Selective Tumor Inhibition Effect of Drug-Free Layered Double Hydroxide-Based Films via Responding to Acidic Microenvironment.

Nickel-titanium alloy stents are widely used in the interventional treatment of various malignant tumors, and it is important to develop nickel-titanium alloy stents with selective cancer-inhibiting and antibacterial functions to avoid malignant obstruction caused by tumor invasion and bacterial colonization. In this work, an acid-responsive layered double hydroxide (LDH) film was constructed on the surface of a nickel-titanium alloy by hydrothermal treatment. The release of nickel ions from the film in the acidic tumor microenvironment induces an intracellular oxidative stress response that leads to cell death. In addition, the specific surface area of LDH nanosheets could be further regulated by heat treatment to modulate the release of nickel ions in the acidic microenvironment, allowing the antitumor effect to be further enhanced. This acid-responsive LDH film also shows a good antibacterial effect against S. aureus and E. coli. Besides, the LDH film prepared without the introduction of additional elements maintains low toxicity to normal cells in a normal physiological environment. This work offers some guidance for the design of a practical nickel-titanium alloy stent for the interventional treatment of tumors.

Novel approach for characterizing clinical load application of superelastic orthodontic wires.

OBJECTIVE: Current standardized in vitro bending experiments for orthodontic archwires cannot capture friction conditions and load sequencing during multi-bracket treatment. This means that clinically relevant forces exerted by superelastic wires cannot be predicted. To address these limitations, this study explored a novel test protocol that estimates clinical load range. METHODS: The correction of a labially displaced maxillary incisor was simulated using an in vitro model with three lingual brackets. Deflection force levels derived from four different protocols were designed to explore the impact of friction and wire load history. These force levels were compared in nickel-titanium (NiTi) archwires with three commonly used diameters. The unloading path varied between protocols, with single or multiple sequences and different load orders and initial conditions. RESULTS: Deflection forces from the new protocol, employing multiple continuous load/unload cycles (CCincr), consistently exceeded those from the conventional protocol using a single continuous unloading path (CUdecr). Mean differences in plateau force ranged from 0.54 N (Ø 0.014" wire) to 1.19 N (Ø 0.016" wire). The CCinr protocol also provided average force range estimates of 0.47 N (Ø 0.012" wire), 0.89 N (Ø 0.014" wire), and 1.15 N (Ø 0.016" wire). SIGNIFICANCE: Clinical orientation towards CUdecr carries a high risk of excessive therapeutic forces because clinical loading situations caused by friction and load history are underestimated. Physiological tooth mobility using NiTi wires contributes decisively to the therapeutic load situation. Therefore, only short unloading sequences starting from the maximum deflection in the load history, as in CCincr, are clinically meaningful.

High-Concentrated Binary-Salt Ether Electrolytes for High-Voltage Lithium Metal Batteries with Ni-Rich Cathode.

The incompatibility of ether electrolytes with a cathode dramatically limits its application in high-voltage Li metal batteries. Herein, we report a new highly concentrated binary salt ether-based electrolyte (HCBE, 1.25 M LiTFSI + 2.5 M LiFSI in DME) that enables stable cycling of high-voltage lithium metal batteries with the Ni-rich (NCM83, LiNi0.83Co0.12Mn0.05O2) cathode. Experimental characterizations and density functional theory (DFT) calculations reveal the special solvation structure in HCBE. A solvation structure rich in aggregates (AGGs) can effectively broaden the electrochemical window of the ether electrolyte. The anions in HCBE preferentially decompose under high voltage, forming a CEI film rich in inorganic components to protect the electrolyte from degradation. Thus, the high-energy-density Li||NCM83 cell has a capacity retention of ≈95% after 150 cycles. Significantly, the cells in HCBE have a high and stable average Coulombic efficiency of over 99.9%, much larger than that of 1 M LiPF6 + EC + EMC + DMC (99%). The result emphasizes that the anionic-driven formation of a cathode electrolyte interface (CEI) can reduce the number of interface side reactions and effectively protect the cathode. Furthermore, the Coulombic efficiency of Li||Cu using the HCBE is 98.5%, underscoring the advantages of using ether-based electrolytes. This work offers novel insights and approaches for the design of high-performance electrolytes for lithium metal batteries.

