Efficient Electrocatalyst For Hydrogen Evolution Research Articles

Combining Highly Dispersed Amorphous MoS3 with Pt Nanodendrites as Robust Electrocatalysts for Hydrogen Evolution Reaction.

Surface modification of electrocatalysts to obtain new or improved electrocatalytic performance is currently the main strategy for designing advanced nanocatalysts. In this work, highly dispersed amorphous molybdenum trisulfide-anchored Platinum nanodendrites (denoted as Pt-a-MoS3 NDs) are developed as efficient hydrogen evolution electrocatalysts. The formation mechanism of spontaneous in situ polymerization MoS4 2- into a-MoS3 on Pt surface is discussed in detail. It is verified that the highly dispersed a-MoS3 enhances the electrocatalytic activity of Pt catalysts under both acidic and alkaline conditions. The potentials at the current density of 10mA cm-2 (η10 ) in 0.5msulfuric acid (H2 SO4 ) and 1mpotassium hydroxide (KOH) electrolyte are -11.5 and -16.3mV, respectively, which is significantly lower than that of commercial Pt/C (-20.2mV and -30.7mV). This study demonstrates that such high activity benefits from the interface between highly dispersed a-MoS3 and Pt sites, which act as the preferred adsorption sites for the efficient conversion of hydrion (H+ ) to hydrogen (H2 ). Additionally, the anchoring of highly dispersed clusters to Pt substrate greatly enhances the corresponding electrocatalytic stability.

Prussian blue-derived hollow carbon-wrapped Fe-doped CoS2 nanocages as durable electrocatalyst for efficient hydrogen evolution

Cobalt disulfide (CoS2) is regarded as a low cost and abundant non-noble electrocatalyst, but some drawbacks limit its application due to its sluggish intrinsic electrocatalytic kinetics and high hydrogen evolution overpotential. In this work, carbon-wrapped Fe-doped CoS2 nanocages (C/Fe–CoS2) were synthesized via gradual sulfurization of cobalt hexacyanoferrate and evaluated as electrocatalysts for hydrogen evolution reaction (HER). The nanocage architecture exposes more electrochemically active site, and carbon wrapping reduces the agglomeration of C/Fe–CoS2 and optimizes the electronic structure, while the Fe doping decreases the hydrogen adsorption free energy of CoS2. Therefore, C/Fe–CoS2 demonstrates a superior HER performance, showing a benchmark current density of 10 mA cm−2 at the low overpotential of 151 mV in acidic electrolyte and a remarkable stability (cyclic voltammetry cycling for 3000 cycles and continuous electrolysis at the overpotential of 180 mV for 25,000 s). The as-designed C/Fe–CoS2 should be one of the most promising catalysts for HER application. This strategy highlights the construction of high performance electrocatalysts via structure designing and heteroatom doping for efficient and stable hydrogen generation.

Atomic Dispersion of Rh on Interconnected Mo2C Nanosheet Network Intimately Embedded in 3D NixMoOy Nanorod Arrays for pH‐Universal Hydrogen Evolution

Herein, a simple synthetic approach is employed for the atomic dispersion of Rh atoms (Rh SAs) over the surface of interconnected Mo2C nanosheets intimately embedded in a three‐dimensional NixMoOy nanorod arrays (NixMoOy NRs) framework; we found that the introduction of both isolated Rh SAs and NixMoOy NRs adjusts the electrocatalytic function of the host Mo2C toward the direction of being an advanced and highly stable electrocatalyst for efficient hydrogen evolution at pH‐universal conditions. As a result, the proposed catalyst outperforms most recently reported transition metal‐based catalysts, and its performance even rivals that of commercial Pt/C, as demonstrated by its ultralow overpotentials of 31.7, 109.7, and 95.4 mV at a current density of 10 mA cm−2, along with its small Tafel slopes of 42.4, 51.2, and 46.8 mV dec−1 in acidic, neutral, and alkaline conditions, respectively. In addition, the catalyst shows remarkable long‐term stability over all pH values with good maintenance of its catalytic activity and structural characteristics after continuous operation.

Modulation of Surface Ti–O Species in 2D-Ti3C2TX MXene for Developing a Highly Efficient Electrocatalyst for Hydrogen Evolution and Methanol Oxidation Reactions

Developing cost-effective and earth-abundant noble-metal-free electrocatalysts is imperative for the imminent electrochemical society. Two-dimensional Ti3C2TX (MXene) exhibits tunable properties with high electrical conductivity and a large specific surface area, which improve its electrochemical performance. Herein, the low-temperature annealing method is used to enrich MXene with a maximum number of Ti-O terminals without formation of titanium dioxide (TiO2) under neutral pH conditions. MXene annealed at 200 °C is found to have a large number of Ti-O termination groups, resulting in a large electrochemically active surface area and increased active sites (-O termination groups) and hence excellent electrocatalytic performance compared to other samples as well as previous reported work. The optimized sample is found to show the lowest overpotential value of 0.07 V at 10 mA cm-2 and a Tafel slope of 0.15 V dec-1 toward the hydrogen evolution reaction (HER), whereas for the methanol oxidation reaction (MOR), the current density is 18.08 mA cm-2, and the onset potential is -0.51 V. In addition, it also shows long-term stability and durability toward HER as well as MOR.

