Prototype Alarm Integrating Pulse-Driven Nitrogen Dioxide Sensor Based on Holey Graphene Oxide/In2O3.

NO2 seriously threatens human health and the ecological environment. However, the fabrication of highly sensitive NO2 sensors with rapid response/recovery rates, low detection limits, and ease of integration remains a challenge. Herein, benefiting from the fast carrier transfer and rich active sites, holey graphene oxide (HGO) was adopted to functionalize the In2O3 nanosheet to construct NO2 gas sensors. Characterization and theoretical calculations established the merits of HGO decoration in the NO2 sensing. The optimal sample, 0.5 wt % HGO/In2O3-sheet, exhibited superior sensing properties, resulting in a 1.37-fold improvement in response to 1 ppm of NO2 compared to the GO/In2O3 counterpart. Gas-sensing kinetics analysis revealed its lower activation energy and higher kinetic rate constants. Importantly, pulsed-temperature modulation was employed to decouple the gas adsorption from surface activation processes, achieving an ultrahigh response of 2776 to 1 ppm of NO2 for the 0.5 wt % HGO/In2O3-sheet sensor. Compared to the isothermal mode, this strategy enhanced the response value by 1.6 times, reduced the response/recovery time by 33%/70%, and enabled the detection of NO2 concentrations as low as 1 ppb. Finally, an NO2 monitoring alarm system based on the 0.5 wt % HGO/In2O3-sheet sensor with pulsed-temperature modulation was demonstrated for hazard warnings.

Two-dimensional metal-organic framework nanosheets coated solid-phase microextraction Arrow coupled with UPLC-Q-ToF-MS for the determination of three veterinary residues in milk and pork.

This study presents a method utilizing solid-phase microextraction Arrow (SPME Arrow) combined with ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) for the selective detection of three veterinary drugs-thiabendazole, sulfamethazine, and clenbuterol-in milk and pork. Two-dimensional metal-organic framework nanosheets (2D-MOFs) were employed as coating materials for the SPME Arrow. Three types of 2D-MOFs (Ni, Mn, and Co based) were synthesized and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and a physical adsorption analyzer. The 2D-MOF coatings were fabricated using the electrospinning technique, with polyacrylonitrile (PAN) serving as the binder. Comparative analysis of the three 2D-MOF coatings revealed that 2D-Ni-MOF was the optimal coating material for the SPME Arrow. Optimization of the coating preparation conditions and SPME procedures included determining the optimal mass ratio of 2D-Ni-MOF to PAN, electrospinning time, and extraction and desorption parameters. Equilibrium extraction was achieved within 60 min, and desorption was completed within 30 min. Subsequently, the 2D-Ni-MOF-SPME Arrow-UPLC-Q-TOF-MS method was established and validated under optimal conditions, demonstrating high precision with inter-day precision ranging from 3.8 % to 9.5 % and intra-day precision ranging from 5.1 % to 11.5 %. The reusability study indicated that the extraction performance of the new SPME Arrow remained consistent after 90 adsorption-desorption cycles. The method exhibited linearity in milk and pork over the ranges of 0.002-5 µg L-1 and 0.01-5 µg L-1, respectively. The detection limits in milk and pork were 0.001-0.004 µg L-1 and 0.003-0.007 µg L-1, respectively. This method demonstrated excellent applicability for determining residues of the three veterinary drugs in milk and pork.

Engineering Injectable Coassembled Hydrogel by Photothermal Driven Chitosan-Stabilized MoS2 Nanosheets for Infected Wound Healing.

The application of enzyme-like molybdenum disulfide (MoS2) in tissue repair was confronted with stable dispersion, solubilization, and biotoxicity. Here, the injectable self-healing hydrogel was successfully designed using a step-by-step coassembly of chitosan and MoS2. Polyphenolic chitosan as a "structural stabilizer" of MoS2 nanosheets reconstructed well-dispersed MoS2@CSH nanosheets, which improved the biocompatibility of traditional MoS2, and strengthened its photothermal conversion and enzyme-like activities, guaranteeing highly efficient radical scavenging and antimicrobial properties. Furthermore, the polyphenol chitosan was employed again as a "molecular cross-linking agent" to form the injectable NIR-responsive MoS2@CSH hydrogel by accelerating hydrogen-bond interaction among chitosan and the multicross-linking reaction among polyphenols. The rapid self-healing ability was conducive to wound closure and dynamic adaptability. An experimental study on infected wound healing demonstrated that MoS2@CSH hydrogel could substantially eradicate bacteria and accelerate the angiogenesis of infected wounds. The photothermal-driven coassembly of MoS2 and polycation provided an alternative strategy for infected wound healing.

Exploring the charge transfer enhancement mechanism in selective SERS detection with Mo1-xWxS2@Ag2S nanosheets.

In order to solve the problem of poor sensitivity and selectivity of conventional SERS substrates, we synthesized Mo1-xWxS2@Ag2S nanosheets in this paper by a two-step hydrothermal method. The structure and morphology of the synthesized Mo1-xWxS2@Ag2S nanosheets were characterized by XRD and SEM,respectively. The results show that the Mo1-xWxS2@Ag2S nanosheet has an irregular layered structure. Further, the SERS properties of Mo1-xWxS2@Ag2S nanosheets were tested by using rhodamine 6G (R6G), crystalline violet (CV), and 4-mercaptobenzoic acid (4-MBA) as probe molecules, respectively. The test results demonstrated that the nanosheets were specific to R6G and CV probe molecules, and the mechanism of selectivity was due to CT enhancement. In addition, Mo1-xWxS2@Ag2S exhibits ultrahigh sensitivity in R6G and CV, with the corresponding detection limit of both reached 10-8 M. And linear fitting of the peak intensities was carried out, with the R2 coefficient of 0.981 and 0.951, respectively. Finally, the relative standard deviations (RSDs) of this Mo1-xWxS2@Ag2S nanosheets was obtained to be 8.56 % by test 1 × 10-4 M R6G at the characteristic peak 613 cm-1, which represents excellent detection repeatability. The Mo1-xWxS2@Ag2S nanosheets are rich in edge-active sites favorable for charge transfer, which can enhance the SERS signals of the target molecules better. Besides, the Raman detection of the surface of Mo1-xWxS2@Ag2S nanosheets using nitrofurantoin (NFT) also reached a detection limit of 10-8 M. Mo1-xWxS2@Ag2S nanosheets substrates can find applications in medicine and provide new strategies for improving the SERS performance.

Accelerated Proton-Coupled Electron Transfer via Engineering Palladium Sub-Nanoclusters for Scalable Electrosynthesis of Hydrogen Peroxide.

Electrosynthesis of H2O2 from oxygen reduction reaction via a two-electron pathway is vital as an alternative for the energy-intensive anthraquinone process. However, this process is largely hindered in neutral and alkaline conditions due to sluggish kinetics associated with the transformation of intermediate O2* into OOH* via proton-coupled electron transfer sourced from slow water dissociation. Herein, we developed Pd sub-nanoclusters on the nickel ditelluride nanosheets (Pd SNCs/NiTe2) to enhance the performance of H2O2 electrosynthesis. The newly-developed Pd SNCs/NiTe2 exhibited a H2O2 selectivity of as high as 99% and a positive shift of onset potential up to 0.81 V. Combined theoretical calculations and experimental studies (e.g., X-ray absorption and attenuated total reflectance-Fourier transform infrared spectra measurements) revealed that the Pd sub-nanoclusters supported by NiTe2 nanosheets efficiently reduced the energy barrier of water dissociation to generate more protons, facilitating the proton feeding kinetics. When used in a flow cell, Pd SNCs/NiTe2 cathode efficiently produced H2O2 with a maximum yield rate of 1.75 mmol h-1 cm-2 and current efficiency of 95% at 100 mA cm-2. Further, an accumulated H2O2 concentration of 1.43 mol L-1 was reached after 10 hours of continuous electrolysis, showing the potential for practical H2O2 electrosynthesis.

Antimicrobial and antibiofilm effects of cyclic dipeptide-rich fraction from Lactobacillus plantarum loaded on graphene oxide nanosheets.

Introduction: One effective method to combat bacterial infections is by using bacteria itself as a weapon. Lactobacillus is a type of fermenting bacterium that has probiotic properties and has demonstrated antimicrobial benefits against other bacteria. Cyclodipeptides (CDPs), present in the supernatant of Lactobacillus, possess several antimicrobial properties. Methods: In this study, the CDP fraction was isolated from the supernatant of Lactobacillus plantarum (L. plantarum). This fraction was then loaded onto graphene oxide nanosheets (GO NSs). The study assessed the substance's ability to inhibit bacterial growth by using the minimum inhibitory concentration (MIC) method on A. baumannii and S. aureus strains that were obtained from clinical samples. To determine the substance's impact on biofilm formation, the microtiter plate method was used. Moreover, the checkerboard technique was employed to explore the potential synergistic effects of these two substances. Results and discussion: According to the study, the minimum inhibitory concentration (MIC) of the desired compound was found to be 1.25 mg/mL against S. aureus and 2.5 mg/mL against A. baumannii. Furthermore, at a concentration of 10 mg/mL, the compound prevented 81.6% (p < 0.01) of biofilm production in A. baumannii, while at a concentration of 1.25 mg/mL, it prevented 47.5% (p < 0.05) of biofilm production in S. aureus. The study also explored the synergistic properties of two compounds using the checkerboard method. Conclusion: In general, we found that GO NSs possess antimicrobial properties and enhance cyclodipeptides' activity against S. aureus and A. baumannii.

Systematic Study on Swelling/Delamination of Layered Metal Oxides with Quaternary Ammonium Ions: Production of Well-Shaped/Oversized Unilamellar Nanosheets.

Enormous swelling of layered host compounds in an aqueous solution of various amines has been investigated as an important step in the synthesis of molecularly thin 2D nanosheets. However, a complete understanding of the reaction process has not been attained, which is the barrier for producing high-quality unilamellar nanosheets. Here, the swelling and delamination behaviors of platelet single crystals of protonated layered metal oxides are systematically examined with a series of tetraalkylammonium (TAA) hydroxide solutions. Upon contact with the solutions, the crystals immediately underwent massive expansion by several tens to hundreds of times. The swollen crystals can be delaminated into elementary layers by the application of external shear force. The exfoliation behavior is dependent on TAA ions, especially in terms of yield and lateral size/shape of the delaminated nanosheets. The swollen crystals with TAA ions with longer alkyl chains are delaminated almost completely, but irregular and fractured small sheets are yielded. Such long alkyl chains become entangled on the oxide layer and resulting hydrophobic interactions may be responsible for the lateral fragmentation. It is found that replacement of aqueous solutions with organic solvents to suppress the hydrophobic interactions is effective to produce oversized nanosheets in rectangular shape with sharp edges.

Robust and Density Tunable Kevlar/Hexagonal Boron Nitride Microribbon Aerogels with Excellent Thermal, Mechanical, and Oil-Absorption Properties.

With rapid advancements in aerospace and supersonic aircraft technology, there is a growing demand for multifunctional thermal protective materials. