Efficient Hydrogen Evolution Reaction Research Articles

Titanium dioxide heterojunction support design induced robust platinum catalytic hydrogen evolution over wide pH range

The development of efficient hydrogen evolution reaction (HER) electrocatalysts is critical for water splitting. Herein, rutile/anatase titanium dioxide heterojunction supported platinum nanoparticles (Pt-NPs) design with interfacial effect was developed as efficient HER catalyst (Pt@R/A-TiO2) over wide pH range. The R/A-TiO2 support design induces aggregated Pt-NPs on the heterojunction interface. In-situ Raman and in-situ infrared investigations over wide pH range reveal that there exists a strong hydrogen spillover from Pt-NPs to R/A-TiO2 support and fast proton transfer HER kinetics on Pt@R/A-TiO2. Theoretical calculations demonstrate that the R/A-TiO2 heterojunction modulates more electrons transferred from TiO2 support to Pt-NPs, and this electron-rich Pt-NPs weakens H adsorption, thus enhancing the hydrogen spillover effect and improving the HER performance of Pt@R/A-TiO2. In acidic/alkaline/neutral media, Pt@R/A-TiO2 demonstrates excellent HER activity and stability. Especially in acidic media, Pt@R/A-TiO2 exhibits high mass activity of 12.57 A mgPt−1 at an overpotential of 100 mV, which is nearly 11 times higher than Pt/C, and outperforms the recently reported Pt-based catalysts as well. This work advances the design of efficient and stable HER catalysts over wide pH range.

Beyond Conventional Catalysts: Monoelemental Tellurium as a Game Changer for Piezo-Driven Hydrogen Evolution.

The increasing demand for clean hydrogen production over fossil fuels necessitates the development of sustainable piezoelectrochemical methods that can overcome the limitations of conventional electrocatalytic and photocatalytic approaches. In this regard, existing piezocatalysts face challenges related to their low piezoelectricity or active site coverage for hydrogen evolution reaction (HER). Driven by global environmental concerns, there is a compelling push to engineer practical materials for highly efficient HER. Herein, monoelemental 2D tellurium (Te) is presented as a class of layered chalcogenide with a non-centrosymmetric crystal structure (P3121 space group). The refined Te nanosheets demonstrate an unprecedented highly efficient H2 production rate ≈9000µmolg-1h-1 under ultrasonic mechanical vibration due to built-in piezo-potential in the system. The remarkable piezocatalytic performance of Te nanosheets arises from a synergistic interplay between their semi-metallic nature, favorable free energy landscape, enhanced electrical conductivity and outstanding piezoelectricity. As a proof of concept, the theoretical approach based on Density Functional Theory (DFT) validates the findings due to the gradual exposure of active sites on the Te nanosheets leading to a self-optimized catalytic performance for hydrogen generation. Therefore, mechanically driven Te emerges as a promising piezocatalyst with the potential to revolutionize highly efficient and sustainable technology for futuristic applications.

Facile synthesis of molybdenum carbide interspersed in biomass-derived N-doped carbon matrix for efficient hydrogen evolution reaction

Facile synthesis of molybdenum carbide interspersed in biomass-derived N-doped carbon matrix for efficient hydrogen evolution reaction

Spatially confined synthesis of large-sized MoS2 nanosheets in molten KSCN toward efficient hydrogen evolution

Low-temperature KSCN molten salt is a promising technique to synthesize defect-rich MoS2 catalysts for hydrogen evolution reaction (HER). However, owing to the fast ion diffusion rate for rapid crystal growth, the resultant catalysts show a morphology of microsphere, which aggregates from MoS2 nanosheets, to suppress the catalytic performance. In this work, large-sized few-layer MoS2 nanosheets are synthesized via a spatial confinement strategy by adding inert NaCl into the KSCN molten salt. With the NaCl spacer to physically block the long-distance ion diffusion and isolate the chemical reaction, the MoS2 nucleation and subsequent crystal growth could be controlled, guiding the nanosheets to grow along the narrow gap between the NaCl crystals to avoid aggregation. As a result, ultrathin MoS2 nanosheets with a large geometry size are constructed. Profiting from the architecture to expose active sites and boost charge transfer kinetics, the large-sized few-layer MoS2 nanosheets exhibit an impressive HER performance, showing a small η 10 of 160 mV and a low Tafel slope of 53 mV dec−1 with excellent stability. This work provides not only an efficient HER catalyst but also a facile spatial confinement technique to design and synthesize a large spectrum of transition metal sulfides for broad uses.

