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Electrocatalytic water splitting technology, as an essential method for storing and converting renewable energy, has garnered significant attention. However, traditional electrolytic water splitting is hampered by issues such as noble metal catalysts are expensive and unstable, limiting its widespread application. To address this challenge, this study proposes an innovative method that utilizes nickel metal-organic framework (Ni-MOF) as a support to firmly anchor platinum (Pt) nanoparticles on its surface. This approach not only overcomes the high cost and instability associated with traditional noble metal catalysts but also leverages the strong chelation effect of ethylenediaminetetraacetic acid disodium salt (EDTA·2Na) and the strong metal-support interaction (SMSI) at the Ni– O –Pt interface, prompting catalysts to possess excellent stability and catalytic activity. The catalyst exhibits excellent performance in promoting the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall electrolysis of water, maintaining stability throughout the entire electrochemical process. At a current density of 10 mA cm−2, the overpotentials for HER and OER with Pt 1·5 /Ni-MOF are only 29 mV and 234 mV, respectively. When Pt 1·5 /Ni-MOF serves as both the cathode and anode for overall water splitting, only a low voltage of 1.557 V is needed. This study offers fresh insights into the development of stable, efficient, and low-budget dual-functional catalysts for water electrolysis, with the potential to drive the commercialization of water electrolysis technology and make significant contributions to the advancement of clean energy. This study proposes an innovative method that utilizes nickel metal-organic framework (Ni-MOF) as a support to firmly anchor platinum (Pt) nanoparticles on its surface. This approach not only overcomes the high cost and instability associated with traditional noble metal catalysts but also leverages the strong chelation effect of ethylenediaminetetraacetic acid disodium salt (EDTA·2Na) and the strong metal-support interaction (SMSI) at the Ni– O –Pt interface, further enhancing the activity and stability of the catalyst. The catalyst exhibits excellent and stable performance in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting, provides new insights into the development of efficient, stable, and low-cost dual-functional catalysts for water electrolysis. [Display omitted] • Ni-MOF anchored Pt was synthesized via solvothermal and low-temperature calcination. • Pt1.5/Ni-MOF structure enhances Pt loading, electrical conductivity, and stability. • Pt1.5/Ni-MOF shows excellent dual-functional electrocatalytic performance. [ABSTRACT FROM AUTHOR]

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]

NS-CQDs were synthesized by a hydrothermal method using high-sulfur lignite as the carbon source. Modification of Ni-MOF and Co/Zr-MOF using NS-CQDs to explore the performance of composite photocatalysts for hydrogen production. It was found that NS-CQDs significantly enhanced the hydrogen precipitation performance of the composite photocatalysts compared with the MOFs catalysts alone, and the highest hydrogen precipitation rate of the novel composite photocatalyst 5%NS-CQDs/NCZ2 reached 3662.68 μmol g−1 h−1. It can be inferred from the conduction band and valence band positions of Ni-MOF, Co/Zr-MOF and NS-CQDs that a double S-type heterojunction is formed. The presence of thiophene and pyrrole nitrogen in NS-CQDs can promote electron transport, reduce the rate of electron-hole pair complexation, and improve the hydrogen evolution activity of the 5%NS-CQDs/NCZ2. • Conversion of high sulfur lignite into NS-CQDs using a hydrothermal method. • The hydrogen evolution rate of 5%NS-CQDs/NCZ2 reached 3662.68 μmol g−1 h−1 at pH = 9. • Thiophene and pyrrole nitrogen in NS-CQDs promote electron transport and reduce the rate of electron-hole pair complexation. [ABSTRACT FROM AUTHOR]

The efficient removal of antibiotic residues from aqueous solution is very important for water security. Studies have found that adsorption is widely used for the removal of antibiotics due to its cost-effectiveness, low energy consumption, simplicity of operation, and environmental friendliness. In this study, a novel magnetic porous carbon adsorbent (Ni-MPC-400) with a high adsorption capacity and saturation magnetization was synthesized via direct carbonization of Ni-MOF at 400 °C pyrolysis temperature and used to efficiently remove tetracycline from an aqueous solution. Adsorption experiments showed that Ni-MPC-400 exhibited excellent tetracycline adsorption capacity (441.51 mg·g–1) from the aqueous solution. Possible adsorption mechanisms were proposed through characterization and analysis. The adsorption mechanisms mainly involved π–π interactions, hydrogen bonding, metal–organic complexation, and pore filling effects. In addition, Ni-MPC-400 showed rapid and sufficient adsorption at a low concentration of tetracycline (5 mg·L–1) and good adsorption performance over a wide pH range. In addition, the material has been tested to have good immunity to interference and regenerative capacity, demonstrating a potential application in the removal of tetracycline contaminants from aqueous solutions. [ABSTRACT FROM AUTHOR]

Among the electrode materials for supercapacitors (SCs), metal-organic framework (MOFs) is attracting huge research interest as a new type of energy storage electrode materia. However, due to their poor conductivity and stability, the practical application of original MOFs in the field of energy storage has been greatly hindered. Here, we demonstrate a special core-shell structure, which the synergistic action of NiCo2O4 and Ni-MOF forms a tight conductive network that speeds up electron transport and larger specific surface area, more active sites were obtained and mechanical stability that indicates its outstanding long life. The test results show that it has a high specific capacity of 4.23 F cm–2 at 5 mA cm–2, and the capacity retention rate is maintained at 97.5% after 8000 cycles. In addition, an asymmetric supercapacitor device, using NiCo2O4@Ni-MOF and activated carbon (AC) as anode and cathode, has a high specific capacity of 3.21 F cm–2 at 5 mA cm–2 and excellent cycling performance (83.8% retention over 8000 cycles at 10 mA cm–2). Our work demonstrates the possibility of using novel structured Ni-MOF-based hybrid arrays as electrodes for SCs with enhanced electrochemical performance compared to Ni-MOF and NiCo2O4, providing a reliable prospect for flexible energy storage devices. [ABSTRACT FROM AUTHOR]

