Electrocatalyst For Hydrogen Evolution Research Articles

Construction of Co-decorated 3D nitrogen doped-carbon nanotube/Ti3C2Tx-MXene as efficient hydrogen evolution electrocatalyst

Rational design of transition metal catalysts with robust and durable electrocatalytic activity for hydrogen evolution reactions (HER) is extremely important for renewable energy conversion and storage, as well as water splitting. Heteroatom doping has emerged as a feasible strategy for enhancing electrocatalytic activity. Here, cobalt nanoparticles (Co-NPs) were coated with nitrogen-doped carbon nanotubes (NCNTs) prepared via an in situ growth on accordion-like Ti3C2Tx-MXene (Co-NCNT/Ti3C2Tx). Such an intriguing structure showed great features: abundant anchoring sites for NCNT in situ growth, intimate integration of Co-NPs and NCNTs, high-speed electron transfer between 1D NCNTs and 2D Ti3C2Tx-MXenes, and a large number of effective catalytic active sites. This Co-NCNT/Ti3C2Tx hybrid catalyst was demonstrated to possess excellent HER performance with low overpotential (η10, 190 mV), small Tafel slope (78.4 mV dec−1), large electrochemically active surface area, and good long-term stability, thus outperforming many reported electrocatalysts. The present strategy provided a facile route for the design of transition metal HER catalysts with NCNT and MXene.

Nanolaminated Ternary Transition Metal Carbide (MAX Phase)-Derived Core–Shell Structure Electrocatalysts for Hydrogen Evolution and Oxygen Evolution Reactions in Alkaline Electrolytes

The development of abundant, cheap, and highly active catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is important for hydrogen production. Nanolaminate ternary transition metal carbides (MAX phases) and their derived two-dimensional transition metal carbides (MXenes) have attracted considerable interest for electrocatalyst applications. Herein, four new MAX@MXene core-shell structures (Ta2CoC@Ta2CTx, Ta2NiC@Ta2CTx, Nb2CoC@Nb2CTx, and Nb2NiC@Nb2CTx), in which the core region is Co/Ni-MAX phases while the edge region is MXenes, have been prepared. Under alkaline electrolyte conditions, the Ta2CoC@Ta2CTx core-shell structure showed an overpotential of 239 mV and excellent stability during the HER with MXenes as the active sites. For the OER, the Ta2CoC@Ta2CTx core-shell structure showed an overpotential of 373 mV and a small Tafel plot (56 mV dec-1), which maintained a bulk crystalline structure and generated Co-based oxyhydroxides that formed by surface reconstruction as active sites. Considering rich chemical compositions and structures of MAX phases, this work provides a new strategy for designing multifunctional electrocatalysts and also paves the way for further development of MAX phase-based materials for clean energy applications.

Fe/Ni bi-metallic organic framework supported 1T/2H MoS2 heterostructures as efficient bifunctional electrocatalysts for hydrogen and oxygen evolution

Due to the high electrical conductivity and abundant active sites, 1T MoS2 shows distinguished electrocatalytic activity in hydrogen evolution reaction (HER). However, 1T MoS2 is metastable and shows low activity toward oxygen evolution reaction (OER), preventing its wide application as bifunctional electrocatalyst. Herein, we demonstrate the preparation of 1T-rich MoS2 composite catalysts for enhanced HER and OER in alkaline condition. The preparation process includes hydrothermal synthesis of Fe/Ni bi-metallic organic framework (b-MOF) and subsequent in-situ fabrication of 1T/2H MoS2. The as-prepared composite MoS2@Fe/Ni-MOF600-x (x = 1, 2, 3) exhibits excellent electrocatalytic performance due to the specific nanoflower 3D structure, electron modulation effect of Fe/Ni, and high content of 1T MoS2. Typically, MoS2@Fe/Ni-MOF600-3 with a relatively high Fe/Ni-MOF600 feeding showed the best catalytic performance, including low overpotential of 140 and 340 mV (to achieve a current density of 10 mA·cm−2) and large electrochemically active surface area (ECSA) of 1312.5 and 912.5 cm2 for HER and OER, respectively. The study provides a novel strategy for the preparation of 1T-rich MoS2 composite catalyst for highly efficient hydrogen evolution and oxygen evolution.