Nanocomposite engineering: Tailoring MXene/Cobalt oxide for efficient electrocatalytic hydrogen and oxygen evolution reactions

Electrocatalytic water splitting has become a significant method of hydrogen production to overcome the energy scarcity and increased rate of pollution caused by the extreme consumption of fossil fuels. Pure cobalt oxide is a potential option for electrocatalytic water splitting due to its higher OER activity but lacks stability, conductivity, and active sites which impair its electrocatalytic performance. In this study, Ti3C2Tx/Co3O4 nanocomposite is synthesized to address the previously noted difficulties along with detailed study of both combinations in three different ratios (1:1, 1:2, 2:1). The outcomes demonstrated that the combination of Ti3C2Tx and Co3O4 in the ratio 1:2 outperformed the component materials in terms of electrocatalytic activity with the lowest overpotential of 270 mV at 50 mA cm‐2−2 for the oxygen evolution reaction (OER), having the least Tafel slope (85 mV dec−1) and Ti3C2Tx/Co3O4 in the ratio 2:1 showed overpotential of 235 mA cm−2, with lowest Tafel slope of 97 mV dec−1 which is the lowest among all electrodes for hydrogen evolution reaction (HER). In Ti3C2Tx MXene with increased O functional group providing adsorption site for hydrogen enables HER in a faster rate. While cobalt oxide enables charge transfer to electronegative MXene which in turn result in stability of the electrocatalyst. In the case of OER, Ti3C2Tx/Co3O4 (1:2) shows the better performance as Co centres act as the active sites for OER while MXene has the role of support matrix for the Co3O4 nanoparticles and prevent aggregation. By choosing these two particular composites, Ti3C2Tx/Co3O4 (2:1) as cathode and Ti3C2Tx/Co3O4 (1:2) as anode overall water splitting was done. For total electrolysis, a potential of 1.73 V was required to provide a current density of 10 mA cm−2 with satisfactory stability. Thus, the produced material is a promising contender for producing green hydrogen in the future.

Layered -bismuthene maximizes the active sites in Bi2Te3 towards electrocatalytic hydrogen evolution reactions

The need of sustainable energy sources drives the development of efficient hydrogen evolution reaction (HER) catalysts, inspiring innovative approaches to boost catalytic performance. Here, we introduce a method harnessing the unique properties of layered bismuthene to enhance the active sites of Bi2Te3. Through comprehensive characterization using XRD, FTIR, SEM, TEM, XPS, and Raman analysis, we elucidate the structural and morphological features of the synthesized material. Electrochemical assessments by employing cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy, and chronoamperometry techniques reveal the superior electrocatalytic performance of bismuthene incorporated Bi2Te3 composite, characterized by reduced overpotential (119 mV vs RHE at −10 mA/cm2) and Tafel slope (95.4 mV/dec). These findings underscore the efficacy of a few layered bismuthene in enhancing hydrogen production activity, particularly in alkaline environments, for sustainable water splitting processes. Our work presents findings that contribute to the development of catalysts which are scalable, eco-friendly and promise to revolutionize renewable energy technologies, paving the way for a cleaner and more accessible era of hydrogen fuel.

N-doped NiS2 nanosheets array on carbon fiber as an efficient hydrogen evolution reaction electrocatalyst

N-doped NiS2 nanosheets array on carbon fiber as an efficient hydrogen evolution reaction electrocatalyst

CoPS/Co4S3 Heterojunction with Highly Exposed Active Sites and Dual-site Synergy for Effective Hydrogen Evolution Reactions.

Cobalt phosphosulphide (CoPS) has recently been recognized as a potentially effective electrocatalyst for the hydrogen evolution reaction (HER). However, there have been no research on the design of CoPS-based heterojunctions to boost their HER performance. Herein, CoPS/Co4S3 heterojunction was prepared by phosphating treatment based on defect-rich flower-like Co1-xS precursors. The high specific surface area of nanopetals, together with the heterojunction structure with inhomogeneous strain, exposes more active sites in the catalyst. The electronic structure of the catalyst is reconfigured as a result of the interfacial interactions, which promote the catalyst's ability to adsorb hydrogen and conduct electricity. The synergistic effect of the Co and S dual-site further enhance the catalytic activity. The catalyst has overpotentials of 61 and 70 mV to attain a current density of 10 mA cm-2 in acidic and alkaline media, respectively, which renders it competitive with previously reported analogous catalysts. This work proposes an effective technique for constructing transition metal phosphosulfide heterojunctions, as well as the development of an efficient HER electrocatalyst.