Vật liệu khung hữu cơ kim loại phân tán trên nền bọt nickel Ni-MOF/NF được tổng hợp bằng phương pháp nhiệt dung môi sử dụng phối tử hữu cơ 2-methylimidazole. Các đặc trưng lý hóa của vật liệu được xác định bằng phép đo XRD, phổ IR, phổ EDX, và ảnh chụp SEM. Vật liệu sau đó được ứng dụng làm xúc tác cho phản ứng điện phân nước giải phóng hydrogen trong dung dịch NaOH 1 M. Kết quả khảo sát cho thấy, Ni-MOF/NF làm giảm đáng kể quá thế và độ dốc Tafel đối với quá trình cathode giải phóng hydrogen. Các điều kiện của quá trình tổng hợp vật liệu đã được nghiên cứu. Kết quả thực nghiệm chỉ ra, vật liệu tổng hợp từ muối nickel nitrate và phối tử 2-methylimidazole theo tỉ lệ số mol 1:8, gia nhiệt ở 180oC trong 8 h có khả năng xúc tác tốt cho phản ứng điện phân nước giải phóng khí hydrogen. Bên cạnh hoạt tính xúc tác cao, vật liệu Ni-MOF/NF còn có độ ổn định cao trước và sau 10 h xúc tác liên tục.

MOFs derived metal composites are found to be a potential electrocatalyst for energy storage and conversion process. In this work, Ni composite with MXene (Ni-Ti 3 C 2) was synthesized by calcination of Ni-MOF at 650 °C and characterized by XRD, FE-SEM, FTIR and BET analysis. After calcination, the derived Ni composited Ti 3 C 2 showed a high porosity and high surface area as compared to Ti 3 C 2. The derived material was further used as electrode for Hydrogen Evolution Reaction (HER) and tested by various electrochemical analysis viz. Cyclic voltammetry (CV), Electrochemical impedance analysis (EIS) and Linear Sweep Voltammetry (LSV) in alkaline medium. The derived Ni-Ti 3 C 2 in basic medium displays a small Tafel value of 56.15 mV/dec with acquired voltage of 181.15 mV due to the surface area and accessible catalytic active sites, which provides excellent mass transfer properties for derived Ni-Ti 3 C 2 composite in basic medium. The kinetics of the HER reaction was found better in Ni-Ti 3 C 2 MXene composite in basic medium than in acidic medium. The charge transfer resistances were obtained from the EIS plot and were found to be 3.98 Ω and 2.34 Ω for Ti 3 C 2 and Ni-Ti 3 C 2 respectively in acidic medium and 3.12 Ω and 1.98 Ω in basic medium. The low resistance observed for Ni-Ti 3 C 2 in basic medium proves a higher electrocatalytic activity in Ni-Ti 3 C 2 than Ti 3 C 2. The cyclic stability of the Ni-Ti 3 C 2 in basic medium was higher than Ti 3 C 2. Thus the overall results show that the prepared composite is a potential catalyst for HER applications. •Ti 3 C 2 T x and Ni-Ti 3 C 2 T x and Ni-MOF based electrodes are used for Hydrogen evolution Reaction (HER). • Ni-Ti 3 C 2 T x showed high catalytic activity in the HER, with a low Tafel slope of 56.56 mV/dec. • The Rate determining step of Ni-Ti 3 C 2 in basic medium follows Volmer-Heyrovsky mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrogen doped carbon nanotubes with encapsulated Ni nanoparticles have been coated with Ni-MOF. • Ni-MOF@Ni-NCNT exhibited a superior UOR activity due to its lower binding strength with CO 2 and more active sites. • HER-UOR system requires only 1.33 V to reach 10 mA cm−2 for Ni-MOF@Ni-NCNT, 270 mV lower than Pt/C-IrO 2. In this work, we report a robust bifunctional electrocatalyst composed of 2D Ni- organic frameworks (Ni-MOF) and nitrogen doped carbon nanotubes encapsulated Ni nanoparticles (Ni-MOF@Ni-NCNT) for C N and H O bonds dissociation. Due to the presence of Ni-NCNT, adsorption of OH– species is enhanced and CO 2 binding strength is simultaneously weakened leading to a boosted urea oxidation reaction performance reflected by decrement in potential at 100 mA cm−2 by 69 mV. The loosened binding strength with CO 2 specie is highlighted by in-situ electrochemical impedance spectroscopy (EIS) test and DFT calculation. Moreover, the alkaline hydrogen evolution reaction (HER) performance of Ni-MOF@Ni-NCNT is better than Ni-MOF and Ni-NCNT evidenced by the overpotential at 50 mA cm−2 decreased by 224 mV and 900 mV ascribed to the synergistic effect, in which Ni-MOF, Ni nanoparticles and Ni-Nx-C facilitates water adsorption, dissociation and adsorption/combination of hydrogen ions, respectively. The assembled HER- urea oxidation reaction (UOR) system requires only 1.33 V to reach 10 mA cm−2, 70 mV lower than water splitting driven by Pt/C-IrO 2. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized a vinyl functional group containing 4, 4′-bis (1, 3-diphenoxypropane) diacrylic acid organic linker, which was used in construction of novel Cu-MOF (1) and Ni-MOF (2) through a solvothermal method. The synthesized MOFs were characterized by FT-IR, PXRD, TGA, FE-SEM, and EDAX. In particular, Cu-MOF can be used as a bifunctional sensor for detection of arginine and H2S by a fluorescence "turn-off" mechanism with low limit of detection of 0.5 µM and 3.1 µM with quick response time (< 1 min) respectively. On the other hand, Ni-MOF demonstrated to have capability for selective detection of H2S only by quenching mechanism in the presence of various other biologically important analytes. The limit of detection was found to be 3.0 µM and showed rapid quenching in fluorescence intensity (< 1 min). Organic linker 4,4′-bis(1,3-diphenoxypropane) diacrylic acid was used to construct Cu-MOF and Ni-MOF, which are showing good selectivity and sensitivity towards arginine and H2S using turn- off quenching mechanism. [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]

