In situ growth of NiTe nanosheet film on nickel foam as electrocatalyst for oxygen evolution reaction

Cobalt telluride regulated by nickel for efficient electrooxidation of 5-hydroxymethylfurfural

Replacing the anodic oxygen evolution reaction (OER) in water splitting with 5-hydroxymethylfurfural oxidation reaction (HMFOR) can not only reduce the energy required for hydrogen production but also yield the valuable chemical 2,5-furandicarboxylic acid (FDCA). Co-based catalysts are known to be efficient for HMFOR, with high-valent Co being recognized as the main active component. However, efficiently promoting the oxidation of Co2+ to produce high-valent reactive species remains a challenge. In this study, Ni-doped CoTe (CoNiTe) nanorods were prepared as efficient catalysts for HMFOR, achieving a high HMFOR current density of 65.3 mA cm-2 at 1.50 V. Even after undergoing five successive electrolysis processes, the Faradaic efficiency (FE) remained at approximately 90.7 %, showing robust electrochemical durability. Mechanistic studies indicated that Ni doping changes the electronic configuration of Co, enhancing its charge transfer rate and facilitating the oxidation of Co2+ to high-valent CoO2 species. This work reveals the effect of Ni doping on the reconfiguration of the active phase during HMFOR.

Microwave Construction of NiSb/NiTe Composites on Ni-Foam for High-Performance Supercapacitors

In this paper, NiSb/NiTe/Ni composites were smoothly developed via the microwave method for supercapacitors. The synthesis of NiSb/NiTe crystals was revealed by X-ray photoelectron spectroscopy and X-ray diffraction. The analytic results of scanning electron microscopy and energy dispersive spectroscopy uncover the microscopic morphology as well as the constituent elements of the composites. Self-supported NiSb/NiTe is a supercapacitor cathode that combines high capacitance with excellent cycling stability. The obtained composite electrode displayed remarkable electrochemical properties, presenting a special capacitance of 1870 F g-1 (1 A g-1) and 81.5% of the original capacity through 30,000 times (10 A g-1) of the charging/discharging process. Further, an asymmetric supercapacitor was prepared employing NiSb/NiTe as a cathode and activated carbon as an anode. NiSb/NiTe//AC exhibited a high energy density of 224.6 uW h cm-2 with a power density of 750 μW cm-2 and provided a favorable cycling stability of 83% after 10,000 cycles.

A Review of Transition Metal Boride, Carbide, Pnictide, and Chalcogenide Water Oxidation Electrocatalysts

Transition metal borides, carbides, pnictides, and chalcogenides (X-ides) have emerged as a class of materials for the oxygen evolution reaction (OER). Because of their high earth abundance, electrical conductivity, and OER performance, these electrocatalysts have the potential to enable the practical application of green energy conversion and storage. Under OER potentials, X-ide electrocatalysts demonstrate various degrees of oxidation resistance due to their differences in chemical composition, crystal structure, and morphology. Depending on their resistance to oxidation, these catalysts will fall into one of three post-OER electrocatalyst categories: fully oxidized oxide/(oxy)hydroxide material, partially oxidized core@shell structure, and unoxidized material. In the past ten years (from 2013 to 2022), over 890 peer-reviewed research papers have focused on X-ide OER electrocatalysts. Previous review papers have provided limited conclusions and have omitted the significance of "catalytically active sites/species/phases" in X-ide OER electrocatalysts. In this review, a comprehensive summary of (i) experimental parameters (e.g., substrates, electrocatalyst loading amounts, geometric overpotentials, Tafel slopes, etc.) and (ii) electrochemical stability tests and post-analyses in X-ide OER electrocatalyst publications from 2013 to 2022 is provided. Both mono and polyanion X-ides are discussed and classified with respect to their material transformation during the OER. Special analytical techniques employed to study X-ide reconstruction are also evaluated. Additionally, future challenges and questions yet to be answered are provided in each section. This review aims to provide researchers with a toolkit to approach X-ide OER electrocatalyst research and to showcase necessary avenues for future investigation.

