High-efficiency Hydrogen Evolution Research Articles

Template-synthesized CdWO4/Cd0.5Zn0.5S hollow microsphere photocatalyst for high-efficient hydrogen evolution under visible light

Photocatalytic water splitting for hydrogen production is a promising strategy for renewable energy. While Cd1-XZnXS catalysts display high photocatalytic hydrogen evolution efficiency in pure water, they are limited by severe photocorrosion and rapid recombination of electron–hole pairs. In this study, HGM (hollow glass microspheres) was used as the support template, Cd0.5Zn0.5S and CdWO4 were successively coated on the template by hydrothermal method. The tightly packed heterojunction interface between the coatings ensures efficient electron transport and suppresses the recombination of electron-hole pairs. Under visible light irradiation, when the theoretical mass ratio of Cd0.5Zn0.5S to CdWO4 is 4:1, the Cd0.5Zn0.5S/CdWO4-25% hollow microsphere photocatalyst exhibits the highest hydrogen evolution rate, reaching 41.40 mmol g−1 h−1, which is approximately 3.4 times higher than the hydrogen evolution rate of pure Cd0.5Zn0.5S (12.31 mmol g−1 h−1). This research provides a novel approach for the design and synthesis of efficient and stable photocatalysts.

Synergistic heterostructural interface of CoP and WC for high-performance wide pH-universal hydrogen evolution electrocatalysis

The development of cost-effective catalysts with high activity and stability over a wide pH range is urgent, but there are great challenges in the selection and design of catalyst materials. In this work, cobalt phosphide nanoparticles were modified onto tungsten carbide nanowire arrays (CoP@WC/CC) on carbon cloth substrate by a two-step method. The construction of CoP@WC heterostructure results in the downward shift of the d-band center, which optimizes the adsorption energy of catalyst and reaction intermediates. Meanwhile, the synergistic effect of CoP and WC contributes to the alkaline HER kinetic process. In addition, binder-free self-supporting nanoarray have excellent electrical conductivity, large specific surface area and strong structure, which is conducive to charge/matter exchange and catalyst stability. The results show that CoP@WC/CC can effectively drive HER over a wide pH range and exhibit better catalytic performance than the single component control sample. In 0.5 M H2SO4 and 1 M KOH, CoP@WC/CC can drive the current density of 10 mA cm−2 with only 52 and 70 mV, while showing excellent stability without obvious performance degradation during 100 h of constant current test. A proton exchange membrane water electrolysis (PEMWE) using CoP@WC/CC catalyst operates stably for 200,000 s at 30 mA cm−2. This study provides a new reference for the design and development of high efficiency, low cost and wide pH-universal hydrogen evolution electrocatalysts.

Construction of Ru-doped Co nanoparticles loaded on carbon nanosheets in-situ grown on carbon nanofibers as self-supported catalysts for efficient hydrogen evolution reaction

Exploring efficient and economical electrocatalysts to replace noble metal electrocatalysts has become a major research focus nowadays. In this paper, Ru-doped Co nanoparticles loaded on carbon nanosheet (CNS) in-situ grown on carbon nanofibers (Ru–Co@CNS/CNFs) were constructed as a self-supporting working electrode for high-efficiency hydrogen evolution. The prepared Ru–Co@CNS/CNFs possessed excellent catalytic activity with only 78 mV overpotential at 10 mA cm−2 current density and good stability with only 102 mV voltage attenuation at 100 mA cm−2 current density for 100 h continuous operation. The excellent catalytic performance could be attributed to the unique microstructure of the nanosheets in-situ grown on the nanofibers, it resulted in a higher Co surface density of 1.28 mg cm−2, indicating more loading of metal to improve catalytic activity of HER, and the formed Ru-doped Co nanoparticles could be evenly distributed on the carbon nanosheets to prevent the aggregation of nanoparticles, which could expose more active sites. Additionally, the density functional theory (DFT) calculations revealed Ru doping could accelerate the dissociation of water, optimize the adsorption energy of hydrogen intermediates and improve the kinetics of the HER reaction. This work provides a new approach to reduce the use of noble metals while improving the catalytic performance of catalysts.

