important way to realize efficient and stable HER electrocatalysts. Herein, Co-doped Cu3P-based sugar-gourd structures (Co─Cu3P/CF) are prepared on copper foam as active electrocatalysts for hydrogen evolution. This hierarchical structure facilitates fast mass transport during electrocatalysis. Notably, the introduction of Co not only induces a charge redistribution but also leads to lattice-mismatch on the atomic scale, which creates defects and performs as additional active sites. Therefore, Co─Cu3P/CF requires an overpotential of only 81, 111, 185, and 230mV to reach currents of 50, 100, 500, and 1000mA cm-2 in alkaline media and remains stable after 10 000 CV cycles in a row and up to 110h i-t stability tests. In addition, it also shows excellent HER performance in water/seawater electrolytes of different pH values. Experimental and DFT show that the introduction of Co modulates the electronic and energy level structures of the catalyst, optimizes the adsorption and desorption behavior of the intermediate, reduces the water dissociation energy barrier during the reaction, accelerates the Volmer step reaction, and thus improves the HER performance.

Effect of carbon black supports on the hydrogen evolution reaction activity of Pd nanoparticle electrocatalysts synthesized via solution plasma sputtering.

The hydrogen evolution reaction (HER) is a pivotal electrochemical process in water electrolysis, essential for hydrogen production. The efficiency and kinetics of HER are significantly influenced by the choice of catalyst and its support material. In this study, we investigated the effect of carbon supports on palladium (Pd) nanoparticle electrocatalysts synthesized via the solution plasma sputtering process for HER. Pd nanoparticles were loaded onto three hierarchically porous carbon black (CB) supports: Vulcan XC-72R, Ketjen Black EC-300J, and Black Pearls 2000. Well-crystalline Pd nanoparticles, ranging in size from approximately 2-6 nm, were distributed on the surface of CB supports with Pd loading contents ranging between 21 and 29 wt%. The catalysts exhibited lower specific surface areas compared to bare CB supports due to a significant decrease in exposed micropores, which were blocked by the Pd nanoparticles at their entrances. Among the CB supports investigated, Pd nanoparticles loaded on Black Pearls 2000 demonstrated the highest HER activity, as evidenced by the lowest overpotential, largest electrochemical surface area, and highest mass activity. This superior activity can be attributed to the unique characteristics of Black Pearls 2000, including its high surface area and abundant micropores. Furthermore, it demonstrated greater HER stability than commercial platinum (Pt)-based catalysts. Our finding suggests that Black Pearls 2000 could serve as a promising CB support for further developing highly efficient and stable HER electrocatalysts.

A Molecular Binuclear Nickel (II) Schiff Base Complex for Efficient HER Electrocatalysis

The hydrogen evolution reaction (HER) has emerged as a focal point in the realm of sustainable energy generation, offering the potential to produce clean hydrogen gas (H2) devoid of pollutants. The pursuit of stable HER electrocatalysts that can reduce our reliance on precious platinum, while still maintaining a high level of catalytic efficiency, presents a significant and ongoing challenge. In this study, we introduce the utilization of a binuclear nickel (II) Schiff base complex known as [Ni]2[L]2 2 for the purpose of HER electrocatalysis. The rational design of this electrocatalyst has yielded optimal HER performance, wherein the strategic placement of electronegative heteroatoms in proximity to the metal centers serves to enhance proton affinity. Consequently, this catalyst manifests outstanding HER activity, characterized by a nearly 100% faradaic efficiency (FE) at an overpotential potential of −0.4 V versus the reverse hydrogen electrode (RHE), sustained catalytic activity over an extended 80 h electrolysis period, and a commendable turnover number (TON) of 0.0006 s−1.

