High-performance Hydrogen Evolution Research Articles

"Synergistic Hybridization of Mn-MOF@rGO and Ti3C2 for High-Performance Supercapattery Devices and Hydrogen Evolution Reaction"

The burgeoning interest in two-dimensional (2D) materials stems from their heightened storage capacity and superior conductivity. Here, we synthesized a metal-organic framework of manganese (Mn-MOF) and introduced reduced graphene oxide (rGO) doping into this heterostructure using a hydrothermal method. Subsequently, Ti3C2Tx MXene was prepared via a template method. The Mn-MOF@rGO was then combined with Ti3C2Tx MXene in a 50/50 wt% ratio using hydrothermal techniques, and their structural and electrochemical characteristics were evaluated. In 3-electrode measurements, the MnMOF@rGO/Ti3C2Tx composite conductor exhibited a precise capacity of 2645 C/g (5.29 C/cm3) at 1.8 A/g. Furthermore, a hybrid device termed a supercapattery was fabricated employing MnMOF@rGO/Ti3C2Tx along with activated carbon (AC) composite electrodes, demonstrating remarkable energy density of 67 Wh/kg and an impressive power density of 880 W/kg. After 8,000 cycles, the electrode exhibited 84% capacity retention and maintained 92% columbic efficiency. In the hydrogen evolution reaction (HER), the MnMOF@rGO/Ti3C2Tx composite displayed a minimal Tafel slope of 54.65 mV/dec. These two-dimensional composite electrodes offer novel avenues for the advancement of high-performance energy device.

Transition metal-modified armchair graphene network for high-performance hydrogen evolution reaction catalysts

This study explores the structural, electronic, and catalytic properties of armchair hexagonal graphene networks (AHGN) modified with single transition metal (TM) atoms from Period V. Substitutions of Ag, Mo, Nb, Pd, Rh, Ru, Tc, Y, and Zr were investigated, revealing significant changes in bond lengths, bond angles, and dihedral angles. The binding energies indicate that TM substitutions do not drastically destabilize AHGN, suggesting potential applications requiring modified electronic properties. Electronic investigations showed that TM substitutions influence the partial density of states (PDOS) and energy gaps (ΔE), with Tc significantly reducing ΔE, indicating a shift towards metallic behavior. Mulliken charge analysis highlighted the electron density redistribution around TM atoms and edge carbons, enhancing electronic conductivity and chemical reactivity. Based on the results, AHGN-Rh-H, AHGN-Pd-H, and AHGN-Mo-H demonstrate the most efficient catalytic performance for the hydrogen evolution reaction (HER), with ΔG values comparable to platinum, underscoring their potential for practical hydrogen production applications. Conversely, materials like AHGN-Nb-H and AHGN-Zr-H exhibit higher ΔG values, indicating lower efficiency for HER. Global reactivity parameters (GRPs) analysis revealed AHGN-Tc with the most negative chemical potential (−4.010 eV) and highest electronegativity (4.010 eV), indicating strong electron-accepting and electron-attracting abilities. These findings underscore the potential of TM-substituted AHGN for advanced electronic applications and efficient hydrogen production.

P3HT/g-C3N4 composite fiber membranes for high-performance photocatalytic hydrogen evolution

As a superstar semiconducting polymer, poly(3-hexylthiophene) (P3HT) demonstrates high efficiency in carrier transport ability and wide absorption range. However, pristine P3HT exhibits minimal photocatalytic activity as a result of its short carrier transport distance and fast electron-hole recombination. Here, we strategically fabricated P3HT/g-C3N4 composites on polymethyl methacrylate (PMMA) fiber (PTCN) via electrospinning and the physicochemical properties were fully investigated. Raman spectroscopy, ultraviolet–visible (UV–Vis) absorption spectra and X-ray photoelectron spectroscopy (XPS) results demonstrated a well-defined p-n heterojunctions can be formed between P3HT and g-C3N4 molecules through π-π interaction and extended conjugated length of P3HT could be achieved by tuning the ratios of P3HT relative to g-C3N4. The presence of the heterojunctions facilitates the effective disconnection of the electron-hole pairs, resulting in a significantly enhanced photocatalytic hydrogen evolution rate of 7327 μ mol/(h·g) for the PTCN fiber membranes. This value exceeds that of P3HT fibers by 57.7 times and powder g-C3N4 by 6.8 times, respectively. The high photocatalytic hydrogen production activity of P3HT/g-C3N4 fiber membrane expands the application of P3HT. More importantly, these results indicate that the construction of heterojunction fiber materials is a promising approach for improving the photocatalytic ability of conjugated semiconducting polymers.