Effects of hesperidin on the histological structure, oxidative stress, and apoptosis in the liver and kidney induced by NiCl2.

The aim of this study was to investigate the effect of hesperidin on the liver and kidney dysfunctions induced by nickel. The mice were divided into six groups: nickel treatment with 80 mg/kg, 160 mg/kg, 320 mg/kg hesperidin groups, 0.5% CMC-Na group, nickel group, and blank control group. Histopathological techniques, biochemistry, immunohistochemistry, and the TUNEL method were used to study the changes in structure, functions, oxidative injuries, and apoptosis of the liver and kidney. The results showed that hesperidin could alleviate the weight loss and histological injuries of the liver and kidney induced by nickel, and increase the levels of lactate dehydrogenase (LDH), alanine aminotransferase (GPT), glutamic oxaloacetic transaminase (GOT) in liver and blood urea nitrogen (BUN), creatinine (Cr) and N-acetylglucosidase (NAG) in kidney. In addition, hesperidin could increase the activities of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GSH-Px) in the liver and kidney, decrease the content of malondialdehyde (MDA) and inhibit cell apoptosis. It is suggested that hesperidin could help inhibit the toxic effect of nickel on the liver and kidney.

Chitosan-sunflower meal biochar hydrogel incorporated with green synthesized NiO nanoparticles for enhanced catalytic reduction of anthropogenic water pollutants.

Anthropogenic activities have been one of the crucial driving factors for water pollution globally, thereby warranting a sustainable strategy for its redressal. In this study, we have developed a hydrogel-biochar nanocomposite for catalytic reduction of water pollutants. To begin with, green synthesis of nickel oxide nanoparticles (NiO NPs) was accomplished from waste kinnow peel extract via the environmentally benign microwave method. The formation of NiO NPs was affirmed from different analytical techniques namely ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS). The FESEM images revealed spherical nature of NiO NPs. The average particle size was found to be 15.61 nm from XRD data. A novel hydrogel-biochar nanocomposite comprising the green NiO NPs, sunflower meal biochar and chitosan was prepared (Cs-biochar@ NiO) and explored as a nanocatalyst towards catalytic reduction of pollutants such as 4-nitrophenol, potassium hexacyanoferrate (III) and organic dyes methyl orange (MO), Congo red (CR), methylene blue (MB) in the presence of a reducing agent, i.e. NaBH4. Under optimized conditions, the reduction reactions were completed by 120 s and 60 s for 4-NP and potassium hexacyanoferrate (III) respectively and the rate constants were estimated to be 0.044 s-1 and 0.110 s-1. The rate of reduction was found to be faster for the dyes and the respective rate constants were 0.213 s-1 for MO, 0.213 s-1 for CR and 0.135 s-1 for MB. The assessment of the nanocatalyst in the reduction of binary dye systems depicted its selectivity towards the anionic dyes CR and MO. The nanocatalyst displayed effective reduction of dyes in real-water samples collected from different sources. Taken altogether, this study validates the design of sustainable hydrogel-biochar nanocatalyst for the efficient reduction of hazardous anthropogenic water pollutants.

Synthesis of para-Acetylated Functionalized Ni(II)-POCOP Pincer Complexes and Their Cytotoxicity Evaluation Against Human Cancer Cell Lines.

A series of three Ni(II)-POCOP complexes para-functionalized with an acetoxyl fragment were synthesized. All complexes (2a-c) were fully characterized through standard analytical techniques. The molecular structure of complex 2b was unambiguously determined by single-crystal X-ray diffraction, revealing that the metal center is situated in a slightly distorted square-planar environment. Additionally, the acetoxy fragment at the para-position of the phenyl ring was found to be present. The in vitro cytotoxic activity of all complexes was assessed on six human cancer cell lines. Notably, complex 2b exhibited selective activity against K-562 (chronic myelogenous leukemia) and MCF-7 (mammary adenocarcinoma) with IC50 values of 7.32 ±â€¯0.60 µM and 14.36 ±â€¯0.02 µM, respectively. Furthermore, this compound showed negligible activity on the healthy cell line COS-7, highlighting the potential therapeutic application of 2b. The cytotoxic evaluations were further complemented with molecular docking calculations to explore the potential biological targets of complex 2b, revealing interactions with cluster differentiation protein 1a (CD1A, PDB: 1xz0) for K-562 and with the progesterone receptor for MCF-7.