Engineering bimetallic single-atom catalysts utilizing the reducibility of HxMoO3 for high efficiency hydrogen evolution

Bimetallic single-atom catalysts have garnered substantial interest due to their extraordinary catalytic prowess, which arises from atomic-level synergistic effects that can significantly enhance hydrogen evolution reaction (HER) kinetics beyond the capabilities of monometallic single-atom catalysts. However, the fabrication of bimetallic single-atom catalysts remains a tremendous challenge. Herein, we introduce an in-situ reduction method to fabricate bimetallic single-atom catalysts anchored on hydrogenated molybdenum trioxide (HxMoO3, 0 < x ≤ 2). Intriguingly, HxMoO3 exhibits inherent reducing capabilities that facilitate the in-situ reduction of some metal ions to metallic single atoms in steps on its surface, thereby enabling the constructing of bimetallic single-atom structures. As a testament to this strategy, the prepared PtM/HxMoO3 catalysts (M = Ag, Au, Pd, Rh) with ultra-low noble metal loadings (wt% < 1%) on the nano-HxMoO3 support exhibit remarkable efficiency in HER. Outperforming both monometallic single-atom catalysts (M/HxMoO3) and commercial Pt/C, these catalysts demonstrate enhanced HER performance, and the PtPd/HxMoO3 exhibits outstanding performance with an overpotentials of 10 mV at 10 mA/cm2, Tafel slope of 36 mV/dec, and long-term durability in acidic media. The presence of Pt single-atom significantly enhances the electrochemical surface area (ECSA) and accelerates the kinetics of the HER for other metal single atoms.

Interfacial engineering of CoP-MoO2/NF heterojunction for high-efficient hydrogen evolution reaction coupled with 5-hydroxymethylfuran electrooxidation

Achieving efficient production of hydrogen and obtaining high value-added products can maximize energy efficiency, but challenging. Herein, a nanoarray-structured heterojunction catalyst (CoP-MoO2/NF) was proposed as a potent bifunctional electrocatalyst for hydrogen evolution reaction (HER) and 5-hydroxymethylfuran oxidation reaction (HMFOR). Density Functional Theory (DFT) showed that heterojunction enhanced the adsorption of reactants on the electrocatalyst surface, the CoP-MoO2/NF exhibits excellent HER activity with an overpotential of 37 mV and a Tafel slope of 43 mV·dec−1 at 10 mA·cm−2. Also, nearly 100% HMF conversion and 98.6% FDCA selectivity demonstrate the favorable performance of the material toward HMFOR. The work here shows a way for producing hydrogen in the future that is low-cost, efficient, reliable and also adds value to the final product.

Construction of P-doped high efficiency hydrogen evolution catalyst

Transition metal hydrogen evolution catalysts have attracted much attention. Here, we prepared a high-efficiency HER electrocatalyst based on nickel foam by constant current electrodeposition. Based on Mo and Co elements, the ternary catalyst was prepared by adding P, and the synthesized CoMoP-NF catalyst showed a remarkable effect in alkaline electrolytes. The overpotential of the CoMoP-NF catalyst is 35.1 mV at a current density of −10 mA cm−2 and 71 mV at −20 mA cm−2. The composition and structure of the catalyst were studied by SEM, XRD, XPS and TEM. And the stability of the CoMoP-NF catalyst with the best catalytic performance was tested for 12 hours, there is only a tiny increase in overpotential, indicating that the catalyst had excellent stability. This work has a certain impact on the preparation of efficient hydrogen evolution catalyst.

The WO2.72/CdS0.25Se0.75-DETA nanocomposite with S-scheme heterojunction structures exhibits high efficiency and stable photocatalytic hydrogen evolution performance

Facing the global energy crisis, identifying impactful solutions is imperative. This research introduces the cutting-edge nanocomposites, WO3/CdS0.25Se0.75-Diethylenetriamine (Diethylenetriamine is abbreviated as DETA) with configurations of 20 %, 30 %, and 40 % WO3 (denoted as 20-WO/CSE, WO/CSE, and 40-WO/CSE), highlighted by its innovative S-scheme heterojunction. WO/CSE nanocomposite stands out in the realm of solar energy materials, achieving a superior photocatalytic hydrogen evolution rate of 16.7 mmol g−1h−1. Additionally, it exhibits exceptional corrosion resistance, maintaining performance integrity over four 12-hour testing cycles. The strategic incorporation of WO3 not only enhances the nanocomposite's photocatalytic efficiency but also underscores its potential in surpassing the capabilities of its individual constituents. Through theoretical calculations, the S-scheme heterojunction's effective charge transfer properties are confirmed, positioning this nanocomposite as a significant leap forward in addressing energy challenges through advanced solar energy materials and nanocomposites.

