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Cobalt Iron -layered double hydroxide (CoFe-LDH) nano sheets were attached to Nickel-metal organic frameworks (Ni-MOF) by utilizing hydrothermal reaction method, and CoFe-LDH@Ni-MOF was synthesized and worked as the cathode catalyst in microbial fuel cell. The surface of this composite material provided generous electrochemical active sites, consisting of wrinkled strips of CoFe-LDH adhering to a lamellar structure of Ni-MOF. In terms of the maximum output power density, CoFe-LDH@Ni-MOF as the catalyst was 211 mW/m 2 , 2.54 times higher than that of Ni-MOF (83 mW/m 2 ), and it was stable at about 225 mV for 150 h. CoFe-LDH@Ni-MOF showed high oxygen reduction reaction capability and high specific surface area, and the electron transfer rate was accelerated. This work might set the stage for the development and utilization of fuel cell cathode catalysts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

In this work, spherical Ni-based metal-organic frameworks (Ni-MOFs) were used as precursors for preparing nanorod-like nickel phosphate (r-NiPO) with enhanced electro-catalytic properties in detection of glucose. It was found that the addition of nickel ion has a profound effect on construction of nickel phosphate with flower-like, rod-like, and ribbon-like structure in presence of H 2 PO 2 . The r-NiPO consisted of multiple phases of nickel phosphate showed porous, interconnected structure and abundant active Ni(II)/Ni(III) pairs, which was beneficial to facilitate glucose oxidation. In comparison with Ni-MOF, r-NiPO exhibited the superior electrocatalytic property on oxidation of glucose because of the exposing more active Ni sites in r-NiPO than that of Ni-MOF precursor. r-NiPO modified glassy carbon electrode (r-NiPO/GCE) showed a good linear response to glucose from 1.0 μM to 3.0 mM with a high sensitivity of 3169 μA mM - . The r-NiPO consisted of multiple phases of nickel phosphate showed porous, interconnected structure and abundant active Ni(II)/Ni(III) pairs, which was beneficial to facilitate glucose oxidation. In comparison with Ni-MOF, r-NiPO exhibited the superior electrocatalytic property on oxidation of glucose because of the exposing more active Ni sites in r-NiPO than that of Ni-MOF precursor. r-NiPO modified glassy carbon electrode (r-NiPO/GCE) showed a good linear response to glucose from 1.0 μM to 3.0 mM with a high sensitivity of 3169 μA mM -1  cm -2 . In addition, r-NiPO/GCE can be used to detect glucose in human serum with satisfactory recoveries (90-97%)., (Copyright © 2022. Published by Elsevier B.V.)

In this work, magnetic Ni doped nanoporous carbon (Ni-C) microspheres were prepared by directly calcinating Ni based metal-organic framework at 400 °C in nitrogen. The morphology and surface area of Ni-C microspheres were characterized by electron microscopy and N 2 adsorption-desorption isotherms. The results demonstrated that Ni nanoparticles were wrapped by the carbon matrix, resulting in the Ni-C microspheres with a strong magnetic response. The Ni-C microspheres also showed high surface area and micro/meso-porous structure, which make them efficient and recyclable magnetic adsorbent. The Ni-C microspheres were employed for magnetic solid phase extraction of phthalate esters from juice and water samples before high performance liquid chromatographic analysis. The limits of detection (S/N = 3) of the method were 0.2-0.3 ng mL -1 for juice sample and 0.02-0.03 ng mL -1 for water sample. The recoveries of all analytes were between 90.0%-100.6%. The Ni-C microspheres showed a great deal of potential to be an adsorbent for enrichment of other organic pollutants in different samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Electrode materials based on organometallic skeleton materials have attracted attention in energy storage applications, because of their high conductivity and stability. A series of nickel-based metal-organic framework derived nanostructures were designed by hydrothermal method combined with post annealing treatment in the temperature. The morphological and electrochemical performances of the synthesized nickel-based MOF derived nanostructures were investigated as a function of post annealing temperature. The successful formation and purity of the synthesized nickel-based MOF derived nanostructures under controlled post annealing process. The formation of different morphologies of nickel-based MOF derived nanostructures owing to the different post annealing temperatures. Nickel-based MOF derived nanostructures prepared at post annealing temperature of 300 °C exhibits improved specific capacitance value of 3921 F/g at current density of 2 A/g. All these results provide an effective way of synthesizing MOF based electrode materials with improved performance for energy storage applications, which are valuable for our energy demands. [ABSTRACT FROM AUTHOR]

