Alkaline capacity decay induced vacancy-rich LDH for high-performance magnesium ions hybrid supercapacitor.

Transition metal double hydroxides (LDHs) are among the most promising electrode materials in electrochemical energy storage. In this study, we synthesized electrodeposited nickel-cobalt layered double hydroxide (NiCo-LDH) to investigate the significant capacity gap in LDHs at different scan rates in an alkaline electrolyte. Experimental results demonstrate that the degradation of capacity at high scan rates is primarily attributed to the slow ion diffusion and the decreased reversibility of active metal ions. Furthermore, by exploiting the low reversibility of the deprotonation reaction at high scan rates, a NiCo-LDH with enriched hydrogen vacancies (Hv-rich LDH) was obtained. Consequently, the Hv-rich LDH, when used as the cathode in a magnesium ions hybrid supercapacitor (Mg-HSC), exhibits a high specific capacity of 94.97mAh g-1 at a current density of 1 A g-1 and maintains a significant capacity of 41.90 mAh g-1 even at 20 A g-1. Moreover, a Mg-HSC device assembled with an Hv-rich LDH cathode and a VS2 anode delivers a high energy density of 48.44 Wh kg-1 and a power density of 937.49 W kg-1, demonstrating its practical application value. This work not only provides a theoretical basis for the defect design of LDHs but also expands their applicability.

A patent review of lactate dehydrogenase inhibitors (2014-present).

INTRODUCTION: Lactate dehydrogenase (LDH) is a key enzyme in glycolysis responsible for the conversion of pyruvate into lactate and vice versa. Lactate plays a crucial role in tumor progression and metastasis; therefore, reducing lactate production by inhibiting LDH is considered an optimal strategy to tackle cancer. Additionally, dysregulation of LDH activity is correlated with other pathologies, such as cardiovascular and neurodegenerative diseases as well as primary hyperoxaluria, fibrosis and cryptosporidiosis. Hence, LDH inhibitors could serve as potential therapeutics for treating these pathological conditions. AREAS COVERED: This review covers patents published since 2014 up to the present in the Espacenet database, concerning LDH inhibitors and their potential therapeutic applications. EXPERT OPINION: Over the past ten years, different compounds have been identified as LDH inhibitors. Some of them are derived from the chemical optimization of already known LDH inhibitors (e.g. pyrazolyl derivatives, quinoline 3-sulfonamides), while others belong to newly identified chemical classes of LDH inhibitors. LDH inhibition has proven to be a promising therapeutic strategy not only for preventing human pathologies, but also for treating treat animal diseases. The published patents from both academia and the pharmaceutical industry highlight the persistent high interest of the scientific community in developing efficient LDH inhibitors.

Two metabolic enzymes, LDH and FASN, serum levels in Bladder cancer patients.

Background: Bladder cancer is one of the most common cancers in the world and is associated with high treatment costs and mortality. The role of different enzymes and molecules in this cancer has been the subject of extensive research in recent years. Among these, the role of metabolic enzymes such as FASN and LDH has been studied less than others. Therefore, the present study was designed to investigate the role of FASN and LDH in bladder cancer patients. Methods: One hundred cases diagnosed with bladder cancer and 50 sex-age- matched healthy individuals as control were examined. FASN and LDH serum levels in both patients and controls were determined by human-specific sandwich ELISA kits. Results: Serum levels of FASN and LDH elevated in bladder cancer patients in comparison to healthy individuals (P= 0.03, P= 0.01, respectively). We also found that than higher stages of bladder cancer (III-IV) had higher serum levels of LDH and FASN compared to early stages (I-II) (P= 0.007 and P= 0.006, respectively). Moreover, there was a statistically significant association between smoking history and serum FASN levels in bladder cancer patients (P=0.015). However, there were no remarkable associations between the serum levels of LDH and FASN with other clinicopathological features including sex, age, tumor grade, and tumor size. Conclusion: The data indicate that LDH and FASN may be good and useful biomarkers in the diagnosis and clinical management of bladder cancer. However, further studies are needed.