Dendritic boron and nitrogen doped high-entropy alloy porous carbon fibers for high-efficiency hydrogen evolution reaction

Among various electrocatalysts, high-entropy alloys (HEAs) have gained significant attention for their unique properties and excellent catalytic activity in the hydrogen evolution reaction (HER). However, the precise synthesis of HEA catalysts in small sizes remains challenging, which limits further improvement in their catalytic performance. In this study, boron- and nitrogen-doped HEA porous carbon nanofibers (HE-BN/PCNF) with an in situ-grown dendritic structure were successfully prepared, inspired by the germination and growth of tree branches. Furthermore, the dendritic fibers constrained the growth of HEA particles, leading to the synthesis of quantum dot-sized (1.67nm) HEA particles, which also provide a pathway for designing HEA quantum dots in the future. This work provides design ideas and guiding suggestions for the preparation of borated HEA fibers with different elemental combinations and for the application of dendritic nanofibers in various fields.

Accelerating water dissociation at hierarchical nanostructured electrocatalyst for efficient hydrogen evolution

The sluggish kinetics of the water electrolysis reaction is a key issue for hydrogen production, so the rational design of a high-efficiency hydrogen evolution reaction (HER) electrocatalyst with various structures has attracted extensive attention. Herein, a coaxial hierarchical three-dimensional (3D) nanostructure, Pt@Mo–S–Ni-CNTs, was prepared. In this nanostructure, carbon nanotubes (CNTs) as the core, Mo–S–Ni ultrathin nanosheets as shells, and ultrasmall metal nanoparticles (NPs) were grown uniformly on the surface of Mo–S–Ni nanosheets (NSs). At a current density of 10 mA m−2, the catalyst under investigation has remarkable hydrogen evolution reaction (HER) activity under acidic conditions. The overpotential (η10) is measured to be 61.2 mV, while the Tafel slope is determined to be 40.2 mV dec−1. Meanwhile, in an alkaline medium, η10 is 80.5 mV and the Tafel slope is 52.3 mV dec−1. It also shows great mass activities of 1.32 A mg−1 and 1.86 A mg−1, which are higher than those of commercial Pt/C HER catalysts. Impressively, the excellent HER activity and durability of Pt@Mo–S–Ni-CNTs are mainly attributed to the close binding effects among Pt, MoS2, and NiS. Theoretical simulations show that the MoS2/NiS interfaces facilitate H2O dissociation and that Platinum (Pt) enhances the absorption of hydrogen atoms (H) and increases the charge transfer kinetics of the Mo–S–Ni, thus significantly improving the HER activity. This work highlights the importance of engineering interface nanosheets based on transition-metal dichalcogenides for enhanced HER performance.

One-step synthesis of nanowoven ball-like NiS-WS2 for high-efficiency hydrogen evolution

One-step synthesis of nanowoven ball-like NiS-WS2 for high-efficiency hydrogen evolution

Design of High-Efficiency Hydrogen Evolution Catalysts in a Chiral Crystal

Design of High-Efficiency Hydrogen Evolution Catalysts in a Chiral Crystal

Polyoxometalate derived bimetallic phosphides electrocatalyst for high-efficiency hydrogen evolution reactions

Polyoxometalate derived bimetallic phosphides electrocatalyst for high-efficiency hydrogen evolution reactions

Promoting water splitting by transforming its presence status for enhanced hydrogen evolution

Converting H2O into carbonic acid by reacting H2O with CO2 can reduce the energy barrier to *H generation on Ni.

Defective Biphenylene as High-Efficiency Hydrogen Evolution Catalysts.

Electrocatalysts play a pivotal role in advancing the application of water splitting for hydrogen production. This research unveils the potential of defective biphenylenes as high-efficiency catalysts for the hydrogen evolution reaction. Using first-principles simulations, we systematically investigated the structure, stability, and catalytic performance of defective biphenylenes. Our findings unveil that defect engineering significantly enhances the electrocatalytic activity for hydrogen evolution. Specifically, biphenylene with a double-vacancy defect exhibits an outstanding Gibbs free energy of -0.08 eV, surpassing that of Pt, accompanied by a remarkable exchange current density of -3.08 A cm-2, also surpassing that of Pt. Furthermore, we find the preference for the Volmer-Heyrovsky mechanism in the hydrogen evolution reaction, with a low energy barrier of 0.80 eV. This research provides a promising avenue for developing novel metal-free electrocatalysts for water splitting with earth-abundant carbon elements, making a significant step toward sustainable hydrogen production.