The chemical inertness of the basalt felt (BF) results in a weak interface bonding between BF and polymer matrix, which hinders the further application of BF reinforced composites. In this study, nickel‐based metal–organic framework (Ni‐MOF) sheets were decorated on the surface of BF by a facile one‐step hydrothermal method to improve the interfacial bonding between BF and epoxy resin (EP) matrix and embed solid paraffin. The mechanical and tribological properties of EP composites reinforced with BF were evaluated. The interfacial shear strength (IFSS) between BF and EP was measured by a single‐fiber drawing test, and the results indicated that the IFSS increased by 15.19% after MOF modification. The surface of BF transformed from hydrophilicity to hydrophobicity, therefore significantly improving the compatibility between EP and BF. Compared with pure EP, the composites exhibited improvements of 37.55% and 203.39% in tensile strength and tensile modulus, respectively. Meanwhile, the friction coefficient and specific wear rate of the composite decreased by 58.82% and 56.50%, respectively. The solid paraffin was observed to be enclosed by Ni‐MOF sheets, which endowed the composite with a self‐lubricating behavior during friction. This study will advance the comprehensive performance of EP and provide a versatile strategy for tuning the interface compatibility between the reinforcement material and the matrix. Highlights: A novel Ni‐MOF decorated BF was developed for storage of PW.The BF/MOF/PW can simultaneously boost the tribological and mechanical properties of EP.Surface tailoring of BF was realized with decorating MOF sheets and embedding PW.A decline in friction coefficient by 58.82% was achieved. [ABSTRACT FROM AUTHOR]

• Composite of Ni-MOF/PANI has been synthesized. • Composite material shows extreme specific capacity of 122 C/g at 5 mVs−1. • The material shows excellent capacitive retention of 99.25 % even after 5000 cycles. This study aimed to develop a more stable and efficient energy storage device, synthesis of nickel-based pristine metal organic framework (MOF) and combined it with the emeraldine base phase of polyaniline (PANI) which is confirmed with XRD, SEM and TEM. Both Ni-MOF and PANI exhibit faradaic (battery-like) behaviour. However, when these two materials are combined, the stability of the resulting material is enhanced. The initial materials, MOF and PANI, exhibit specific capacities of 42 C/g and 72 C/g, respectively. However, when these two materials are combined, their composite exhibits an enhanced specific capacity of 122 C/g. The cyclic voltammetry (CV) analysis shows oxidation and reduction peaks, indicating faradaic behaviour. This behaviour is further confirmed by electrochemical impedance spectroscopy (EIS). Upon comparing it with prior results, the specific capacity appears to be slightly lower. However, it is anticipated to exhibit stronger stability, which is contradictory. The composite material (Ni-MOF/PANI) exhibits remarkable capacitive retention of 99.25 % even after undergoing 5000 cycles, as anticipated. In order to validate the aforementioned findings and determine the extent of the current contribution from capacitive and diffusive control, Dunn's model was employed. The data demonstrates the prevalence of diffusive-controlled (faradaic) current over capacitive current. The highest proportion of current resulting from diffusion is 96 %, achieved at a scan rate of 5 mV/s. The highest proportion of current resulting from capacitance is 24 %, achieved at a scan rate of 300 mV/s. At lower scan rates, the material exhibits a greater faradaic behaviour, whereas at higher scan rates, there is a progressive increase in non-faradaic processes. The insufficient time for diffusive process at higher scan rates is the cause. The Dunn's model with quadratic correction is also performed and comparative results were shown. Overall, the material exhibits more stability and dominance in the faradaic process, which paves the path for improved performance. [Display omitted] [ABSTRACT FROM AUTHOR]

This work reports an ultrafast mode-locked fiber laser at the less investigated region of the O-band using a nickel metal-organic framework (Ni-MOF), which works as a saturable absorber (SA). Ni-MOF was prepared using the high-power laser-induced method. A stable mode-locked laser of 450 fs pulse duration was obtained. The repetition rate and signal-to-noise ratio (SNR) were 0.408 MHz and 52.5 dB, while the lasers operate at a wavelength of 1298.1 nm. At the pump power of 88 mW, the mode-locked laser was characterized to have an average output power of 0.69 mW, corresponding to a pulse energy of 1.69 nJ and a pulse peak power of 3.53 kW. Additionally, harmonic mode-locked laser operation was also achieved above the pump power of 88 mW. With the harmonic mode-locked laser operation, the pulse repetition rate increased to 2.45 MHz when the pump power was 125.7 mW. To the author's knowledge, this is the first report of novel MOF material used as an SA in praseodymium-doped fluoride fiber (PDFF) laser. • Generation of mode-locked pulses using nickel metal-organic framework (Ni-MOF). • The femtosecond mode-locked laser had a center wavelength of 1298.1 nm. • The fundamental mode-locked pulses had a frequency of 0.408 MHz. • The highest stable harmonics frequency was 2.45 MHz, observed at the 6th harmonics. • A short pulse width of 450 fs was obtained for the fundamental pulse. [ABSTRACT FROM AUTHOR]