As an emerging class of nanoporous materials, Metal Organic Framework (MOFs) are distinguished for environmental remediation. ZIFs and Ni-MOF chosen as fluoride (F-) scavengers due to their robust structures and straightforward synthesis routes. F- adsorption was studied as a function of the ZIFs geometry and structural properties. The efficacy of MOFs for F- abatement was in the order of ZIF-67-NO3 (70.1%) > ZIF-8-Cube (64.7%) > ZIF-67-OAc (62.4%) > ZIF-8-Cuboid (59.2) > Ni-MOF (58.5%) > ZIF-8-Octahedron (57.1%) > ZIF-8-Leaf (55.3%) > ZIF-67-SO4 (55.1%) > and ZIF-67-Cl (52.3%). The key operating variables i.e. pH, mixing time, F- concentration, and ZIF-67-NO3 dose were modeled using the Box-Behnken design (BBD). The model revealed the process mainly influenced by solution pH. The model optimized the operating condition and obtained a maximum 85.9% F- removal by mixing time = 41.1 min, ZIF-67-NO3 dose = 0.9 g/L, solution pH = 4.86, and F- = 6.5 mg/L. Non-linear form of isotherm and kinetic models disclosed the multilayers F- adsorption onto ZIF-67-NO3 with an qmax =25.9 mg/g, and chemisorption as the rate-controlling step. F- sorption decreased slightly by temperature in the range of 303 to 323 K. The structure of ZIF-67-NO3 remained stable under three consecutive use-reuse cycles with an about 10% loss in removal efficiency.

Sulfur-nitrogen doped porous carbon (SNPC) material was first synthesized by the hydrothermal method and high-temperature carbonization. Then, the three-dimensional cube SNPC-Ni-metal organic frameworks (SNPC-Ni-MOF) composite was finally synthesized by hydrothermal method and applied in oxygen evolution reaction (OER). BET analysis proved the porosity and higher specific surface area of SNPC. FTIR analysis implied that the coordination of trimesic acid with metal ions was successful. SEM images showed that the as-synthesized carbon materials presented beautiful spherical. The overpotential of the as-synthesized composite was conducted by the LSV test, and it was found that the SNPC-Ni-MOF composite exhibited the lower overpotential (400 mV). Electrochemical impedance spectroscopy showed the SNPC-Ni-MOF had the smaller Rct value (1.744 Ω cm−2). Tafel plot indicated that the doping of sulfur and nitrogen improved the electrochemical properties of carbon materials to some extent. The cyclic voltammetry test illustrated that the electrochemical active surface area of SNPC-Ni-MOF was 48.75 cm2. The turnover frequency ​​for OER was 0.016 s−1. In addition, the i-t curve test indicated that the SNPC-Ni-MOF composite possessed better stability, the retention rate reaches 96.7% after 20,000 cycles. All results illustrate that the OER performance of the as-prepared SNPC-Ni-MOF composite has been improved and can be used as electro-catalysts for water splitting. [ABSTRACT FROM AUTHOR]

A novel and cost-efficient electrochemical sensor was designed by immobilizing IL/Ni-MOF/Co 3 O 4 nanodiamonds on the graphite (GE) electrode, marking the first application for the detection of aspartame. The graphite electrode was extracted and recycled from discharged batteries to serve as a working electrode. The nanocomposite features unique Co 3 O 4 nanodiamonds, generated using Coriandrum sativum seed extract, alongside Ni-metal organic framework (MOF), which were synthesized through a solvothermal method. The conductivity and stability of the electrochemical sensor were enhanced through the incorporation of the ionic liquid (IL) ([BMIM][MeSO 4 ]. The phytochemical profile of Coriandrum sativum seed extract, analyzed by GC-MS, identified key compounds involved in the synthesis of Co 3 O 4 nanodiamonds. A comprehensive characterization of the nanocomposite was performed using UV-Vis, FTIR, DLS, Zeta potential, XRD, XPS, FE-SEM, TEM, optical profilometry, and AFM to confirm the structural and elemental modifications. Electrochemical characterization of the bare and modified electrodes was conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The GE/IL/Ni-MOF/Co 3 O 4 nanodiamonds modified electrode displayed enhanced electroanalytical performance for aspartame detection, characterized by signal amplification at +7.0 V. Quantitative analysis by Differential Pulse Voltammetry (DPV) and Square Wave Voltammetry (SWV) revealed a linear detection range of 3–15 µM for aspartame. A comparison of SWV and DPV revealed superior analytical performance for SWV, with limit of detection (LOD) and limit of quantification (LOQ) values of 1.02 µM and 3.1 µM (R2 = 0.993) compared to 1.81 µM and 5.5 µM (R2 = 0.986) for DPV. This study reveals the excellent adsorption capabilities of Ni-MOF and Co 3 O 4 nanodiamonds (Co 3 O 4 NDs), attributed to their high porosity and large surface area, paving the way for the development of affordable sensing devices for artificial sweeteners. [Display omitted] • Novel and specific nanocomposite of GE/IL/Ni-MOF/Co 3 O 4 NDs for the detection of aspartame. • A waste-derived electrochemical sensor constructed from household discharged batteries. • GE/IL/Ni-MOF/Co 3 O 4 NDs promote the electron transfer, results in the signal amplification. [ABSTRACT FROM AUTHOR]