An electrochemical sensor based on porous heterojunction hollow NiCo-LDH/Ti3C2Tx MXenes composites for the detection of quercetin in natural plants.

Cubic hollow-structured NiCo-LDH was synthesized using a solvothermal method. Subsequently, clay-like Ti3C2Tx MXenes were electrostatically self-assembled with NiCo layered double hydroxides (NiCo-LDH) to form composites featuring three-dimensional porous heterostructures. The composites were characterized using SEM, TEM, XRD, XPS, and FT-IR spectroscopy. Ti3C2Tx MXenes exhibit excellent electrical conductivity and hydrophilicity, providing abundant binding sites for NiCo-LDH, thereby promoting an increase in ion diffusion channels. The formation of three-dimensional porous heterostructural composites enhances charge transport, significantly improving sensor sensitivity and response speed. Consequently, the sensor demonstrates excellent electrochemical detection capability for quercetin (Qu), with a detection range of 0.1-20 µM and a detection limit of 23 nM. Additionally, it has been applied to the detection of Qu in natural plants such as onion, golden cypress, and chrysanthemum. The recovery ranged from 97.6 to 102.28%.

EASIX (endothelial activation and stress index) predicts mortality in patients with coronary artery disease.

BACKGROUND: Coronary interventions reduce morbidity and mortality in patients with acute coronary syndrome. However, the risk of mortality for patients with coronary artery disease (CAD) additionally depends on their systemic endothelial health status. The 'Endothelial Activation and Stress Index' (EASIX) predicts endothelial complications and survival in diverse clinical settings. OBJECTIVE: We hypothesized that EASIX may predict mortality in patients with CAD. METHODS: In 1283 patients undergoing coronary catheterization (CC) and having a diagnosis of CAD, EASIX was measured within 52 days (range - 1 year to - 14 days) before CC and correlated with overall survival. In an independent validation cohort of 1934 patients, EASIXval was measured within 174 days (+ 28 days to + 11 years) after CC. RESULTS: EASIX predicted the risk of mortality after CC (per log2: hazard ratio (HR) 1.29, 95% confidence interval: [1.18-1.41], p < 0.001) in multivariable Cox regression analyses adjusting for age, sex, a high-grade coronary stenosis ≥ 90%, left ventricular ejection fraction, arterial hypertension and diabetes. In the independent cohort, EASIX correlated with EASIXval with rho = 0.7. The long-term predictive value of EASIXval was confirmed (per log2: HR 1.53, [1.42-1.64], p < 0.001) and could be validated by integrated Brier score and concordance index. Pre-established cut-offs (0.88-2.32) associated with increased mortality (cut-off 0.88: HR training: 1.63; HR validation: 1.67, p < 0.0001 and cut-off 2.32: HR training: 3.57; HR validation: 4.65, p < 0.0001). CONCLUSIONS: We validated EASIX as a potential biomarker to predict death of CAD patients, irrespective of the timing either before or after catheterization.

Doxorubicin-Intercalated Li-Al-Based LDHs as Potential Drug Delivery Nanovehicle with pH-Responsive Therapeutic Cargo for Tumor Treatment.

Clinical oncology is currently experiencing a technology bottleneck due to the expeditious evolution of therapy defiance in tumors. Although drugs used in chemotherapy work for a sort of cell death with potential clinical application, the effectiveness of chemotherapy-inducing drugs is subject to several endogenous conditions when used alone, necessitating the urgent need for controlled mechanisms. A tumor-targeted drug delivery therapy using Li-Al (M+/M3+)-based layered double hydroxide (LDHs) family has been proposed with the general chemical formula [M+1-x M3+x (OH)]2x+[(Am-)2x/m. n(H2O)]2x-, which is fully biodegradable and works in connection with the therapeutic interaction between LDH nanocarriers and anticancerous doxorubicin (DOX). Compositional variation of Li and Al in LDHs has been used as a nanoplatform, which provides a functional balance between circulation lifetime, drug loading capacity, encapsulation efficiency, and tumor-specific uptake to act as self-regulatory therapeutic cargo to be released intracellularly. First-principle analyses based on DFT have been employed to investigate the interaction of bonding and electronic structure of LDH with DOX and assess its capability and potential for a superior drug carrier. Following the internalization into cancer cells, nanoformulations are carried to the nucleus via lysosomes, and the mechanistic pathways have been revealed. Additionally, in vitro along with in vivo therapeutic assessments on melanoma-bearing mice show a dimensional effect of nanoformulation for better biocompatibility and excellent synergetic anticancer activity. Further, the severe toxic consequences associated with traditional chemotherapy have been eradicated by using injectable hydrogel placed just beneath the tumor site, and regulated release of the drug has been confirmed through protein expression applying various markers. However, Li-Al-based LDH nanocarriers open up new design options for multifunctional nanomedicine, which has intriguing potential for use in cancer treatment through sustained drug delivery.

