Fabrication of Te@NiTe2/NiS heterostructures for electrocatalytic hydrogen evolution reaction

Active site engineering of intermetallic nanoparticles by the vapour-solid synthesis: carbon black supported nickel tellurides for hydrogen evolution

The development and design of catalysts have become a major pillar of latest research efforts to make sustainable forms of energy generation accessible. The production of green hydrogen by electrocatalytic water splitting is dealt as one of the most promising ways to enable decarbonization. To make the hydrogen evolution reaction through electrocatalytic water splitting usable on a large scale, the development of highly-active catalysts with long-term stability and simple producibility is required. Recently, nickel tellurides were found to be an interesting alternative to noble-metal materials. Previous publications dealt with individual nickel telluride species of certain compositions due to the lack of broadly applicable synthesis strategies. For the first time, in this work the preparation of carbon black supported nickel telluride nanoparticles and their catalytic performance for the electrocatalytic hydrogen evolution reaction in alkaline media is presented. The facile vapour-solid synthesis strategy enabled remarkable control over the crystal structure and composition, demonstrating interesting opportunities of active site engineering. Both single- and multi-phase samples containing the Ni-Te compounds Ni3Te2, NiTe, NiTe2-x & NiTe2 were prepared. Onset potentials and overpotentials of -0.145 V vs. RHE and 315 mV at 10 mA cm-2 respectively were achieved. Furthermore, it was found that the mass activity was dependent on the structure and composition of the nickel tellurides following the particular order: Ni3Te2 > NiTe > NiTe2-x > NiTe2.

Interfacial Electronic Structure Engineering of NiCo2Se4 and NiTe2 Nanorods for Enhanced Hydrogen Evolution Reaction

Finding the best candidates with outstanding electrocatalytic capabilities for the hydrogen evolution reaction is essential for realizing large-scale hydrogen production through electrolysis. In this study, we synthesized NiCo2Se4 (NCS) and NiTe2 (NT) nanorod arrays using a hydrothermal method. The confirmation of catalyst formation was achieved through X-ray diffraction analysis, electron microscopy imaging, and X-ray photoelectron spectroscopy. Leveraging the plentiful heterointerfaces and synergistic effects arising from the incorporation of bimetallic components, the NCS/NT electrocatalyst demonstrates remarkable efficacy in catalyzing the hydrogen evolution reaction. It achieves a minimal overpotential of 163 mV to attain a current density of 50 mA cm-2, showcasing exceptional catalytic activity. Further exploration has revealed that the engineering of heterogeneous interfaces and the morphology of nanorods not only guarantee the exposure of numerous active sites and expedite electron-mass transfer but also trigger electron modulation. Such modulation serves to fine-tune the adsorptive and desorptive dynamics of reaction intermediates, culminating in an enhancement of the catalyst's inherent activity. This study illuminates the novel composite electrocatalyst with robust synergy, highlighting the pivotal role of their unique nanostructures in achieving high-efficiency hydrogen production via electrolysis.

Evolution of Metal Tellurides for Energy Storage/Conversion: From Synthesis to Applications

Metal telluride (MTe)-based nanomaterials have emerged as a potential alternative for efficient, highly conductive, robust, and durable electrodes in energy storage/conversion applications. Significant progress in the material development of MTe-based electrodes is well-sought, from the synthesis of its nanostructures, integration of MTes with supporting materials, synthesis of their hybrid morphologies, and their implications in energy storage/conversion systems. Herein, an extensive exploration of the recent advancements and progress in MTes-based nanomaterials is reviewed. This review emphasizes elucidating the fundamental properties of MTes and providing a systematic compilation of its wet and dry synthesis methods. The applications of MTes are extensively summarized and discussed, particularly, in energy storage and conversion systems including batteries (Li-ion, Zn-ion, Li-S, Na-ion, K-ion), supercapacitor, hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and CO2 reduction. The review also emphasizes the future prospects and urgent challenges to be addressed in the development of MTes, providing knowledge for researchers in utilizing MTes in energy storage and conversion technologies.