In this work, we reported the development of a nickel metal-organic framework nanosheet array on Timesh (Ni-MOF/TM) as an enzyme-free electrochemical sensing platform for H2O2 determination. The as-obtained sensor exhibited outstanding detection properties of H2O2, which might be gifted from the large specific surface area, abundant active sites of Ni-MOF nanoarrays. The sensor displayed a good linear range (0.8 µM-4.6× 10³ µM), a detection limit as low as 0.26 µM, a high sensitivity (307.5 µAmM-1cm-2), and a rapid response. Moreover, this enzyme-free sensor is promising for pointofcare (POC) testing of H2O2 in human serum attribute to the excellent performance of Ni-MOF and the simple preparation process of the sensor. [ABSTRACT FROM AUTHOR]

• Composite catalyst was constructed by Ni-MOF and Al 2 O 3. • Addition Al 2 O 3 solves the Ni agglomeration caused by Ni-MOF decomposition. • Ni/NA-MOF-450 exhibits excellent hydrogenation performance for benzene. Metal-organic frameworks (MOFs) is easy to agglomerate at high temperature, resulting in the rapid collapse of the MOFs structure and the aggregation of metal sites. In this paper, Al 2 O 3 is used as the support material to support the in-situ synthesis of Ni-MOF on the surface, and the metal Ni nanoparticles are successfully fixed on the Al 2 O 3. The results showed that both Ni/Ni-MOF-300 and Ni/NA-MOF-300 catalysts reduced at 300 ℃ have good hydrogenation activity of benzene, and Ni/Ni-MOF-450 catalysts reduced at 450 ℃ formed huge Ni aggregates, which significantly reduced the hydrogenation activity of benzene. However, Ni/NA-MOF-450 catalyst reduced at 450 ℃ can effectively resist the metal Ni agglomeration caused by the collapse of MOFs structure at high temperature, and has better hydrogenation activity of benzene. [ABSTRACT FROM AUTHOR]

Porous coordination polymers, alternatively identified as metal-organic frameworks (MOFs) nanoparticles, are becoming more and more important in the field of nanomaterials science, especially in catalysis. The intricate structures of MOFs enable the integration of metal nodes, encapsulating substrates, and functional linkers, facilitating synergistic engineering. This study underscores the importance of Ni-MOFs in synthetic chemistry, particularly their role in organic compound synthesis. It investigates their utility in oxidation, hydrogenation, coupling reactions, C-H activation, and N-heterocyclic compound generation. Ni-MOFs, functioning as well-defined heterogeneous catalysts are pivotal in addressing societal challenges across synthesis, energy, and environmental domains. Despite notable achievements, there remains a significant need for further advancements to deepen our understanding of these processes beyond initial demonstrations, especially concerning the synthesis of bioactive compounds. This focused examination of Ni-MOFs is anticipated to offer valuable insights for future research endeavors exploring MOF catalytic applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Using inexpensive terephthalic acid as a substitute for isophthalic acid, nitrogen-doped carbon coated nickel nanoparticles (Ni@NC) materials were synthesized by pyrolysis of Ni-MOF precursor, which were applied to the selective hydrogenation of p-nitrophenol under mild conditions (60 °C, 2 h) and showed better catalytic performance (>99.9 % conversion of p-nitrophenol and >99.9 % selectivity for p-aminophenol). The excellent catalytic performance may be mainly attributed to their core–shell structure, i.e., zero-valent nickel nanoparticles encapsulated within a nitrogen-doped carbon layer with an appropriate microporous structure, whereas zero-valent nickel nanoparticles have the ability to activate dihydrogen and block dioxygen. [Display omitted] The catalytic hydrogenation of aromatic nitro compounds under mild conditions to generate amino compounds is a great challenge in terms of conversion, selectivity and stability. In this paper, two classes of nitrogen-doped carbon coated nickel nanoparticles, coined Ni@NC-P and displaced Ni@NC-T were prepared by high-temperature pyrolysis of MOFs using inexpensive terephthalic acid and high-priced trimesic acid as carbon source, respectively. One from the former class, namely the Ni@NC-P-500 catalyst, exhibits the best catalytic performance, which is superior to Ni@NC-T-500 Samples. For the selective hydrogenation of p -nitrophenol under mild conditions (60 °C, 2 h), the Ni@NC-P-500 catalyst shows >99.9 % conversion of p -nitrophenol and >99.9 % selectivity for p -aminophenol and can be recycled five times without obvious decrease of conversion and selectivity, thanks to its larger specific surface area (382.02 m2·g−1), smaller nickel particle size (8.2 nm), higher nitrogen content (especially pyridine nitrogen), higher electron-rich nickel content and less hydrophilic properties than that of the Ni@NC-T-500. The excellent stability and recyclability of the catalysts are mainly attributed to their core–shell structure, i.e., zero-valent nickel nanoparticles encapsulated within a nitrogen-doped carbon layer with an appropriate microporous structure, whereas zero-valent nickel nanoparticles have the ability to activate dihydrogen and block dioxygen. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs)-based electrode materials have drawn wide interest in energy storage applications. Herein, a nickel-based metal–organic framework (Ni-MOF) has been synthesized by simple hydrothermal reaction with different reaction times. The hydrothermal reaction time has an impact on the energy storage performance of the synthesized material. Structural characterization confirms the layered structure and purity of the synthesized Ni-MOF. Significantly, improved energy storage performance was found for the Ni-MOF prepared under reaction time 30 h as compared to other reaction times. It exhibits the highest specific capacity of 1498.6 F/g at a current density of 1 A/g along with good rate of capability. This investigation provides useful approach to improve the capacitive performance of MOF-based electrode materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three series of catalysts with varying Ni and bpy concentration were prepared. • Ni and bpy functionalized MOFs catalyze ethene dimerization co-catalyst free. • The main products were linear 1- and 2-butenes (99 % selectivity). • Low-nuclearity Ni-multimers docked at bpy were identified as main active sites. Ni functionalized metal organic frameworks (MOF) are promising heterogeneous ethene dimerization catalysts. Activities comparable to or higher than Ni-aluminosilicates have been reported in literature. However, unlike the Ni-aluminosilicates, those Ni-MOFs require a large excess of co-catalyst to initiate the dimerization process and some catalysts generate polymers which lead to catalyst deactivation. Herein, we report a series of Ni(II) and 2,2′-bipyridine-5,5′-dicarboxylate (bpy) functionalized UiO-67 MOF that catalyze the ethene dimerization reaction co-catalyst free. The catalysts were active for ethene dimerization (up to 850 mg butene g cat −1 h−1) after activation at 300 °C in 10 % O 2 for 360 min and subsequent exposure to flowing ethene (P(ethene) =26 bar, 250 °C) for 240 min. The catalysts yielded up to 6 % conversion with 99 % selectivity to linear 1- and 2-butenes, which formed in non-equilibrated ratios. Overall, the test data indicate that all three linear butenes are formed on a single active site, in accordance with the Cossee-Arlman mechanism. Ex situ XAS and CO FT-IR spectroscopy studies point towards Ni monomers or, plausibly, low-nuclearity Ni-multimers, docked at bpy linkers with Ni-Ni distances > 4 Å, as the main active site for the ethene dimerization reaction. [ABSTRACT FROM AUTHOR]