MOF-derived CoS2/WS2 electrocatalysts with sulfurized interface for high-efficiency hydrogen evolution reaction: Synthesis, characterization and DFT calculations

Developing high-efficiency, economical and non-noble-metal electrocatalysts is of great importance to produce hydrogen through hydrogen evolution reaction (HER) in water splitting. Transition metal dichalcogenide has received increasing interests in the application in efficient catalysis, energy conversion and storage. Now, a unique bimetallic sulfide composite (CoS2/WS2) has been prepared by calcination and one-pot hydrothermal method using metal–organic frameworks (MOFs) as precursors. The presence of suitable thioacetamide (TAA) plays a great role in forming the best sulfide interface between CoS2 and WS2 to enhance HER performance. Herein, the overpotential and Tafel slope of as-synthesized CoS2/WS2 at 10 mA cm−2 in 0.5 M H2SO4 medium are obtained as 79 mV and 52 mV dec–1, respectively, which are much lower than those of most non-noble metal-based electrocatalysts. Density Functional Theory (DFT) calculations verify that the bimetallic configuration through the sulfide interface changes the electronic structure, enhances the electrical conductivity and reduces the hydrogen adsorption energy (ΔGH*), effectively accelerating the Heyrovsky step in the HER process. Meanwhile, CoS2/WS2 shows excellent stability in durability tests. The method proposed in this work provides a feasible solution for synthesizing low-cost electrocatalysts.

Ruthenium co-anchored by nitrogen and oxygen on lignin derived carbon for high-efficient hydrogen evolution

Developing efficient electrocatalysts for hydrogen evolution reaction (HER) is crucial to hydrogen production by water electrolysis. Ruthenium (Ru) supported on nitrogenated carbon catalysts as well as the active sites on them have been widely investigated in HER. Nevertheless, the loading of Ru is still high and some oxygen species usually exist in the nitrogenated carbon and their roles are seldom discussed. Herein, we report a novel HER catalyst of 2 wt% Ru/CNO that Ru clusters uniformly dispersed on O-rich nitrogenated carbon (O-rich CN) synthesized from renewable lignin and low-cost melamine. In 1.0 M aqueous KOH, it presents low overpotential of 13 mV at 10 mA cm−2, comparing to that of 39 mV on a commercial 20 wt% Pt/C catalyst. In particular, it also exhibits low value of 659 mV and excellent stability at a large current density of 2000 mA cm−2. The combination of various spectroscopic experiments and density functional theory calculations reveals that Ru cluster co-anchored by nitrogen and oxygen is the active site. This study unveils the crucial role of O in nitrogenated carbon to HER and demonstrates a lignin derived carbon as an excellent electrocatalyst support, supplying a strategy for developing high-efficient HER catalysts.

Smoothing effect of H3BO3 on hydrogen evolution catalyst and the promotion of hydrogen evolution

Hydrogen is a vital clean energy, and reducing overpotential in hydrogen evolution has become necessary research, in which CoMo bimetal material is a promising high-efficiency hydrogen evolution material. In this study, boron was added to MoCo bimetallic ion catalysts with carbon cloth and copper foil substrates, and it was found that adding boron could significantly reduce the hydrogen evolution overpotential of the catalysts. The morphology analysis by SEM showed that the addition of boric acid in the electrolyte could change the morphology of the catalyst, making the surface of the catalyst smooth and uniform distribution on the carrier, while the surface of the catalyst without boric acid formed agglutination. The prepared CoMoB-CC catalyst has an overpotential of 44.1 mV when the current density is -10 mA·cm−2. This paper primarily presents interesting phenomenon of the smooth effect of boric acid on the catalytic electrode, and the prepared catalyst has good catalytic performance, which provides some help for the preparation of hydrogen evolution materials.