Catalytic effect of nickel oxide nanoparticles from Lupinus Albus extract on green synthesis and photocatalytic reduction of methylene blue: kinetics and mechanism.

Green synthesis of nanomaterials is advancing due to their ease of synthesis, cheapness, nontoxicity, and renewability. An environmentally friendly biogenic method has been developed for the green synthesis of nickel oxide nanoparticles (NiO NPs) using phytochemical-rich bioextract. They are rich in bioextract phenolics, flavonoids, and berberine. These phytochemicals successfully reduce and stabilize NiNO3 into NiO NPs. In this study, NiO NPs were synthesized by the green synthesis method from Lupinus Albus. Characterization of NiO NPs was carried out by TEM, XRD, SEM, UV, XRF, BET, and EDX analyses. According to XRD analysis, TEM results also support this, where the NiO NPs particle size diameter is 5 nm. It was determined by the Tauc equation that the band energy gap of NiO NPs is 1.69 eV. It was determined that the BET surface area of NiO NPs was 49.6 m2/g. NiO nanoparticles synthesized from Lupinus Albus extract by the green synthesis method were used as catalysts in the photocatalytic reduction of methylene blue with NaBH4. In the photocatalytic reduction of methylene blue with NaBH4, it was determined that there was no color change in 48 h without a catalyst, and in the presence of NiO nanoparticle catalyst, methylene blue was reduced by 97% in 8 min. The kinetics of the photocatalytic reduction of methylene blue with NaBH4 is a pseudo-first-order kinetic model and the kinetic rate constant is determined as 0.66 min-1, indicating that the catalytic effect of NiO NPs is very high at this value. NiO NPs were used five times in the photocatalytic reduction of methylene blue with NaBH4 and it was determined that the reduction of methylene blue was over 90% in each use.

NiO nanoparticles were synthesized from Lupinus Albus extract by green synthesis, which is an easily applied, cost-effective, and environmentally friendly method. The synthesized NiO nanoparticles were characterized using various characterization techniques. NiO nanoparticles have a high catalytic effect in the photocatalytic reduction of methylene blue with NaBH₄. Photocatalytic reduction of methylene blue with uncatalyzed NaBH₄ could not be achieved, and 97% reduction of methylene blue was completed in 8 min in the presence of NiO nanoparticle catalyst.

ECO-FRIENDLY TRANSFORMATION OF BIOETHANOL INTO ETHYLENE OVER BIMETALLIC NICKEL-COPPER CATALYSTS.

The conversion of bioethanol to ethylene in gas phase and atmospheric pressure was investigated over γ-Al2O3 supported copper and nickel catalysts. These catalysts were prepared by co-precipitation and pre-treated with hydrogen at 450 °C. Six catalysts were studied at 450 °C under a nitrogen atmosphere. It was found that the monometallic Cu/γ-Al2O3 catalyst exhibited the highest ethylene concentration, with a selectivity of around 90%. The bioethanol conversion obtained was between 57%-86%. Another catalyst that exhibited high concentration values was the NiCu1:7 bimetallic catalyst. The catalysts were characterised using XRD, SEM, EDS, TEM, TGA, FTIR, Raman, and N2-physisoption techniques. Furthermore, the Cu/γ-Al2O3 catalyst was studied under different reduction temperatures and gas flow conditions. It was found that the catalysts reduced at 350 °C and 35 ml/min N2 flow presented ethylene concentrations between (0.18-0.21) g/L. Moreover, the catalyst deactivation was identified to be first order and the equation of the Cu/γ-Al2O3 catalyst deactivation model was determined. Carbonaceous deposits over the used sample were not detected by Raman and FTIR. It was determined that the Cu/γ-Al2O3 catalyst deactivation could be mainly attributed to the blocking of the catalytic sites by strongly adsorbed compounds and hydroxylation of the catalyst surface.

Microwave-assisted synthesis of Ni-doped europium hydroxide for photocatalytic degradation of 4-nitrophenol.

Microwave-assisted synthesis method was used to prepare europium hydroxide (Eu(OH)3) and different percentages of 1, 5, and 10 % nickel-doped Eu(OH)3 (Ni-Eu(OH)3) nanorods (NRs). X-ray diffraction study showed a hexagonal phase with an average crystallite size in the range of 21 - 35 nm for Eu(OH)3 and Ni-Eu(OH)3 NRs. FT-IR and Raman studies also confirmed the synthesis of Eu(OH)3 and Ni-Eu(OH)3. The synthesized materials showed rod-like morphology with an average length and diameter between 27 - 50 nm and 8 - 13 nm, respectively. The band gap energies of Ni-Eu(OH)3 NRs were reduced (4.06 - 3.50 eV), which indicates that the doping of Ni2+ ions has influenced the band gap energy of Eu(OH)3. The PL study exhibited PL quenching with Ni doping. The photocatalytic degradation of 4-nitrophenol (4-NP) by the synthesized materials under UV light irradiation was investigated, in which 10 % Ni-Eu(OH)3 NRs showed the best response. A kinetic study was also conducted which shows pseudo-first-order kinetics. Based on this, Ni-Eu(OH)3 NRs have shown a potential to be a UV-light active material for photocatalysis.

An ecofriendly approach to bioremediate nickel oxide nanoparticles using a macrofungus, Pleurotus fossulatus.

Nowadays, nickel oxide nanoparticles are in great demands owing to their use in many sectors. These nanoparticles may release into aquatic environment from different industries and cause negative effect on aquatic flora and fauna. Therefore, an effective and efficient method is required to remove these nanoparticles from contaminated water. Hence, the aim of this study was to bioremediate nickel oxide nanoparticles using a macrofungus, Pleurotus fossulatus, and to analyze its impact on fungal physiology. For this purpose, fungal spawns were inoculated in malt dextrose agar media containing different concentrations of nickel oxide nanoparticles (24 mg/l, 48 mg/l, and 100 mg/l) as well as control group (having no nickel oxide nanoparticles) and allowed to grow for a period of 20 days. Fungal mycelia as well as media were collected at different time intervals (5th day, 10th day, 15th day, and 20th day) for evaluation of Ni concentration and different biochemical parameters. Ni removal efficiency of P. fossulatus from media was found to be highest in 48 mg/l (66.98%) followed by 24 mg/l (60.83%) and 100 mg/l (18.03%), respectively. Increased level of metallothionein, lipid peroxidation, activity of different antioxidant enzymes (superoxide dismutase, catalase, glutathione s transferase, glutathione reductase), activity of ligninolytic enzymes (laccase, lignin peroxidase, manganese peroxidase), and shift in FTIR spectra were also reported in mycelia cultured in malt dextrose agar media containing nickel oxide nanoparticles. This study suggests that P. fossulatus has great efficiency to remediate nanoparticles from contaminated water and it can be utilized as potential agent in wastewater treatment plants by different industries.

Synthesis, crystal structure and thermal properties of catena-poly[[bis-(4-methyl-pyridine)-nickel(II)]-di-µ-thio-cyanato], which shows an alternating all-trans and cis-cis-trans-coordination of the NiS2Np 2Nt 2 octa-hedra (p = 4-methyl-pyridine, t = thio-cyanate).

The title compound, [Ni(NCS)2(C6H7N)2] n , was prepared by the reaction of Ni(NCS)2 with 4-methyl-pyridine in water. Its asymmetric unit consists of two crystallographically independent NiII cations, of which one is located on a twofold rotational axis whereas the second occupies a center of inversion, two independent thio-cyanate anions and two independent 4-methyl-pyridine co-ligands in general positions. Each NiII cation is octa-hedrally coordinated by two 4-methyl-pyridine coligands as well as two N- and two S-bonded thio-cyanate anions. One of the cations shows an all-trans, the other a cis-cis-trans configuration. The metal centers are linked by pairs of µ-1,3-bridging thio-cyanate anions into [101] chains. X-ray powder diffraction shows that a pure crystalline phase has been obtained and thermogravimetry coupled to differential thermoanalysis reveals that the title compound loses half of the 4-methyl-pyridine coligands and transforms into Ni(NCS)2(C6H7N). Nearly pure samples of this compound can be obtained by thermal annealing and a Rietveld refinement demonstrated that it is isotypic to its recently reported Cd analog [Neumann et al., (2020 ▸). CrystEngComm. 22, 184-194] In its crystal structure, the metal cations are linked by one µ-1,3(N,S)- and one µ-1,3,3(N,S,S)-bridging thio-cyanate anion into single chains that condense via the µ-1,3,3(N,S,S)-bridging anionic ligands into double chains.