ZnIn2S4 nanosheets with geometric defects for enhanced solar-driven hydrogen evolution and wastewater treatment

The key to development of high-performance and low cost photocatalysts hydrogen evolution and waste degradation is to realize efficient photo-generated charge carrier separation and surface catalytic reaction simultaneously without noble metal co-catalyst. To achieve this goal, a noble metal free ZnIn2S4 photocatalyst with geometric defects has been constructed, in which [In-S]4 tetrahedral vacancies (named as (InS)v) on the surface are created by removing the In and S atoms. Further mechanistic investigation has revealed that the (InS)v not only works as the active sites for reductive reaction, but also improves photo-generated electron-hole separation. As a result, the solar-driven hydrogen evolution rate reaches 10.70 mmol/gh without co-catalyst after optimizing the densities of the (InS)v. The apparent quantum efficiency at 380 nm, 395 nm, 420 nm, 450 nm and 520 nm is as high as 14.0 %, 17.1 %, 12.1 %, 8.2 % and 2.4 %, respectively. In addition, these photocatalysts also achieve a rate of 97.78 % and 91.27 % of RhB and MO within 3 and 60 min, respectively. This work show-case a novel approach to develop dual functional and noble metal free photocatalysts for efficiently utilizing solar energy for hydrogen generation and wastewater treatment.

Uniform carbon pillars array grown on boron doped diamond for high-performance supercapacitors and hydrogen evolution reactions

Carbon materials have marvelous ability in energy storage and microelectronics as a result of the high specific surface area and electrical conductivity. However, the low stability and the low power density caused by low potential window make it particularly difficult for their application in aqueous electrolysis. In this study, boron doped diamond (BDD) with wide potential window is used as substrate and Ni as catalyst to grow uniform carbon pillars (CP) by microwave plasma chemical vapor deposition method. The composite structure (CP/BDD) yields significant specific capacity (91.64 mF cm−2 at 0.1 mA cm−2) and cycling stability (92.3 % retention rate after 20,000 cycles) when used as the electrode of supercapacitors, superior to most of BDD-based electrodes. The prepared symmetrical supercapacitor devices maintain their excellent electrochemical performance characteristics (power density of 4.4 mW cm−2 and energy density of 13.4 μW h cm−2), as well as high cycling stability. In addition, the electrode has considerable application potential in electrochemical hydrogen production with low hydrogen evolution potential and small Tafel slope value. These results illustrate the potential of BDD based composites for using as energy storage electrodes for electronic products and energy conversion equipment.

Advances in Shell and Core Engineering of Carbonized Polymer Dots for Enhanced Applications.

ConspectusCarbon dots (CDs), as a novel type of fluorescent nanocarbon material, attract widespread attention in nanomedicine, optoelectronic devices, and energy conversion/storage due to their excellent optical properties, low toxicity, and high stability. They can be classified as graphene quantum dots, carbon quantum dots, and carbonized polymer dots (CPDs). Among these, CPDs exhibit tunable structures and components that allow fine-tuning of their optoelectronic properties, making them one of the most popular types of CDs in recent years. However, the structural complexity of CPDs stimulates deep exploration of the relationship between their unique structure and luminescent performance. As an organic-inorganic hybrid system, the diversity of self-limited quantum state carbon cores and polymer-hybrid shell layers makes understanding the underlying mechanisms and structure-property relationships in CPDs a very challenging task. In this context, elucidating the structural composition of CPDs and the factors that affect their optical properties is vital if the enormous potential of CPDs is to be realized. Achieving controllable structures with predefined optical properties via the adoption of specific functionalization strategies is the prized goal of current researchers in the field.In this Account, we describe the efforts made by our group in the synthesis, mechanism analysis, structural regulation, and functional applications of CPDs, with particular emphasis on the design of CPDs core-shell structures with tailored optoelectronic properties for applications in the fields of optoelectronics and energy. Specifically, through the rational selection of precursors, optimization of reaction conditions, and postmodification strategies for CPDs, we have demonstrated that it is possible to regulate both the carbon core and polymer shell layers, thereby achieving full-spectrum emission, high quantum yield, persistent luminescence, thermally activated delayed fluorescence, and laser action in CPDs. Furthermore, we have established structure-performance relationship in CPDs and proposed a universal strategy for synergistic interactions between hybrid carbon-based cores and surface micronanostructures. In addition, we unveiled a novel luminescence mechanism in cross-linked CPDs, specifically "cross-linking synergistically inducing quantum-state luminescence", which addresses the challenge of efficient circularly polarized luminescence in the liquid and solid phases of CPDs. Subsequently, strong cross-linking, dual-rigidity, and ordering preparation methods were introduced, thereby pioneering tunable laser emission from blue to near-infrared wavelengths. Additionally, we developed a new strategy of "confined composite nanocrystals of CPDs", leading to various high-performance hydrogen evolution catalysts for water electrolysis. The CPDs developed by this strategy not only possessed excellent optical properties but also enabled high efficiencies in field of energy conversion, thus maximizing the utilization of CPDs. Finally, we discuss important new trends in CPD research and development. Overall, this Account summarizes the latest advancements in CPDs in recent years, providing case-studies that enable deep understanding of structure-property-performance relationships and regulation strategies in CPDs, guiding the future expansion and application of CPDs.