Electrodeposition of NiCo on stainless steel substrate using deep eutectic solvent for efficient hydrogen evolution and methanol oxidation reactions

The electrodeposition of NiCo on a stainless-steel substrate using Deep eutectic solvent (DES) was carried out using constant current methods. A 1:2 mol ratio of ChCl (Choline chloride) and crystalline urea was used to prepare DES. The XRD analysis of the fabricated NiCo@SS showed a highly crystalline nature, and the SEM image revealed the fabricated electrode surface morphology. The composition and oxidation state of the deposited material were confirmed by EDAX and XPS techniques. The prepared electrodes were subjected to LSV and CV studies with 1 M KOH using a three-electrode system to analyse its catalytic ability in the Hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). Among all the deposited electrocatalysts, NiCo@SS demonstrated the highest catalytic activity and excellent stability for the hydrogen evolution reaction (HER), achieving an overpotential of 257 mV at a current density of 100 mA/cm2. Additionally, NiCo@SS exhibited a remarkable current density of 240 mA at a potential of 0.8 V towards the MOR. The synthesized NiCo@SS possessed excellent low overpotential, low charge transfer resistance, high current density, and large surface area. The explored catalyst of NiCo@SS was examined with different concentrations of methanol using the CV technique. Finally, the stability of NiCo@SS, as examined by chronoamperometry and LSV with 3000 cycles, revealed it to be a robust, stable catalyst towards HER and OER.

Lattice strain induced by trace Pt single atoms in nickel for accelerating industrial hydrogen evolution

Strategically designing the electrocatalytic system and cleverly inducing strain is an effective approach to balance the cost and activity of Pt-based electrocatalysts for industrial-scale hydrogen production. Herein, we present a unipolar pulsed electrodeposition (UPED) strategy to induce strain in the Ni lattice by introducing trace amounts of Pt single atoms (SAs) (0.22 wt%). The overpotential decreased by 183 mV at 10 mA cm−2 in 1.0 M KOH after introducing trace amounts of PtSAs. The industrial electrolyzer, assembled with PtSAsNi cathode and a commercial NiFeOx anode, requires a cell voltage of 1.90 V to attain 1 A cm−2 of current density and remains stable for 280 h, demonstrating significant potential for practical applications. Spherical aberration corrected scanning transmission electron microscopy (AC-STEM), X-ray absorption (XAS), and geometric phase analysis (GPA) indicate that the introduction of trace amounts of Pt SAs induces tensile strain in the Ni lattice, thereby altering the local electronic structure and coordination environment around cubic Ni for enhancing the water decomposition kinetics and fundamentally changing the reaction pathway. The doping-strain strategy showcases conformational relationships that could offer new ideas to construct efficient hydrogen evolution reaction (HER) electrocatalysts for industrial hydrogen production in the future.

Mn incorporated RuO2 nanocrystals as an efficient and stable bifunctional electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction in acid and alkaline

The development of efficient and stable bifunctional overall water-splitting is a crucial goal for clean and renewable energy, which is a challenging task. Herein, we report an Mn-incorporated RuO2 (Mn-RuO2) catalyst for highly efficient electrocatalytic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acid and alkaline media. Benefiting from a more electrochemical active area with the incorporation of Mn, the Mn-RuO2 required an overpotential of 200 mV to attain a current density of 10 mA/cm2 for OER in acid. DFT result indicates that the doping of Mn into RuO2 can enhance the OER activity. An acidic overall water-splitting electrolyzer with good stability constructed by bifunctional Mn-RuO2 only requires a cell voltage of 1.50 V to afford 10 mA/cm2 and can operate stably for 50 h at 50 mA/cm2, which is better than the state-of-the-art Ru-based catalyst. Additionally, the Mn-RuO2 exhibits excellent HER and OER activity in alkaline media, and it shows superior activity and durability for overall water-splitting, only needing a cell voltage of 1.49 V to attain 10 mA/cm2. The present work provides an efficient approach to designing and constructing efficient Ru-based electrocatalysts for overall water-splitting.

Hydrothermal synthesis of (NiFe/NiCo)S@NF bilayer electrocatalyst for efficient hydrogen evolution reaction

