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The application of MOFs in electrochemical energy fields has attracted great attention in recent years. In this regard, Ni-MOF was synthesized via a solvothermal method using 1,4-benzene dicarboxylic acid (H 2 BDC) as a linker. XRD confirmed the structure of the synthesized Ni-MOF as [Ni 3 (OH) 2 (H 2 O) 4 (C 8 H 4 O 4) 2 ] 2H 2 O. Its porous nature and specific surface area of 82.7 m2 g⁻1 were estimated using BET analysis. Thermal stability was evaluated by TGA, allowing for the calculation of decomposition parameters (E a , ΔH∗, ΔS∗, and ΔG∗). The chemical structure was further validated using FTIR. Ni-MOF powder was blended with carbon black (XC-72) in various ratios to enhance the conductivity and electrocatalytic activity, and the resulting composite was ink-casted onto graphite electrodes. Surface morphology, particle size, and elemental composition were assessed by SEM and EDX, while chemical composition was analyzed through XPS. Notably, the 1:1 Ni-MOF/C composite electrode showed promising catalytic activity for the electrooxidation of methanol, ethanol, ethylene glycol, and glycerol, achieving oxidation current densities of 132, 96, 67, and 57 mA cm⁻2 at +0.8 V (Hg/HgO/OH−), respectively, along with impressive stability. Electrocatalytic performance was further evaluated by calculating electrochemical parameters like diffusion coefficient (D), transfer coefficient (α), catalytic rate constant (K o), Tafel slope, and charge transfer resistance (R ct). The effectiveness of electron transfer processes on Ni-MOF/C relies on the oxidation state of Ni metal ions and the synergistic effect of Ni-MOF and conductive carbon black. EIS results indicated rapid charge transfer processes during alcohol electrooxidation, with the order of efficiency being: methanol > ethanol > ethylene glycol > glycerol. DFT studies investigated the interactions between Ni-MOF crystal facets and alcohol molecules, HOMO−LUMO calculations showed that alcohols possess strong electron donation capabilities, suggesting a favorable affinity for the electrooxidation process. [Display omitted] • Ni-MOF composites with carbon black (XC-72) enhance electrocatalytic activity. • The Ni-MOF: C (1:1) composite exhibited high catalytic activity and durability. • The composite's high performance is due to its porosity and Ni catalytic activity. • DFT revealed that alcohols exhibit strong electron donation abilities. [ABSTRACT FROM AUTHOR]

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]

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]

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]

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]

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]

Magnetic carbon-based materials derived from nickel organic framework (Ni-MOF) are considered to be a kind of electromagnetic wave (EMW) absorbing materials with great potential and application value. However, the precise design of Ni-MOF-derived magnetic carbon-based materials remains a huge challenge. In the present work, through the modulation of organic ligand and pyrolysis temperature, Ni/C composites with excellent electromagnetic absorption properties are obtained due to their improved multiple loss and optimized impedance matching. Specifically, the organic ligand and pyrolysis temperature affect the degree of graphitization of the carbon frame and the specific surface area of the Ni/C composites, thus changing the conductivity, magnetic properties and electromagnetic parameters. In particular, the sample Ni/C-2-500 using H 2 BPDC as the organic ligand and calcined at 500 °C gives an RL min of −50.37 dB and an EAB of 6.0 GHz at a packing rate of 30 wt% and a thickness of 2.5 mm, which covers the entire Ku band. In addition, Ni/C-2-500 exhibits good thermal conductivity. Therefore, this study provides an idea for exploring MOF materials and their derivatives with tunable EMW absorbing properties and heat conduction advantages prepared by different organic ligands. [Display omitted] [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]

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]

[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]

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]

Ni-based metal organic frameworks have attracted great interests as novel electrode materials for applications in supercapacitors, in virtue of their large specific surface area, high porosity and diverse coordination structure. Unfortunately, their specific capacitance and rate property are usually unsatisfying because of the poor conductivity of MOF materials. Herein, 3D Co-doped Ni-based MOF (Co x -Ni-MOF, x = 100 n (Co / Ni) = 0.5, 2 and 5) flower-like hierarchical microspheres are prepared via a facile hydrothermal process. The introduction of Co promotes the electrochemical behaviors of Ni-MOF, especially Co 2 -Ni-MOF. It exhibits a prominent specific capacitance of 1300 F/g at 1 A/g along with a superb rate performance (1021 F/g at 10 A/g). Meanwhile, capacitance for Co 2 -Ni-MOF retains 71% of the original capacitance even after 3000 cycles. The improvement of electrochemical performance could be due to their unique structural and morphological characteristics including the 3D flower-like hierarchical microspheres structure, higher specific surface area and enhanced electrical conductivity. Moreover, a hybrid supercapacitor based on the Co 2 -Ni-MOF achieves an excellent energy density of 25.92 Wh/kg at a power density of 375 W/kg. Unlabelled Image • A series of Co-doped Ni-based Ni-MOF synthesized by a facile one-step hydrothermal • The introduction of low amount of Co contributes to a 3D flower-like morphology and enhanced electrical conductivity. • Optimized Co-doped Ni-MOFs exhibited excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful synthesis of Pt/Ni-MOF nanocomposite with different Pt/Ni molar ratio. • The Ni-MOF services as good supporter for the absorption of Pt nanoparticles. • Pt nanoparticles provide an abundance of active sites for methanol oxidation. • Catalyst exhibits excellent performance for MOR in acidic media. A series of Pt/Ni-MOF nanocomposites with different atom molar ratio of Pt/Ni were synthesized by the traditional hydrothermal method. Various methods including element mapping, X-ray diffraction (XRD) were employed to characterize the crystal structure and surface morphology of the materials. TEM (Transmission Electron Microscopy) confirms that the Pt nanoparticles are highly dispersed onto the Ni-MOF nanosheet surface, which can provide an abundance of active sites for efficient oxidation of methanol. Electrochemical measurements showed that Catalyst b (the atomic molar ratio of Pt to Ni is 2:1 in the precursor materials) exhibited a higher oxidation current density in MOR and larger electrochemically active surface area (ECSA) than other catalysts with different atomic ratios and commercial Pt/C. Meanwhile, the synthesized catalysts showed long-term activity and good resistance to toxicity. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoFe-LDH@Ni-MOF was prepared by simple hydrothermal method. • The maximum power density in CoFe-LDH@Ni-MOF MFC was 211 mW/m2. • The lamellar stacked structure formed by CoFe-LDH and Ni-MOF promoted ORR performance. 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/m2, 2.54 times higher than that of Ni-MOF (83 mW/m2), 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. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) gain the popularity among studies due to their exclusive modular and buildable structure, tunable pore size distribution and diversity of functions, which provide tremendous possibilities for the production of high-performance supercapacitors and are considered as one of the vital energy storage materials. Among MOFs, Ni-MOF shows great application outlooks of the energy storage field because of its big specific capacitance and the ability to provide active sites during the reaction. However, the shortcomings of conductivity, rate performance and cycle stability are not very outstanding. This study uses one simple hydrothermal method to synthesize a three-dimensional bimetallic metal nanosheet structure by doping different ratios (including Ni: Cr=1:1, 2:1, 3:1, 4:1, 5:1 and 6:1) in Ni-MOF structure on nickel foam to improve electrochemical performance. Cr-doped materials have abundant active sites due to their large specific surface area. It promotes the reaction of the material surface in the electrolyte, thus enhancing the particular capacitance. At the same time, Cr3+ can also strengthen the lattice stability and gives a more stable nanostructure, effectively promoting conductivity and cycling stability. Therefore, after a series of tests, the obtained electrode material with the optimal ratio of Ni: Cr=4: 1 in Ni-MOF (NC 4 M@NF) reaches high specific capacity up to 853.00 C g−1 at 1 A g−1, better rate capacity of 64.48 % at 10 A g−1 with 3 M KOH in three-electrode system. Besides, the assembled NC 4 M@NF//AC ASC supplies an energy density of 64.41 Wh kg−1 at 850.31 W kg−1, and exceptional cycling stability with only decays 17.89 % after 5000 cycles. [Display omitted] [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]

• 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]

• A engineering green TiO 2 /Ni-MOF-based superhydrophobic sponge was firstly fabricated. • Silane groups of ODSOSS cages endowed MOF-based sponge with superhydrophobic properties. • The coatings can achieve in-situ adsorption and photocatalytic degradation of pesticides. • The coated sponge can selectively and synchronously remove MPs and pesticides from high-salinity water. • The coatings have excellent absorption recyclability and salt tolerance. Microplastics (MPs) and pesticides are becoming an intractable environmental issue due to their wide spreading and non-degradable nature, posing serious threat to ecosystem and human health. To settle such dilemma, this work reasonably designed a superhydrophobic MOF-based coated sponge (ODSOSS/TiO 2 /Ni-MOF/PDA@Sponge) through the combination of an environmentally friendly in-situ supersaturated coprecipitation and polysesiloxane modification method. Among them, (I) the introduction of polydopamine (PDA) not only improves the adhesion between coatings and sponge, but also enhances the growth of MOF structure through complexation. (II) The obtained Ni-MOF shows large-area microscale anthemy structure with multilayered flaky texture, forming heterogeneously hierarchical structure with the deposited TiO 2 nanoparticles, which promotes photodegradation ability of TiO 2 owing to great specific surface area of Ni-MOF. (III) The high specific large area Ni-MOF supplies sufficient action sites for linkage of PDA and polysesiloxane molecules with unique nanocage-like structure, thus further greatly increasing adsorption force for various pollutants. (IV) The superhydrophobicity protect the porous channels of MOF from contamination of various absorbed pollutants, while TiO 2 nanoparticles effectively photodegrade the absorbed organic pollutants, endowing the sponge superior recyclability. The superhydrophobic sponge selectively rapidly and synchronously adsorbs various MPs (maintained almost 100% after 60 cycles) and pesticides (adsorption rates 71.6%–95.1%) from high-salinity water. The large-area sponge (9 cm × 6 cm × 1 cm) simultaneously removes almost 100% MPs (40 mg/L), Sudan Ⅲ (10 mg/L), kerosene (30 mL/L), and four pesticides (10 mg/L) within 1 min. Particularly, four pesticides are quickly photocatalytic degraded by the coated sponge. The free radical capture trials show that hydroxyl radicals (·OH) are the main active species of pesticide degradation. Furthermore, we reveal the negative centers where pesticide molecules are most vulnerable to ·OH attack, on basis of the charge distribution and molecular electrostatic potential (MEP) analysis. The adsorption mechanisms are carefully clarified through theoretical calculation and experimental data. This work not only provide an effective superhydrophobic candidate for MPs and pesticides removal in a broad applicable scope (especially in high-salinity wastewater), but also opens a new strategy for environmental remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

Mixed-potential solid-electrolyte (MPSE) gas sensors have important applications for the detection of hazardous NO 2. However, limited by the poor conductivity of conventional electrolytes at low temperatures, the realization of high performance of MPSE gas sensors usually requires a compromise to high working temperatures, hindering their application. To this end, we developed a novel ultrasensitive and selective MPSE NO 2 sensor based on K 2 Fe 4 O 7 solid electrolyte and Ni-MOF|N 2 sensing electrode (SE), which can achieve a low detection limit (LOD) as low as 5 ppb at room temperature (RT) without additional energy supply. Simultaneously, the selectivity of the sensor to the interfering gas NO achieves a 31-fold improvement by the enhanced participation of H 2 O molecules and unsaturated coordinated Ni ions, which are obtained by the sintering in anoxic atmospheres like N 2 or Ar. Moreover, the sensor is further used as the information collection terminal of the Internet of Things (IoT) system, building a NO 2 monitoring network for remote monitoring, different environment evaluation, and information sharing. This work fills the gap of the ultrasensitive MPSE NO 2 sensor in the RT field and provides new insights for the construction of NO 2 portable sensor networks. [Display omitted] • The fabricated NO 2 sensor works at room temperature with a LOD of 5 ppb. • A 31-fold selectivity improvement between NO 2 and NO is obtained. • An IoT system with a portable device, wireless data transmission, and intelligent display terminals was designed. [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. [ABSTRACT FROM AUTHOR]