Significantly Enhanced Energy-Saving H2 Production Coupled with Urea Oxidation by Low- and Non-Pt Anchored on NiS-Based Conductive Nanofibers

Rational designing electrocatalysts is of great significance for realizing high-efficiency H2 production in the water splitting process. Generally, reducing the usage of precious metals and developing low-potential nucleophiles oxidation reaction to replace anodic oxygen evolution reaction (OER) are efficient strategies to promote H2 generation. Here, NiS-coated nickel-carbon nanofibers (NiS@Ni-CNFs) are prepared for low-content Pt deposition (Pt-NiS@Ni-CNFs) to attain the alkaline HER catalyst. Due to the reconfiguration of NiS phase and synergistic effect between Pt and nickel sulfides, the Pt-NiS@Ni-CNFs catalyst shows a high mass activity of 2.74-fold of benchmark Pt/C sample. In addition, the NiS@Ni-CNFs catalyst performs a superior urea oxidation reaction (UOR) activity with the potential of 1.366 V versus reversible hydrogen electrode (RHE) at 10 mA cm-2 , which demonstrates the great potential in the replacement of OER. Thus, a urea-assisted water splitting electrolyzer of Pt-NiS@Ni-CNFs (cathode)||NiS@Ni-CNFs (anode) is constructed to exhibit small voltages of 1.44 and 1.65 V to reach 10 and 100 mA cm-2 , which is much lower than its overall water splitting process, and presents a 6.5-fold hydrogen production rate enhancement. This work offers great opportunity to design new catalysts toward urea-assisted water splitting with significantly promoted hydrogen productivity and reduced energy consumption.

A tri-functional self-supported electrocatalyst featuring mostly NiTeO3 perovskite for H2 production via methanol-water co-electrolysis

A self-supported NiTeO3 perovskite is made by deploying an extended hydrothermal tellurization strategy with a restricted Te content, which was found to be exceptionally active towards the oxidation of water and methanol and the reduction of water in 1.0 M KOH where it delivered -10 mA cm-2 at just -1.54 V for a full cell featuring MOR‖HER.

Synthesis of NiMoO4/NiMo@NiS Nanorods for Efficient Hydrogen Evolution Reactions in Electrocatalysts

As traditional energy structures transition to new sources, hydrogen is receiving significant research attention owing to its potential as a clean energy source. The most significant problem with electrochemical hydrogen evolution is the need for highly efficient catalysts to drive the overpotential required to generate hydrogen gas by electrolyzing water. Experiments have shown that the addition of appropriate materials can reduce the energy required for hydrogen production by electrolysis of water and enable it to play a greater catalytic role in these evolution reactions. Therefore, more complex material compositions are required to obtain these high-performance materials. This study investigates the preparation of hydrogen production catalysts for cathodes. First, rod-like NiMoO₄/NiMo is grown on NF (Nickel Foam) using a hydrothermal method. This is used as a core framework, and it provides a higher specific surface area and electron transfer channels. Next, spherical NiS is generated on the NF/NiMo₄/NiMo, thus ultimately achieving efficient electrochemical hydrogen evolution. The NF/NiMo₄/NiMo@NiS material exhibits a remarkably low overpotential of only 36 mV for the hydrogen evolution reaction (HER) at a current density of 10 mA·cm^-2 in a potassium hydroxide solution, indicating its potential use in energy-related applications for HER processes.

Construction of nickel sulfide phase-heterostructure for alkaline hydrogen evolution reaction

Constructing transitionmetalsulfides (TMSs) heterostructure is an effective strategy to optimize the catalytic performance for hydrogen evolution reaction (HER) in alkaline medium. Herein, the rhombohedral nickel sulfide/hexagonal nickel sulfide (r-NiS/h-NiS) catalysts with the NiS phase-heterostructure were successfully fabricated by a simple one pot method. The r-NiS/h-NiS (1.25) (1.25 means the theoretical mole ratio of S and Ni added to reaction) displayed the excellent HER performance with low overpotential (101 ± 1 mV@10 mA cm^-2) and small Tafel slope (62.10 ± 0.1 mV dec^-1), which were superior to the pure phase r-NiS and h-NiS. In this work, the improved HER catalytic performances were attributed to the dense coupling interfaces between the r-NiS and h-NiS. This work shows the feasibility of construction NiS phase-heterostructure and provides a novel strategy for the application of NiS for water splitting.

Recent Advances in Transition Metal Tellurides (TMTs) and Phosphides (TMPs) for Hydrogen Evolution Electrocatalysis

The hydrogen evolution reaction (HER) is a developing and promising technology to deliver clean energy using renewable sources. Presently, electrocatalytic water (H₂O) splitting is one of the low-cost, affordable, and reliable industrial-scale effective hydrogen (H₂) production methods. Nevertheless, the most active platinum (Pt) metal-based catalysts for the HER are subject to high cost and substandard stability. Therefore, a highly efficient, low-cost, and stable HER electrocatalyst is urgently desired to substitute Pt-based catalysts. Due to their low cost, outstanding stability, low overpotential, strong electronic interactions, excellent conductivity, more active sites, and abundance, transition metal tellurides (TMTs) and transition metal phosphides (TMPs) have emerged as promising electrocatalysts. This brief review focuses on the progress made over the past decade in the use of TMTs and TMPs for efficient green hydrogen production. Combining experimental and theoretical results, a detailed summary of their development is described. This review article aspires to provide the state-of-the-art guidelines and strategies for the design and development of new highly performing electrocatalysts for the upcoming energy conversion and storage electrochemical technologies.

Hydrogen Evolution Reaction Activities of Room-Temperature Self-Grown Glycerol-Assisted Nickel Chloride Nanostructures

Three-dimensional nanomaterials of desired structural/morphological properties and highly porous with a high specific surface area are important in a variety of applications. In this work, glycerol-mediated self-growth of 3-D dandelion flower-like nickel chloride (NiCl2) from nickel-foam (NiF) is obtained for the first time using a room-temperature (27 °C) processed wet chemical method for electrocatalysis application. Glycerol-mediated self-grown NiCl2 flowers demonstrate an excellent electrocatalytic performance towards the hydrogen evolution reaction (HER), which is much superior to the NiF (303 mV) and NiCl2 electrode prepared without glycerol (208 mV) in the same electrolyte solution. With a Tafel slope of 41 mV dec−1, the NiCl2 flower electrode confirms improved reaction kinetics as compared to the other two electrodes, i.e., NiF (106 mVdec−1) and NiCl2 obtained without glycerol (56 mV dec−1). The stability of the glycerol-based NiCl2 electrode has further been carried out for 2000 cycles with the overpotential diminution of just 8 mV, approving an electrocatalyst potential of glycerol-based NiCl2 electrode towards HER kinetics. This simple and easy growth process involves nucleation, aggregation, and crystal growth steps for producing NiCl2 nanostructures for electrocatalytic water splitting application through the HER process.

Potentiostatic electrodeposition of Ni-Se-Cu on nickel foam as an electrocatalyst for hydrogen evolution reaction

Development of cost-effective and efficient earth-abundant catalysts for hydrogen evolution reaction (HER) is a great challenge. In this study, by one-step potentiostatic electrodeposition, the Ni-Se-Cu electrocatalyst on nickel foam was fabricated as a binder-free HER electrocatalyst. As compared with Ni-Se electrocatalysts, such fabricated Ni-Se-Cu electrocatalyst exhibited prominent electrocatalytic activity to the HER in alkaline electrolyte. This Ni-Se-Cu electrocatalyst exhibits a small overpotential of 136 mV to achieve a current density of 10 mA·cm^-2 and high electrochemical stability. The remarkable HER properties of Ni-Se-Cu electrocatalyst mainly originate from high electronic conductivity induced by Cu-doping. This work shows a cheap and simple avenue to develop high efficient non-noble electrochemical electrocatalysts for HER.

Hydrogen Evolution Reaction-From Single Crystal to Single Atom Catalysts

Hydrogen evolution reaction (HER) is one of the most important reactions in electrochemistry. This is not only because it is the simplest way to produce high purity hydrogen and the fact that it is the side reaction in many other technologies. HER actually shaped current electrochemistry because it was in focus of active research for so many years (and it still is). The number of catalysts investigated for HER is immense, and it is not possible to overview them all. In fact, it seems that the complexity of the field overcomes the complexity of HER. The aim of this review is to point out some of the latest developments in HER catalysis, current directions and some of the missing links between a single crystal, nanosized supported catalysts and recently emerging, single-atom catalysts for HER.