Ni-based MOFs Research Articles

Spherical NiCo-MOFs catalytic hydrogenolysis of lignin dimers and enzymatic lignin to value-added liquid fuels under nitrogen atmosphere

Ni-based MOFs catalysts are promising candidates that can be used to achieve biomass valorization following the process of selective hydrogenolysis process. Here we report a spherical NiCo-based MOFs catalyst, which provides a larger BET surface to enhance 2-phenoxy-1-phenylethan-1-ol molecules enrichment and promote the hydrogenolysis on spherical NiCo-based MOFs catalyst surface. In addition, the synergistic interaction between Ni and Co species also shows great effect on catalytic hydrogenolysis of 2-phenoxy-1-phenylethan-1-ol molecules and enzymatic lignin. The yields of ethylcyclohexane and cyclohexanol are dramatically improved to more than 90 mol% over Ni3Co1-based MOFs catalyst under nitrogen atmosphere. Various lignin dimers derivatives are investigated over Ni3Co1-based MOFs catalyst, which indicates oxygen-containing functional groups played a critical role in the hydrogenolysis process. Isopropanol is used as solvent in the hydrogenolysis of 2-phenoxy-1-phenylethan-1-ol molecules and enzymatic lignin. 21% of H2 is observed in the GC/MS, suggesting that it is a catalytic transfer hydrogenolysis process. Catalytic hydrogenolysis of enzymatic lignin is also carried out under 280 ℃ over optimal Ni3Co1-based MOFs catalyst for 6 h, giving highest lignin oil yield (75.6 wt%) and lower O/C ratio (0.17). This work can be extended to different biomass valorizations to promote the catalytic behavior of spherical MOFs catalysts.

Ni-Based Mofs Catalytic Oxidative Cleavage of Lignin Models and Enzymatic Lignin Under O2 Atmosphere

Ni-Based Mofs Catalytic Oxidative Cleavage of Lignin Models and Enzymatic Lignin Under O2 Atmosphere

Selective Activation of Ni-Based Mof of Both Half-Reactions of Water Splitting

Selective Activation of Ni-Based Mof of Both Half-Reactions of Water Splitting

Bimetallic electronic effects of Mn-doped Ni-MOF shuttle-like nanosheets remarkably enhance the supercapacitive performance

We explored a new class of binder-free Mn doped Ni-based MOFs nanosheets through a polarity-induced solution-phase method for HSCs. The relationship between the electronic structure and the electrochemical activity has been further identified.

Selective Activation of Ni-Based Mof of Both Half-Reactions of Water Splitting

Selective Activation of Ni-Based Mof of Both Half-Reactions of Water Splitting

Activating transition metal via synergistic anomalous phase and doping engineering towards enhanced dehydrogenation of ammonia borane

Seeking high-performing non-noble transition metal catalysts for hydrogen evolution from chemical hydrogen storage media is significant. Herein we demonstrate for the first time that anomalous crystal phase engineering coupled with heteroatom doping can remarkably activate transition metal (Ni as a proof-of-concept study) for boosting ammonia borane (AB) dehydrogenation. Ni nanoparticles with designated phase (fcc or hcp phase) encapsulated in carbon (fcc-Ni/C and hcp-Ni/C) can be readily derived from Ni-based MOF. Intriguingly, hcp-Ni/C featuring unconventional hcp phase can remarkably outperform fcc-Ni/C with common fcc phase in AB dehydrogenation. Moreover, by doping Cu, dramatically promoted catalysis can be further achieved for hcp-CuNi/C. From experimental and theoretical results, delicate crystal phase together with heteroatom doping engineering can optimize electronic structure of hcp-CuNi/C, facilitating rate-determining step (H2O dissociation), thereby boosting AB hydrolysis. This study details the first insight into the phase and doping engineering over non-noble transition metals for promoting AB dehydrogenation.

Trimesic acid-Ni based metal organic framework derivative as an effective destabilizer to improve hydrogen storage properties of MgH2

Herein, a new type of trimesic acid-Ni based metal organic framework (TMA-Ni MOF) was synthesized and then, its derivative Ni@C was introduced into MgH2 as destabilizer through high energy ball milling to prepare a Mg–Ni@C–H composite. X-ray diffraction analyses indicate the formation of Mg2Ni/Mg2NiH4 as major phases after dehydrogenation/rehydrogenation of the composite, respectively. Two hydrogen absorption plateaus are observed in the Mg–Ni@C–H composite, corresponding to the hydrogenation of Mg and Mg2Ni, with the enthalpy change values of −75.8 and −52.3 kJ mol−1 H2 respectively. Thus, it can be concluded that a destabilization effect is brought by Ni@C on thermodynamic properties of MgH2. In addition, the hydriding/dehydriding kinetics of MgH2 is notably accelerated with the addition of Ni-based MOF derivative. The activation energy values of both hydrogen absorption and desorption are significantly lowered down with the assistance of Ni@C. Moreover, stable hydrogen de/absorption capacity and kinetics are remained during 25 cycles of high-rate re/dehydrogenation, which can be ascribed to the carbon-wrapped structure of the composite, with which the aggregation of the nanosized particles can be evidently avioded.

Vertically oriented Ni-MOF@Co(OH)2 flakes towards enhanced hybrid supercapacitior performance

Two dimensional (2D) materials, with ideal interlayer spacing for ion intercalation/de-intercalation, are quite appealing for hybrid supercapacitors (HSCs) in the pursuit of harvesting promising electrochemical performance. Integrating different 2D materials together is one effective strategy to achieve such goals. However, preserving the ion diffusion channel and accelerating electron transfer should be considered during the compositing process. Herein, we propose a two-step strategy to efficiently composite cobalt hydroxide (Co(OH)2) and Ni-based MOF (Ni-MOF-24), in which a vertically oriented Ni-MOF@Co(OH)2 array on nickel foam is obtained. The maximum specific capacitance of 1448 Fg−1 (2 Ag−1) is delivered by Ni-MOF@Co(OH)2. Accordingly, a hybrid Ni-MOF@Co(OH)2//AC HSC is thereof assembled, which outputsa high specific power of 22,400 W kg−1 and a considerable specific energy of 45.7 Wh kg−1.

Facile synthesis of 3D Ni@C nanocomposites derived from two kinds of petal-like Ni-based MOFs towards lightweight and efficient microwave absorbers.

The development of lightweight and high-efficiency microwave absorption materials has attracted wide attention in the field of electromagnetic wave absorption. Herein, two kinds of petal-like Ni-based MOFs were grown on the surface of graphene nanosheets, and then pyrolyzed to obtain new microwave absorbers. The extraordinary microwave absorption performance mainly comes from: the unique petal-like porous carbon framework of MOFs, the 3D conductive network formed by the connection of GNs, the polarization process between the interfaces of multiple heterogeneous components and high impedance matching brought about by magnetic Ni nanoparticles. By adjusting the filling ratio to only 10 wt%, the optimum reflection loss of the prepared composites is up to -53.99 dB, and the effective absorption bandwidth reaches 4.39 GHz when the matching thickness is only 1.4 mm. This work provides not only a facile method for the design and fabrication of two high-efficiency microwave absorbers, but also a reference for the precise control of electromagnetic absorption properties.

Drastic promotion of the photoreactivity of MOF ultrathin nanosheets towards hydrogen production by deposition with CdS nanorods

In this paper, inorganic semiconductor CdS nanorods (CdS-NRs) with strong visible-light absorption was used to modify hierarchically structured Ni-based MOF NMOF-Ni assembled from ultrathin nanosheets. It was found that the HER under simulated sunlight irradiation sharply increases 55.6 times (from 81 to 4500 μmolg−1 h−1) after modification of NMOF-Ni with 10 wt.% CdS-NRs. This enhanced performance originating from the CdS-NRs greatly improves the light absorption, and the imitate contact between NMOF-Ni and CdS-NRs stimulates the charge separation and migration. In addition, CdS-NRs/NMOF-Ni hybridized photocatalyst exhibits excellent photo-stability in hydrogen production due to the protection of NMOF-Ni, which can efficiently prevent the photo-corrosion of CdS-NRs. A direct Z-scheme electron transfer mechanism is proposed for the enhanced simulated sunlight photoreactivity of CdS-NRs/NMOF-Ni hydized photocatalyst towards hydrogen production.