Ni-MOF@BiOBr composites were prepared by solvothermal method, and the effects of different contents of BiOBr on the photocatalytic performance of the composites were investigated. Through the photocatalytic degradation of methylene blue (MB) and ciprofloxacin (CIP), it could be concluded that the best results were obtained when the Ni-MOF/Bi(NO 3) 3 ·5H 2 O quality ratio of 1:1. After 120 min irradiation with xenon lamp light source, the degradation rate of MB solution and CIP solution could reach 82.8% and 92.8%. The photocatalytic mechanism analysis speculates that Ni-MOF@BiOBr was an n-n type heterostructure composite material. This heterogeneous junction could physically isolate electrons and holes and effectively inhibit the recombination of the two. Therefore, it can effectively highlight the catalytic performance. In addition, the free radical trapping experiments proved that the free radicals that play a major role in the photocatalytic degradation of CIP solution are h+ and hydroxyl radicals (· OH). [Display omitted] • The heterogeneous junction Ni-MOF@BiOBr composites synthesized by a one-step solvothermal method. • The methylene blue and ciprofloxacin degradation rate over the optimal catalyst reached 82.8% and 92.8% within 120 min. • The as-synthesized material exhibited high stability and reusability. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) derived metal oxides with large surface and more metal active sites were beneficial for photoelectrochemical (PEC) water splitting. In this work, we used a novel and easy method for the Ni-MOF attached on BiVO 4 photoelectrode surface by electrostatic attraction, afterwards the Ni-MOF/BiVO 4 photoelectrodes were annealed at muffle to obtain MOF derived NiO/BiVO 4 p-n heterojunction composite photoelectrodes. The thickness of NiO thin film with ultrathin structure was tested by atomic force microscopy (AFM). The photoelectrochemical (PEC) performance of NiO/BiVO 4 composites photoelectrodes for water splitting was enhanced compared to the pure BiVO 4 photoelectrode. The best NiO/BiVO 4 photoelectrodes with about 70 nm thickness of NiO thin film showed the max photocurrent density with 1.94 mA/cm2 (1.23 V vs RHE) which was about 4.2 times than the pure BiVO 4 with 0.46 mA/cm2 (1.23 V vs RHE). The charge injection and separation efficiency of NiO/BiVO 4 photoelectrodes enhancement indicate that the NiO as a co-catalysis and form p-n heterojunction has improved the photoexcited carrier mobility which was benefited for the PEC performance of water splitting. [Display omitted] [ABSTRACT FROM AUTHOR]

Accurate and rapid determination of blood glucose levels is essential for real-time monitoring and management of diabetes mellitus, and nanomaterials-based nonenzymatic glucose sensing plays an increasingly significant role in this regard. Here, a simple two-step electrodeposition technique that was efficient, environmentally friendly, easily manipulated, and exceedingly controllable was adopted for the synthesis of metal-organic framework (MOF)/carbon material composites on a titanium mesh (TM), namely α-cyclodextrin functionalized reduced graphene oxide/nickel-based MOF (α-CD-rGO/Ni-MOF/TM), in which Ni-MOF served as the electrocatalyst for glucose oxidation, and rGO greatly enhanced the electrochemical performance of Ni-MOF, benefiting from α-CD effectively preventing aggregation of rGO nanosheets while also improving the stability of the composites, so that these endow the obtained nanomaterials exhibited remarkable electrocatalytic ability for glucose. Consequently, the as-prepared glucose sensor revealed two linear dynamic ranges of 0.65 μM− 4.828 mM with a sensitivity of 1395 μA mM−1 cm−2 and 4.828 − 9.178 mM with a sensitivity of 760 μA mM−1 cm−2 together with a rapid response time of only 1.9 s and a low detection limit of 0.3 μM as well as distinguished reproducibility, selectivity, and stability, further demonstrating the synergistic effects of this composite. The newly manufactured glucose sensing platform was also successfully used to detect glucose in real serum. Considering the convenience and controllability of two-step electrodeposition, the α-CD-rGO/Ni-MOF/TM composite holds great promise for commercial potential, and also provides direction and technical reference for the synthesis of MOF/carbon material composites. [Display omitted] • α-CD-rGO/Ni-MOF was firstly prepared with two-step electrodeposition method and used as electrode material for glucose sensor. • The sensor exhibited wide linear range and low detection limit under optimized conditions. • The synergistic effect of composite electrocatalyst in detection of glucose was confirmed. • This simple and controllable strategy provides some guidance for the preparation of other MOF/carbon material composites. [ABSTRACT FROM AUTHOR]