Partially amorphous NiFe layered double hydroxides enabling highly-efficiency oxygen evolution reaction at high current density.

Layered double hydroxide (LDH) serves as an innovative catalyst for water electrolysis, showcasing outstanding performance in the oxygen evolution reaction (OER) under alkaline conditions. However, it faces challenges due to its low electrical conductivity and limited accessibility to active sites. In this work, the flexibility advantages of disordered amorphous and ordered crystals in NiFe LDH were combined to improve OER performance and maintain long-term stability. This combination induces a variety of effects, including improving the intrinsic activity, changing the OER mechanism from adsorb evolution mechanism (AEM) to lattice oxygen mechanism (LOM), and promoting the reaction kinetics of the catalyst. Moreover, the porous structure of NiFe LDH can efficiently alleviate the issue of local acidic environment induced by prolonged OER reaction, satisfying the criteria for long-term stability. Therefore, the NiFe-2.0 LDH catalyst only requires an ultralow overpotential of 189 mV at a current density of 10 mA cm-2 with Tafel slope of 43 mV dec-1. More importantly, the catalyst not only displays excellent electrocatalytic activity with an overpotential of 289 mV but also represents an outstanding stability over 80 h at an ultra-high current density of 1 A cm-2. This study provides a promising strategy for optimizing the catalytic activity and stability of catalyst at ampere current density, which is expected to achieve commercial applications.

Enhance the Proportion of Fe3+ in NiFe-Layered Double Hydroxides by utilizing Citric Acid to Improve the Efficiency and Durability of the Oxygen Evolution Reaction.

NiFe-layered double hydroxides (NiFe-LDH) are a type of catalyst known for their exceptional catalytic performance during the oxygen evolution reaction (OER). In this study, citric acid was incorporated into the synthesis process of NiFe-LDH, resulting in the NiFe-LDH-CA catalyst with superior OER performance. The catalytic efficacy is evaluated using linear sweep voltammetry (LSV), which demonstrates a significant reduction in the OER overpotential from 320 mV to 240 mV at a current density of 100 mA cm-2. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectrum (XAS) indicate that the distribution of nickel valence states showed no significant difference between two samples, yet the NiFe-LDH-CA has a significantly higher proportion of Fe3+ ions in its iron content. In-situ Raman spectroscopes reveal that Fe3+ broadens the redox potential of nickel and Pourbaix diagrams indicate that higher Fe3+ levels could facilitate the interaction with oxygen active sites. Based on the analysis of test data, we propose a hypothesis that the high proportion of Fe3+ in catalysts may accelerate the oxygen evolution process by modulating the redox potential of nickel and engaging with reactive oxygen species. This provides valuable insights into how to improve the reaction rate of nickel-based catalysts.

The application of lung immune prognostic index in predicting the prognosis of 302 STS patients.