The efficient hydrogenolysis of C O ether bonds in lignin is the key for producing bio-oil and high-value chemicals. In this work, we synthesized a series of Ni-MOF-derived porous carbon spheres anchored Ni catalysts (Ni/C-x-T) with different metal/ligand molar ratios and calcination temperatures through solvothermal and carbothermal reduction method, and evaluated their catalytic transfer hydrogenolysis (CTH) performance for lignin model compounds using isopropanol as H-donor. The Ni/C-2-400 catalyst exhibited the excellent CTH performance, affording almost 100 % conversion of 2-phenoxy-1-phenylethanol even at a low reaction temperature of 120 °C. It was worth noting that the further hydrogenation of hydrogenolysis products phenol and ethylbenzene could be controlled by adjusting the reaction conditions, achieving phenol and ethylbenzene as main products at 120 °C, cyclohexanol and ethylbenzene at 140 °C, and cyclohexanol and ethylcyclohexane at 200 °C for 4 h. Based on the characterization results, the high catalytic activity of Ni/C-2-400 was attributed to the good dispersion and small particle size of metal Ni particles. Mechanistic studies showed that the cleavage of C O ether bonds was the main reaction pathway, and high temperature helped accelerate hydrogenolysis and subsequent hydrogenation. Moreover, the Ni/C-2-400 catalyst had good stability and applicability to other model compounds. This work could provide some help for the upgrading of lignin and its derivative. In this study, a series of Ni-MOF-derived Ni/C-x-T catalysts with different metal/ligand molar ratios and calcination temperatures through solvothermal and carbothermal reduction method, and their catalytic transfer hydrogenolysis (CTH) performances for lignin model compounds were evaluated using isopropanol as H-donor. [Display omitted] [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]

[Display omitted] • Ni-BDC was synthesized with different solvent compositions through a solvothermal process. • High capacitance performance of Ni-BDC (1124 F/g) was achieved in 1:1 DMF and ethanol. • Fabricated ASSC shows ultrahigh energy density (87 Wh/Kg) and power density (3040.7 W/Kg) in 2 M KOH at 10 A/g. • Excellent cycling stability (89 % at 20 A/g) is achieved up to 3000 GCD cycles. An innovative solvent-controlled technique has been devised to fabricate Ni-BDC through the impurity-free-solvothermal method. X-ray diffraction analysis shows that the synthesized material has a triclinic phase and belongs to the P -1 space group. FESEM and TEM analyses elucidated the nanosheet-like morphology of Ni-BDC (NB1) in a 1:1 solvent mixture comprising of ethanol and DMF. In a three-electrode setup, NB1 displays an outstanding specific capacitance (C S) of 1124 F/g and remarkable cyclic stability (98.2 %) in a 2 M KOH aqueous electrolyte. Moreover, a device was constructed with a voltage range of 1.4 V, utilizing a positive electrode (NB1) in conjunction with a negative electrode composed of activated carbon (AC). The as-fabricated supercapacitor device displays a high capacitance of 359.3 F/g at a current density of 2 A/g, an impressive energy density of 97.8 Wh/kg at a power density of 484.2 W/kg. Three devices were linked in series, they collectively illuminated a green LED. [ABSTRACT FROM AUTHOR]

This study investigates the electrochemical performance and selectivity of a nickel-based metal-organic framework (Ni-MOF) catalyst synthesized from waste PET plastic using a one-pot approach in aqueous media. The Ni-MOF electrode was evaluated for glycerol electrooxidation reaction (GEOR), ethanol electrooxidation reaction (EEOR), and methanol electrooxidation reaction (MEOR). Linear sweep voltammetry (LSV) revealed current densities of 30 mA/cm² at 0.5639 V for GEOR, 50.07 mA/cm² at 0.35 V for EEOR, and 45.73 mA/cm² at 0.39 V for MEOR, indicating superior catalytic activity. Nyquist plots showed lower charge transfer resistance (R ct) values of 11.0 Ω for GEOR, 2.79 Ω for EEOR, and 2.69 Ω for MEOR, confirming efficient electron transfer. Bode impedance plots demonstrated lower impedance for alcohol electrooxidation compared to oxygen evolution reaction (OER). Chronoamperometry (CA) tests indicated excellent stability with 76% glycerol conversion for GEOR and selectivities of 94% for glyceric acid, 66% for acetic acid in EEOR, and 71% for formic acid in MEOR. These results highlight the potential of Ni-MOF derived from recycled PET plastic for sustainable and efficient electrooxidation of C 1 -C 3 alcohols. [Display omitted] • Ni-MOF electrocatalyst synthesized from waste PET plastic using eco-friendly, one-pot aqueous synthesis. • High catalytic activity demonstrated for C1-C3 alcohols with superior current densities, low onset potentials, and stability. • Achieved high selectivity: glyceric acid (94%), acetic acid (66%), and formic acid (71%) from glycerol, ethanol, and methanol. • High-resolution XPS confirms in situ formation of NiOOH species on Ni-MOF electrode during reaction. • Cost-effective, sustainable alternative to noble metal electrocatalysts for green chemistry and renewable energy. [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 study, novel nanostructures based on Ni-MOF/polysulfone nanofibers were fabricated by microwave-assisted electrospinning method. The final Ni-MOF/polysulfone fibrous nanostructure were immobilized on SiO2 substrates with high physicho-chemical properties. These nanostructures with an average diameter of 20 nm and a specific surface area of 1690 m2/g were used as novel adsorption for CH4 gas adsorption. It seems that the integration of novel Ni-MOF compounds into the fibrous network has differentiated these materials from previous samples. Since the experimental parameters significantly affect the specific surface area, the parameters including voltage, concentration, and distance between the collector and source are designed by the fractional factorial method. The results were optimized by contour plots, ANOVA and surface plots, theoretically. The results show that the sample has an adsorption rate of about 5.14 mmoL/g. The improved CH4 gas adsorption performance is attributed to the large specific surface area and porous nature of the Ni-MOF/Ps nanostructure which is more convenient and accessible for CH4 gas adsorption.