Two new NiO-based catalysts, NiO BDP and Ni/NiO BDP , were synthesized by a calcination of NiBDP MOF (BDP = 1,4-bis(pyrazol-4-yl)benzene) in air. Calcination performed in a N 2 /O 2 (80:20 %) atmosphere in the absence of any reducing agent, led to a mixed composite Ni/NiO BDP containing some Ni(0) NPs. In contrast , thermal decomposition of Ni-MOF in an air atmosphere provided only NiO BDP. Both catalysts presented high activity in selective transfer hydrogenation of acetophenone and 4-nitrophenol in mild conditions, using 2-propanol/NaOH or NaBH 4 /H 2 O as reducing agents. Catalytic activity of Ni/NiO BDP was higher compared to NiO BDP suggesting the participation of Ni(0) in the hydrogenation process. [Display omitted] The NiO BDP and Ni/NiO BDP composites obtained by calcination of NiBDP MOF (MOF = metal–organic framework; BDP = 1,4-Bis(pyrazol-4-yl)benzene) in air at 700 °C were characterized by XRD (X-ray diffraction), TEM (Transmission electron microscopy), XPS (X-ray photoelectron spectroscopy) and Raman spectroscopy. Both nanocatalysts presented high activity in selective transfer hydrogenation of acetophenone (APh) and 4-nitrophenol (4-NP) in mild conditions, using 2-propanol/NaOH or NaBH 4 /H 2 O as reducing agents. In both reactions, the catalytic activity of Ni/NiO BDP was higher compared to NiO BDP suggesting the participation of Ni(0) in the hydrogenation process. [ABSTRACT FROM AUTHOR]

Zinc-functionalized nickel metal-organic framework (Zn/Ni-MOF) was grown directly on nickel foam (NF) and used as an efficient binder-free electrode for supercapacitor application. The structural characteristics of the composite materials were analyzed by different analytical techniques. The results obtained revealed flower-decorated ball-shape microstructures were obtained from Zn functionalization of the surface of Ni-MOF microsheets, with a relatively larger surface area and unique pore characteristics. The electrochemical performance measured using a 3 M KOH electrolyte solution indicated that Zn-doped Ni-MOF containing Zn/Ni in the ratio 1:2 (ZNN1) exhibited the optimum performance. ZNN1 revealed good rate capability with a maximum specific capacitance of 391 Fg-1 at a current density of 1 Ag-1 and retained about 70% of its initial capacitance at 10 Ag-1. The electrode also possessed maximum energy and power density of 12 Wh kg−1 and 2000 Wkg-1, respectively, with a high cycling stability of 85% after 5000 cycles. The enhanced electrochemical performance of ZNN1 was attributed to the increase in the surface area and electrical conductivity of Ni-MOF occasioned by incorporation of an optimum concentration of Zn dopant. The charge storage mechanism was predominantly controlled by the diffusion process, which suggests that the method employed in this study is promising for the fabrication of pseudocapacitive materials. Zn-doped Ni-MOF was fabricated and used as an efficient binder-free electrode for supercapacitor application. The optimum Zn/Ni concentration delivered the best performance with respect to specific capacitance and energy/power density and was linked to the textural properties and low charge transfer resistance of the electrode materials. The storage mechanism was further probed using electrochemical kinetics. [Display omitted] • Zn-doped Ni-MOF was assembled without incorporating binders and used as an efficient supercapacitor electrode. • Controlling the amount of Zn ion dopant affords optimum Zn-doped Ni-MOF performance. • ZNN1 (Zn/Ni (1:1)) electrode gives the highest capacitance of 391 Fg-1 at 1 Ag-1 • The low charge-transfer resistance value of ZNN1 suggests good conductivity. • Electrochemical kinetic analysis helps to probe the storage mechanism of the electrodes. [ABSTRACT FROM AUTHOR]