Rational Assembly of the NiMoP/NiCoZn Heterostructure Electrocatalyst for the Hydrogen Evolution Reaction at High Current Densities

Developing a cost-effective hydrogen (H2) evolution electrocatalyst can effectively solve the problem of environmental pollution caused by excessive fossil fuel use. Herein, we report an innovative synthetic strategy, involving hydrothermal electrodeposition of a NiCoZn film on commercial carbon fiber paper (CFP) and in situ cyclic voltammetric electrodeposition of NiMoP to prepare a heterostructure electrocatalyst (NiMoP/NiCoZn/CFP) with synergistic electrocatalytic activity toward the hydrogen evolution reaction (HER). To deliver high current densities of 500 and 1000 mA cm–2, the NiMoP/NiCoZn/CFP electrode only required overpotentials of 230 and 268 mV, respectively, which were considerably superior to those of Pt–C/CFP (457 and 592 mV, respectively). Moreover, this electrode exhibited excellent ultrastability (40 h at 500 mA cm–2 or 80 h at 1 A cm–2). The superior electrocatalytic HER activity is attributed to (1) cooperative electronic interactions between NiMoP and NiCoZn in the heterointerface and (2) the complete wettability, which is advantageous for gas formation and desorption and considerably reduces bubble adhesion and reaction resistance. This work provides a rational electrodeposition strategy for constructing heterointerface electrocatalysts for H2 production at high current densities.

An efficient metal oxyhydroxide catalyst for electrocatalytic hydrogen evolution reaction

An enormous amount of research is being carried out in electrocatalysis, notably for hydrogen evolution reactions (HER), because of the growing demand for sustainable and clean energy sources. Electrochemical water splitting, which results in hydrogen gas, is a practical path to a carbon–neutral energy system. It is essential to create efficient, cost-effective electrocatalysts to achieve this. In recent years, FeOOH-based catalysts have emerged as intriguing HER candidates due to their excellent activity, stability, and accessibility. This work investigates FeOOH quantum dots as an electrocatalyst for hydrogen evolution and sheds an insight on their unique properties, manufacturing processes, and catalytic activity. The quantum dots have demonstrated good electrochemical activity due to their increased surface area and noticeably higher active sites. With the use of UV–vis spectroscopy, XRD, TEM, and electrochemical studies of the catalyst activity, the catalyst has been well characterised. The catalyst demonstrated amazing activity, a decreased Tafel slope, and a lower overpotential, making it a potential option for use in the future.

Insights into alloy/oxide or hydroxide interfaces in Ni-Mo-based electrocatalysts for hydrogen evolution under alkaline conditions.

Nickel-molybdenum (Ni-Mo) alloys are promising non-noble metal electrocatalysts for the hydrogen evolution reaction (HER) in alkaline water; however, the kinetic origins of their catalytic activities still remain under debate. In this perspective, we systematically summarize the structural characteristics of Ni-Mo-based electrocatalysts recently reported and find that highly active catalysts generally have alloy-oxide or alloy-hydroxide interface structures. Based on the two-step reaction mechanism under alkaline conditions, water dissociation to form adsorbed hydrogen and combination of adsorbed hydrogen into molecular hydrogen, we discuss in detail the relationship between the two types of interface structures obtained by different synthesis methods and their HER performance in Ni-Mo based catalysts. For the alloy-oxide interfaces, the Ni4Mo/MoO x composites produced by electrodeposition or hydrothermal combined with thermal reduction exhibit activities close to that of platinum. For only the alloy or oxide, their activities are significantly lower than that of composite structures, indicating the synergistic catalytic effect of binary components. For the alloy-hydroxide interfaces, the activity of the Ni x Mo y alloy with different Ni/Mo ratios is greatly improved by constructing heterostructures with hydroxides such as Ni(OH)2 or Co(OH)2. In particular, pure alloys obtained by metallurgy must be activated to produce a layer of mixed Ni(OH)2 and MoO x on the surface to achieve high activity. Therefore, the activity of Ni-Mo catalysts probably originates from the interfaces of alloy-oxide or alloy-hydroxide, in which the oxide or hydroxide promotes water dissociation and the alloy accelerates hydrogen combination. These new understandings will provide valuable guidance for the further exploration of advanced HER electrocatalysts.