Unlocking high-performance hydrogen evolution: Argon-induced Ni segregation in NiO/TiO2 of core/shell catalysts

This study introduces novel core-shell structured electrocatalysts synthesized via an optimized one-pot sol-gel method, aimed at enhancing the efficiency of the Hydrogen Evolution Reaction (HER) in water splitting. The Ni–NiO/TiO2 and NiO/TiO2 composites demonstrate superior catalytic performance, with the Ni–NiO/TiO2 requiring a remarkably low potential of −0.125 V versus Ag/AgCl to achieve a current density of 10 mA.cm-2. This performance surpasses that of NiO/TiO2 and pure NiO, offering a viable alternative to Pt catalysts. Advanced characterization techniques, including X-ray diffraction, electron microscopy, and X-ray photoelectron spectroscopy, elucidate the crystalline phases, morphologies, and chemical states, enhancing our understanding of the electrocatalysts' efficiency. In particular, Rietveld refinement analysis provides detailed insights into the structural properties that underpin the observed catalytic performance. Electrochemical assessments highlighted the Ni–NiO/TiO2 composite's reduced overpotential needs, high Faradaic efficiency (∼98%), and notable long-term durability, positioning these materials as promising candidates for sustainable hydrogen production.

Magnetic Co2Si monolayer with high performance hydrogen evolution reaction: a first-principle prediction

Magnetic Co2Si monolayer with high performance hydrogen evolution reaction: a first-principle prediction

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.

High-performance hydrogen evolution reaction in quadratic nodal line semimetal Na2CdSn

Topological nodal line semimetals (TNLSMs), which exhibit one-dimensional (1D) band crossing in their electronic band structure, have been predicted to be potential catalysts in electrocatalytic processes. However, the current studies are limited to the TNLSMs where the dispersion around the nodal line is linear in all directions. Here, the potential application of the quadratic nodal line (QNL) semimetal Na2CdSn in hydrogen evolution reaction is explored. Based on the bulk-boundary correspondence, we find that the topological surface states (TSSs) of the QNL are extended in the entire Brillouin zone. A linear relationship between the density of states of the TSSs and the Gibbs free energy is established in Na2CdSn. Remarkably, the best performance of Na2CdSn can be comparable to that of the noble metal Pt. Therefore, our work not only identifies an innovative type of topological catalyst with a QNL state but also confirms the relationship between TSSs and catalytic performance.

Hybrid Molecular Layer Deposition of Molybdenum-Aminates as Hydrogen Evolution Reaction Electrocatalysts