The poor conductivity of metal-organic frameworks (MOFs) has greatly restricted their widespread application in water splitting. Herein, the Ni-MOF is used to be a precursor to support a stable three-dimensional structure, high surface areas and to prepare various contents of Pd doped Ni alloys (Pd/Ni-1, Pd/Ni-2 and Pd/Ni-3). The hydrogen evolution reaction (HER) activity of samples is compared in alkaline electrolyte (1.0 M KOH). As-prepared catalysts exhibit uniform dispersion, good crystallinity, high purity and a small particle size according to the physical characterization. What is more, based on the electrochemical characterization, Pd/Ni-3 has an exclellent HER performances with a lower overpotential (50 mV in base at 10 mA·cm−2), smaller Tafel slope (102 mV·dec−1) and more positive initial potential (ƞ at 1 mA·cm−2; Δ ƞ = 660 mV) than that of Ni-MOF. The reduction percentage of resistance charge transfer (R ct) relative to Ni-MOF of Pd/Ni-3 is up to 95.6%. This work may offer guidance to make up the low conductivity of MOF for HER in alkaline electrolyte. • Ni-MOF as a precursor supports a stable three-dimensional structure. • The R ct reduction percentage of Pd/Ni-3 is up to 95.6%. • Pd/Ni-3 exhibits satisfactory performance for HER (50 mV at j 10). [ABSTRACT FROM AUTHOR]

Metal–organic framework Ni2(BDC)2(DABCO) (Ni-MOF)/porous graphene aerogel (PGA) composites were fabricated for the first time. The introduction of PGA enhances conductivity of Ni-MOF, prevents Ni-MOF from accumulating, reduces the size of Ni-MOF, and increases the pore size of composites, which improve the electrocatalytic activity of Ni-MOF@PGA-2. The prepared sensors based on Ni-MOF@PGA-2 composite show the highest catalytic current towards electroreduction of 2-nitrochlorobenzene (2-NCB), 3-nitrochlorobenzene (3-NCB), and 4-nitrochlorobenzene (4-NCB) at around − 0.61 V, − 0.56 V, and − 0.57 V (vs. Ag/AgCl) with respect to other sensors. The reaction mechanisms also are discussed. Under optimized experiment conditions, the Ni-MOF@PGA-2/GCE displays the widest linear range (6–1260, 4–980, and 2–1280 μM for 2-NCB, 3-NCB, and 4-NCB, respectively) for determination of individual nitrochlorobenzene isomers (NCBIs) compared to that of recent reports, and relatively low detection limit (0.093, 0.085, and 0.051 μM for 2-NCB, 3-NCB, and 4-NCB, respectively). More importantly, three NCBIs in the mixture were for the first time simultaneously determined by combining differential pulse voltammetry (DPV) based on Ni-MOF@PGA-2/GCE with partial least squares (PLS) chemometrics modeling method. The proposed method was evaluated towards the determination of NCBI mixtures in tap water and Jing lake water, and satisfactory recoveries were obtained. [ABSTRACT FROM AUTHOR]