In recent years, metal–organic framework (MOF) has become a hot electrode material for electrochemistry. However, it has rarely been studied in uric acid detection. In this paper, cubic Ni-based MOF has been synthesized by Ni(NO3)2·6H2O and H3BTC in room temperature; then, Au nanoparticles (Au NPs) were decorated on Ni-MOF by in situ synthesis method. This electrochemical sensor can response to uric acid (UA) in solution and enhance response signal of UA detection. Next, some experiment conditions including pH, scan rate, and proportion between Au NPS and Ni-MOF have been optimized with cyclic voltammetry (CV) and differential pulse voltammetry (DPV). And then, the Au/Ni-MOF has been charactered with scanning electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy. Experiment finding, this electrochemical sensor has a wide linearity range from 15 to 500 μM with a low detection limit of 5.6 μM (S/N = 3). Besides, the sensor constructed also has excellent selectivity and stability. Finally, the Au/Ni-MOF sensor was successfully applied in uric acid detection in the body's serum. [ABSTRACT FROM AUTHOR]

In a new approach, we considered the special affinity between Ni and poly-histidine tags of recombinant urate oxidase to utilize Ni-MOF for immobilizing the enzyme. In this study, a carbon paste electrode (CPE) was modified by histidine-tailed urate oxidase (H-UOX) and nickel-metal–organic framework (Ni-MOF) to construct H-UOX/Ni-MOF/CPE, which is a rapid, sensitive, and simple electrochemical biosensor for UA detection. The use of carboxy-terminal histidine-tailed urate oxidase in the construction of the electrode allows the urate oxidase enzyme to be positioned correctly in the electrode. This, in turn, enhances the efficiency of the biosensor. Characterization was carried out by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and field emission scanning electron microscopy (FE-SEM). At optimum conditions, the biosensor provided a short response time, linear response within 0.3–10 µM and 10–140 µM for UA with a detection limit of 0.084 µM, repeatability of 3.06%, and reproducibility of 4.9%. Furthermore, the biosensor revealed acceptable stability and selectivity of UA detection in the presence of the commonly coexisted ascorbic acid, dopamine, L-cysteine, urea, and glucose. The detection potential was at 0.4 V vs. Ag/AgCl. [ABSTRACT FROM AUTHOR]

Efficient electrocatalyst for alkaline oxygen evolution reaction is the critical core to the wide application of metal-air energy storage and water electrolysis hydrogen energy. Therefore, appropriate design of highly active and stable non-noble metal oxygen evolution electrocatalyst with good electronic structure and multilevel structure is both a goal and a challenge. Here, we report a Fe–Ni 2 P electrocatalyst (NiFeP-MOF) with multilevel structure, which was obtained by anion exchange on the basis of Fe–Ni(OH) 2 (NiFe-MOF) grown on nickel foam in situ by solvothermal method. As expected, Fe substitution regulates the Ni oxidation state in the NiFeP-MOF and realizes electronic structure coupling, showing a highly active and stable oxygen evolution reaction (OER) in alkaline electrolyte solution. Specifically, the NiFeP-MOF demonstrates an ultralow overpotentials (232 mV, 10 mA cm−2; 267 mV 100 mA cm−2), respectively, an extremely small Tafel slope (34 mV dec−1). Separately, the electrocatalyst shows an excellent cycle stability at 10 mA cm−2 for 12 h (43,200 s). More importantly, this work come up with an available policy for the preparation of excellent alkaline hydrolysis electrolysis catalysts and air cathodes with excellent performance. • Fe–Ni 2 P (NiFeP-MOF) electrocatalyst with multilevel structure is obtained. • The synthesized catalysts have excellent OER performance and catalytic stability. • The catalyst with Ni:Fe ratio of 2:1 has high activity and good stability. • Fe substitution regulates the Ni oxidation state realizes electronic structure coupling. [ABSTRACT FROM AUTHOR]

Transition metal sulfides exhibit notable catalytic activity and possess a high theoretical specific capacity as host materials in lithium-sulfur batteries. However, their restricted conductivity and sluggish Li+ transport hinder their broader application. In this research, we developed a Ni-based metal-organic framework (Ni-MOF) using nitrogen-containing benzimidazole and coupled it with a highly conductive carbon nanotube (CNT) to form Ni x S y (NiS 2 –Ni 17 S 18)–C/CNT. The N-doped carbon skeleton derived from the MOF enhances the adsorption and chemical anchoring of polysulfides, while the even distribution of NiS 2 and Ni 17 S 18 enhances the redox reaction kinetics. Additionally, the conductive CNT networks aid in rapid electron transport, resulting in improved sulfur utilization. Consequently, the Ni x S y -C/CNT@S electrode demonstrates an impressive initial specific capacity of 1468 mAh g−1 at 0.2C and maintains 904.4 mAh g−1 after 200 cycles. Moreover, Ni x S y -C/CNT@S displays exceptional cycle stability, with a capacity retention of 76.20 % and a decay rate of only 0.05 % per cycle after 500 cycles at 0.5C. This study paves the way for the development and synthesis of cathode materials with outstanding electrochemical performance in LSBs. [Display omitted] • Ni x S y –C showed stronger adsorption and catalytic activity. • Ni x S y –C/CNT@S exhibits high capacity and cycling stability. [ABSTRACT FROM AUTHOR]

The novel TiO 2 and Ni-MOF materials were synthesized and utilized for the detection of permethrin (PET). A highly sensitive solid-state electrochemiluminescence (ECL) sensor was developed based on Ni-MOF@Ru(bpy) 3 2+ and Au NPs@TiO 2. In this sensing platform, Ru(bpy) 3 2+-Tripropyl Amine (TPrA) was used as a luminescent signal, Ni-MOF acted as a carrier to carry more luminescent reagents Ru(bpy) 3 2+. Au NPs acted as promoters facilitated electron transport and TiO 2 could further enhance the luminescence intensity of the system by synergistical interaction with Au NPs. The possible mechanisms of signal amplification were investigated. The ECL intensity decreased significantly with increasing PET concentration, enabling the determination of PET amount through the observation of the change in ECL signal intensity (ΔI). Under optimal experimental conditions, the linear range of PET concentration from 1.0 × 10−11 mol L−1 to 1.0 × 10−6 mol L−1, with a detection limit of 3.3 × 10−12 mol L−1 (3S/N). This method was successfully applied to determine PET in various vegetable samples. Ni-MOF can host a higher amount of the luminescent reagent Ru(bpy) 3 2+. Au NPs can facilitate electron transport, TiO 2 as a luminescent substance, can with AuNPs to increase the luminescence intensity. [Display omitted] • A solid-state electrochemiluminescent sensor for permethrin detection was developed. • The novel TiO 2 and Ni-MOF materials were prepared. • The synergistic effect of Au NPs@TiO 2 and Ni-MOF@Ru(bpy) 3 2+ enhanced the ECL signal. • The electrochemiluminescence sensor had good stability and low detection limit. [ABSTRACT FROM AUTHOR]