Strong metal–support interaction boosts the electrocatalytic hydrogen evolution capability of Ru nanoparticles supported on titanium nitride

AbstractRuthenium (Ru) has been regarded as one of the most promising alternatives to substitute Pt for catalyzing alkaline hydrogen evolution reaction (HER), owing to its inherent high activity and being the cheapest platinum‐group metal. Herein, based on the idea of strong metal–support interaction (SMSI) regulation, Ru/TiN catalysts with different degrees of TiN overlayer over Ru nanoparticles were fabricated, which were applied to the alkaline electrolytic water. Characterizations reveal that the TiN overlayer would gradually encapsulate the Ru nanoparticles and induce more electron transfer from Ru nanoparticles to TiN support by the Ru–N–Ti bond as the SMSI degree increased. Further study shows that the exposed Ru–TiN interfaces greatly promote the H2 desorption capacity. Thus, the Ru/TiN‐300 with a moderate SMSI degree exhibits excellent HER performance, with an overpotential of 38 mV at 10 mA cm−2. Also, due to the encapsulation role of TiN overlayer on Ru nanoparticles, it displays super long‐term stability with a very slight potential change after 24 h. This study provides a deep insight into the influence of the SMSI effect between Ru and TiN on HER and offers a novel approach for preparing efficient and stable HER electrocatalysts through SMSI engineering.

Effectively enhanced activity of hydrogen evolution through strong interfacial coupling on SnS2/MoS2/Ni3S2 heterostructured porous nanosheets

Designing electrocatalysts appropriately is of great significance for the sustainable development of hydrogen evolution technology under alkaline water electrolysis. However, engineering the active site at the surface interface in order to improve the catalytic activity of the catalyst has been a great challenge. Herein, an interface engineering heterojunction consisting of SnS2 nanoparticles anchored on a MoS2/Ni3S2 porous nanosheet array is developed. The three-dimensional (3D) MoS2/Ni3S2 nanosheet arrays can uniformly restrict the SnS2 nanoparticle agglomeration, and contribute significantly to the hydrogen evolution reaction (HER) performance. The introduction of Sn can protect the 3D structure of MoS2/Ni3S2 nanosheet arrays from damage. Additionally, the strong coupling between SnS2, MoS2 and Ni3S2 facilitates charge transfer, thereby enabling fast reaction kinetics at the three-phase heterointerface. The resulting SnS2/MoS2/Ni3S2/NF electrocatalysts exhibit excellent HER performance, requiring only 232 mV overpotential to drive a current density of 100 mA cm−2, and can operate continuously for at least 100 h to achieve long-term stability. This study potentially provides a new channel for rationally establishing multi-phase heterointerfaces to achieve high-performance, long-term stable HER electrocatalysts.

A review on recent advances and progress in Mo2C@C: A suitable and stable electrocatalyst for HER

In this review, the environmental issues and the energy crisis caused due to overuse of diminishing fossil fuels have been introduced and discussed. The need for new renewable, non-carbon emission energy sources and the importance of hydrogen (H2) as clean and efficient energy generated via hydrogen evolution reaction (HER) through electrochemical water splitting is discussed. The role of an efficient electrocatalyst for HER has been highlighted. The requirement of low-cost, efficient, and durable electrocatalysts for HER to replace the costly platinum (Pt) electrocatalysts is introduced. The importance of nano transition metal carbides (TMCs), especially molybdenum carbide (Mo2C), as an efficient and stable electrocatalyst has been discussed in detail. The progress and advances to improve the electrocatalytic performance of nano Mo2C on the basis of synthesis, size, shape, and carbon support in different forms have been presented. The role of different carbon species over Mo2C on HER activity has been discussed. The importance of nitrogen (N) doping within the carbon structure encapsulating Mo2C particles to improve the HER activity has been highlighted. The importance of in-situ developed surface carbon over Mo2C has been discussed in detail. The utilization of waste carbon materials to address the environmental issues caused due to non-biodegradable wastes is also discussed. In the end, the future scope has been highlighted to commercialize Mo2C as a low-cost electrocatalyst for hydrogen production through HER.

NiCoCuP foam with a 3D hierarchical porous structure as all-pH efficient and stable HER electrocatalyst

Though various active electrocatalysts for hydrogen evolution reaction (HER) have been reported, it remains a challenge to develop efficient non-noble HER catalysts with pH-independent catalytic activity and high stability. In this work, novel porous NiCoCuP was prepared by combining the dynamic hydrogen bubble templated deposition with a low-temperature phosphorization process. The three-dimensional hierarchical porous structure provided the NiCoCuP with both self-supporting ability and ideal channels for fast mass transportation. As a consequence, the NiCoCuP foam exhibited excellent HER catalytic activity and outstanding durability over the entire pH range.

Recent Advances in Transition Metal Tellurides (TMTs) and Phosphides (TMPs) for Hydrogen Evolution Electrocatalysis.

The hydrogen evolution reaction (HER) is a developing and promising technology to deliver clean energy using renewable sources. Presently, electrocatalytic water (H2O) splitting is one of the low-cost, affordable, and reliable industrial-scale effective hydrogen (H2) production methods. Nevertheless, the most active platinum (Pt) metal-based catalysts for the HER are subject to high cost and substandard stability. Therefore, a highly efficient, low-cost, and stable HER electrocatalyst is urgently desired to substitute Pt-based catalysts. Due to their low cost, outstanding stability, low overpotential, strong electronic interactions, excellent conductivity, more active sites, and abundance, transition metal tellurides (TMTs) and transition metal phosphides (TMPs) have emerged as promising electrocatalysts. This brief review focuses on the progress made over the past decade in the use of TMTs and TMPs for efficient green hydrogen production. Combining experimental and theoretical results, a detailed summary of their development is described. This review article aspires to provide the state-of-the-art guidelines and strategies for the design and development of new highly performing electrocatalysts for the upcoming energy conversion and storage electrochemical technologies.

Amorphous Co‐P Film: an Efficient Electrocatalyst for Hydrogen Evolution Reaction in Alkaline Seawater

AbstractSeawater electrolysis is considered an attractive alternative to conventional freshwater electrolysis for hydrogen production due to the abundance of seawater in nature. For this reason, efficient electrocatalysts for hydrogen evolution reaction (HER) in alkaline seawater are highly desired. In this study, we report an amorphous Co−P alloy on nickel foam (Co−P/NF) that behaves as an efficient and stable HER electrocatalyst for alkaline seawater electrolysis. The Co−P/NF presents high catalytic performance for HER, requiring a low overpotential of 213 mV to drive a current density of 100 mA cm−2 and a Tafel slope of 120.2 mV dec−1 in alkaline seawater. Furthermore, it shows remarkable electrochemical and structural stability in alkaline seawater.

CuS nanoparticles: An efficient electrocatalyst for hydrogen evolution reaction in a wide pH range

The design and fabrication of eco-friendly, highly sustainable and efficient, and non-noble metal-based electrodes are in high demand for the hydrogen evolution reaction (HER) in a wide pH range. Herein, we report the synthesis CuS nanoparticles and fabrication of paper-based electrodes. Robust and electrocatalytically active CuS nanoparticles shows the obvious hydrogen evolution reaction in broad pH range. Flexible, large area and binder free electrodes on paper substrate show the efficient catalytic performance in HER with small over potentials of 79, 258, 375 mV at 10 mA/cm2 in 0.5 M H2SO4, 0.5 M KOH, and 3 M NaCl, respectively. This result shows the highly active and stable electrocatalyst for HER in a wide pH range. Encouragingly, CuS/Ag/Paper electrodes advocates the significant technical development for industrial level hydrogen gas.

In situ synthesis of heterogeneous NiSe2/MoSe2 nanocomposite for high‐efficiency electrocatalytic hydrogen evolution reaction