Direct ethanol fuel cells (DEFCs), with their boosted energy density and efficiency, are poised to supplant secondary batteries in the near future. However, the pricy and low-durability of Pt-based anode catalyst used in these cells have hampered the development of this technology. We successfully created a Ni-MOF @ nickel foam (NF) to operate as an anode for a DEFC. We next enhanced the electrical conductivity of these produced electrodes with graphene and tested them towards ethanol oxidation in a basic solution. The study looked at the electrodes' surface shape, crystalline structure, chemical and electrical properities, among other things. Furthermore, the electrochemical activity and durability of the prepared electrodes were examined. These tests demonstrated the successful formation of the MOF @ the surface of the NF, with and without reduced graphene oxide. The produced materials outperformed plain Ni foam in terms of ethanol oxidation activity, and the graphene doping significantly enhanced this activity. A 0.35 V onset potential was obtained, with current output increasing concurrently with ethanol oxidation up to 0.5 M before stabilizing. The superior activity was attributed to the prepared electrodes' perfect nano-sheet structure, high porosity, and outstanding mass and charge transport characteristics. The addition of reduced graphene oxide enhanced charge transfer and thus improved the overall performance. [Display omitted] • Ni-MOF @ nickel foam with and without reduced graphene oxide was successfully prepared. • The activity of the prepared electrodes towards ethanol oxidation was investigated. • Results discussed based on charge and mass transfer properties of the prepared materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • β-CD /Ni-MOFs composite nanomaterials have been applied to sensors for the first time, and have good stability and accuracy in human serum and dopamine hydrochloride injection samples. Dopamine (DA) is an important neurotransmitter in human's brain, which has direct connection to diseases like Parkinson's disease, schizophrenia, etc. Therefore, the sensitive and rapid quantitative detection of DA is essential for medical diagnosis and disease prevention. To construct a novel electrochemical sensor for DA detection, nickel-based metal–organic frameworks (Ni–MOF) were synthesized through a hydrothermal method and combined with β-cyclodextrin. Under optimal experimental conditions, the sensor exhibited a wide linear detection range (0.7–310.2 μM) and a low detection limit (0.227 μM). Furthermore, the sensor exhibited satisfactory stability and accuracy in an electrochemical study involving human serum and dopamine hydrochloride injection samples containing DA, and the redox mechanism of the sensor was elucidated. Overall, this study presents a novel electrochemical sensor based on cyclodextrins and MOFs for DA detection. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs), serving as a promising electrode material in the supercapacitors, have attracted tremendous interests in recent years. Here, through modifying the molar ratio of the Ni 2+ and Co 2+ , we have successfully fabricated Ni-MOF and Ni/Co-MOF by a facile hydrothermal method. The Ni/Co-MOF with a dandelion-like hollow structure shows an excellent specific capacitance of 758 F g −1 at 1 A g −1 in the three-electrode system. Comparing with Ni-MOF, the obtained Ni/Co-MOF has a better rate capacitance (89% retention at 10 A g −1 ) and cycling life (75% retention after 5000 circulations). Besides, the assembled asymmetric supercapacitor based on Ni/Co-MOF and active carbon exhibits a high specific energy density of 20.9 W h kg −1 at the power density of 800 W kg −1 . All these results demonstrate that the mixed-metal strategy is an effective way to optimize the morphology and improve the electrochemical property of the MOFs. [ABSTRACT FROM AUTHOR]

Abstract: Crystalline porous metal–organic frameworks (MOFs) with nanometer‐sized void spaces, large surface areas and ordered reticular motifs have offered a platform for achieving disruptive successes in divisional fields. Great progress in exploring the linear and nonlinear optical features of MOFs has been achieved, yet third‐order optical nonlinearities in two‐dimensional (2D) MOFs have rarely been studied. Here, a broadband nonlinear optical amplitude modification and phase shift are demonstrated in a few‐layer nickel‐p‐benzenedicarboxylic acid MOF (Ni‐MOF). The calculated bandgap of Ni‐MOF decreases from 3.12 eV to 0.85 eV as the doping of Ni ions increases, indicating the ability of this material to be used for optical amplitude modulation from the visible to the near‐infrared region, which is experimentally confirmed via a Z‐scan technique. The determined third‐order optical nonlinearities resemble those of other low‐dimensional nonlinear optical materials, suggesting the wide potential of Ni‐MOF for application in optoelectronics. As an example, a Ni‐MOF‐based saturable absorber was implemented into fiber resonators to demonstrate its broadband mode‐locking operations. A femtosecond laser pulse was readily obtained in the telecommunication wavelength window in an integrated all‐fiber resonator. Considering the chemical compatibility and rich variability, these primary investigations pave the way towards advanced photonics based on multifeature MOF materials. [ABSTRACT FROM AUTHOR]