Background: Soft tissue sarcoma (STS) are heterogeneous and rare tumors, and few studies have explored predicting the prognosis of patients with STS. The Lung Immune Prognostic Index (LIPI), calculated based on baseline serum lactate dehydrogenase (LDH) and the derived neutrophils/(leukocytes minus neutrophils) ratio (dNLR), was considered effective in predicting the prognosis of patients with pulmonary cancer and other malignancies. However, the efficacy of the LIPI in predicting the prognosis of patients with STS remains unclear. Methods: This study retrospectively reviewed patients with STS admitted to our center from January 2016 to January 2021. Their hematological and clinical characteristics were collected and analyzed to construct the LIPI specific to STS. The correlations between various predictive factors and overall survival (OS) were examined using Kaplan-Meier and Cox regression analyses. Independent risk factors for OS were identified using univariate and multivariate analyses. Finally, a LIPI nomogram model for STS was established. Results: This study enrolled 302 patients with STS, of which 87 (28.9%), 162 (53.6%), and 53 (17.5%) were classified into three LIPI-based categories: good, moderate, and poor, respectively (P < 0.0001). The time-dependent operator curve showed that the LIPI had better prognostic predictive ability than other hematological and clinical characteristics. Univariate and multivariate analyses identified the Fédération Nationale des Centres de Lutte Contre le Cancer grade (FNCLCC/G), tumor size, and LIPI as independent risk factors. Finally, a nomogram was constructed by integrating the significant prognostic factors. Its C-index was 0.72, and the calibration curve indicated that it could accurately predict the three- and five-year OS of patients with STS. The decision and clinical impact curves also indicated that implementing this LIPI-nomogram could significantly benefit patients with STS. Conclusion: This study explored the efficacy of the LIPI in predicting the prognosis of 302 patients with STS, classifying them into three categories to evaluate the prognosis. It also reconstructed a LIPI-based nomogram to assist clinicians in predicting the three- and five-year OS of patients with STS, potentially enabling timely intervention and customized management.

Synthesis of magnetic multi-walled carbon nanotubes with layered double hydroxide (M-MWCNTs@MnAl-LDH) nanocomposite as an adsorbent for lead extraction.

MnAl layered double hydroxide hybrid with magnetic-multiwalled carbon nanotubes was synthesized by a hydrothermal method and used for the extraction of Pb(II) (lead) from spices and water samples in the dispersive solid phase microextraction (dSPµE) technique using FAAS. The as-prepared adsorbent MMWCNTs@MnAl-LDH was characterized by XRD, FTIR, EDX, and SEM techniques. Various analytical parameters were optimized, including pH 8, adsorbent dosage of 5 mg, HNO3 eluent concentration of 1 mol L-1, eluent volume of 3 mL, eluent time of 60 s, and sample volume of 20 mL, for quantitative lead recoveries, with an LOD of 0.314 µg L-1, an LOQ of 1.048 µg L-1, and PF of 11.53. Under the optimized conditions, the linearity ranges from 0.5 to 500 µg L-1 (R2 = 0.9997). For the validation test of the established dSPµE procedure, Certified reference materials (CRMs) were used, yielding satisfactory recovery results ranging from 97.8 to 102.7 %. The method was applied to determine lead in turmeric, tap water, and industrial water samples.

An Experimental and Simulation Study on the Formability of Commercial Pure Titanium Foil.

In order to understand the formability of as-received tempered commercial pure titanium grade 2 foils (CP Ti Gr2) with a thickness of 38 µm, a series of micro limited dome height (µ-LDH) tests were conducted in quasi-static speed (0.01 mm/s) at room temperature without the use of a lubricant. A technique developed at NIU was also used to create micro-circular grids (ϕ50 µm) on the as-received material. The forming limit curve (FLC) of the CP Ti Gr2 foils was obtained through the proposed µ-LDH test. For having mechanical properties of the CP Ti Gr2 foils for LS-Dyna FEA (Finite Element Analysis) simulations, a series of tensile tests in three directions were also conducted at room temperature with the same speed. The obtained FLC has been validated using a micro deep drawing case study in which both FEA simulations and experiments were conducted and compared. It has been proven in this study that the FLC obtained using the proposed µ-LDH test can be used for an extremely thin sheet-metal-forming process by the automotive, aerospace, medical, energy, and electronic industries, etc., right away for product design, forming process development, tool and die designs, and simulations, etc.