PMo12 induced MoP as hydrogen evolution electrocatalysts

In recent years, electrolytic water has become the mainstream method of producing hydrogen energy, in which the development of efficient electrocatalysts is particularly important. Herein, MoP@C was synthesized by simple hydrothermal following one-step calcination process. MoP@C shows excellent catalytic activity in acidic environment, requiring only a small overpotential (196 mV) at the current density of 10 mA cm-2 and exhibiting a small Tafel slope (91 mV dec-1). Meanwhile, MoP@C displays good stability within 24 hours. This work has a positive effect for the subsequent large-scale preparation of phosphides electrocatalysts.

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.

Development and perspectives of multi-site electrocatalysts for neutral hydrogen evolution

This review offers an overview of the design principles, progress, and perspectives of applying multi-site electrocatalysts for the HER in neutral media.

Cu5FeS4 quantum dots as a single-component photo-assisted electrocatalyst for efficient hydrogen evolution

Cu5FeS4 quantum dots as a single-component photo-assisted electrocatalyst for efficient hydrogen evolution reaction superior to Pt/C.

A synergistic heterogeneous interface of a NC-Co-MoS2/CC-450 electrocatalyst for efficient alkaline hydrogen evolution

A novel electrocatalyst, NC-Co-MoS2/CC-450, featuring a Co0.75Mo3S3.75/MoS2 heterogeneous interface and co-doped nitrogen and carbon on carbon cloth, demonstrates exceptional performance and stability in alkaline hydrogen evolution.

Electrocatalytic hydrogen evolution by robust square planar nickel complexes in an S2P2coordination environment

A new series of heteroleptic nickel complexes [p-CH3OC6H4N(PPh2)2]Ni[S2C2(C6H4R-p)2)] as stable and effective molecular electrocatalysts for hydrogen evolution are investigated with TOFs of 423–894 s−1and overpotentials of 0.91–1.02 V.

One-step molten-salt synthesis of adjustable composition molybdenum carbide-based electrocatalysts for hydrogen evolution in both acidic and alkaline media

Molybdenum carbide is deemed a potential electrode material for the hydrogen evolution reaction (HER) under different pH condition electrolytes because of its unique metal-like electronic structure.

Reconstruction of the ZIF-67 structure and boosted hydrogen evolution reaction in an alkaline medium

This work reports the preparation and characterization of a CoPB@ZIF-67/NF heterogeneous electrocatalyst for hydrogen evolution, which was found to have more active sites and improved charge transfer kinetics compared to other catalysts.

SnO2/CoS1.097 heterojunction as a green electrocatalyst for hydrogen evolution linking to assistant glycerol oxidation

Different ratios of Sn and Co sources were designed and mixed to obtain SnO2/CoS1.097 heterojunctions. As a potential electrocatalyst, the 0.5SnO2/0.5CoS1.097 is superior to the commercial RuO2 and Pt/C electrocatalysts.