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.

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.

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.

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.

Single platinum atoms anchored on N-doped carbon materials composed of bipyridine as efficient hydrogen evolution electrocatalysts

Potassium tetrachloroplatinate among three platinum salts shows the most favorable binding energy to a N-doped carbon material composed of bipyridine, and enables the anchoring of Pt single atoms as efficient hydrogen evolution electrocatalysts.

Palladium nanoparticles confined in uncoordinated amine groups of metal-organic frameworks as efficient hydrogen evolution electrocatalysts.

Hydrogen obtained through the electrolysis of water is a potential solution to the growing demand of human society for energy. In addition, water electrolysis generates less environmental pollution than fossil energy sources. However, the preparation of highly active and low-cost electrocatalysts remains a key challenge. Here, we report a facile and inexpensive method to prepare palladium nanoparticles (Pd NPs) supported on aminated (-NH2) metal-organic frameworks (MOF). The obtained electrocatalyst (Pd@Uio-66-NH2) exhibits excellent electrocatalytic performance for the hydrogen evolution reaction (HER), featuring an ultralow overpotential (34 mV at 10 mA cm-2), small Tafel slope (41 mV dec-1), and superior stability in acid electrolyte. Systematic characterization demonstrated that -NH2 can effectively stabilize palladium acetate as the Lewis base. Meanwhile, the strong interaction between the lone pair electrons and the d-orbital ensures that the Pd atoms are uniformly distributed in the MOF material, inhibiting the agglomeration of metal NPs in the reaction. This strategy provides an avenue to prepare inexpensive and highly active catalysts for HER in acidic media.

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.

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.

Highly dispersed ultra-small RuO2 nanoparticles on NiO nanosheet arrays as efficient pH-universal hydrogen evolution electrocatalysts

Extremely active RuO2/NiO/NF nanosheet arrays with efficient pH-universal HER electrocatalysis were fabricated via a simple in situ hydrothermal growth strategy.

Laser induced trace doping of Pd on Ru nanoparticles for an efficient hydrogen evolution electrocatalyst.

Improving the activity and stability of electrocatalysts for the hydrogen evolution reaction (HER) plays an essential role in the practical application of electrochemical water splitting under alkaline conditions. Here, trace Pd-doped Ru nanoparticles have been achieved using the pulsed laser ablation in liquid technology, which exhibit efficient HER catalytic performance. It is evidenced that the Pd doping amount is maintained at a trace level and increases nonlinearly with the concentration of the Pd precursor. Molecular dynamics simulations demonstrate that the trace doping of Pd is due to the slow thermal decomposition rate of the Pd precursor. This work improves the mechanistic explanation of the metal doping induced by liquid-phase laser ablation, which may promote the fabrication and application of advanced laser-based nanostructures.

Exploring efficient hydrogen evolution electrocatalysts of nonmetal atom doped Mo2CO2 MXenes by first-principles screening.

Non-metal doping engineering has shown great potential for designing high-performance MXene-based catalysts for electrocatalytic hydrogen evolution. We rationally design 14 kinds of nonmetal atom-doped Mo2CO2 catalysts and investigate the effects of nonmetal doping on the thermal stability and hydrogen evolution reaction (HER) catalytic activity of these structures through first-principles calculations. The results show that the addition of nonmetal dopants, such as Si, Cl, Br and I, on the Mo2CO2 surface can effectively improve the HER activity, making them promising candidates for effective HER catalysts. Besides, we studied the thermal stability of nonmetal doped Mo2CO2 by calculating the binding energy and explored the reason behind the variation in the binding energy. Furthermore, the origin of the HER activity difference regulated by various nonmetal dopants is explained based on the analysis of their electronic properties. We found that the number of valence electrons and Bader charge coupling of doped nonmetal atoms are effective electronic descriptors of the hydrogen adsorption strength and HER activity, which provide a clue for future prediction of highly efficient MXene-based HER catalysts.