Hydrogen is widely recognized as a renewable and clean energy source that has the potential to reduce dependence on fossil fuels. However, it is crucial to develop efficient, affordable, and sustainable electrocatalysts for hydrogen production through water splitting. To tackle this challenge, a bilayer Ni–Fe–Co-based sulfide was hydrothermally grown on Ni foam to boost the hydrogen evolution reaction (HER). SEM images revealed the micro-sized NiFe sheets decorated with NiCo nanosheets on the surface. The (NiFe/NiCo)S@NF electrocatalyst demonstrated outstanding performance towards HER in a 1 M KOH solution, where only a low overpotential of 185 mV vs. RHE was required at −10 mA/cm2, being considerably lower than those for NiFeS@NF (230 mV), NiCoS@NF (229 mV), NiFe@NF (237 mV) and NiCo@NF (256 mV) electrodes. This improvement could be attributed to the synergistic effect between constituents, the presence of Ni3S2 and NiCo2S4 phases, and the higher exposed area provided by the 3D nano/micro structure of the (NiFe/NiCo)S@NF electrocatalyst. Furthermore, this electrocatalyst exhibited the lowest Tafel slope of 76 mV/dec compared to NiFeS@NF (92 mV/dec), NiCoS@NF (87 mV/dec), NiFe@NF (89 mV/dec), and NiCo@NF (102 mV/dec), indicating its faster HER kinetics. Finally, in a two-electrode system of (NiFe/NiCo)S@NF||(NiFe/NiCo)S@NF, a low voltage of 1.58 V was required to obtain a current density of 10 mA/cm2 and the synthesized electrocatalyst had excellent stability over 12 h electrolysis. The achieved results proved that the (NiFe/NiCo)S electrocatalyst has great potential as a highly efficient electrode material for alkaline HER.

N-doped hollow nanofibers loaded with RuCoNi ternary alloy as an efficient catalyst for hydrogen evolution reaction

Alloying noble metals with abundant transition metals is an effective strategy for preparing cost-effective electrocatalysts for efficient hydrogen evolution reaction. In this study, hollow carbon nanofibers loaded with RuCoNi ternary alloy nanofiber catalysts (RuCoNi/CNFs) were synthesized by coaxial electrostatic spinning and a high-temperature carbonization approach. The interconnected three-dimensional hollow nanofibers, uniformly loaded with RuCoNi alloy nanoparticles, provided a large specific surface area and a hierarchical porous structure to enhance the interaction between the electrolyte and the active sites. Additionally, the hollow structure facilitated active sites exposure, charge transport, and gas diffusion, resulting in excellent HER activity of RuCoNi/CNFs. The overpotential required to achieve a current density of 10 mA cm−2 under alkaline conditions was only 47 mV, outperforming the homemade Pt/C catalyst (54 mV). Moreover, the carbon structure acted as a conductive carrier for efficient electron transfer, protecting the alloy nanoparticles from aggregation and corrosion. The RuCoNi/CNFs demonstrated remarkable stability and durability, maintaining consistent performance even after 100 hours of continuous operation. Importantly, the catalyst also exhibited favorable HER activity (186 mV@100 mA cm−2) at high current density, highlighting its potential for practical applications in large-scale industry.

Synthesis of polymetallic oxide nanoarrays as efficient hydrogen evolution reaction electrocatalyst for alkaline seawater and urea splitting

Nowadays, with the depletion of traditional fossil resources, hydrogen energy comes into our eyes as a renewable and sustainable energy source. Electrocatalytic water splitting has been widely studied as an environmentally friendly method to produce hydrogen rapidly and large-scale. Since 96.5 % of the world’s abundant water resources are seawater, exploring an economical and efficient catalyst for seawater splitting is an attractive method to realize industrial hydrogen production. In this paper, polymetallic oxide Mn-MoWNi catalyst was in situ synthesized on nickel foam using one-step hydrothermal approach and composite strategy. The catalyst has excellent hydrogen evolution reaction (HER) performance in seawater and urea solution containing 1 M KOH. In 1 M KOH alkaline seawater solution, Mn-MoWNi only requires overpotential of 261 mV to drive the current density of 100 mA cm−2. When the current density of 100 mA cm−2 was reached in the alkaline solution of 1 M KOH + 0.5 M Urea, the overpotential of Mn-MoWNi catalyst was only 206 mV. After 15 h stability measurement in 1 M KOH alkaline seawater solution, the surface morphology of Mn-MoWNi was changed and corroded, indicating that its stability needs to be improved. Density functional theory calculations show that in Mn-MoWNi catalysts, MoO3 promotes the hydrogen adsorption ability of the material, while MnO2 promotes the electrical conductivity of the electrode, and both of them work synergistically with WO3 and NiWO4 to jointly improve the activity of the catalyst.