• The unique chestnuts-like heterostructure was constructed via the carbonization and sulfidation of Ni-MOF. • Rational structure design and synergistic effect of different components and architectures co-boost capacitive behaviors. • The assembled asymmetric supercapacitor with outstanding cycling stability of 94.8% after 10,000 cycles at 1 A/g. Nickel sulfides are seemed as potential electrode materials of supercapacitors (SCs). Unfortunately, the unsatisfied structural stability of nickel sulfides lies in the way of their long-term working and applications. Herein, inspired by the biological structure of chestnuts, a ternary heterostructure composed of carbon nanotubes (CNTs) linked with NiS 2 @carbon microspheres (xNCC) was constructed by using Ni-MOF as precursor. Electrochemical evaluations showed that the as-obtained xNCC composites presented an optimal specific capacitance of 1572 F/g at 0.5 A/g. Additionally, the aqueous supercapacitor device exhibited a superior energy density of 21.6 Wh/kg, as well as a performance of 94.8% superior cycling stability after 10,000 cycles. It is supposed that the unique ternary heterostructure avoids/relieves the agglomeration of NiS 2 , weakens volume expansion and provides abundant as well as promote the stability of electrochemical active sites. More importantly, the 3D structural features of xNCC impart the electrodes with porous microstructures that are able to shorten the distance of ion-diffusion, thus enhancing the cycling stability and electrochemical performance. The present strategy may enlighten the structural design of electrode materials that can be further applied in SCs and other energy storage devices. [Display omitted] [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are a class of porous organic-inorganic crystalline materials that have attracted much attention as H2 storage devices and catalytic supports. In this paper, the synthesis of highly-dispersed Ni nanoparticles (NPs) for the hydrogenation of olefins was achieved by employing Ni-MOF-74 as a precursor. Investigations of the structural transformation of Ni species derived from Ni-MOF-74 during heat treatment were conducted. The transformation was monitored in detail by a combination of XRD, in situ XAFS, and XPS measurements. Ni NPs prepared from Ni-MOF-74 were easily reduced by the generation of reducing gases accompanied by the decomposition of Ni- MOF-74 structures during heat treatment at over 300 °C under N2 flow. Ni-MOF-74-300 exhibited the highest activity for the hydrogenation of 1-octene due to efficient suppression of excess agglomerated Ni species during heat treatment. Moreover, Ni-MOF-74-300 showed not only high activity for the hydrogenation of olefins but also high size-selectivity because of the selective formation of Ni NPs covered by MOFs and the MOF-derived carbonaceous layer. [ABSTRACT FROM AUTHOR]

Objective(s): According to the unique properties of magnetic nanoparticles, Nickel Metal-Organic Frameworks (MOF) were synthesized successfully by ultrasound irradiation. Metal-organic frameworks (MOFs), are organic–inorganic hybrid extended networks that are constructed via covalent linkages between metal ions/metal clusters and organic ligands called a linker. Materials and Methods: The nanoparticles were synthesized by Ultrasound Method Under a synthesis conditions, All chemicals were used as received without further purification. Scanning electron microscopy (SEM) images were obtained on LEO- 1455VP equipped with an energy dispersive X-ray spectroscopy at university of Kashan in Iran. Transition electron microscopy (TEM) images were obtained on EM208 Philips transmission electron microscope with an accelerating voltage of 200 kV. Results: Results showed that Ni-MOF synthesized by this method, had smaller particle size distribution and It was found that the different kinds of ligand leads to preparation products with different morphologies and textural properties. Moreover, ultrasound irradiation method has significant effect on microstructures of as-synthesized MOFs and can improve their textural properties compared to method without using hydrothermal route.The XRD patterns of the samples obtained from ultrasound irradiation was well matched with that of as-prepared Ni-MOF by solvothermal method. Conclusion: This rapid method of ultrasonic radiation as compared to the classical solvothermal synthesis, showed promising results in terms of size distribution, surface area, pore diameter and pore volume. [ABSTRACT FROM AUTHOR]