While semiconductor nanocrystals with different crystal forms typically show different catalytic performances, such behavior has been scarcely documented for metal-organic frameworks (MOFs). Herein, two Ni-MOF catalysts with different crystal forms have been successfully prepared and used in photo-reduction of CO 2. With a prolonged lifetime (5 h vs 2 h) and higher yield of the product CO (34 μmol vs 18 μmol), Ni-MOF(H 2 O) demonstrates a much better performance than Ni-MOF. Theoretical studies reveal that the adsorption energy of a CO 2 molecule is more negative on Ni-MOF(H 2 O) than on Ni-MOF (−0.85 eV vs −0.62 eV). Furthermore, the transfer and separation of the photo-generated charge carriers are also more efficient in the Ni-MOF(H 2 O) system. This study not only presents a superior Ni-MOF catalyst but also promotes the fabrication of highly active catalysts for the photo-reduction of CO 2. [Display omitted] • Ni-MOF catalysts with different crystal forms have been fabricated via a facile process for the first time. • Ni-MOF(H 2 O) exhibits a much better performance than the Ni-MOF in photo-reduction of CO 2. • Ni-MOF(H 2 O) system exhibits stronger adsorption ability for CO2 molecules and lower charge transfer resistance. • Ni-MOF(H 2 O) system also exhibits lower recombination rate of photo-generated charge carriers. [ABSTRACT FROM AUTHOR]

A mixed-potential type solid-electrolyte (MPSE) NO sensor working at room-temperature is of great significance for reducing the power consumption and expanding its application. However, the low sensitivity of the MPSE sensor at room temperature is an urgent problem to be solved. Herein, a highly sensitive room-temperature MPSE NO sensor based on K 2 Fe 4 O 7 electrolyte and Ni-MOF (coordinated with 1, 4-H 2 BDC)/MWCNT compound sensing electrode (SE) was reported. Superior NO sensing performances (sensitivities: −68.0 mV/ppm in 20–500 ppb and −55.1 mV/decade in 0.5–1 ppm, low detection limit (LOD): 20 ppb, speedy response and recovery rates: 19 s and 25 s) were demonstrated at 25 °C. Moreover, with the introduction of MWCNT into Ni-MOF-SE, the MPSE sensor's response to 500 ppb NO (25 °C, 60%RH) has a threefold increase from − 8 mV to − 34 mV. The exciting sensitivity benefits from the enlarged electrochemical active area (ECSA) and improved electrocatalytic activity. This novel and efficient sensitization strategy provides a new idea for constructing highly sensitive room-temperature MPSE sensors. • A room-temperature MPSE NO sensor was first successfully developed. • The sensor after introducing MWCNT into SE obtains a three-fold increasement of ΔV. • The detection of the sensor at 25 °C and 60%RH is as low as 20 ppb. [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]

Layered double hydroxides (LDHs) are a promising positive electrode material for super-capacitors (SCs) due to multiple oxidation reduction states. However, the structure of LDH is prone to collapse during the redox reaction and has low conductivity, which further hinders the improvement of capacity performance. Here in, nitrogen-doped graphene quantum dot (N-GQD) is assembled on nickel gallium layered double hydroxide (NiGa-LDH) derived from two-dimension nickel metal organic frameworks (Ni-MOF) on nickel foam (NF) to prepare stable interlaced nano-sheets hybrid structures. As a result of the above synergies, the NiGa-LDH/N-GQD/NF electrode has a high specific capacitance of 2160 F g−1 at 1 A g−1 and good cycling stability with a capacity retention rate of 87.5% in 5000 cycles. In addition, we also make ASC device using NiGa-LDH/N-GQD/NF and Carbon NSs as positive/negative electrodes. The energy density of the assembled ASC device is 78.8 Wh kg−1 at power density of 1432.7 W kg−1, while the capacitance retention after 8000 cycles reaches 81.2%. Meanwhile, individually assembled ASC device can power multiple LEDs in parallel. This work provides an effective way to construct new electrode materials with high energy storage density, good cycling performance and power density by assembling quantum dots into LDH nano-sheets derived from MOF through reasonable design. The NiGa-LDH/N-GQD electrode material prepared on nickel foam has good capacity and cycling stability due to the synergistic effect of interleave NiGa-LDH nano-sheet derived from Ni-MOF and N-GQD embedded in it. [Display omitted] • NiGa-LDH/N-GQD/NF is firstly synthesized by simple hydrothermal method. • The NiGa-LDH derived from the Ni-MOF prepared on nickel foam with interleaved nano-sheet hybrid structure have large specific surface area and can provide more reaction sites. • The introduction of N-GQD plays an important role in improving the electrical conductivity and surface wettability of electrodes. • The NiGa-LDH/N-GQD-2/NF//Carbon NSs asymmetric supercapacitors device (78.8 Wh kg−1) can light multiple LEDs in parallel. [ABSTRACT FROM AUTHOR]