• The specific surface area of the organic framework affects the electrochemical properties. • Ni-MOF has excellent electrochemical properties. • The acid-base environment affects the growth of the organometallic framework materials. • The highest specific capacitance of the prepared sample was 2567.23 F/g. In this paper, we investigate the effect of hydrochloric acid on the energy storage characteristics of nickel-based metal–organic framework (Ni-MOF) nanostructures. Electrochemical tests reveal that Ni-MOF exhibit high capacitance under hydrochloric acid regulation, achieving a current density of 2567.23 F/g at 2 A/g in 1 ml. Additionally, the synthesized Ni-MOF demonstrate low electrical resistance, with a resistance (Rs) of 1.209 Ω at a hydrochloric acid volume of 1 ml. After 5000 cycles of galvanostatic charge–discharge testing, the cycle retention efficiency of Ni-MOF-0.5 ml remains at 85.71 %. [ABSTRACT FROM AUTHOR]

In the present work, a composite (Ti 3 C 2 T x /Ni-MOF) of titanium carbide MXene (Ti 3 C 2 T x) and nickel-based metal-organic framework (Ni–NH 2 BDC MOF) has been studied for supercapacitor application. The idea behind using the mentioned composite lies in the fact that composite formation helped prevent the restacking and oxidation of MXene sheets, thus inducing stability in the overall system. The improvement in the stability of these Ti 3 C 2 T x nanosheets intercalated with MOFs could be observed in their electrochemical properties in the form of significant enhancement of capacitance and power density before and after composite formation. The symmetric supercapacitor device was assembled using two electrodes of similar weight with polymer-based gel electrolyte (Polyvinyl alcohol in 1 M H 2 SO 4). The device provided the potential window of 0–2.0 V with a specific capacitance of 139.4 F/g at a current density of 1 A/g with energy density and power density of 19.4 Wh/kg and 331.8 W/kg, respectively. Capacitive retention of 95 % was observed even after 5000 charging-discharging cycles. The observed response confirms that the synthesised composite can be a suitable electrode material for future energy storage applications. [Display omitted] • Ni-MOF sheets were intercalated between the sheet of MXenes which showed an enhanced specific capacitance of 536 F/g. • A solid-state device was assembled using PVA/H 2 SO 4 solid gel electrolyte, which was able to light up an LED. • Incorporating Ni-MOF into Ti3C2Tx sheets enhanced the cyclic stability up to 5000. • The device shows an energy and power density of 19.4 Wh/Kg and 331.8 W/kg, respectively. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells (DMFCs) can permit the utilization of noble-metal-free electrocatalysts, which certainly reduces the cost and accelerates their practical implementation. With the exploration of efficient and economical methanol oxidation reaction (MOR) catalysts, Ni-based nanostructures have been recognized as the most promising MOR catalysts in alkaline media. Herein, we construct a novel heterojunction MOR electrocatalyst composed of Ni-based metal-organic framework (Ni-MOF) and NiFe-based layered double hydroxides (LDHs) through a coordination-induced self-assembly strategy. Owing to the synergic effect between Ni and Fe sites, coupled with the effect of hetero-interface, the resultant Ni-MOF/NiFe-LDH composite exhibits remarkable MOR activity in 0.1 M KOH electrolyte with the oxidation current density (32.66 mA cm−2) is 2.65 and 2.44 times higher than that of the primitive NiFe-LDH and Ni-MOF. The excellent stability of the Ni-MOF/NiFe-LDH electrocatalyst has also been confirmed by long-term chronoamperometry (CA) analysis. Our work paves a facile controllable way for fabricating MOF/LDH heterostructure targets on MOR and underlines its potential to boost energy conversion efficiency through the manipulation of synergic components. A novel Ni-MOF/NiFe-LDH heterojunction MOR electrocatalyst has been successfully constructed through a coordination-induced self-assembly strategy, which exhibits a collaborative enhancement in electrocatalytic properties toward alkaline MOR. [Display omitted] • A heterojunction composite has been constructed through a coordination-induced self-assembly strategy. • Ni-MOF/NiFe-LDH exhibits remarkable electrocatalytic activity toward alkaline MOR. • This work underlines the potential of MOF/LDH heterostructure in enhancing energy conversion efficiency. [ABSTRACT FROM AUTHOR]

In this study, Ni-MOF was synthesized using ultrasound irradiation under optimal conditions, which included a microwave power of 370 W, time duration of 20 min, and a temperature of 25 °C. The final Ni-MOF nanostructures were immobilized in a PVA fibrous polymeric network using electrospinning under optimal conditions (concentration: 8% wt; nozzle tip with flow rates of 0.10 mL/h; temperature: 25 °C and humidity: 22%; voltages: 20 kV; spinning distance: 12 cm). It has been characterized using elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis-derivative of thermogravimetric analysis (TG-DTG) and Scanning electron microscopy- energy dispersive X-ray analysis (SEM–EDS). The Barrett-Joyner-Halenda (BJH) technique confirmed the role of the substrate in increasing the surface area of the final products. The Ni-MOF/PVA fibrous network's final products were used as an adsorbent in the adsorption of CH4 gas. [ABSTRACT FROM AUTHOR]