Integration of amorphous CoSnO3 onto wrinkled MXene nanosheets as efficient electrocatalysts for alkaline hydrogen evolution

Two-dimensional (2D) MXenes-based nanostructures have recently emerged as effective electrocatalysts because of their excellent electrical conductivity and superior hydrophilicity. Nevertheless, the low electrocatalytic activity and the poor stability have hampered their applications in practical hydrogen production. Herein, a novel method to modulate the electronic structure and improve the catalytic activity of MXene by integrating amorphous CoSnO3 onto wrinkled Ti3C2Tx MXene nanosheets is reported, producing a promising electrocatalyst (MXene@CoSnO3) toward alkaline hydrogen evolution reaction (HER). It is found that CoSnO3 nanocubes are well grown on the surface of Ti3C2Tx MXene, stabilizing MXene nanosheets against spontaneous oxidation. More importantly, the strong interfacial electronic coupling between the two components greatly prompts the redistribution of electrons at the MXene and CoSnO3 interfaces and alters the electronic structure around Co, which enables the activation of high-potential Sn to have an optimal *H adsorption (ΔG*H), promoting the H* conversion for HER. The fabricated MXene@CoSnO3 exhibits high alkaline HER performances with an ultralow overpotential of 45 mV at 10 mA cm−2, a small Tafel slope of 51 mV dec-1 and the long-term stability in 1 M KOH, which even compares with commercial Pt/C catalyst.

General Synthesis of MOF Nanotubes via Hydrogen-Bonded Organic Frameworks toward Efficient Hydrogen Evolution Electrocatalysts.

The application scope of metal-organic frameworks (MOFs) can be extended by rationally designing the architecture and components of MOFs, which can be achieved via a metal-containing solid templated strategy. However, this strategy suffers from low efficiency and provides only one specific MOF from one template. Herein, we present a versatile templated strategy in which organic ligands are weaved into hydrogen-bonded organic frameworks (HOFs) for the controllable and scalable synthesis of MOF nanotubes. HOF nanowires assembled from benzene-1,3,5-tricarboxylic acid and melamine via a simple sonochemical approach serve as both the template and precursor to produce MOF nanotubes with varied metal compositions. Hybrid nanotubes containing nanometal crystals and N-doped graphene prepared through a carbonization process show that the optimized NiRuIr alloy@NG nanotube exhibits excellent electrocatalytic HER activity and durability in alkaline media, outperforming most reported catalysts. The strategy proposed here demonstrates a pioneering study of combination of HOF and MOF, which shows great potential in the design of other nanosized MOFs with various architectures and compositions for potential applications.

Two-dimensional ruthenium-doped cobalt oxide as an efficient electrocatalyst for hydrogen evolution

The sluggish hydrogen evolution reaction (HER) kinetics undertaken at alkaline electrolytes has prevented large-scale hydrogen production from industrial electrolysis technology. Herein, a convenient rapid thermal annealing (RTA) strategy is proposed to prepare the two-dimensional (2D) ruthenium-doped Co3O4 nanosheets electrocatalysts for HER. The as-prepared ruthenium-doped Co3O4 nanosheets achieve a pretty low overpotential of 28.8 mV at 10 mA cm−2 under 1 M KOH solution, which is better than commercial Pt/C. This finding provides a promising strategy for the preparation of noble-metal doped oxide nanosheets and sheds light on design and fabrication of advanced nano-catalysts.

Interfacial Electronic Engineering of NiSe–Anchored Ni–N–C Composite Electrocatalyst for Efficient Hydrogen Evolution

Rational design and construction of cost–effective electrocatalysts for efficient hydrogen production has attracted extensive research attention worldwide. Herein, we report the construction of a transition metal selenide/carbon composite catalyst featuring uniform NiSe nanoparticles anchored to single Ni atom doped porous carbon structure (NiSe/Ni–N–C) via a facile one–pot pyrolysis of low–cost solid mixtures. NiSe/Ni–N–C exhibits remarkable catalytic performance towards hydrogen evolution reaction (HER) in 1.0 M KOH, requiring a low overpotential of 146 mV to reach a current density of 10 mA cm−2. The unique carbon layer encapsulation derived from the enwrapping of fluid catalytic cracking slurry further renders NiSe/Ni–N–C excellent for long–term durability in electrolyte corrosion and nanostructure aggregation. This work paves the way for the design and synthesis of highly efficient composite HER electrocatalysts.

MOF-Derived Pt/ZrO2 Carbon Electrocatalyst for Efficient Hydrogen Evolution.

One type of porous carbon nanomaterial decorated by abundant Pt/ZrO2 nanoparticles can be conveniently prepared, which is pyrolyzed from flower-shaped Zr-based UiO-67 precursor with a small amount of H2PtCl6 molecules in its large pores. In addition, the obtained Pt/ZrO2 carbon electrocatalyst can bring efficient electrocatalytic hydrogen evolution performance and long-term stability.