Showing papers on "Nickel boride published in 2021"

Metal–organic framework (MOF)-derived amorphous nickel boride: an electroactive material for electrochemical energy conversion and storage application

Abstract: The search for an efficient single electrode material having both electrochemical energy conversion and storage activities is a cutting-edge approach for sustainability. In this report, an effective chemical redox approach is presented for the tuning of the crystalline and electronic structures of a metal–organic framework (Ni-MOF) to improve its electrocatalytic and charge storage performance. The single step redox approach transformed the crystalline Ni-MOF to amorphous nickel boride (NiB), showing increased exposed catalytic active centers and accessible surface area thereby improving its electrochemical performance. Interestingly, the NiB efficiently catalyzes the OER, delivering a benchmark current density (10 mA cm−2) at only 240 mV as well as excellent electrocatalytic durability. On the other hand, it shows a higher value of specific capacitance (2580 F g−1) and remarkable energy (72.55 W h kg−1) and power (33.43 kW kg−1) densities with outstanding cycle life (85.45% retention of the initial capacitance after 5000 cycles). In order to validate the practical application of the material, an asymmetric supercapacitor (ASC) was devised in a Swagelok-type electrode with rGO and NiB as the cathode and anode electrode material, respectively. The rGO//NiB ASC device showed a specific capacitance of 83.33 F g−1 (at 0.5 A g−1) with an energy density of 26.04 W h kg−1 at a specific power of 2.08 kW kg−1 with excellent durability (96% specific capacitance retention after 5000 GCD cycles). This synthesis approach realizes the tuning of faradaic redox properties and sheds substantial light on motivating materials researchers to derive MOF-based nanostructures for future energy conversion and storage systems.

Application of the Heat Balance Integral Method to the growth kinetics of nickel boride layers on an Inconel 718 superalloy

Abstract: New results about the growth kinetics of nickel boride layers on an Inconel 718 superalloy were obtained. The nickel boride layers were developed by means of the powder-pack boriding process at 1173–1223 K with different exposure times for each temperature. According to optical and scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and nanoindentation techniques, the microstructure of the boride layer consisted in three zones: a high content of Ni4B3 on the outer-zone of the borided surface, while Ni2B and Ni3B were revealed at the inner zone of the layer and diffusion zone, respectively. Moreover, the boriding growth kinetics of nickel boride layers was estimated using the Heat Balance Integral Method (HBIM) based on a numerical resolution of a system formed by differential algebraic equations, and considering that the evolution of the layers is governed by the parabolic growth law. For the range of boriding temperatures, the boron activation energies in the Ni4B3, Ni2B and Ni3B resulted in 233, 206 and 218 kJ mol−1, respectively.

Nickel Boride/Boron Carbide Particles Embedded in Boron-Doped Phenolic Resin-Derived Carbon Coating on Nickel Foam for Oxygen Evolution Catalysis in Water and Seawater Splitting.

Abstract: Electrolysis of seawater can be a promising technology, but chloride ions in seawater can lead to adverse side reactions and the corrosion of electrodes. A new transition metal boride-based self-supported electrocatalyst was prepared for efficient seawater electrolysis by directly soaking nickel foam (NF) in a mixture of phenolic resin (PR) and boron carbide (B4 C), followed by an 800 °C annealing. During PR carbonization process, the reaction of B4 C and NF generated nickel boride (Nix B) with high catalytic activity, while PR-derived carbon coating was doped with boron atoms from B4 C (B-CPR ). The B-CPR coating fixed Nix B/B4 C particles in the frames and holes to improve the space utilization of NF. Meanwhile, the B-CPR coating effectively protected the catalyst from the corrosion by seawater and facilitates the transport of electrons. The optimal Nix B/B4 C/B-CPR /NF required 1.50 and 1.58 V to deliver 100 and 500 mA cm-2 , respectively, in alkaline natural seawater for the oxygen evolution reaction.

Safety Assessments of Nickel Boride Nanoparticles on the Human Pulmonary Alveolar Cells by Using Cell Viability and Gene Expression Analyses

Abstract: Nickel boride is generally used in the steel industry as a melting accelerator due to its feature of creating a protective and stable attribute at high temperatures. It is also used to improve the hardenability of the steel with boron addition in the production. Thus, safety studies and biocompatibility analysis of nickel boride should be performed comprehensively to understand the limitations of use in various areas. In the present study, nickel boride nanoparticles (Ni2B NPs) were synthesized by a single-step method and molecule characterizations were performed via the use of X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analyses. Cytotoxicity properties of Ni2B NPs were identified on human pulmonary alveolar epithelial cells (HPAEpiC) by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), neutral red (NR), and lactate dehydrogenase (LDH) assays. Illumina human ht-12 v4.0 whole-genome microarray analysis was conducted to investigate NiB2 NPs effects on gene expression regulations of HPAEpiC cells. The database for annotation, visualization, and integrated discovery (DAVID) analysis was performed to reveal the relationship between Ni2B NP application and cellular pathway alterations. According to cytotoxicity analysis, the IC50 value for Ni2B NP application was found as 81.99 mg/L concentration. Microarray analysis of Ni2B NP application was shown for the first time that 693 gene expression changes (FC ≥ 2) occurred significantly over 40.000 gene probes and Ni2B NPs were observed to affect microtubule regulation, centrosome organization, and phosphoprotein synthesis.