To develop high-performance microwave absorption materials with the features of lightweight, thin thickness, broad bandwidth, and strong absorption, an ultralight Ni3S2@N, S-codoped graphene aerogel with a density of 13.5 mg/cm3 has been fabricated by the use of metal-organic frameworks (MOFs) to directly initiate the gelation of graphene oxide strategy. In such a strategy, dual-functional 1D Ni-MOF nanorods not only act as the gelation agent but also afford the doping elements (N and S) originated from the organic species and the precursor for metal sulfide. Due to the synergistic effects of good impedance matching and multiple losses, the optimal reflection loss (RL) of as-prepared Ni3S2@N, S-codoped graphene aerogel reaches −46.9 dB at 17.1 GHz with only 2.0 mm and ultralow filling content (1.75 wt%). The maximum effective absorption bandwidth (EAB) reaches 6.3 GHz (11.7–18.0 GHz) at 2.38 mm, covering the whole Ku band. Moreover, the value of EAB with the RL less than −30 dB can be tuned to 12.2 GHz (5.8–18 GHz) at the absorber thickness ranging from 1.9 to 5.0 mm. This work provides insight for rational design and fabrication of multicomponent-containing graphene aerogels, showing the potential application in lightweight and high-performance microwave absorption. [ABSTRACT FROM AUTHOR]

[Display omitted] The preparation of strong absorption, thin thickness and wide band electromagnetic wave absorbers has always been the focus of research. In this paper, NiFe 2 S 4 /PC composites, an electromagnetic wave absorbing material with excellent performance, is prepared by introducing Ni-MOF, Fe and S elements into porous carbon framework. The material has a minimum reflection loss (RL min) of −51.41 dB and the matching thickness is only 1.8 mm. In addition, the effective absorption bandwidth (EAB) is 4.08 GHz when the thickness is 1.9 mm. The rich interface and good impedance matching characteristics are the main reasons for the excellent absorbing performance of the material. The experimental results show that NiFe 2 S 4 /PC composites is a reasonable and effective electromagnetic wave absorption material. [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]

A Ni-MOF-based novel electrochemical sensor was synthesized with high surface area of 1381 m2/g, significant porosity of 1.14–9.6 nm and average particle size of 80 nm. The final products was developed for the detection of glucose with high sensitivity and accuracy. The amperometric response of the electrode toward glucose was achieved at a steady state in 3 s. The linear range, detection limit, and sensitivity of the developed electrode toward glucose was 1–1600 µM, 0.76 µM (S/N = 3) and 2859.95 µA mM−1 cm−2 (R2 = 0.9966), respectively. Compared with the non-enzymatic sensors, the developed electrode exhibited a lower detection limit and higher sensitivity, which are promising criteria for the development of a chemical sensor. [ABSTRACT FROM AUTHOR]

The application of Ni‐MOF in supercapacitors has received widespread attention, but its poor conductivity and bad stability hinder its application. Therefore, Ni‐MOF derived CMs@Ni(OH)2/NiSe with a core‐shell structure was designed. Here, carbon microspheres (CMs) were explored as the conductive substrate to enhance the stability and in situ prepared Ni‐MOF was anchored on the surface of CMs. Then, alkali‐treatment and selenylation were carried out on CMs@Ni−MOF to improve stability and conductivity. The obtained core‐shell nanostructure material possesses a high contact area, excellent synergistic effect and can provide more reactive active sites. The prepared CMs@Ni(OH)2/NiSe shows a higher specific capacitance (2106 F g−1) and excellent cycling performance with a capacitance retention of 95 % after 30000 cycles. Furthermore, the assembled CMs@Ni(OH)2/NiSe//AC device delivers a high energy density of 70.84 Wh kg−1 at the power density of 756.8 W kg−1 and maintains 100 % of the initial capacitance after 40000 cycles. [ABSTRACT FROM AUTHOR]

EOR is a semi-reaction of direct ethanol fuel cells (DEFCs), and determines the performance of the DEFCs. Therefore, it is very important for EOR to rationally design an electrocatalyst with excellent activity, stability and CO-resistance. Based on this, we report the synthesis of MOF based composite catalysts by a facile method, which is formed by combining polyaniline hydrogel (PANH) with MOF 1 and carbon cloth (CC). At the same time, the structures of the composites were characterized by XRD, SEM and XPS. Under the optimum conditions, the j value for EOR is 107 mA cm−2 under alkaline conditions at 0.6 V, which indicates that composite 2 has excellent catalytic activity for EOR, and is superior to that of the previously reported nickel-based catalysts for EOR. The Tafel slope and the exchange current density of composite 2 are 88.9 mV dec−1 and 1.95 × 10−5 A cm−2 respectively. In addition, the j value of composite 2 was 65% of the original value after 1000 CV cycles. However, when the electrolyte was changed into the original one (1 M KOH + 1 M EtOH), the j value returned to 74% of the original value. Based on the excellent electrocatalytic performance, good stability and anti-CO poisoning, composite 2 is expected to be an economic, efficient and CO poisoning resistant electrocatalyst for EOR. Ni-MOF based composites, which is formed by combining polyaniline hydrogel (PANH) with MOF 1 and carbon cloth (CC), were used as excellent activity, good stability and carbon monoxide resistant catalysts for methanol oxidation reaction under alkaline medium. [Display omitted] • Composites of Ni-MOF and polyaniline hydrogel were synthesized by a facile method. • Composite 2 has excellent activity, stability and carbon monoxide resistant. • The excellent activity of composite 2 is due to the enhanced conductivity of MOFs. [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]