Regio- and Diastereoselective Synthesis of Trisubstituted Alkenes Through Hydroalkylation of Alkynyl Boronamides.

Hydroalkylation of alkynes is a powerful method for alkene synthesis. However, regioselectivity has been difficult to achieve in transformations of internal alkynes hindering applications in the synthesis of trisubstituted alkenes. To overcome these limitations, we explored using boryl groups as versatile directing groups that can control the regioselectivity of the hydroalkylation and subsequently be replaced in a cross-coupling reaction. The result of our exploration is a nickel-catalyzed hydroalkylation of alkynyl boronamides that provides access to a wide range of trisubstituted alkenes with high regio- and diastereoselectivity. The reaction can be accomplished with a variety of coupling partners, including primary and secondary alkyl iodides, α-bromo esters, α-chloro phthalimides, and α-chloro boronic esters. Preliminary studies of the reaction mechanism provide evidence for the hydrometalation mechanism and the formation of alkyl radical intermediates.

A Novel Hydrated Iron Vanadate Cathode Material for Advanced Aqueous Nickel-Ion Batteries.

Aqueous nickel-ion batteries (ANIBs) as an emerging energy storage device attracted much attention owing to their multielectron redox reaction and dendrite-free Ni anode, yet their development is hindered by the divalent properties of Ni2+ and the lack of suitable cathode materials. Herein, a hydrated iron vanadate (Fe2V3O10.5∙1.5H2O, FOH) with a preferred orientation along the (200) plane is innovatively proposed and used as cathode material for ANIBs. The FOH cathode exhibits a remarkable capacity of 129.3 mAh g-1 at 50 mA g-1 and a super-high capacity retention of 95% at 500 mA g-1 after 700 cycles. The desirable Ni2+ storage capacity of FOH can be attributed to the preferentially oriented and tunnel structures, which offer abundant reaction active planes and a broad Ni2+ diffusion path, the abundant vacancies and high specific surface area further increase ion storage sites and accelerate ion diffusion in the FOH lattice. Furthermore, the Ni2+ storage mechanism and structural evolution in the FOH cathode are explored through ex situ XRD, ex situ Raman, ex situ XPS and other ex situ characteristics. This work opens a new way for designing novel cathode materials to promote the development of ANIBs.

Unveiling Key Interface Characteristics of Ni/Yttria-Stabilized Zirconia Solid Oxide Cell Electrodes in H2O Electroreduction Using Operando X-ray Photoelectron Spectroscopy.

Nickel/yttria-stabilized zirconia (YSZ) composites are the most commonly used fuel electrodes for solid oxide cells. While microstructural changes of Ni/YSZ during operational conditions have been thoroughly investigated, there is limited knowledge regarding Ni/YSZ surface chemistry under working conditions. In this study, we examine the interaction between Ni/YSZ electrodes and water vapor under open circuit and polarization conditions, utilizing near ambient pressure soft and hard X-ray photoelectron spectroscopies. Miniature cells with conventional porous Ni/YSZ composite cermet cathodes were modified to facilitate the direct spectroscopic observation of the functional electrode's areas close to the interface with the YSZ electrolyte. The results highlight dynamic changes in the oxidation state and composition of Ni/YSZ under H2 and H2O atmospheres. We also quantify the accumulation of impurities on the electrode surface. Through adjustments in the pretreatment of the cell, the correlation between the nickel surface oxidation state and the cell's electrochemical performance during H2O electroreduction is established. It is unequivocally shown that nickel surface oxidation in H2O electrolysis favors NiO over Ni(OH)x, providing critical insights into the mechanism of Ni-phase redistribution within the electrode during long-term operation. Depth-dependent photoemission measurements, combined with theoretical quantitative simulations, reveal that NiO and Ni phases are uniformly mixed on the surface during H2O electrolysis. This differs from the conventional expectation of a NiO-shell/Ni-core configuration in gas phase oxidation. These findings provide crucial insights into the surface chemistry of Ni/YSZ electrodes under conditions relevant to H2O electrolysis, elucidating their impact on the electrochemical performance of the cell.

