Efficient Hydrogen Evolution Reaction Research Articles

Simultaneous Defect Passivation and Co-Catalyst Engineering Leads to Superior Photocatalytic Hydrogen Evolution on Metal Halide Perovskites.

Metal halide perovskites (MHPs) have emerged as attractive candidates for producing green hydrogen via photocatalytic pathway. However, the presence of abundant defects and absence of efficient hydrogen evolution reaction (HER) active sites on MHPs seriously limit the solar-to-chemical (STC) conversion efficiency. Herein, to address this issue, we present a bi-functionalization strategy through decorating MHPs with a molecular molybdenum-sulfur-containing co-catalyst precursor. By virtue of the strong chemical interaction between lead and sulfur and the good dispersion of the molecular co-catalyst precursor in the deposition solution, a uniform and intimate decoration of the MHPs surface with lead sulfide (PbS) and amorphous molybdenum sulfide (MoSx) co-catalysts is obtained simultaneously. We show that the PbS co-catalyst can effectively passivate the Pb-related defects on the MHPs surface, thus retarding the charge recombination and promoting the charge transfer efficiency significantly. The amorphous MoSx co-catalyst further promotes the extraction of photogenerated electrons from MHPs and facilitates the HER catalysis. Consequently, drastically enhanced photocatalytic HER activities are obtained on representative MHPs through the synergistic functionalization of PbS and MoSx co-catalysts. A solar-to-chemical (STC) conversion efficiency of ca. 4.63 % is achieved on the bi-functionalized FAPbBr3-xIx (FA=CH(NH2)2), which is among the highest values reported for MHPs.

3D hierarchical nanostructured NiCo-LDH/Cu electrode for efficient alkaline hydrogen evolution

The development of an efficient and cost-effective electrocatalyst for the Hydrogen Evolution Reaction (HER) that can be widely applied in industrial settings poses a multifaceted challenge. This research involved fabricating a NiCo-LDH/Cu electrode as a self-supported catalyst for hydrogen evolution on nickel foam using a solvothermal method and constant potential electrodeposition. In comparison to the NiCu electrocatalyst produced through a single-step electrodeposition, the NiCo-LDH/Cu hydrogen evolution electrode prepared via this combined approach exhibited significant electrocatalytic performance for HER in an alkaline electrolyte. The NiCo-LDH/Cu catalytic electrode requires only an overpotential of 78.0 mV to achieve a current density of 10 mA·cm−2 in 1 M KOH. The current density required to catalyze the hydrogenation reaction is reduced by 64 % compared to pure nickel foam. This reduction accelerates the hydrogenation catalytic reaction and enhances electrochemical stability. The remarkable HER efficiency of the NiCo-LDH/Cu catalytic electrode primarily stems from the increased active surface area facilitated by the LDH structure and the synergistic impact generated during the NiCu co-deposition process. This work shows an economical and practical method for developing efficient non-precious metal catalytic electrodes.

Evaluation of anion exchange membrane water electrolysis performance using synthesised NiMoO4/Ni cathode via solution combustion synthesis in applied thermal reduction approach

The development of sustainable electrocatalysts is essential for the advancement of anion exchange membrane water electrolysis (AEMWE) technologies. Nickel molybdate-based catalysts may improve the efficiency of hydrogen evolution reaction (HER) during alkaline water electrolysis. This study investigated the influence of thermal reduction temperature on the synthesised NiMoO4-based catalyst via solution combustion synthesis (SCS) and its performance in HER and single-cell AEMWE. The optimal conditions for stable and active HER electrocatalysts were determined by investigating synthesised NiMoO4 catalysts at 450 °C, 550 °C and 750 °C. A NiMoO4 catalyst was characterised at different reduction temperatures through X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS) and Brunauer–Emmett–Teller (BET) analysis. Results revealed that the NiMoO4-450/Ni cathode became the highest performance 1 A/cm2 current density at 2.2 V and the NiMoO4-550/Ni cathode became the most stable performance among the catalysts, attaining. The average current density of NiMoO4-550/Ni fluctuated by only 22% from 24 h to 100 h.