Nitrogen-doped Fe2O3/NiTe2 as an excellent bifunctional electrocatalyst for overall water splitting

The development of inexpensive, high efficiency electrocatalysts is a major challenge for electrolytic water to hydrogen production. Herein, an efficient porous nanoblock catalyst N-doped Fe₂O₃/NiTe₂ heterojunction for overall water splitting is reported. Notably, the obtained 3D self-supported catalysts exhibit good hydrogen evolution. reaction (HER) activity and oxygen evolution reaction (OER) properties in alkaline solution (only 70 mV and 253 mV of overpotential are needed to provide 10 mA cm^-2 current density, respectively). This is mainly due to the N-doped electronic structure optimized, the strong electronic interaction between Fe₂O₃ and NiTe₂ that facilitates rapid electron transfer, the porous structure which allows the catalyst to have large surface area for effective gas release, and their synergistic effect. When used as a dual function catalyst with overall water splitting, it achieved a current density of 10 mA cm^-2 under 1.54 V with good durability (at least 42 h). The present work provides a new methodology for the study of high-performance, low-cost, and corrosion-resistant bifunctional electrocatalysts.

A CoNi telluride heterostructure supported on Ni foam as an efficient electrocatalyst for the oxygen evolution reaction

The excellent oxygen evolution reaction performance of a CoNi telluride heterostructure (0.4CoNi LDH@Te-180C) can be attributed to the inherent layered structure, interconnected nanoarray structures and the synergistic effect of Co and Ni species.

Solvent-Free Mechanochemical Synthesis and Characterization of Nickel Tellurides with Various Stoichiometries: NiTe, NiTe2 and Ni2Te3

The paper reports the synthesis of nickel tellurides via a mechanochemical method from elemental precursors. NiTe, NiTe₂, and Ni₂Te₃ were prepared by milling in stainless steel vials under nitrogen, using milling times from 1 h to 12 h. The products were characterized by powder X-ray diffraction (pXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), UV-VIS spectrometry, and thermal analysis (TGA and DSC). The products were obtained in the form of aggregates, several hundreds of nanometers in size, consisting of smaller nanosized crystallites. The magnetic measurements revealed a ferromagnetic behavior at room temperature. The band gap energies calculated using Tauc plots for NiTe, NiTe₂, and Ni₂Te₃ were 3.59, 3.94, and 3.70 eV, respectively. The mechanochemical process has proved to be a simple and successful method for the preparation of binary nickel tellurides, avoiding the use of solvents, toxic precursors, and energy-consuming reaction conditions.

Recasting Ni-foam into NiF2 nanorod arrays via a hydrothermal process for hydrogen evolution reaction application

A promising electrode for hydrogen evolution reaction (HER) has been prepared via a reduction process to form NiF2 nanorod arrays directly grown on a 3D nickel foam. We reveal NiF2@Ni nanorod arrays for a stable hydrogen evolution reaction (HER) application. The computational analysis for H2O, OH and H and experimentally in aqueous KOH endow considerable shift in Fermi levels for Ni (111) unlike for NiF2 (110) on account of an effective coalition of p-orbitals of fluorine and d-orbitals of Ni in NiF2, NiF2 under pinning the reduced overpotential of 172 mV at 10 mA cm-2 compared to Ni (242 mV) in same electrolyte. The electrocatalytic mechanism has been proposed using density functional theory (DFT) and is found in well accordance with the experimental findings of the present study. The preparation of self-grown porous nanostructured electrodes on the 3D nickel foam via a displacement reaction is possibly valuable for other metal halides for energy storage and conversion applications as these materials have inherently smaller overpotentials.