Constructing molybdenum vacancy defect for MoP with optimized p-band center towards high-efficiency hydrogen evolution

Vacancy engineering has been widely used to enhance the hydrogen evolution reaction (HER) performance due to its effective electronic modulation effect. Herein, the molybdenum (Mo) vacancies were introduced into molybdenum phosphide (MoP) towards high-efficiency hydrogen evolution for the first time. Benefiting from the charge redistribution around the Mo vacancies, the exposed P sites can serve as ideal catalytic sites with a free energy of hydrogen adsorption close to zero. Meanwhile, an internal polarization field from terminal Mo atoms to exposed P atoms can offer a more efficient “H delivery” mechanism, achieving fast HER kinetics with a dominant Volmer-Heyrovsky mechanism at a wide range of current density and ultimately exceeding the commercial Pt/C catalyst for high-efficiency hydrogen evolution. More importantly, we first report that the P p-band center can be used as an alternative descriptor to evaluate the HER performance of the electrocatalysts which utilize P atoms as the main active sites. Furthermore, this work also demonstrates that metal vacancies provide an effective tactic to optimize catalytic activity for metal compound-based electrocatalysts.

P-doped nanorod MoO3 and nanoflower NiAl-LDH construct S-type heterojunction for photocatalytic high-efficiency hydrogen evolution

S-type heterojunction is a new type of photocatalytic heterojunction that can efficiently enhance the performance of photocatalytic hydrogen-producing. In this paper, NiAl-LDH/P-MoO3 composite catalysts were prepared, NiAl-LDH, P-MoO3 and NiAl-LDH/P-MoO3 were characterized, tested and analyzed from the aspects of morphology, structure and spectrum. The 5 h hydrogen-producing amount of NiAl-LDH/P-MoO3 reaches 298.72 μmol, which is 160 times and 16 times that of MoO3 and NiAl-LDH under the visible light, respectively. The doping of P narrows the band gap of MoO3 and is more helpful to the electronic transmission. The irregular P-MoO3 nanorods with a diameter of about 200 nm are attached to 3-4 μml NiAl-LDH nanoflower. The construction of S-type heterojunction changes the electronic transmission pathway of NiAl-LDH/P-MoO3 while improving the electron-hole pair separation ratio of NiAl-LDH/P-MoO3. The strong oxidizing ability of P-MoO3 and the strong reducing ability of NiAl-LDH are retained. Effective control of electronic transmission path improves the photocatalytic hydrogen-producing activity and stability of NiAl-LDH/P-MoO3, which provides a certain theoretical support for the realization of photocatalytic high-efficiency HER by constructing heterojunction.

Tuning the interface of MIMII(OH)F@MIMII1-xS (MⅠ: Ni, Co; MⅡ: Co, Fe) by atomic replacement strategy toward high performance overall water splitting

Constructing heterostructure is considered as one of the most promising strategies to reveal high efficiency hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance. Nevertheless, it is highly challenging to obtain stable interfaces and sufficient active sites via conventional method. In addition, Ni, Co and Fe elements share the valence electron structures of 3d6-84s2, the appropriate integration of these metals to induce synergistic effect in multicomponent electrocatalysts can enhance electrochemical activity. Herein, in this work, the MIMII(OH)F@MIMII1-xS (NiFe(OH)F@NiFe1-xS, NiCo(OH)F@NiCo1-xS, CoFe(OH)F@CoFe1-xS) autogenous heterostructure on nickel foam are constructed. As a result, NiFe(OH)F@NiFe1-xS-0.05, NiCo(OH)F@NiCo1-xS-0.05, and CoFe(OH)F@CoFe1-xS-0.05 demonstrate outstanding overpotential for HER (70 mV, 90 mV, 81 mV at −10 mA cm−2) and OER (370 mV, 470 mV, 370 mV at 10 mA cm−2) in alkaline electrolyte, while the overpotential for HER is 176 mV, 189 mV, 167 mV at −10 mA cm−2 and corresponding OER is 290 mV, 390 mV, 300 mV at 10 mA cm−2 in simulated seawater, respectively. In addition, the NiFe, NiCo, CoFe-based electrolyzer acquire favorable overall water splitting activity in alkaline (1.72 V, 1.87 V, 1.66 V) and simulated seawater (1.73 V, 1.75 V, 1.69 V) at 10 mA cm−2. Overall, the above results authenticate the feasibility of developing autogenous heterostructure electrocatalysts for providing hydrogen and oxygen in alkaline and simulated seawater.