• Ni-MOF on MXene is vulcanized to sandwiched p-MXene/Ni 3 S 4 /CuS in the presence of copper. • p-MXene/Ni 3 S 4 /CuS show the remarkable specific capacitance. • The p-MXene/Ni 3 S 4 /CuS//AC has a high energy density and ultrahigh cyclic stability. [Display omitted] Metal-organic frameworks (MOFs) have ordered porous structure and intriguing properties for supercapacitors, however, poor conductivity and cycle stability limits their application. To solve these problems, hence, a simple strategy is proposed, by which MOFs are in-situ grown in the porous conductive p-MXene substrate. And then, along with the introduction of CuS, the grown Ni-MOF is derived to Ni 3 S 4 , which is more stable and more electrochemically active. Due to higher contact area, excellent synergistic effect and more exposed active sites, the prepared sandwiched p-MXene@Ni 3 S 4 /CuS nanostructure displays a big specific capacitance (1917 F·g−1) and superior cycling performance (91.2%@30000). What's more, the assembled p-MXene@Ni 3 S 4 /CuS//AC asymmetric device delivers a high energy density of 87.62 Wh·Kg−1 at the power density of 775.02 W·Kg−1, suggesting that this material provides a brilliant candidate for energy storage. [ABSTRACT FROM AUTHOR]

• UOB-8 was applied as an oxidative and a reusable solid acid metal organic framework. • Ultrasound-assisted direct oxidative amidation of benzyl alcohols with amines catalyzed by UoB-8 or MOF-Ni. • Direct oxidative amidation of alcohols takes place under ultrasonic irradiation. • Corresponding amides were obtained in good to excellent yields and short reaction times. A novel and green protocol was developed for the synthesis of amides via the reaction of benzyl alcohols with amines in the presence of Ni-MOF named UoB-8 as catalyst. The morphological, structural, and physicochemical characteristics of the Ni-MOF were investigated by FT-IR, XRD, FESEM, EDX, TEM, BET, CHN and ICP analyses. The products were obtained in good to excellent yields, with short reaction times, under ultrasound irradiation (40 ºC) in ethanol as solvent. In addition, low-cost catalyst was recovered and reused at least 5 times without detecting a noticeable reduction in efficiency. [Display omitted] [ABSTRACT FROM AUTHOR]

• A "signal off" electrochemical aptasensor strategy for the detection of ENR is constructed. • AuNPs/Ni-MOF for electrode sensing platform preparation are used for catalyst thionine and signal amplification. • AuTSs acts as a bridge between cDNA and thionine, speeding up electron transfer. • The protocol possesses accepted specificity and can be applied in real sample. In this project, we developed an electrochemical aptamer sensor based on the coordinated catalysis toward thionine (Thi) of nickel metal-organic framework (Ni-MOF) and gold nanoparticles (AuNPs) to sensitively detect the enrofloxacin (ENR), which belonged to a third-generation quinolone antibiotic for treat diseases caused by bacteria. In order to improve the analytical performance of the sensor, Ni-MOF and gold AuNPs, as the substrate material, could increase the load of the aptamer (Apt) and synergistically catalyze thionine (Thi). Therefore, ultrathin sheets of gold triangular nanosheets (AuTNSs) were prepared as signal labeling materials, which were loaded with a large amount of Thi and complementary deoxyribonucleic acid (cDNA). With the help with Ni-MOF and AuNPs catalysis toward Thi, under optimal conditions, the aptasensor exhibited a massive detection range of 1×10−2 pg·mL−1 to 1×103 pg·mL−1 (S/N = 3) and a detection limit of 5.6×10−3 pg·mL−1 for ENR. Meanwhile, the proposed sensor has a high sensitivity, satisfactory repeatability and long-time stability, and could be well applied to the detection of food samples. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are promising adsorbents for adsorptive desulfurization (ADS) because MOF structure can be tuned to match the application. However, data on the ADS of liquid fuels using Ni-BDC are still scarce. In this study, modulated synthesis was used to prepare a group of Ni-doped MOF absorbents using formic acid as the modulator. The activities of these adsorbents for the ADS of model fuels were investigated, with initial sulfur concentrations of 150, 151, and 153 ppm for thiophene (TH), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (4,6 DMDBT), respectively. Although Ni-doping decreased the crystallinity and crystallite size of the MOFs, the addition of formic acid significantly increased both the crystallite size and crystallinity of all the (xNi/Zn)-BDC materials. In addition, it was observed that modulated synthesis reduced the interpenetration of the MOF-5 crystallites. The adsorption experimental results showed that the modulated synthesis of Ni-BDC using formic acid improved the overall adsorptive activity of Ni-BDC almost twofold. This increase in activity was attributed to increased crystallinity and a higher number of atoms with low coordination for modulated Ni-BDC compared with MOF-5 (100). Formic acid as a modulator was observed to have three effects: i) accelerating MOF synthesis, ii) modulating crystallite size, and iii) controlling crystallinity. The most active adsorbent, Ni-BDC treated with formic acid, was observed to have higher activity toward TH than DBT and 4,6 DMDBT. The overall adsorption capacity and partition coefficient for this adsorbent were 4.14 mg/g and 0.053 mg/g/ppm, respectively. [Display omitted] • Ni-BDC was synthesized using formic acid as a modulator. • Ni-BDC synthesized had more low coordination atoms compared to MOF-5. • Adsorption order was observed to correlate well with crystallinity of Ni-BDC. • The adsorption order for MOFs was as follows: Ni-BDC 15eq>MOF-5>Ni-BDC. [ABSTRACT FROM AUTHOR]