Facial synthesis of FeS2@Carbon nanotube composite as an efficient electrocatalyst for hydrogen evolution reaction

Iron disulfide (FeS2) has attracted extensive research interest due to its excellent catalytic efficiency. In this work, FeS2 was composited with carbon matrix to prepare a highly efficient electrocatalyst for hydrogen evolution. Two uniformly composites, namely, FeS2 @carbon nanotube (FeS2@CNT) and FeS2@carbon particle (FeS2@CP), were successfully prepared by pyrolysis and sulfuration processes. The structures of the synthesized composites were characterized by powder X-ray diffraction (PXRD), scanning electron microscope, transmission electron microscope, and X-ray photoelectron spectroscopy. It was found that the catalytic performances of the composites were obviously improved compared to pure FeS2. Moreover, compared to FeS2@CP, the FeS2@CNT nanotubes achieved a much lower overpotential and a smaller Tafel slope. The enhanced HER kinetics and hydrogen generation rate of FeS2@CNT may be due to its more efficient charge transport, uniform distribution of active sites, and higher surface areas. This work provides a new clue for the preparation of FeS2-based composite for hydrogen evolution.

Highly active bimetallic phosphide electrocatalysts for hydrogen evolution

MoP/MoNiP@NC as electrocatalyst was synthesized through a one-step high-temperature calcination and phosphating method. MoP/MoNiP@NC displays superior HER performance in both 0.5 M H2SO4 and 1.0 M KOH.

Cu-doped La0.5Sr0.5CoO3-δ perovskite as a highly efficient and durable electrocatalyst for hydrogen evolution.

The preparation of a high-efficiency and durable electrocatalyst for the alkaline hydrogen evolution reaction (HER) is essential for realizing renewable energy technologies. Herein, a series of La0.5Sr0.5CoO3-δ perovskites with different amounts of Cu cations substituting at B-sites were fabricated for the HER. Specifically, the optimized La0.5Sr0.5Co0.8Cu0.2O3-δ (LSCCu0.2) exhibits a significantly enhanced electrocatalytic activity with an ultralow overpotential of 154 mV at 10 mA cm-2 in 1.0 M KOH, which is reduced by 125 mV compared with that of pristine La0.5Sr0.5CoO3-δ (LSC, 279 mV). It also delivers a robust durability with no obvious degradation after 150 h. Impressively, the HER activity of LSCCu0.2 is superior to that of commercial Pt/C at large current densities (>270 mA cm-2). XPS analysis indicates that Co2+ ions replaced by an appropriate amount of Cu2+ ions can increase the proportion of Co3+ and generate high content of oxygen vacancies in LSC, which leads to an increased electrochemically active surface area, thereby greatly facilitating the HER. This work offers a simple way for the rational design of cost-effective and highly efficient catalysts, which may be extended to other Co-based perovskite oxides for the alkaline HER.

Stepwise construction of Ag29 nanocluster-based hydrogen evolution electrocatalysts.

Although several silver-based nanoclusters have been controllably prepared and structurally determined, their electrochemical catalytic performances have been relatively unexplored (or showed relatively weak ability towards electro-catalysis). In this work, we accomplished the step-by-step enhancement of the electrocatalytic hydrogen evolution reaction (HER) efficiency based on an Ag29 cluster template. A combination of atomically precise operations, including the kernel alloying, ligand engineering, and surface activation, was exploited to produce a highly efficient Pt1Ag28-BTT-Mn(10) nano-catalyst towards HER, derived from both experimental characterization and theoretical modelling. The precision characteristic of the Ag29-based cluster system enables us to understanding the correlations between nanocluster structures and HER performances at the atomic level. Overall, the findings of this work will hopefully provide more opportunities for the customization of new cluster-based nano-catalysts with enhanced electrocatalytic capacities.

Ru–Fe4C nanoparticles loaded on N-doped carbon nanofibers as self-supporting high-efficiency hydrogen evolution electrocatalysts

The Ru–Fe4C/NCNF (Ru : Fe = 1 : 6) catalyst exhibits excellent catalytic performance (η10 = 106 mV and η100 = 254 mV). The prepared catalyst can be used as a self-supporting working electrode and it shows excellent stability.