The 3D hierarchical structure of CdS/Ni-MOF inhibits the agglomeration of CdS, improve light harvesting, increase active surface area, reaction sites, promote charge transfer and separation, which greatly improves the efficiency of CO 2 conversion. However, when the CdS is overloaded and its hierarchical structure is destroyed, the heterostructure plays a major role in improving the performance. Based on the above results, we propose the preliminary mechanism of 20%-CdS/Ni-MOF photocatalytic reduction of CO 2. Firstly, under UV–Vis illumination, Ni-MOF and CdS are excited to produce electrons (e−) and holes (h+). Then, because of the tight interface contact, the e- excited by Ni-MOF could be transferred to CdS with more positive CB, and CdS as the active site could reduce CO 2 to CO more effectively. At the same time, the h+ in the VB of Ni-MOF and CdS participate in the oxidation reaction to produce O 2 and H 2 O 2 , which achieving the elimination of holes. Such charge separation and transfer of the electron-hole pairs facilitate enhanced photocatalytic activity. [Display omitted] • The 3D hierarchical heterostructure was synthesized by a simple strategy. • 20%-CdS/Ni-MOF showed excellent performance in the vapor–solid reaction system. • The hierarchical structure and heterostructure of CdS/Ni-MOF play a synergistic role. Fabricating the hierarchical heterostructure is efficient way for enhancing CO 2 conversion of semiconductor photocatalysts. Herein, a simple strategy has been employed to prepare several 3D hierarchical CdS/Ni-MOF heterostructure photocatalysts, and the selective photoreduction of CO 2 to CO under simulated sunlight in the gas–solid phase reactor. Among the prepared photocatalysts, 20%-CdS/Ni-MOF shows the best CO yield, which was 16 times and 7 times that of Ni-MOF and CdS, respectively. By controlling the morphology of the catalyst, we found that the significant improvement in photocatalytic activity can be ascribed to the synergistic effect of heterostructure in CdS/Ni-MOF and its unique hierarchical structure, which can improve the efficiency of charge transmission and provides abundant active sites, etc. Finally, the preliminary photocatalytic mechanism was discussed by in situ FTIR and liquid ultraviolet spectrophotometer. [ABSTRACT FROM AUTHOR]

• Ni-MOF derived Ni-C composites are used as separator coating layer of Li-S battery. • The influence of different morphology Ni-C composites are compared. • Ni nanodots are proved to have catalytic effect on the conversion of polysulfides. In order to solve the problems caused by the low conductivity of sulfur and the shuttle effect of polysulfides in lithium-sulfur battery (LSB), we conducted a series of studies and successfully prepared Ni-C composite materials employing Ni-MOF as the precursor, which were used as coating materials for the separator of LSB. Two kinds of ligands, terephthalic acid and trimesic acid were used to react with nickel nitrate to obtain Ni-MOF precursors and their carbonized products were named as Ni-C(B) and Ni-C(T) respectively. Ni-MOF precursors with different morphologies were obtained by different ligands, the precursor of Ni-C(B) is the petal-like layered microspheres and the morphology maintained after calcination, the precursor of Ni-C(T) has the structure of drug flake and agglomerates into a massive structure during the reaction. Because of the uniform distribution of nickel particles and the advantages in morphology and specific surface area, the performance of batteries equipped with Ni-C(B) modified separator is better than that of Ni-C(T) sample. Through a series of electrochemical performance tests, the results are consistent with our expectations. When the sulfur area density in positive electrode is 3 mg cm−2, the highest discharge capacity of the battery using Ni-C(B) coated separator is 1413.7 mAh g−1 at 0.05C, 1169.7 mAh g−1 at 0.1C and 997.3 mAh g−1 at 0.3C. Furthermore, the initial discharge capacity is 926 mAh g−1 at 0.5 C and can retain a capacity of 600 mAh g−1 after 300 cycles. [ABSTRACT FROM AUTHOR]