Fabrication of nickel nanoparticles anchored on a 2D double transition metal MXene for efficient hydrogen and oxygen evolution reactions

Creating cost-effective and high-performing bifunctional electrocatalysts is a viable alternative to expensive noble metal electrocatalysts for water-splitting applications. A double transition metal MXene (Mo2TiC2Tx) has recently shown exceptional electrocatalytic activity because of its high conductivity, hydrophilicity, mechanical stability, electron mobility, and rich surface chemistry. In this study, we have created efficient bifunctional electrocatalytic properties of nano Ni decorated Mo2TiC2Tx MXene (Ni–Mo2TiC2Tx). The efficient and homogeneous incorporation of Ni on the 2D Mo2TiC2Tx surface and between the layers demonstrates remarkable electrocatalytic efficiency for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Among the different combinations, the 15 mmol Ni–Mo2TiC2Tx showed lower overpotential for the HER (ƞ10 = 153.9 mV) and OER (ƞ10 = 200.5 mV). Moreover, the Ni–Mo2TiC2Tx based electrocatalysts exhibit satisfactory electrochemical stability up to 5000 cycles. During the HER and OER process, Ni and Mo cations form a new oxy-hydroxide layer on the surface in the OH− environment indicating a faster surface self-reconstruction process of the surface structure and Ni/Mo oxy-hydroxide layer interacts with O and H atoms of adsorbed water and thus leading to superior HER and OER activity. This study introduces a straightforward and effective approach to creating a new category of MXene heterostructures, which significantly boosts the performance and durability of catalysts for the HER and the OER showing promise for future applications.

Copper restructured transition metal/metal oxide heterostructure with a hierarchical nanostructure for accelerated water dissociation kinetics and alkaline hydrogen evolution

The slow kinetics of water dissociation on electrocatalysts lacking platinum hinders the advancement of cost-effective hydrogen production via alkaline water electrolysis. Herein, a hierarchically peach-flower-shaped electrocatalyst consisting of copper-restructured cobalt–nickel/cobalt–nickel oxide heterostructure anchored on copper nanowires (Cu-CoNiO/CoNi@Cu NWs) is developed for efficient hydrogen evolution reaction (HER). Benefiting from the optimized electronic configuration and geometric structure, this Cu-CoNiO/CoNi@Cu NWs catalyst performs an outstanding alkaline HER activity of 29 mV at 10 mA cm−2 and 98 mV at 100 mA cm−2, which is comparable with the state-of-the-art Pt/C catalyst (26 mV at 10 mA cm−2 and 117 mV at 100 mA cm−2). Our findings rank among the topmost catalytic efficiencies when compared to all previously reported non-noble metal catalysts and numerous noble metal catalysts. The combined experimental exploration and theoretical studies reveal that the incorporation of Cu dopant into CoNiO/CoNi heterostructure enhances electron transfer from metal atoms to O atom, leading to the formation of the polarized electric field to accelerate water dissociation and H evolution, eventually facilitating the overall alkaline HER process. The boosted electron exchange and mass transportation deriving from the introduction of Cu NWs and hierarchically peach-flower-shaped nanostructure further reinforce the HER activity of the Cu-CoNiO/CoNi catalyst.

Synergistic effects of 1T–2H MoS2 and laser-reduced graphene Oxide–ZnO scaffold composite catalyst for efficient hydrogen evolution reaction

A composite catalyst, zinc-doped laser-reduced graphene oxide (LrGO), is synthesized with highly dispersed molybdenum disulfide (MoS2) nanolayers using laser exfoliation followed by a hydrothermal process. The resultant LrGO–ZnO/1T–2H MoS2 (GZM3) catalyst exhibits enhanced hydrogen evolution reaction (HER) catalytic performance and improved stability. It achieves small overpotentials of 94 and 191.5 mV at a current density of 10 mA cm−2, under acidic and alkaline conditions, respectively. This superior catalytic activity is attributed to the high electrical conductivity and large electrochemical surface area of graphene, along with efficient charge transfer facilitated by Zn ions between LrGO–ZnO and 1T–2H MoS2.

Harnessing the clean energy: Phosphorus-alkynyl covalent organic frameworks for photocatalytic hydrogen production

Given the diminishing reserves of fossil fuels, the development of renewable alternative energy sources is of global importance. Photocatalytic hydrogen (H2) evolution stands out as a promising and cost-effective method to harness sunlight for producing carbon-free H2 fuel. Recently, two-dimensional (2D) covalent organic frameworks (COFs) have garnered considerable research interest in photocatalysis on account of their exceptional surface area and predictable assembly of diverse molecules with adjustable electronic properties. Herein, six 2D COFs are constructed by topologically assembling phosphorus-alkynyl functional moieties and benzene-based building units, including benzene (COF-1), triazine (COF-2), heptazine (COF-3), triphenyl-benzene (COF-4), triphenyl-triazine (COF-5), and triphenyl-heptazine (COF-6), employing first-principles calculations. Our computational results illustrate that the variation of benzene-based building units significantly regulates the electronic structures of COFs, all of which possess semiconductor properties with tunable bandgaps spanning from 1.56 to 2.56 eV. Of particular importance, COF-1, COF-2, COF-4, COF-5, and COF-6 can spontaneously stimulate the hydrogen evolution reaction (HER) under their own light-induced bias without the need for sacrificial agents and co-catalysts. Among them, COF-4 and COF-5 show the best HER activity without light-induced bias, with ΔG values of 0.02 and −0.01 eV, respectively, whose excellent photocatalytic performance can be ascribed to their appropriate electronic band structures, pronounced optical absorption, and low work functions. This finding offers profound insights for exploring other highly efficient HER photocatalysts.

Facile preparation of PtNi/Cs derived from the precipitation polymerization of a Poly(amic acid) for efficient hydrogen evolution reaction catalysis

Hydrogen evolution reaction (HER) of water is currently one of the most potential ‘green hydrogen’ production technology to alleviate the energy scarcity and environmental contamination. In this study, ultrafine platinum/nickel bimetallic nanoparticles loaded porous carbon nanocomposite, noted as PtNi/Cs, is facilely prepared by employing the precipitation polymerization of a poly (amic acid) (PAA), which shows superior catalytic performance toward HER. The synthesis of PAA is achieved via a stepwise polymerization of 4,6-diaminino-2-mercaptopyrimidine and pyromellitic dianhydride at room temperature, and the porous precursor is formed during the polymerization. Upon pyrolysis of the precursor in an inert atmosphere, carbon nanoaggregates with inherited porosity are fabricated. Ultrafine PtNi bimetallic nanoparticles with size of 3.3 ± 0.7 nm can be efficiently deposited, exhibiting an overpotential of 26.4 mV at 10 mA cm−2 and a mass activity of 2.92 A mgPt−1, superior than commercial Pt/C of 36.8 mV. The excellent HER performance can be attributed to the formation of ultrafine PtNi bimetallic nanoparticles and the electron transfer from PtNi to the nitrogen atoms on the carbon support.

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.

Facile synthesis of NiCo2O4 nanosheets efficient for electrocatalysis of water

Effective regulation of transition metal spinel morphology is crucial for stable bifunctional catalysts in the electrocatalysis of water. In this work, we crafted a fine NiCo2O4 (F-NCO) microflower structure assembled by nanosheet arrays, which exhibited highly efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), outperforming most of the previous transition metal catalysts. Electronic microscope analysis revealed that the thickness of the F-NCO catalyst was only 1.6 nm, much smaller than that (58.8 nm) of bulk NiCo2O4 (B-NCO), and the ultrathin lamellar structure facilitated the exposure of active sites and improved the reaction kinetics. Compared with the B-NCO catalyst, the overpotential of the F-NCO catalyst in HER and OER was reduced by 36 and 82 mV, the active surface area increased by 2.68 and 4.16 times, and the charge transfer resistance values were reduced by 0.42 and 0.61 times, respectively. In the assembled cell, F-NCO/CFP(+)||F-NCO/CFP(−) electrolyzer was able to achieve 10 mA cm−2 at a low cell voltage of 1.74 V, which was much lower than B-NCO/CFP(+)||B-NCO/CFP(−) electrolyzer. In the 12-hour stability test, the potentiometric time dropped by only 30 mV, lower than 70 mV of the B-NCO catalyst. This work presents a facile strategy for developing a bifunctional catalyst for the electrocatalysis of water.

Optimizing interactions for efficient hydrogen evolution reaction by incorporating rhenium nanoparticles on defect-rich carbon

The rich anchoring site on carbon renders it a promising support for catalytically active metal nanoparticles (NPs), thereby enhancing their intrinsic catalytic activity towards hydrogen evolution reaction (HER) through interactions between the support and the metal. However, complex synthesis conditions often compromise the synergy between the metal and support. Herein, we report Re NPs embedded on XC-72 carbon support to investigate the robust interactions in affecting the HER activity. Consequently, Re NPs anchored on defect-rich XC-72 exhibit efficient and robust HER activity in acidic conditions, achieving an extremely low overpotential of 25 mV to deliver a current density of 10 mA cm−2 and a Tafel slope of 78 mV dec−1, surpassing that of Pt/C catalyst. Based on experimental investigations and density functional theory calculations, the high catalytic activities of as-obtained Re/C can be attributed to the enhanced electron transport kinetics facilitated by the interactions between Re NPs and carbon support, the exposure of the active site on Re NPs, and lowered reaction energy barrier towards HER. This study provides valuable insights for the rational development of Re-based efficient catalysts for HER.

Heterogeneous Structure of Ni-Mo Nanoalloys Decorated on MoOx for an Efficient Hydrogen Evolution Reaction Using Hydrogen Spillover.

Herein, a heterogeneous structure of Ni-Mo catalyst comprising Ni4Mo nanoalloys decorated on a MoOx matrix via electrodeposition is introduced. This catalyst exhibits remarkable hydrogen evolution reaction (HER) activity across a range of pH conditions. The heterogeneous Ni-Mo catalyst showed low overpotentials only of 24 and 86, 21 and 60, and 37 and 168mV to produce a current density of 10 and 100mAcm-2 (η10 and η100) in alkaline, acidic, and neutral media, respectively, which represents one of the most active catalysts for the HER. The enhanced activity is attributed to the hydrogen spillover effect, where hydrogen atoms migrate between the Ni4Mo alloys and the MoOx matrix, forming hydrogen molybdenum bronze as additional active sites. Additionally, the Ni4Mo facilitated the water dissociation process, which helps the Volmer step in the alkaline/neutral HER. Through electrochemical analysis, in situ Raman spectroscopy, and density functional theory calculations, the fast HER mechanism is elucidated.

Nanocrystalline transition metal tetraborides as efficient electrocatalysts for hydrogen evolution reaction at the large current density

While great efforts have been made to improve the electrocatalytic activity of existing materials toward hydrogen evolution reaction (HER), it is also importance for searching new type of nonprecious HER catalysts to realize the practical hydrogen evolution. Herein, we firstly report nanocrystalline transition metal tetraborides (TMB4, TM=W and Mo) as an efficient HER electrocatalyst has been synthesized by a single-step solid-state reaction. The optimized nanocrystalline WB4 exhibits an overpotential as low as 172 mV at 10 mA/cm2 and small Tafel slope of 63 mV/dec in 0.5 M H2SO4. Moreover, the nanocrystalline WB4 outperforms the commercial Pt/C at high current density region, confirming potential applications in industrially electrochemical water splitting. Theoretical study reveals that high intrinsic HER activity of WB4 is originated from its large work function that contributes to the weak hydrogen-adsorption energy. Therefore, this work provides new insights for development of robust nanocrystalline electrocatalysts for efficient HER.

Electrodeposition of Nickel–Molybdenum–Phosphide on copper foam electrode for efficient hydrogen evolution reaction

In the quest for efficient and cost-effective catalysts to drive the hydrogen evolution reaction (HER) in electrochemical water splitting, copper foam (CuF) is a favorable candidate for electrode coating. Precious metal catalysts like Pt/C dominate the field but must be improved because of their high cost and scarcity. Therefore, we have synthesized and evaluated a sequence of nickel-originated electrocatalysts (Ni, NiMo, NiP, and NiMoP) with the electrodeposition of CuF to facilitate substantial improvements in HER performance. Herein, the Ni–Mo–P ternary system, owing to its desirable electronic structure and catalytic mechanism, contributes to enhancing the thermodynamics and kinetics of the HER. Performance analysis reveals that all studied catalysts follow the order of Ni/CuF > NiMo/CuF > NiP/CuF > NiMoP/CuF regarding both the Tafel slope and overpotential. Hence, the top performer, NiMoP/CuF, exhibits tremendous thermodynamics with an η10 = 159 mV and Tafel slope kinetics of 126.66 mV·dec⁻1 at 1.0 M KOH in water splitting. Overall, this report presents a well-capable way of optimizing the electrocatalytic function and stability of CuF-electro-coated catalysts for the HER. This research opens new avenues for cost-effective, stable, and efficient HER catalysts, showcasing the potential of NiMoP/CuF in advancing sustainable hydrogen production technologies.

Harnessing Metal-Organic Frameworks for NIR-II Light-Driven Multiphoton Photocatalytic Water Splitting in Hydrogen Therapy.

The construction of near-infrared (NIR) light-activated hydrogen-producing materials that enable the controlled generation and high-concentration release of hydrogen molecules in deep tumor tissues and enhance the effects of hydrogen therapy holds significant scientific importance. To address the key technical challenge of low-efficiency oxidation-reduction reactions for narrow-bandgap photocatalytic materials, this work proposes an innovative approach for the controllable fabrication of multiphoton photocatalytic materials to overcome the limitations imposed by traditional near-infrared photocatalysts with "narrow-bandgap" constraints. Herein, an NIR-responsive multiphoton photocatalyst, ZrTc-Co, is developed by utilizing a post-synthetic coordination modification strategy to introduce hydrogenation active site CoII into a multiphoton responsive MOF (ZrTc). The results reveal that with the introduction of the CoII site, electron-hole recombination can be efficiently suppressed, thus promoting the efficiency of hydrogen evolution reaction. In addition, the integration of CoII can effectively enhance charge transfer and improve static hyperpolarizability, which endows ZrTc-Co with excellent multiphoton absorption. Moreover, hyaluronic acid modification endows ZrTc-Co with cancer cell-specific targeting characteristics, laying the foundation for tumor-specific elimination. Collectively, the proposed findings present a strategy for constructing NIR-II light-mediated hydrogen therapeutic agents for deep tumor elimination.

Engineered 2-D Heterostructures for Electrocatalysis

Atomically thin layered transition metal dichalcogenides (TMDs) such as MoS2, WS2, MoSe2 and WSe2 have been emerging as the cutting edge in materials science and engineering, due to their interesting electronic properties.1 These materials open up new opportunities for a variety of applications, including optoelectronics, energy conversion, and catalysis. To realize their potential device applications, it is highly desirable to achieve controllable growth of these layered nanomaterials, with tunable structure and morphology. TMDs exhibit promising catalytic properties for hydrogen generation and several approaches including defect engineering have been shown to increase the active catalytic sites.2,32D heterostructures based on various 2D layered materials with distinct properties have been demonstrated to exhibit novel physicochemical properties for their potential application in electrocatalytic hydrogen production. Here we present some of our efforts on morphological and photo/electrocatalytic studies of engineered 2D nanomaterials and their heterostructures.4-6 A seed-assisted chemical vapor transport (CVT) growth of ultra-thin triangular flakes of highly crystalline trigonal selenium (t-Se) oriented in (0001) direction, with lateral size >30 μm is demonstrated.[5,6] To study their promising photo-electrocatalytic properties and further realize the device applications, we employed a single-step CVT approach to grow selenene/WSe2 heterostructures. Vertical heterostructures of bi-layer selenene and monolayer WSe2 domains obtained via the CVT method are characterized by optical microscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The micro electrocatalytic reactor fabricated with Se/WSe2 heterostructure shows significantly improved HER activities upon shining the light. The work further extends to explore strain-engineered TMDs and their heterostructures towards efficient electrocatalytic hydrogen evolution reaction. References H. R. Gutiérrez, N. Perea-López, A. L. Elías, A. Berkdemir, B. Wang, R . Lv, F. López-Urías, V. H. Crespi, H. Terrones, M. Terrones, Nano Lett. 2013, 13 (8), 3447-3454.P.V. Sarma, T.V.Vineesh, R.Kumar, V.Sreepal, R.Prasannachandran, A.K. Singh, and M.M. Shaijumon, ACS Catalysis(2020), 10,6753–6762P. V. Sarma, A. Kayal, C. H. Sarma, M. Thalakulam, J. Mitra, and M. M. Shaijumon, ACS Nano, 13, 10448-10455 (2019).R. Prasannachandran, T. V. Vineesh, A. Anil, B. M. Krishna and M. M. Shaijumon, ACS Nano, 12, 11511–11519 (2018).R. Prasannachandran, T. V. Vineesh, M.B.Lithin, R. Nandakishore, M. M. Shaijumon, Chem. Commun., 56, 8623-8626 (2020).P.V. Sarma, N. Renjith et al., 2D Mater., 9, 045004 (2022)

Oxophilic gallium single atoms bridged ruthenium clusters for practical anion-exchange membrane electrolyzer