Investigating the impact of different routes of nano and micro nickel oxide administration on rat kidney architecture, apoptosis markers, oxidative stress, and histopathology.

Although the production and use of nickel oxide nanoparticles (NiONP) are widespread, environmental and public health problems are associated with it. The kidney is the primary organ in excretion and is among the target organs in nanoparticle toxicity. This study aimed to compare the renal toxicity of nickel oxide (NiO) microparticles and nickel oxide nanoparticles by different routes of administration, such as oral, intraperitoneal (IP), and intravenous (IV). Seven groups were formed, with 42 male rats and six animals in each group. NiO oral (150 mg/kg), NiO IP (20 mg/kg), NiO IV (1 mg/kg), NiONP oral (150 mg/kg), NiONP IP (20 mg/kg), and NiONP IV (1 mg/kg) was administered for 21 days. After NiO and NiONP administration, a decrease in antioxidant activities and an increase in lipid peroxidation occurred in the kidney tissue of rats. Increased kidney urea, uric acid, and creatinine levels were observed. Inhibition of acetylcholinesterase activity and an increase in interleukin 1 beta were detected. Apoptotic markers, Bax, caspase-3, and p53 up-regulation and Bcl-2 down-regulation were observed. In addition, histopathological changes occurred in the kidney tissue. In general, it was observed that nickel oxide microparticles and nickel oxide nanoparticles cause inflammation by causing oxidative stress in the kidney tissue, and NiONP IV administration is more effective in renal toxicity.

High-efficient nickel-doped lignin carbon dots as a fluorescent and smartphone-assisted sensing platform for sequential detection of Cr(VI) and ascorbic acid.

Using lignin as a raw material to prepare fluorescent nanomaterials represents a significant pathway toward the high-value utilization of waste biomass. In this study, Ni-doped lignin carbon dots (Ni-LCDs) were rapidly synthesized with a yield of 63.22 % and a quantum yield of 8.25 % using a green and simple hydrothermal method. Exploiting the inner filter effect (IFE), Cr(VI) effectively quenched the fluorescence of the Ni-LCDs, while the potent reducing agent ascorbic acid (AA) restored the quenched fluorescence, thus establishing a highly sensitive fluorescence switch sensor platform for the sequential detection of Cr(VI) and AA. Importantly, the integration of a smartphone facilitated the portability of Cr(VI) and AA detection, enabling on-site, in-situ, and real-time monitoring. Ultimately, the developed fluorescence and smartphone-assisted sensing platform was successfully applied to detect Cr(VI) in actual water samples and AA in various fruits. This study not only presents an efficient method for the conversion and utilization of waste lignin but also broadens the application scope of the CDs in the field of smart sensors.

Cytotoxic effects and comparative analysis of Ni ion uptake by osteoarthritic and physiological osteoblasts.

Nickel(Ni)-containing materials have been widely used in a wide range of medical applications, including orthopaedics. Despite their excellent properties, there is still a problem with the release of nickel ions into the patient's body, which can cause changes in the behaviour of surrounding cells and tissues. This study aims to evaluate the effects of Ni on bone cells with an emphasis on the determination of Ni localization in cellular compartments in time. For these purposes, one of the most suitable models for studying the effects induced by metal implants was used-the patient's osteoarthritic cells. Thanks to this it was possible to simulate the pathophysiological conditions in the patient's body, as well as to evaluate the response of the cells which come into direct contact with the material after the implantation of the joint replacement. The largest differences in cell viability, proliferation and cell cycle changes occurred between Ni 0.5 mM and 1 mM concentrations. Time-dependent localization of Ni in cells showed that there is a continuous transport of Ni ions between the nucleus and the cytoplasm, as well as between the cell and the environment. Moreover, osteoarthritic osteoblasts showed faster changes in concentration and ability to accumulate more Ni, especially in the nucleus, than physiological osteoblasts. The differences in Ni accumulation process explains the higher sensitivity of patient osteoblasts to Ni and may be crucial in further studies of implant-derived cytotoxic effects.