The development of high-performance hydrogen evolution reaction (HER) electrocatalysts from noble metal-free materials is critical to achieving cost-effective water splitting and ultimately realizing affordable hydrogen based on renewable energy. Compounds based on earth-abundant transition metals have been the subject of great research interest for this purpose, with metal nitrides gaining recent attention due to their high conductivity and corrosion resistance. Molybdenum nitride-based electrocatalysts have shown particular promise, with many of the best reported activities occurring in composite systems wherein crystalline MoNx domains are embedded in an amorphous N-doped carbon matrix. The present work demonstrates the formation of such uniquely active morphologies in films deposited by organic-inorganic hybrid molecular layer deposition (MLD).Hybrid MLD is a hybridization of other well-established layer-by-layer deposition techniques – namely atomic layer deposition (used to deposit inorganic films) and purely organic MLD. This family of techniques involves the cyclical exposure of a growth surface to alternating vapor-phase chemical precursors which react in a self-limiting fashion to saturate available surface sites, offering atomic- and molecular-level control over the resulting films. This presentation will introduce the successful development of hybrid MLD deposition procedures for new Mo-aminate materials using Mo(CO)6 as a Mo precursor and various amine precursors, including ethylenediamine, p-phenylenediamine, and tris(2-aminoethyl)amine.We will describe how the molecular level of control offered by this technique enables tunable variations in film composition and structure, lending unique insights into how the local bonding environment of Mo active sites affects their catalytic properties towards HER. Increased nitrogen loading in the MLD films was shown to decrease the overpotentials required to drive HER in acidic media (0.5 M H2SO4) and improve film stability. Catalysts with N/Mo ratios above 2 demonstrated the best performance, with overpotentials lower than 400 mV at -10 mA/cm2. By incorporating organic components in the MLD films, it was possible to induce desirable morphological changes in the catalytic material – notably including the development of increased active site density – simply through initial exposure to HER testing conditions. The choice of organic precursor affected the rate and extent of these changes through structural effects like crosslinking and crystallinity, which led to more stable catalysts, slowed the rate of morphological changes, and impacted final film structure.

Regulating the electronic structure of Pt SAs-Ni2P for enhanced hydrogen evolution reaction

The single atom catalysts (SACs) show immense promise as catalytic materials. By doping the single atoms (SAs) of precious metals onto substrates, the atomic utilization of these metals can be maximized, thereby reducing catalyst costs. The electronic structure of precious metal SAs is significantly influenced by compositions of doped substrates. Therefore, optimizing the electronic structure through appropriate doping of substrates can further enhance catalytic activity. Here, Pt single atoms (Pt SAs) are doped onto transition metal sulfide substrate NiS2 (Pt SAs-NiS2) and phosphide substrate Ni2P (Pt SAs-Ni2P) to design and prepare catalysts. Compared to the Pt SAs-NiS2 catalyst, the Pt SAs-Ni2P catalyst exhibits better hydrogen evolution catalytic performance and stability. Under 1 M KOH conditions, the hydrogen evolution mass activity current density of the Pt SAs-Ni2P catalyst reaches 0.225 A mgPt–1 at 50 mV, which is 33 times higher than that of commercial Pt/C catalysts. It requires only 44.9 mV to achieve a current density of 10 mA cm−2. In contrast, for the Pt SAs-NiS2 catalyst, the hydrogen evolution mass activity current density is 0.178 A mgPt–1, requiring 77.8 mV to achieve a current density of 10 mA cm−2. Theoretical calculations indicate that in Pt SAs-Ni2P, the interaction between Pt SAs and the Ni2P substrate causes the Pt d-band center to shift downward, enhancing the H2O desorption and providing optimal H binding sites. Additionally, the hollow octahedral morphology of Ni2P provides a larger surface area, exposing more reactive sites and improving reaction kinetics. This study presents an effective pathway for preparing high-performance hydrogen evolution electrocatalysts by selecting appropriate doped substrates to control the electronic structure of Pt SAs.

Pt cluster incorporated NiO nanoflower boosts hydrogen evolution reaction via enhanced metal support interaction

Hydrogen serves as a potent and environment friendly energy source, and developing high performance hydrogen evolution reaction (HER) electrocatalysts is crucial for water splitting. In this work, Pt nanoparticles incorporated NiO nanoflower (Pt-NiO) is synthesized using an ethylene glycol reduction method. The incorporation of Pt not only introduces extra high active sites, but also induces strong interaction between NiO and Pt. Meanwhile, the NiO nanoflower support enables the dispersion of Pt and ensure high electrochemically surface area as well as fast mass transport, which greatly improves catalytic activity of Pt-NiO. Pt-NiO-3 only requires a small overpotential of 26 mV to reach 10 mA cm−2 and the Tafel slope is only 19.49 mV dec−1. In addition, the mass activity can achieve 2000 mA mgPt−1 at an overpotential of 63 mV. Moreover, obvious bubbles can be observed in the assembled H-type for overall water splitting, and the Faraday efficiency is close to 100 %, highlighting the superiority of Pt-NiO-3. This work provides insights for designing high effective electrocatalysts for HER.