Electrochemically Activated Conductive Ni-Based MOFs for Non-enzymatic Sensors Toward Long-Term Glucose Monitoring.

Continuous intensive monitoring of glucose is one of the most important approaches in recovering the quality of life of diabetic patients. One challenge for electrochemical enzymatic glucose sensors is their short lifespan for continuous glucose monitoring. Therefore, it is of great significance to develop non-enzymatic glucose sensors as an alternative approach for long-term glucose monitoring. This study presented a highly sensitive and selective electrochemical non-enzymatic glucose sensor using the electrochemically activated conductive Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 MOFs as sensing materials. The morphology and structure of the MOFs were investigated by scanning SEM and FTIR, respectively. The performance of the activated electrode toward the electrooxidation of glucose in alkaline solution was evaluated with cyclic voltammetry technology in the potential range from 0.2 V to 0.6 V. The electrochemical activated Ni-MOFs exhibited obvious anodic (0.46 V) and cathodic peaks (0.37 V) in the 0.1 M NaOH solution due to the Ni(II)/Ni(III) transfer. A linear relationship between the glucose concentrations (ranging from 0 to 10 mM) and anodic peak currents with R2 = 0.954 was obtained. It was found that the diffusion of glucose was the limiting step in the electrochemical reaction. The sensor exhibited good selectivity toward glucose in the presence of 10-folds uric acid and ascorbic acid. Moreover, this sensor showed good long-term stability for continuous glucose monitoring. The good selectivity, stability, and rapid response of this sensor suggests that it could have potential applications in long-term non-enzymatic blood glucose monitoring.

Fast Immobilization of Human Carbonic Anhydrase II on Ni-Based Metal-Organic Framework Nanorods with High Catalytic Performance

Carbonic anhydrase (CA) has received considerable attention for its ability to capture carbon dioxide efficiently. This study reports a simple strategy for immobilizing recombinant carbonic anhydrase II from human (hCA II) on Ni-based MOFs (Ni-BTC) nanorods, which was readily achieved in a one-pot immobilization of His-tagged hCA II (His-hCA II). Consequently, His-hCA II from cell lysate could obtain an activity recovery of 99% under optimal conditions. After storing for 10 days, the immobilized His-hCA II maintained 40% activity while the free enzyme lost 91% activity. Furthermore, during the hydrolysis of p-nitrophenyl acetic acid, immobilized His-hCA II exhibited excellent reusability and still retained more than 65% of the original activity after eight cycles. In addition, we also found that Ni-BTC had no fixation effect on proteins without histidine-tag. These results show that the Ni-BTC MOFs have a great potential with high efficiency for and specific binding of immobilized enzymes.

The fixation of CO2 by epoxides over nickel-pyrazolate-based metal–organic frameworks

Ni-based MOFs with Lewis acid sites was developed for CO2 fixation with epoxides into cyclic carbonates, and a comparative study shows that the density and accessibility of the Lewis acid sites in the MOFs greatly influence the catalytic performance.

Investigation of the carbon dioxide adsorption behavior and the heterogeneous catalytic efficiency of a novel Ni-MOF with nitrogen-rich channels.

MOFs have attracted remarkable attention as solid sorbents in CO2 capture processes for their low-energy post-combustion. In this paper, a new Ni-based MOF, Ni4(TATB)1.5(EtO)3.5(NEt3)4, was synthesized and characterized using various physicochemical techniques. The efficiency of the as-prepared Ni-MOF as a solid sorbent for CO2 capture was investigated, and acceptable adsorption was exhibited. Furthermore, this Ni-MMOF was used as a catalyst in toluene selective oxidation, for eliminating a volatile organic compound, with tert-butyl hydroperoxide as an oxidant in the absence of organic solvents. The obtained results indicated that Ni-MOF has good catalytic activity and could be reused three times without considerable loss of its catalytic activity. This study highlights the great potential of developing MOFs to achieve green chemistry goals with the removal of hazardous liquid and gas compounds such as toluene and CO2.