Ultrasensitive Detection of Trace Silver Ions Using MoS42--Intercalated LDH Nanosheets Enhanced SPR Sensor.

The widespread use of silver raises concerns about environmental and health risks, necessitating highly sensitive detection methods for trace silver ions (Ag+). Surface plasmon resonance (SPR) sensors offer benefits like label-free detection and rapid response, but their sensitivity for Ag+ detection is limited due to weak ion adsorption. Here, we developed an SPR sensor with MoS42--intercalated NiAl-layered double hydroxide (LDH) as the adsorption layer of Ag+ to enhance detection sensitivity. Our sensor achieves a sensitivity of 254.75 nm/µg/L and detects Ag+ at a low concentration of 2.8 pM, outperforming various existing sensors. It also shows excellent repeatability, long-term stability, and selectivity, proving effective in real-world environmental samples. This work advances high-performance SPR sensors for heavy metal ion detection.

Ultrathin 2D-2D MXene-LDH Interlayer with High Polysulfide Adsorption Ability for Advanced Li-S Batteries.

Lithium-sulfur (Li-S) batteries are considered as promising energy storage systems due to the high energy density of 2600 W h kg-1. However, the practical application of Li-S batteries is hindered by the inadequate conductivity of sulfur and Li2S, as well as the shuttle effect caused by polysulfides during the charge-discharge process. Introducing a conductive interlayer between the cathode and the separator to physically resist polysulfides represents an effective and straightforward approach to mitigate the shuttle effect in Li-S batteries. In this paper, an ultrathin (<1 µm) 2D-2D MXene-LDH interlayer with high polysulfide adsorption ability was introduced to Li-S batteries. The synergistic effect between MXene and layered double hydroxide greatly improved the adsorption effect of the interlayers: the conductive Ti3C2Tx MXene chemically adsorbs polysulfides and promotes their fast transfer, and the NiCo-LDH alleviates the restack of MXene and facilitates Li+ diffusion. After inserting the MXene-LDH interlayer, the Li-S batteries exhibit an enhanced specific capacity of 1137.6 mA h g-1 at 0.1 C and retain 622.6 mA h g-1 after 100 cycles. The ultrathin 2D-2D interlayer offers a feasible way for the development of highly efficient and lightweight interlayers in Li-S batteries.

Fluorine-lodged high-valent high-entropy layered double hydroxide for efficient, long-lasting zinc-air batteries.

Efficient and stable bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts are urgently needed to unlock the full potential of zinc-air batteries (ZABs). High-valence oxides (HVOs) and high entropy oxides (HEOs) are suitable candidates for their optimal electronic structures and stability but suffer from demanding synthesis. Here, a low-cost fluorine-lodged high-valent high-entropy layered double hydroxide (HV-HE-LDH) (FeCoNi2F4(OH)4) is conveniently prepared through multi-ions co-precipitation, where F- are firmly embedded into the individual hydroxide layers. Spectroscopic detections and theoretical simulations reveal high valent metal cations are obtained in FeCoNi2F4(OH)4, which enlarge the energy band overlap between metal 3d and O 2p, enhancing the electronic conductivity and charge transfer, thus affording high intrinsic OER catalytic activity. More importantly, the strengthened metal-oxygen (M-O) bonds and stable octahedral geometry (M-O(F)6) in FeCoNi2F4(OH)4 prevent structural reorganization, rendering long-term catalytic stability. Furthermore, an efficient three-phase reaction interface with fast oxygen transportation was constructed, significantly improving the ORR activity. ZABs assembled with FeCoNi2F4(OH)4@HCC (hydrophobic carbon cloth) cathodes deliver a top performance with high round-trip energy efficiency (60.6% at 10 mA cm-2) and long-term stability (efficiency remains at 58.8% after 1050 charge-discharge cycles).

"Advancements in minimally invasive treatment for lumbar disc herniation: insights into condoliase and chondroitin sulfate ABC endolyase".