AbstractDeveloping high‐efficiency electrocatalysts for hydrogen evolution reaction (HER) has been considered as a crucial way to reduce energy loss in water‐splitting. Herein, heterogeneous NiSe2/MoSe2 (H‐NiSe2/MoSe2) nanocomposite constructed by metallic NiSe2 nanocrystallites embedded in few‐layer MoSe2 nanosheets has been in situ synthesized by a simple hydrothermal reaction. As an HER electrocatalyst, it delivers superior performance with an ultra‐small onset overpotential of 103 mV, a small overpotential of 147 mV at 10 mA cm−2, a low Tafel slope of 43.5 mV dec−1, and long‐term stability up to 18 h in 0.5 M H2SO4. The superior performance for HER can be ascribed to the unique embedded nanostructure, which can not only improve the overall conductivity of the nanocomposite but also greatly increase the exposed active sites. Furthermore, the synergistic effect of NiSe2 and MoSe2 hybrid facilitates the rapid electrons transfer from the electrode to the exposed MoSe2 edges to take part in the HER reaction, and thus promotes the HER performance. This study provides a simple route for fabricating bi‐metallic selenides‐based nanocomposite as an efficient and stable electrocatalyst for HER.

Ethanol-Induced Hydrogen Insertion in Ultrafine IrPdH Boosts pH-Universal Hydrogen Evolution.

Engineering Pt-free catalysts for hydrogen evolution reaction (HER) with high activity and stability is of great significance in electrochemical hydrogen production. Herein, in situ chemical H intercalation into ultrafine Pd to activate this otherwise HER-inferior material to form the ultrafine IrPdH hydride as an efficient and stable HER electrocatalyst is proposed. The formation of PdIrH depends on a new hydrogenation strategy via using ethanol as the hydrogen resource. It is demonstrated that H atoms in IrPdH originate from the OH and CH2  of ethanol, which fills the gap of ethanol as the hydrogen source for the preparation of Pd hydride. Thanks to the incorporation of H/Ir atoms and ultrafine structure, the IrPdH exhibits superior HER activity and stability in the whole pH range. The IrPdH delivers very low overpotentials of 14, 25 and 60mV at a current density of 10mA cm-2 respectively in 0.5m H2 SO4 , 1m KOH, and 1m PBS electrolytes, which are much better than those of commercial Pt/C and most reported noble metal electrocatalysts. Theoretical calculations confirm that interstitial hydrogen availably refines the electronic density of Pd and Ir sites, which optimizes the adsorption of *H and leads to the significant enhancement of HER performance.

In Situ Growth of NiSe2-MoSe2 Heterostructures on Graphene Nanosheets as High-Performance Electrocatalyst for Hydrogen Evolution Reaction

Developing highly efficient and stable electrocatalysts for hydrogen evolution reaction (HER) is regarded as a crucial way to reduce energy loss in water splitting. Herein, NiSe2/MoSe2 heterostructures grown on graphene nanosheets (NiSe2-MoSe2 HTs/G) have been in situ synthesized by a simple hydrothermal reaction. As an electrocatalyst for HER, NiSe2-MoSe2 HTs/G delivers superior performance with a low Tafel slope of 65 mV dec−1, a small overpotential of 144 mV at 10 mA cm−2, and long-term stability up to 24 h. The superior performance for HER can be mainly ascribed to the synergistic effects of NiSe2-MoSe2 heterostructures, which can facilitate the rapid electron transfer from the electrode to the exposed MoSe2 edges to take part in the HER reaction, thus boosting the HER kinetics. Moreover, the graphene matrix with high conductivity can not only improve the overall conductivity of the composite but also greatly increase the exposed active sites, therefore further promoting the HER performance. This study provides a simple route for fabricating bimetallic selenides-based heterostructures on graphene as an efficient and stable electrocatalyst for HER.

Mo2C-MoS2 heterojunction a suitable and stable electrocatalyst for HER and supercapacitor Applications

In the present work, Mo2C-MoS2 heterojunction structures have been prepared by the wet impregnation method. For heterojunction species, the content of MoS2 was varied from 5 to 20% by weight. The effect of the loading content of MoS2 over Mo2C on hydrogen evolution reaction (HER) activity and electrochemical (EC) capacitance performance has been studied in detail. The Mo-C-S junction plays a key role in enhancing the HER activity and EC capacitance performance than the individual components. The prepared structures show enhanced HER activity with high current density ~36.2-78.3 mAcm-2 at very low applied potential (0.45 V), exhibiting a lower Tafel slope of 102.4 mVdec-1. The EC capacitor performance determined by CV and galvanic charge-discharge (GCD) reveals that the synthesized samples exhibit an electrochemical double-layer capacitor (EDLC, Cdl) behavior. The higher EDLC (43.9 mFcm-2) and specific capacitance (2Fg-1) obtained for the synthesized samples determine their potential applicability for the new generation supercapacitors.