Room-temperature chemical synthesis of 3-D dandelion-type nickel chloride (NiCl2@NiF) supercapattery nanostructured materials

A simple, room-temperature operable, glycerol-supported single beaker-inspired, and binder-free soft-chemical protocol has been developed to synthesize 3-D dandelion flower-type nickel chloride (NiCl₂) supercapattery (supercapacitor + battery) nanostructured electrode material from solid 3-D nickel-foam (NiF). The dandelion flower-type NiCl₂@NiF labeled as B electrode, demonstrates a battery-type electrochemical performance as obtained 1551 F·g^-1 specific capacitance (SC) and 95% cyclability over 50,000 cycles is higher than that of a setaria viridis-type NiCl₂@NiF electrode, prepared without glycerol labeled as A electrode. As a commercial market product, assembled NiCl₂@NiF@ (cathode)// BiMoO₃ (anode) pouch-type asymmetric supercapacitor energy storage device demonstrates moderate energy density and power density (28 Wh·kg^-1 and 845 W·kg^-1). By utilizing three devices in series, three different colored LEDs can be operated at full brightness. The as-proposed low temperature protocol impeccably effective and efficient on account of the low-cost, easy synthesis methodology for scalability, and high crytallinity as well as solvent-free and non-toxic as pyrolated gases were used while synthesis processing.

Phosphorus-doped CoTe2/C nanoparticles create new Co-P active sites to promote the hydrogen evolution reaction

Doping has been widely recognized as an effective method for adjusting the performance of electrocatalysts. It can cause changes in the electronic structure of substances. Thereby, it can affect the intrinsic catalytic performance. Herein, we report a facile doping method in which phosphorus can be simultaneously doped into both CoTe2 and C. In the acidic solution, the hydrogen evolution reaction (HER) performance of the obtained P-CoTe2/C nanoparticles was significantly improved compared with that of undoped nanoparticles. At a current density of 10 mA cm-2, the overpotential decreased from 430 mV to 159 mV. Density functional theory (DFT) calculations show that phosphorus doping can produce new high activity Co-P catalytic sites. In addition, phosphorus can be doped into the carbon in the composite at the same time, which enhances the electrical conductivity of the composite. Moreover, in the process of calcination and doping, the electric double layer capacitance (Cdl) of the composite is significantly increased, which helps in exposing more active sites. This work has developed a multi-effect doping method that simultaneously increases the intrinsic activity, conductivity and active sites of the material. This method provides a new strategy for the performance regulation of other electrocatalysts.

Rechargeable Nickel Telluride/Aluminum Batteries with High Capacity and Enhanced Cycling Performance

Rechargeable aluminum-ion batteries (AIBs) possess significant advantages of high energy density, safety performance, and abundant natural resources, making them one of the desirable next-generation substitutes for lithium battery systems. However, the poor reversibility, short lifespan, and low capacity of positive materials have limited its practical applications. In comparison with semiconductors, the metallic nickel telluride (NiTe) alloy with enhanced electrical conductivity and fast electron transmission is a more favorable electrode material that could significantly decrease the kinetic barrier during battery operation for energy storage. In this paper, the NiTe nanorods prepared through a simple hydrothermal routine enable an initial reversible capacity of approximately 570 mA h g^-1 (under the current density of 200 mA g^-1) to be delivered on the basis of the ionic liquid electrolyte, along with the average voltage platform of about 1.30 V. Moreover, the cycling performance could be easily enhanced using a modified separator to prevent the diffusion of soluble intermediate species to the negative electrode side. At a high rate of 500 mA g^-1, the NiTe nanorods could retain a specific capacity of about 307 mA h g^-1 at the 100th cycle. The results have important implications for the research of transition metal tellurides as positive electrode materials for AIBs.

An Fe-doped NiTe bulk crystal as a robust catalyst for the electrochemical oxygen evolution reaction

An Fe doped NiTe bulk crystal was demonstrated to exhibit an extremely active and stable performance for the electrochemical oxygen evolution reaction.

Self-ZIF template-directed synthesis of a CoS nanoflake array as a Janus electrocatalyst for overall water splitting

Self-ZIF template-directed synthesis of a CoS nanoflake array as a Janus electrocatalyst for overall water splitting.

A novel FeS–NiS hybrid nanoarray: an efficient and durable electrocatalyst for alkaline water oxidation

A novel FeS–NiS/TM nanosheet array was developed for alkaline OER; this catalyst only requires an overpotential of 260 mV to afford a current density of 10 mA cm⁻² in 1.0 M KOH.

Electronic modulation of carbon-encapsulated NiSe composites via Fe doping for synergistic oxygen evolution

Carbon-encapsulated Fe-doped NiSe was easily synthesized as an efficient OER catalyst.