This study examines the efficacy and safety of condoliase chemonucleolysis (CC) in treating lumbar disc herniation (LDH) and highlights emerging alternatives like chondroitin sulfate ABC endolyase. Research indicates that condoliase, an enzyme used to degrade glycosaminoglycans in the nucleus pulposus, provides effective and prompt relief of leg pain, with significant reductions observed within a day of treatment. Studies reveal that a lower pretreatment straight leg raising (SLR) angle may predict early symptom relief, and condoliase is generally effective at doses up to 1.25 U, balancing efficacy and safety. Despite promising results, concerns about long-term safety, including disc height reduction and imaging changes, persist. Additionally, chondroitin sulfate ABC endolyase shows potential as a safer and more effective alternative, though further research is needed to optimize treatment protocols and assess long-term outcomes. Future investigations should address current limitations, such as small sample sizes and short follow-up periods, to better understand the long-term benefits and risks of these treatments.

Synthesis of LDH-MgAl and LDH-MgFe composites for the efficient removal of the antibiotic from water.

In this study, novel lamellar double hydroxide composites (LDH-MgAl and LDH-MgFe) were synthesized at different metal salt ratios (1:1 to 3:1) and fully characterized using various techniques such as XRD, FTIR, SEM, EDS, and TGA. The resulting LDHs demonstrated a high affinity for efficiently removing tetracycline (TC) antibiotic from water, particularly at a moderate molar ratio of 3:1. This ratio exhibited improved structural characteristics, resulting in better TC uptake from water. The improved performance was supported by the increased abundance of surface functional groups (OH, NO3, CO32-, C-O-C, Fe-O, and Al-O-Al). The TGA analysis established the high stability of the LDHs when subjected to high temperatures. The kinetics of TC adsorption onto LDH fitted with the PSO (R2 = 0.935-0.994) and Avrami (R2 = 0.9528-0.9824) models, while the equilibrium data fitted the Liu and Langmuir isotherm models, with maximum monolayer adsorption capacities of 101.1 mg g-1 and 70.83 mg g-1, respectively-significantly higher than many reported values in the literature. The positive values of ΔH0 and ΔS0 indicate an endothermic process, with TC removal mechanisms influenced by physical interactions, such as hydrogen bonding, electrostatic interaction, and π-cation with the surface functional groups of the LDH adsorbents. These results suggest that LDH-MgAl and LDH-MgFe are promising adsorbents for the removal of TC from water.

N/O-bridge stimulated robust binding energy and fast charge transfer between carbon nanofiber and NiCo LDH for advanced supercapacitors.

Layered double hydroxide (LDH)-carbon composites effectively mitigate the inherent issues of agglomeration and poor conductivity in LDH. However, the weak binding energy and insufficient charge transfer capability between LDH and carbon substrate significantly compromise the active substance loading, cyclic stability and practical capacity of the composites. Herein, N/O co-doping porous carbon nanofibers (NOPCNFs) are first prepared by blending diminutive zinc imidazolate framework-8 nanoparticles with polyacrylonitrile for electrospinning, and then densely packed NiCo LDH nanosheets are homogeneously anchored on NOPCNFs to form NiCo LDH@NOPCNFs heterostructure via a hydrothermal method. The experimental findings and density functional theory calculation results indicate that N/O atoms exhibit robust binding forces with metal atoms through enhanced electrostatic adsorption and p-d covalent hybridization, which facilitates the nucleation and development of NiCo LDH on carbon nanofibers. Meanwhile, these heteroatoms also serve as the bridge for electron transfer from NiCo LDH to NOPCNF, leading to a strong interfacial electric field, thus accelerating charge transfer behaviors. Benefitting from the synergistic interaction between NiCo LDH and NOPCNF, the obtained NiCo LDH@NOPCNFs demonstrate an elevated mass loading of active substance (55 wt%), an impressive specific capacitance of 1340 F/g at 1 A/g (based on the mass of NiCo LDH, 2463 F/g), and good cyclic durability for 5000 cycles. Moreover, an all-solid-state asymmetric supercapacitor using NOPCNFs and NiCo LDH@NOPCNFs shows promising practical application prospects. This work gives insights into the important influence of heteroatom doping in carbon, and provides a feasible approach for the efficient integration of electroactive and carbon material.