[Display omitted] • A novel BiOBr/Ni-MOF heterostructure was fabricated via a simple precipitation process. • BiOBr/Ni-MOF composite has rich porous structure and higher specific surface area. • BiOBr/Ni-MOF composite exhibited superior photodegradation of RhB. • The BiOBr/Ni-MOF composite has a type Z carrier transfer and migrate mechanism. A novel BiOBr/Ni-MOF composite was fabricated by in-situ growth of BiOBr nanosheets on Ni-MOF through a convenient precipitation process. The optimal photocatalytic performance was achieved with a Ni-MOF mass content of 45 wt% in the BiOBr/Ni-MOF composite. This composite exhibited remarkable efficiency, degrading 98.33 % of Rhodamine B in 90 min, surpassing the degradation rate constants of pristine BiOBr and Ni-MOF by 4.2 and 160 times, respectively. The superior performance was primarily ascribed to the efficient separation of photogenerated carriers facilitated by the formation of heterojunctions. Additionally, the increased specific surface area and pore structure provided numerous adsorption and active sites. Radical scavenger experiments and electron spin resonance experiments further revealed that O 2 − and h+ played crucial roles in the degradation process. Furthermore, the structural properties of the prepared photocatalysts and the effects of different photocatalytic conditions on the degradation of RhB were investigated. This work offers an alternative perspective on the design and fabrication of BiOBr-based composite photocatalysts. [ABSTRACT FROM AUTHOR]

To further improve the electrochemical performance of supercapacitor, the construction of composite based electrode material was proved to be an effective strategy. Herein, CoS-decorated Ni-MOF composites with hierarchical structures and obvious synergistic effects were synthesized by one-step hydrothermal and subsequent electrodeposition route. Benefitting from the increased surface roughness with more exposed active sites, the hierarchical structure with high space utilization rate for rapid ion transport as well as the improved conductivity and entire robustness, the optimal composites exhibited an excellent specific capacitance (2167.5 F g−1 at 1 A g−1), outstanding rate performance (up to 70.1% even at 5 A g−1) and the good cycle stability (80.12% capacity retention after 3500 cycles). The corresponding assembled asymmetric supercapacitors could reach an energy density 92.18 Wh kg−1 when the power density of was 1626.71 W kg−1, which overwhelmed most other reported works. What is more, the capacity retention could maintain 73.34% even after 7000 cycles, indicating the excellent cycle stability. Overall, to our knowledge, this is the first report on a synergistic effect of a combination of Ni-MOF and CoS. The constructed composites exhibited great potential as promising candidates for high-performance energy storage devices. [Display omitted] • The Ni-MOF@CoS composite was prepared via hydrothermal and subsequent electrodeposition route. • The prepared composites provided more exposed active sites, rapid ion transport as well as the improved conductivity and stability. • The synergistic effect between Ni-MOF and CoS was demonstrated. • The obtained electrode exhibited an excellent specific capacitance, rate performance and the stability. • The corresponding asymmetric supercapacitor overwhelmed most other reported works. [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]

To develop high-performance microwave absorption materials with the features of lightweight, thin thickness, broad bandwidth, and strong absorption, an ultralight Ni3S2@N, S-codoped graphene aerogel with a density of 13.5 mg/cm3 has been fabricated by the use of metal-organic frameworks (MOFs) to directly initiate the gelation of graphene oxide strategy. In such a strategy, dual-functional 1D Ni-MOF nanorods not only act as the gelation agent but also afford the doping elements (N and S) originated from the organic species and the precursor for metal sulfide. Due to the synergistic effects of good impedance matching and multiple losses, the optimal reflection loss (RL) of as-prepared Ni3S2@N, S-codoped graphene aerogel reaches −46.9 dB at 17.1 GHz with only 2.0 mm and ultralow filling content (1.75 wt%). The maximum effective absorption bandwidth (EAB) reaches 6.3 GHz (11.7–18.0 GHz) at 2.38 mm, covering the whole Ku band. Moreover, the value of EAB with the RL less than −30 dB can be tuned to 12.2 GHz (5.8–18 GHz) at the absorber thickness ranging from 1.9 to 5.0 mm. This work provides insight for rational design and fabrication of multicomponent-containing graphene aerogels, showing the potential application in lightweight and high-performance microwave absorption.

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]

The fabrication of non-metallic semiconductor heterojunction with superior redox capability for hydrogen (H 2) evolution from water and environmental remediation has been emerging as a prospective strategy. Herein, a novel two-dimensional (2D) g-C 3 N 4 /Ni-MOF Z-scheme heterojunction was prepared by a facile sonication-gel self-assembly method with g-C 3 N 4 and nickel metal-organic framework (Ni-MOF) nanosheets. The ultra-thin nanosheet structure of Ni-MOF was conducive to the formation of stable 2D heterojunctions. The opposite surface charge and matched band difference caused the charge flow from g-C 3 N 4 to Ni-MOF, resulting in an interfacial built-in electric field. The optimized NMF/CN-9 attained the optimal 3aphotocatalytic activity towards the degradation of tetracycline (TC) and H 2 evolution from water. Under visible light irradiation, the reaction rate for TC degradation (0.00497 min−1) and H 2 evolution (15.6 μmol·h−1) over NMF/CN-9 was nearly 2.4 and 2.1 folds higher than that of g-C 3 N 4 , respectively. Besides, the photocatalytic performance of NMF/CN-9 was also nearly 2 times higher than that of g-C 3 N 4 under simulated solar illumination. Such improvements were originated from higher photo-excited charge separation and superior redox ability derived from Z-scheme interfacial charge transfer. A possible photocatalytic mechanism was also proposed and the results indicated that efficient photo-induced electrons and reactive hole (h+), superoxide radical (·O 2 -) and hydroxyl radical (·OH) played a major role during the photocatalytic route. This work offers an intense insight into the construction of non-metallic semiconductor 2D heterojunctions for H 2 evolution and environmental wastewater treatment. [Display omitted] • 2D–2D NMF/CN was prepared by a facile sonication-gel self-assembly method at room temperature. • Z-scheme heterostructure was established between Ni-MOF with midgap and g-C 3 N 4. • The direct Z-scheme channels favored the spatial charge separation and transfer. • NMF/CN has 2-fold increase in photocatalytic H 2 evolution and tetracycline degradation activity. [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]