Three-Dimensional Nickel Foam-Based Lithiophilic LPP-Ni3S2@Ni Current Collector for Dendrite-Free Lithium Anode.

Lithium metal has been treated as one of the most promising anode materials for next-generation rechargeable batteries due to its extremely high theoretical capacity. However, its practical application is hindered by inhomogeneous lithium deposition and uncontrolled dendrite growth. In this work, we prepared a three-dimensional nickel foam (NF)-based current collector with a lithiophilic interface layer through facile hydrothermal and coating methods. The lithiophilic Ni3S2 array synthesized via a hydrothermal method has been demonstrated to facilitate the nucleation of Li+. Moreover, it has been observed that the outer coating comprising LPP effectively enhances the inward diffusion of Li+. Additionally, this interface layer can serve as an isolating barrier between the electrodes and the electrolyte. The prepared LPP-Ni3S2@Ni shows significant reversibility both in symmetric cells (1200 h, 1 mA cm-2) and half-cells (CE: 99.60%, 500 cycles, 1 mA cm-2) with low interfacial resistance (35 Ω). Full cells with LiFePO4 as a cathode also exhibit promising electrochemical performance with over 76.78% capacity retention over 200 cycles at 1 C.

Precursor-Driven Catalytic Performances of Al2O3-Supported Earth-Abundant Ni Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural into Added-Value Chemicals.

It has been shown that the nature of the metal precursor and the thermal effects during calcination determine the physicochemical properties of the catalysts and their catalytic activity in the levulinic acid (LA) and 5-hydroxymethylfurfural (HMF) hydrogenation reactions. The endothermic effect during calcination of the inorganic nickel precursor promoted higher metal dispersion and stronger interaction with the alumina surface. In contrast, the exothermic effects during the calcination of organic nickel precursors resulted in smaller metal dispersion and lower interaction with the support surface. A clear relationship was found between the size of the metal crystallites and the yield of LA hydrogenation reaction. The smaller crystallites were more active in the LA hydrogenation reaction. In turn, the size of the metal particles and their nature of interaction with the surface of the alumina influence the hydrogenation pathways of the HMF.

Cr-doping promoted surface reconstruction of Ni3N electrocatalysts toward efficient overall water splitting.

Understanding and utilizing the dynamic changes of electrocatalysts under working conditions are important for advancing the sustainable hydrogen production. Here, we for the first time report that Cr-doping can promote the in situ reconstruction of a self-supported Ni3N electrocatalyst (Cr-Ni3N/NF) during oxygen and hydrogen evolution reactions (OER and HER), and therefore improve the electrocatalytic water splitting performance. As identified by in situ measurements and theoretical calculations, Cr-doping enhances OH- adsorption during OER at anode and thereby boosts the transformation of Ni3N pre-catalysts to defect-rich nickel oxyhydroxide (NiOOH) active species. Meanwhile, it facilitates the generation of Ni3N/Ni(OH)2 at cathodes due to effective H2O activation, leading to the fast HER kinetics on the Ni3N/Ni(OH)2 interfaces. Notably, the optimal Cr-Ni3N/NF displays good OER and HER performance in 1.0 M KOH electrolytes, with low overpotentials of 316 and 188 mV to achieve the current density of ± 100 mA cm-2, respectively. Benefiting from its bi-functionality and self-supporting property, an alkaline electrolyzer equipped with Cr-Ni3N/NF as both anode and cathode affords a small voltage of 1.72 V at 100 mA cm-2, along with 100 h operation stability. Elucidating that Cr-doping can boost in situ reconfiguration and consequently the electrocatalytic activity, this work would shed new light on the rational design and synthesis of electrocatalysts via directional reconstructions.