Lamellar membranes are attracting extensive attention for high throughput and precise molecules/ions sieve separation. However, the energy-consuming exfoliation and low yield of single-layer nanosheets restrict the massive production of membranes. Herein, we facilely fabricated 2D Ni-mediated metal-organic framework (Ni-MOF) membranes directly from multiply stacked nanosheets (MSNs) for both aqueous and organic molecular sieve separation. Multiply layered nanosheets were obtained from a high concentration dispersion via simple ultrasonic treatment. The morphology and chemistry of synthesized Ni-MOF nanosheets were characterized via scanning electron microscopy (SEM), N 2 adsorption-desorption, Fourier transform infrared spectra (FTIR), and X-ray photoelectron spectra (XPS). The thickness of Ni-MOF membranes could be well regulated by the volume of dispersion. The membrane exhibited high molecular rejection to 8GX (97.29%), EB (96.28%), CR (99.69%), and CBB (93.31%) in water, respectively and a stable perm-selectivity in continuous 24 h filtration. The lamellar membrane showed excellent pressure and pH (2–10) resistance. The membrane achieved rational permeance of various organic solvents mainly depending on viscosity and good rejection to MB (91.37%), BY (92.01%), and EB (96.90%) in isopropanol. Ni-MOF membranes directly prepared by multiply stacked nanosheets (MSNs) and exhibited a stable aqueous/organic molecular sieve separation. [Display omitted] • 2D Ni-mediated metal-organic framework (Ni-MOF) membranes were fabricated directly from multiply stacked nanosheets (MSNs). • Ni-MOF membrane exhibited high molecular rejection in water or organic solvent. • Ni-MOF membrane showed excellent pressure and pH (2–10) resistance. [ABSTRACT FROM AUTHOR]

The nickel organic framework capped with polyvinylpyrrolidone was prepared and synergistically immobilized onto porous silica surface as the mixed-mode stationary phase for high-performance liquid chromatography. Here, polyvinylpyrrolidone firstly was chosen as functional molecules to change morphology and size of the metal organic framework. The silica microspheres were then modified by them via a simple bonding method rather than in-situ growth method with the aid of electrostatic interaction commonly used before. The stationary phase showed flexible selectivity for separation of both hydrophilic and hydrophobic compounds, especially for hydrophilic compounds such as carbohydrates, alkaloids and sulfonamides etc. The chromatographic behaviors were evaluated by investigating various factors, and a typical mixed-mode retention feature of the column was observed. The composites could be prepared repetitively, and relative standard deviations of retention time of objective compounds among different batches were less than 1.75%. It also showed excellent chromatographic reproducibility, stability and potentiality for application in real samples. In short, the composites can be used for a feasible option for analysis of multiple compounds as the mixed-mode stationary phase and it provides a general approach for preparing MOFs-based composites by changing morphology and size of MOFs. [Display omitted] • The polyvinylpyrrolidone was chosen as functional molecules to change morphology and size of the Ni-MOF. • The silica microspheres were modified by Ni-MOF capped with PVP via a simple bonding method. • The new composites showed flexible selectivity for separation of both hydrophilic and hydrophobic compounds. [ABSTRACT FROM AUTHOR]

• A sol-gel method was developed to load Ni-MOF to silica. • The sol-gel method was optimized to reduce the preparation cost. • A highly dispersed Ni/SiO 2 catalyst without using MOF was designed. • The Ni/SiO 2 catalysts exhibited high catalytic property for CO 2 methanation. The CO 2 methanation is an important process in coal-to-gas, power-to-gas and CO 2 removal for spacecraft. Recently, metal-organic framework (MOF) derivatives have been demonstrated as high-performance catalysts for CO 2 upgrading processes. However, due to the high costs and low stability of MOF derivatives, it still remains challenge for the development of alternative synthesis methods avoiding MOF precursors. In this work, we present the sol-gel method for loading Ni-MOF to silica support in two-steps. Upon modifying the procedure, a more simplified one-step sol-gel method has been developed. Furthermore, the obtained Ni/SiO 2 catalyst still exhibits great catalytic performance with a CO 2 conversion of 77.2% and considerable CH 4 selectivity of ~100% during a stability test for 52 h under a low temperature of 310 °C and high GHSV of 20,000 mL·g−1·h−1. Therefore, this work provides a ground-breaking direct strategy for loading MOF derived catalysts, and might shed a light on the preparation of highly dispersed Ni/SiO 2 catalyst. [ABSTRACT FROM AUTHOR]