Highly Stable Ultrafine Boron‐Doped NiCo@Carbon Nanoparticles as a Robust Electrocatalyst for the Hydrogen Evolution Reaction

AbstractDeveloping robust, stable, low‐cost, and highly active environmentally friendly electrocatalysts for the hydrogen evolution reaction (HER) is necessary for realizing alternative clean energy sources. We prepared highly stable ultrafine NiCo@boron‐doped carbon (NiCo@BC) by using a simple reduction method. As an excellent and highly stable HER electrocatalyst, the as‐prepared NiCo@BC 500 °C nanoparticle catalyst displays a satisfying HER performance, delivering a low geometrical overpotential of 209 mV at 10 mA cm−2 current density, a small Tafel slope of 60 mV dec−1, and an outstanding time‐dependent stability after 200 hours in an alkaline solution, which is one of the best reported B‐doped HER electrocatalysts. The outstanding catalytic activity arises from synergetic relationships between B‐doped carbon and NiCo, coexisting in the as‐prepared hybrid product with the crystalline nature of the hybrid NiCo@BC products bearing plentiful catalytically active sites and good electrical conductivity. The promising combination of robust stability, high catalytic performance, and a simplistic preparation approach provides a new‐type of electrocatalyst for clean energy technologies.

Interface engineering: PSS-PPy wrapping amorphous Ni-Co-P for enhancing neutral-pH hydrogen evolution reaction performance

Transition metal phosphides have shown Pt-like hydrogen evolution reaction (HER) activity in acid and alkaline solution, while their HER performance in neutral-pH is really poor owing to the high resistance and inefficient mass transfer in neutral-pH electrolyte. In this work, the well-arranged core/shell PSS-PPy/Ni-Co-P growing on Cu foil, in which Ni-Co-P is the core and the mixed polymer of pyrrole and sodium polystyrene sulfonate is the shell, has been demonstrated to be a highly efficient electrocatalyst for HER in neutral-pH electrolyte. The PSS-PPy/Ni-Co-P/CF self-supporting electrode was easily synthesized by electrodeposition and chemical deposition at room temperature. According to the experiment and DFT calculation results, PSS-PPy not only improves the conductivity and hydrophilicity of Ni-Co-P, but also optimizes the electronic structure of Ni-Co-P. Thus, the PSS-PPy/Ni-Co-P shows remarkable HER activity with only overpotential of 106 and 67 mV at the current density of 10 mA cm−2 in neutral-pH and alkaline electrolytes, respectively. Furthermore, PSS-PPy/Ni-Co-P has excellent stability in neutral-pH, alkaline electrolytes and even seawater. The current surface modification method directs us to design more low-cost, high-efficiency and stable electrocatalysts for HER in neutral-pH electrolyte.

Perpendicularly anchored ReSe2 nanoflakes on reduced graphene oxide support for highly efficient hydrogen evolution reactions

Hydrogen evolution reaction (HER) by water splitting has made a significant contribution to producing large amounts of hydrogen gas as the next generation fuel. Development of highly efficient, economically viable, and electrochemically stable HER electrocatalysts has accordingly become a prerequisite for practical implementation of large scale water electrolysis. Mono/few-layered transition metal dichalcogenide (TMD) based HER-electrocatalysts have recently garnered great interest due to their diverse tunable electrochemical properties. However, they still face intrinsic limitations such as self-aggregation, rare active sites, high electrical resistance, and long-term electrochemical instability. To tackle these challenges, we designed and synthesized a novel electrocatalyst comprising active site-rich rhenium diselenide (ReSe2) nanoflakes perpendicularly anchored on a reduced graphene oxide (rGO) nanosheet support via a facile one-step hydrothermal synthesis. The rGO support provides a growing platform for few-layered ReSe2 nanoflakes while facilitating plentiful exposure of edge/corner sites of ReSe2, highly desirable for maximizing the catalytic activity of ReSe2@rGO. The synthesized ReSe2@rGO exhibits a low overpotential of 145.3 mV at a current density of 10 mA·cm−2 with a Tafel slope of 40.7 mV·dec−1 for the HER process due to the synergistic combination of high surface density of unsaturated coordination sites, remarkably accelerated electron transfer, and enhanced electrochemical stability. This outcome suggests using structurally regulated hybridization of TMDs and graphene as a platform toolkit for developing high performance HER catalysts.