The development of highly efficient and durable alkaline hydrogen evolution reaction (HER) catalysts is crucial for achieving high-performance practical anion exchange membrane water electrolyzer (AEMWE) at ampere-level current density. Herein, we report a design concept by employing Ga single atoms as an electronic bridge to stabilize the Ru clusters for boosting alkaline HER performance in practical AEMWE. Experimental and theoretical results collectively reveal that the bridged Ga sites trigger strong metal-support interaction for the homogeneous distribution of Ru clusters with high density, as well as optimize the Ru–H bond strength due to the electron transfer between Ru and Ga for enhanced intrinsic HER activity. Moreover, the oxophilic Ga sites near the Ru clusters tend to adsorb the hydroxyl species and accelerate the water dissociation for sufficient proton supplement in an alkaline medium. The Ru–GaSA/N–C catalyst exhibits a low overpotential of 4 ± 1 mV (10 mA cm−2) and high mass activity of 9.3 ± 0.5 A mg−1Ru at −0.05 V vs RHE. In particular, the Ru–GaSA/N–C-based AEMWE in 1 M KOH delivers a voltage of only 1.74 V to reach an industrial current density of 1 A cm−2, and can steadily operate at 1 A cm−2 for more than 170 h.

Eco-friendly and large-scale fabrication of NiMoN/Ni(OH)2/NF as highly efficient and stable alkaline hydrogen evolution reaction electrode

Bimetallic nickel-molybdenum nitride (NiMoN) catalysts have attracted great attention due to their remarkable similarity to group VIII noble metals in terms of electronic structure, good electron conductivity, and durability for the hydrogen evolution reaction (HER). However, the existing approaches for fabricating NiMoN catalysts usually entail a series of multiple steps and hazardous ammoniated ingredient. As a result, these methods are difficult to be scaled up for large-area fabrication towards industrial water splitting. Herein, a hierarchical composite NiMoN@Ni(OH)2@NF composite electrode with a sheet morphology was synthesized based on a rational combination of seawater etching and magnetron sputtering. This method is easily scalable for producing large-area electrodes with minimal pollution. The incorporation of Ni(OH)2@NF nanoarray carriers enhances the exposure of additional active sites on the NiMoN layer, thereby augmenting the electrochemically active specific surface area of the electrode.The as-synthesized NiMoN@Ni(OH)2@NF electrode demonstrates excellent HER activity, with an overpotential of 57 mV at 10 mA cm−2, and exhibits remarkable long-term catalytic stability for over 100 h at a current density of 100 mA cm−2.This study presents an eco-friendly and straightforward method for preparing large-scale transition metal nitride catalysts with high catalytic activity.

Electronic properties modulation for two-dimensional materials of boron phosphorus monolayer and derived single atom catalysts for the hydrogen evolution reaction

Electrocatalytic hydrogen evolution reaction (HER) is the core of the future renewable energy field and an important part of clean energy technology. It is urgent to find a noble metal free catalyst with high stability, good conductivity and economic efficiency for HER. Two-dimensional (2D) materials such as hexagonal boron nitride formed by the combination of B and N atoms of group III-V elements have been substantiated with significant electronic properties. We predict that 2D materials composed of B and P atoms of the same main group also have good electronic properties. This paper reports for the first time the application of two recent 2D boron phosphorus monolayer compounds (BS-B1P1 and PH-B1P1) as excellent single-atom catalysts (SACs) for HER. We have demonstrated that boron phosphorus compounds can obviously improve its electrical conductivity through single-atom transition metal (TM) doping through the density of state (DOS) calculations, which promises their applications in HER. Hence, an electrocatalyst is computer-aided designed with isolated TM single atom of 3d, 4d, and 5d supported on BS-B1P1 and PH-B1P1 to construct SACs with excellent HER performance. Interestingly, we find that the these SACs can show high HER activity in a wide pH-range. Among all SACs studied, Sc-, Ti-, Nb-, Ag-,and Hf-embedded BS-B1P1 have excellent catalytic activity in acidic conditions while Mn-, Ta-, Re-, Os-, Ir-, and Au-embedded BS-B1P1 show high catalytic activity in alkaline conditions. Mn@PH-B1P1 shows high catalytic activity only in acidic conditions. Especially, Tc@BS-B1P1 system exhibits promising catalytic activity, which owns high active in either neutral, acidic and alkaline conditions. Our work provides a highly active HER catalyst with pH regulation, providing a cost-effective alternative to traditional Pt-based catalysts for sustainable hydrogen extraction.

β-Mo2C nanoparticles/carbon nanotubes Mott-Schottky nanoarray on carbon cloth as freestanding cathodes for efficient hydrogen evolution reaction

β-Mo2C nanoparticles/carbon nanotubes Mott-Schottky nanoarray on carbon cloth as freestanding cathodes for efficient hydrogen evolution reaction