Scale-Up, Continuous and Low-Temperature Production of Multimetal Based Electrocatalysts toward Water Electrolysis.

Electrocatalytic water splitting is a crucial strategy for advancing hydrogen energy and addressing the global energy crisis. Despite its significance, the need for a straightforward and swift method to synthesize electrocatalysts with exceptional performance remains pressing. In this study, we demonstrate a novel approach for the preparation of multimetal-based electrocatalysts in a continuous flow reactor, enabling the quick synthesis of a large number of products through a streamlined process. The resultant NiFe-LDH comprises nanoflakes with a high specific surface area and requires only 255.4 mV overpotential to achieve a current density of 10 mA·cm-2 in 1 M KOH, surpassing samples fabricated by conventional hydrothermal methods. Our method can also be applied to craft a spectrum of other multimetal-based electrocatalysts, including CoFe-LDH, CoAl-LDH, NiMn-LDH, and NiCoFe-LDH. Additionally, the NiFe-LDH electrocatalyst is further applied to anodic methanol electrooxidation coupled with cathodic hydrogen evolution. Moreover, the simplicity and generality of our fabrication method render it applicable for the facile preparation of various multimetal-based electrocatalysts, offering a scalable solution to the quest for high-performance catalysts in advancing sustainable energy technologies.

Ultrasonic-assisted Fenton reaction inducing surface reconstruction endows nickel/iron-layered double hydroxide with efficient water and organics electrooxidation.

Nickel/iron-layered double hydroxide (NiFe-LDH) tends to undergo an electrochemically induced surface reconstruction during the water oxidation in alkaline, which will consume excess electric energy to overcome the reconstruction thermodynamic barrier. In the present work, a novel ultrasonic wave-assisted Fenton reaction strategy is employed to synthesize the surface reconstructed NiFe-LDH nanosheets cultivated directly on Ni foam (NiFe-LDH/NF-W). Morphological and structural characterizations reveal that the low-spin states of Ni2+ (t2g6eg2) and Fe2+ (t2g4eg2) on the NiFe-LDH surface partially transform into high-spin states of Ni3+ (t2g6eg1) and Fe3+ (t2g3eg2) and formation of the highly active species of NiFeOOH. A lower surface reconstruction thermodynamic barrier advantages the electrochemical process and enables the NiFe-LDH/NF-W electrode to exhibit superior electrocatalytic water oxidation activity, which delivers 10 mA cm-2 merely needing an overpotential of 235 mV. Besides, surface reconstruction endows NiFe-LDH/NF-W with outstanding electrooxidation activities for organic molecules of methanol, ethanol, glycerol, ethylene glycol, glucose, and urea. Ultrasonic-assisted Fenton reaction inducing surface reconstruction strategy will further advance the utilization of NiFe-LDH catalyst in water and organics electrooxidation.

Microplasma-assisted construction of cross-linked network hierarchical structure of NiMoO4 nanorods @NiCo-LDH nanosheets for electrochemical sensing of non-enzymatic H2O2 in food.

The accumulation of small doses of hydrogen peroxide (H2O2) into food can cause many diseases in the human body, and it is urgent to develop efficient detection methods of H2O2. Herein, the hierarchical structure composite of NiCo-LDH nanosheets crosslinked NiMoO4 nanorods was grown in situ on carbon cloth (NiMoO4 NRs@NiCo-LDH NSs/CC) by micro-plasma assisted hydrothermal method. Thanks to the synergistic effect of three metals and (NiMoO4 NRs@NiCo-LDH NSs/CC) provided by nanorods/nanosheets hierarchical structure, NiMoO4 NRs@NiCo-LDH NSs/CC exposes more active sites and achieves rapid electron transfer. The H2O2 electrochemical sensor was constructed as the working electrode with a linear range of 1 µmol L-1 to 9.0 mmol L-1 and detection limit of 112 nmol L-1. In addition, the sensor has been successfully applied to the detection of H2O2 in food samples, the recovery rate is 95.2%-106.62%, RSD < 4.89%.