Synergism of 1D/2D boride/MXene nanosheet heterojunctions for boosted overall water splitting

Abstract: Transition metal boride (TMB) as a new type of catalyst has attracted much attention in recent years. To further enhance their catalytic performance, much effort has been made on improving their electrical conductivity and specific surface area. Herein, we have constructed a heterojunction by anchoring 1D nickel boride (NixB) nanoparticles on the surface of 2D N-doped Ti3C2 MXene (N10TC) to overcome these limitations. The resulting heterojunction (NixB/N10TC) electrode exhibited improved catalytic activities and stability on water splitting. In particular, this NixB/N10TC electrode exhibits excellent stability within 50 h continued testing.

The effect of aging treatment on the indentation properties of a nickel boride layer

Abstract: The mechanical performance of a nickel boride layer formed on an Inconel 718 superalloy at 1173 K with an exposure time of 6 h and a double aging treatment (DAT) was obtained. The effect of the DAT led to the redistribution of boron and niobium along the depth of the layer-substrate system, increasing the depth of the diffusion zone, and extending the depth of the compressive residual stresses in the layer. In particular, the DAT enhanced the fracture resistance by approximately 1.5 times compared with that of the layer not exposed to the treatment.

Nickel Boride Catalyzed Reductions of Nitro Compounds and Azides : Nanocellulose-supported Catalysts in Tandem Reactions

Abstract: Nickel boride catalyst prepared in situ from NiCl2 and sodium borohydride allowed, in the presence of an aqueous solution of TEMPO-oxidized nanocellulose (0.01 wt%), the reduction of a wide range of nitroarenes and aliphatic nitro compounds. Here we describe how the modified nanocellulose has a stabilizing effect on the catalyst that enables low loading of the nickel salt pre-catalyst. Ni-B prepared in situ from a methanolic solution was also used to develop a greener and facile reduction of azides, offering a substantially lowered catalyst loading with respect to reported methods in the literature. Both aromatic and aliphatic azides were reduced and the protocol is compatible with a one-pot Boc-protection of the obtained amine yielding the corresponding carbamates. Finally, bacterial crystalline nanocellulose was chosen as a support for the Ni-B catalyst to allow an easy recovery step of the catalyst and its recyclability for new reduction cycles.

Reductive desulfurization of aromatic sulfides with nickel boride in deep eutectic solvents

Abstract: In order to improve the desulfurization rate, deep eutectic solvents (DESs) were used for the first time as solvents in the reductive desulfurization process with nickel boride (NB). DES plays a dual role of stabilizer and extracting agent in the desulfurization process. NBs prepared in different solvents were characterized by PSZPA, SAPA, XRD and FTIR spectroscopy. Results indicate that the NBs with small particle size and high specific surface area can be obtained by using DES as the solvent. The desulfurization rate of aromatic sulfides using DESs as the solvent is much higher than that using MeOH/THF as the solvent. The desulfurization rate in different DESs follows the order of tetrabutyl ammonium chloride (TBAC)/polyethylene glycol > TBAC/ethylene glycol > TBAC/glycerol. No chemical reactiong takes place between NB and DESs, and the structures of the DESs remain unchanged after regeneration.

Phase relations, and mechanical and electronic properties of nickel borides, carbides, and nitrides from ab initio calculations

Abstract: Based on density functional theory and the crystal structure prediction methods, USPEX and AIRSS, stable intermediate compounds in the Ni–X (X = B, C, and N) systems and their structures were determined in the pressure range of 0–400 GPa. It was found that in the Ni–B system, in addition to the known ambient-pressure phases, the new nickel boride, Ni2B3-Immm, stabilizes above 202 GPa. In the Ni–C system, Ni3C-Pnma was shown to be the only stable nickel carbide which stabilizes above 53 GPa. In the Ni–N system, four new phases, Ni6N-R, Ni3N-Cmcm, Ni7N3-Pbca, and NiN2-Pa, were predicted. For the new predicted phases enriched by a light-element, Ni2B3-Immm and NiN2-Pa, mechanical and electronic properties have been studied.