The Role of Phosphate Group in Doped Cobalt Molybdate: Improved Electrocatalytic Hydrogen Evolution Performance.

The hydrogen evolution reaction (HER) is a critical process in the electrolysis of water. Recently, much effort has been dedicated to developing low‐cost, highly efficient, and stable electrocatalysts. Transition metal phosphides are investigated intensively due to their high electronic conductivity and optimized absorption energy of intermediates in acid electrolytes. However, the low stability of metal phosphide materials in air and during electrocatalytic processes causes a decay of performance and hinders the discovery of specific active sites. The HER in alkaline media is more intricate, which requires further delicate design due to the Volmer steps. In this work, phosphorus‐modified monoclinic β‐CoMoO4 is developed as a low‐cost, efficient, and stable HER electrocatalyst for the electrolysis of water in alkaline media. The optimized catalyst shows a small overpotential of 94 mV to reach a current density of 10 mA cm−2 for the HER with high stability in KOH electrolyte, and an overpotential of 197 mV to reach a current density of 100 mA cm−2. Combined computational and in situ spectroscopic techniques show P is present as a surface phosphate ion; that electron holes localize on the surface ions and both (P—O1−) and Co3+—OH− are prospective surface active sites for the HER.

Promoted Alkaline Hydrogen Evolution Reaction Performance of Ru/C by Introducing TiO2 Nanoparticles

AbstractHigher water dissociation (Volmer step) energy barrier leads to the sluggish alkaline hydrogen evolution reaction (HER) rate. Since hydrophilic TiO2 can reduce water dissociation barrier while the widely studied Ru has nearly zero hydrogen adsorption Gibbs free energy, the combination of TiO2 and Ru/C might collectively enhance Volmer and Heyrovsky/Tafel step and finally promote HER performance. Herein, Ru/C−TiO2 with average size of 3.6 nm for Ru was synthesized by a two‐step process. It presented superior alkaline HER activity with η10 of 44 mV, better than that of Ru/C (107 mV), Pt/C (84 mV) and C−TiO2 with negligible activity. The prominent HER performance was due to synergistic effect between TiO2 and Ru, which greatly expedited water dissociation for intermediate hydrogen production and the following electrochemical hydrogen desorption for producing H2. This work combines specific active sites for different elementary steps and then boosts alkaline HER performance, which provide a guide for designing efficient and stable HER electrocatalyst.

Strong interfacial interaction significantly improving hydrogen evolution reaction performances of MoS2/Ti4O7 composite catalysts

A catalytic non-carbon composite composed of molybdenum disulfide (MoS2) and conducting Magnéli phase Ti4O7 is firstly synthesized by a facile hydrothermal method. The MoS2/Ti4O7 composite catalyst shows significantly improved hydrogen evolution reaction (HER) activity in 0.5 M H2SO4 especially at high overpotentials mainly due to the fast electron transfer ability caused by the newly formed interfacial S–O–Ti bonds and the enhanced electrochemical surface area. Tafel slope of the optimized MoS2/Ti4O7 catalyst is as low as 48 mV · dec−1. It also presents an impressive stability with smaller activity degradation (5 mV potential shift at 10 mA cm−2) after 1000 cycles of cyclic voltammetry (CV) scanning. This is the first exploration on HER performances of MoS2 and conductive metal oxide composite electrocatalysts, shedding light on the research of non-noble metal (sulphide)-metal oxide interface in energy catalysis significantly crucial for the development of cost-effective and stable HER electrocatalysts and even other electrocatalytic materials.