Zeolitic Imidazolate Framework-8 enhanced with tungsten carbide for high-performance hybrid supercapacitors and hydrogen evolution

A promising metal-organic framework (MOF) called Zeolitic Imidazolate Framework-8 (ZIF-8) stands out for its electrochemical applications. Its versatility in physicochemical properties makes it a strong candidate for breakthroughs in energy storage and electrochemical water splitting. The electrode nanomaterials lower specific capacity, small charging/discharging rate, and low conductivity limit its supercapacitor and hydrogen evaluation reaction (HER) applications. The ZIF-8 zeolite structure was decorated with tungsten carbide (WC) to overcome these issues. These modifications result in improved porosity, surface area, density, and pore size, shape, and structure. These characteristics contribute significantly to enhanced electrochemical activity. ZIF-8 MOF/WC nanocomposites have excellent dispersion and stability due to their porosity and strong connection between embedded WC nanoclusters and the framework. The prepared electrode showed a 118.11 mV overpotential and 36.45 mV/dec Tafel slope throughout HER activity. ZIF-8 MOF/WC was used for electrochemical studies and to make a hybrid energy storage device using activated carbon (AC). The hybrid supercapacitor had higher energy and power densities (87 W h/kg and 850 W/kg). The theoretical technique (Dunn model) was also employed to analyze experimental results more thoroughly.

Dandelion-like VSe2-embellished CuSe-Co3Se4 hollow nanotube clusters as bifunctional catalysts for high-performance alkaline hydrogen evolution and solar cells

Among the various non-precious metal catalysts that drive hydrogen evolution reactions (HERs) and dye-sensitized solar cells (DSSCs), transition metal selenides (TMSs) stand out due to their unique electronic properties and tunable morphology. Herein, the multicomponent selenide CuSe-Co3Se4@VSe2 was successfully synthesized by doping with metal element vanadium and selenization on the copper-cobalt carbonate hydroxide (CuCo-CH) template. CuSe-Co3Se4@VSe2 exhibited the dandelion-like cluster structure composed of hollow nanotubes doped with VSe2 nanoparticles. Due to the unique structure and the synergistic effect of various elements, CuSe-Co3Se4@VSe2 showed excellent alkaline HER and DSSC performances. The DSSC based on CuSe-Co3Se4@VSe2 exhibited an impressive power conversion efficiency (PCE) of 9.64 %, which was much higher than that of Pt (8.39 %). Besides, it possessed a low HER overpotential of 76 mV@10 mA cm−2 and a small Tafel slope of 88.9 mV dec−1 in 1.0 M KOH.

High-performance photocatalytic hydrogen evolution in a Zn0.5Cd0.5S/MoS2 p–n heterojunction

With respect to solid-solution photocatalysts for water splitting, researchers have focused on improving the loading and stability of catalysts, which have been major concerns and research interests. Herein, the fabrication of Zn0.5Cd0.5S/MoS2 nanocomposites involved a two-step method that encompassed hydrothermal synthesis and physical mixing. Experimental results confirmed that the Zn0.5Cd0.5S/MoS2 nanocomposites exhibited outstanding photocatalytic performance. In particular, they exhibited a notable hydrogen precipitation rate of 19.41 mmol/(g*h). The hydrogen production performance of Zn0.5Cd0.5S/MoS2 was approximately nine times greater than that of pure Zn0.5Cd0.5S, indicating a considerable increase. The observed enhancement in photocatalytic efficiency can be attributed to the formation of a p–n heterojunction between Zn0.5Cd0.5S and MoS2. This particular junction helped in separating and migrating photoinduced charge carriers, ultimately improving the photocatalytic performance. Furthermore, the addition of excess thiourea in MoS2 preparation produced Mo–O defects and increased the layer spacing of the involved material, improving the electron transfer and visible-light utilization of the material. The inhibition of carrier recombination was beneficial for synthesizing efficient and long-lasting photocatalysts.

Co/CoO nanoparticles loaded on multi-walled carbon Nanotubes@Covalent organic frameworks for electrocatalytic hydrogen evolution

Producing hydrogen by electrolyzing water has received increased attention. Nevertheless, a major challenge remains in the search for high performance hydrogen evolution reaction (HER) electrocatalysts. In this work, multi-walled carbon nanotubes (MWCNTs) capped by TpPa covalent organic framework (TpPa-COF) react with cobalt nitrate hexahydrate (Co(NO3)2·6H2O) to form a novel ternary one-body complex (MWCNTs@TpPa-COF@Co/CoO). Wherein, TpPa-COF is constructed from 2,4,6-Triformylphloroglucinol (Tp) and p-phenylenediamine (Pa) as structural units. This COF is relatively inexpensive, provides more coordination sites for metal loading, and is particularly stable in acidic and basic media. The results show that the composite material has high electrocatalytic HER activity in a potassium hydroxide (KOH) condition with an overpotential value of 28.8 mV and a Tafel slope of 69.07 mV dec−1 at a current density of 10 mA cm−2. Meanwhile, the MWCNTs@TpPa-COF@Co/CoO showed excellent stability after 2000 cycles in alkaline media. The characterization demonstrated that the material provided low resistance during the charge transfer process, which resulted in improved electrochemical performance. In addition, the COF loaded with cobalt nanoparticles provided more active sites for the reaction. Thus, the synthesized MWCNTs@TpPa-COF@Co/CoO emerges turns out to be a Pt-free, stable and efficient HER electrocatalyst, holding significant promise for practical applications.

Synergistic Effect of P and Co Dual Doping Endows CuNi with High-Performance Hydrogen Evolution Reaction.

The rational design of highly active and durable non-noble electrocatalysts for hydrogen evolution reaction (HER) is significantly important but technically challenging. Herein, a phosphor and cobalt dual doped copper-nickel alloy (P, Co-CuNi) electrocatalyst with high-efficient HER performance is prepared by one-step electrodeposition method and reported for the first time. As a result, P, Co-CuNi only requires an ultralow overpotential of 56mV to drive the current density of 10mA cm-2, with remarkable stability for over 360h, surpassing most previously reported transition metal-based materials. It is discovered that the P doping can simultaneously increase the electrical conductivity and enhance the corrosion resistance, while the introduction of Co can precisely modulate the sub-nanosheets morphology to expose more accessible active sites. Moreover, XPS, UPS, and DFT calculations reveal that the synergistic effect of different dopants can achieve the most optimal electronic structure around Cu and Ni, causing a down-shifted d-band center, which reduces the hydrogen desorption free energy of the rate-determining step (H2O + e- + H* → H2 + OH-) and consequently enhances the intrinsic activity. This work provides a new cognition toward the development of excellent activity and stability HER electrocatalysts and spurs future study for other NiCu-based alloy materials.

Confining ruthenium nanoparticles in MOF pores for high-performance hydrogen evolution reaction

The exploration of low-cost catalysts for hydrogen evolution reaction holds great significance in application. Ruthenium nanoparticles (Ru NPs)-based composites have emerged as a type of promising candidates. This study focuses on the impact of metal–organic framework (MOF) pore structure on the growth of Ru NPs, as well as the resulting effects on their electrocatalytic properties using two Ru@MOFs electrodes (Ru@Ni-BPM/NF and Ru@Ni-BPDC/NF). 3D Ni-BPM can effectively load Ru NPs with uniform and controlled size, while 2D Ni-BPDC leads to uncontrolled growth of Ru NPs. Consequently, Ru@Ni-BPM/NF shows superior catalytic performance with a smaller overpotential of 12 mV at 10 mA cm−2 and a lower Tafel slope of 40.3 mV dec-1, outperforming Ru@Ni-BPDC/NF and commercial Pt/C in alkaline media. Meanwhile, the pore confinement effect of Ni-BPM significantly reduces the aggregation of Ru NPs during extended stability testing, guaranteeing the structural integrity of the electrode and sustained exposure of the active sites.

Interface engineering of MoS2–CoS2 heteronanosheets for enhanced electrochemical hydrogen evolution reaction

The heterostructured electrocatalysts with tunable electronic interaction and distinct synergetic effects have been confirmed as an efficient strategy for realizing high-performance hydrogen evolution reaction (HER). Herein, a simple synthetic strategy is reported for the growth of MoS2–CoS2 nanosheets on highly conductive reduced graphene oxide (MoS2–CoS2/RGO) to innovatively construct an electron-reconfiguration heterointerface. The strong electronic interactions between MoS2 and CoS2 interfaces lead to the redistribution of charge, which optimizes the adsorption-desorption of intermediates. Thus, the MoS2–CoS2/RGO exhibits superior catalytic activity toward HER with small overpotentials of 67 mV (1.0 M KOH) and 95 mV (0.5 M H2SO4), and remarkable stability. In addition, theoretical calculations reveal the redistribution of charge at the heterointerfaces, which decreases the energy barrier of adsorption for H intermediates and simultaneously enhances the kinetic of water dissociation. This work provides a simple strategy for designing heterostructured bimetallic electrocatalysts with a highly active interface.