RuMo nanoalloy confined on N-doped carbon toward efficient alkaline and acidic hydrogen evolution reaction

Noble metal-based electrocatalysts have been demonstrated significant efficiency in the production of hydrogen. However, the sluggish kinetics of the hydrogen evolution reaction (HER) in alkaline media due to high water dissociation energy greatly hinders this electrochemical process. Here, we report a RuMo nanoalloy electrocatalyst mounted on a nitrogen-doped carbon skeleton (RuMo@NC). The RuMo@NC catalyst exhibits excellent HER performance in both alkaline and acidic media, displaying small overpotentials of 18 mV and 14 mV for driving the current density of 10 mA⊡cm−2, respectively. This performance surpasses the majority of noble metal electrocatalysts and 20 % commercial Pt/C. Theoretical calculations reveal that the interaction between Ru and Mo results in a modification of the electronic structure. Consequently, this interaction effectively weakens the adsorption energy of hydrogen on the surface of the RuMo alloy, ultimately improving its catalytic performance in the hydrogen evolution reaction. This work offers new ways to design efficient and economical HER electrocatalysts, advancing the exploration of HER catalysts.

Synergistic effect between Co single atoms and Pt nanoparticles for efficient alkaline hydrogen evolution

In the pursuit of sustainable energy solutions, the efficiency of the hydrogen evolution reaction (HER) in alkaline conditions has been a significant challenge, primarily due to the sluggish dissociation of water molecules on platinum (Pt) catalysts. Addressing this critical issue, our study introduces an innovative Pt-Co@NCS catalyst. This catalyst synergistically combines Pt nanoparticles with Co single atoms on a nitrogen-doped carbon scaffold, overcoming the traditional bottleneck of slow water dissociation. Its unique porous concave structure and nitrogen-enriched surface not only provide abundant anchoring sites for Co atoms but also create a conducive hydrophilic environment around the Pt particles. This design leads to a drastic improvement in the water dissociation process, as demonstrated by CO stripping and deuterium labeling experiments. Achieving an outstanding current density of 162.8 mA cm−2 at −0.1 V versus RHE, a Tafel slope of 26.2 mV dec−1, and a superior nominal mass activity of 15.75 mA μgPt −1, the Pt-Co@NCS catalyst represents a significant step forward in enhancing alkaline HER efficiency, indicating promising advancements in the field.

Double loading of nickel phosphide surface for efficient hydrogen evolution reaction

Metal phosphide, as a highly conductive, chemically stable catalyst material, modulating its hydrogen adsorption is crucial to enhance hydrogen evolution reaction (HER) activity. In this study, we propose a double loading strategy to build Ag and AgP2 heterogeneous structures on Ni2P nanosheets (Ag-AgP2/Ni2P). This is the first application of AgP2 materials in HER. This innovative synthesis was achieved by liquid-phase adsorption of precursors and heat-treatment phosphorization, surface adsorbed AgNO3 is converted to Ag-AgP2 double loading at the same time as Ni2P formation. Density functional theory (DFT) calculations reveal that the double loading structure optimizes charge distribution and d-band center. Its hydrogen adsorption free energy is closer to electroneutrality than that of single loading and simple heterostructures. Benefiting from the special structure, Ag-AgP2/Ni2P exhibits excellent HER performance in alkaline media, requiring only 78 mV overpotential to reach 10 mA cm−2 and stability up to 200 h. This dual loading strategy broadens the perspective of heterogeneous electrocatalyst development.

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.

Highly efficient pH-universal hydrogen evolution reaction catalyzed by rapidly reconstructed bimetallic cobalt-molybdenum alloy cuboids arrays

Highly efficient pH-universal hydrogen evolution reaction catalyzed by rapidly reconstructed bimetallic cobalt-molybdenum alloy cuboids arrays

Rapid Joule-heating fabrication of Ce-doped Co/CoO on carbon nanotubes for efficiently electrocatalytic hydrogen production

In this work, Ce-doped Co/CoO grown on carbon nanotubes was prepared by a novel Joule-heating method. The rapid heating and cooling process caused lattice disorder, which effectively exposed active sites and further improved electrocatalytic activity in the hydrogen evolution reaction (HER). As prepared Ce-Co/CoO@CNTs by the rapid Joule-heating method exhibited excellent performance with an overpotential of only 47.6 mV @10 mA cm−2 in 1 M KOH electrolyte. Furthermore, as-prepared samples maintained exceptional chemical stability, with almost no decay observed even at high current densities (700 mA cm−2) for 200 h. In addition, using Ce-Co/CoO@CNTs catalyst in the alkaline exchange membrane (AEM) electrolyzers, an outstanding operating performance (1.62 V at 10 mA cm−2) was tested for overall water splitting. The formation of a large number of surface defects increased the number of active sites and accelerate the charge transfer. Additionally, the construction of Co/CoO heterojunctions modulated the electronic structure of the interfacial domains, optimizing reaction kinetics and providing a new pathway for designing and synthesizing efficient HER catalysts.