Investigation of superior sodium storage and reversible Na2S conversion reactions in a porous NiS2@C composite using in operando X-ray diffraction

Porous-NiS2@C is successfully synthesized via a solvothermal method using Ni-based MOFs. In operando XRD analysis provides evidence for reversible Na2S conversion during the sodiation/desodiation process.

NiRu nanoparticles encapsulated in a nitrogen-doped carbon matrix as a highly efficient electrocatalyst for the hydrogen evolution reaction.

The design and fabrication of low-cost, efficient, and robust electrocatalysts for the hydrogen evolution reaction (HER) is of great importance in accelerating the development of water electrolysis technology. Herein, NiRu alloy nanostructures embedded in a nitrogen-doped carbon matrix (NiRu@NC) have been fabricated through a facile metal-organic framework-derived (MOF-derived) strategy. Benefiting from their advantages in the unique structures and components, the resulting NiRu@NC possesses excellent activity and durability towards the HER, which exhibits low overpotentials of 85 and 53 mV at a current density of 10 mA cm-2 in acidic and alkaline electrolytes, respectively. Furthermore, NiRu2@NC-600 also exhibits excellent hydrogen oxidation reaction (HOR) activity in an alkaline electrolyte. Therefore, this work provides a facile MOF-derived strategy for the design and synthesis of low-cost and efficient electrocatalysts for the HER.

Enhanced CO2/CH4 Separation Performances of Mixed Matrix Membranes Incorporated with Two-Dimensional Ni-Based MOF Nanosheets

Blending porous inorganic fillers into polymers to fabricate mixed matrix membranes (MMMs) is an efficient method to acquire good-quality membranes for CO2 separation and purification. The poor int...

2D Free-Standing Nitrogen-Doped Ni-Ni3 S2 @Carbon Nanoplates Derived from Metal-Organic Frameworks for Enhanced Oxygen Evolution Reaction.

2D metal-organic frameworks (2D MOFs) are promising templates for the fabrication of carbon supported 2D metal/metal sulfide nanocomposites. Herein, controllable synthesis of a newly developed 2D Ni-based MOF nanoplates in well-defined rectangle morphology is first realized via a pyridine-assisted bottom-up solvothermal treatment of NiSO4 and 4,4'-bipyridine. The thickness of the MOF nanoplates can be controlled to below 20 nm, while the lateral size can be tuned in a wide range with different amounts of pyridine. Subsequent pyrolysis treatment converts the MOF nanoplates into 2D free-standing nitrogen-doped Ni-Ni3 S2 @carbon nanoplates. The obtained Ni-Ni3 S2 nanoparticles encapsulated in the N-doped carbon matrix exhibits high electrocatalytic activity in oxygen evolution reaction. A low overpotential of 284.7 mV at a current density of 10 mA cm-2 is achieved in alkaline solution, which is among the best reported performance of substrate-free nickel sulfides based nanomaterials.

Fabrication of 3D Co-doped Ni-based MOF hierarchical micro-flowers as a high-performance electrode material for supercapacitors

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 (Cox-Ni-MOF, x = 100n (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 Co2-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 Co2-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 Co2-Ni-MOF achieves an excellent energy density of 25.92 Wh/kg at a power density of 375 W/kg.

Tuning the porosity of mesoporous NiO through calcining isostructural Ni-MOFs toward supercapacitor applications

NiO has an unusually high theoretical specific capacitance and possess relatively high electrical conductivity compared to other metal oxides. However, the reported specific capacitance of the NiO-based electrodes is far below the theoretical value up to now. In this paper, three porous NiO materials with different specific surface area were synthesized simply by calcining iso-structural Ni-based MOFs templates. The formation mechanism of NiO was discussed by taking into account the thermal behavior and intrinsic structural features of the Ni-MOFs. Taking advantages of the Ni-MOFs precursors, all prepared NiO compounds are mesoporous and their porosity can be tuned by the structure of MOFs. Specially, due to the high porosity, three NiO exhibited an improved electrochemical performance and the specific discharge capacitances are of 102, 105, and 116 F g−1 at the current density of 1 A g−1, respectively. The specific capacitance of 1-NiO-450 is approximately 93.2% of its maximum value after 3000 cycles, which obviously superior to most of the previously reported NiO electrode materials and suggests their promising applications in supercapacitors.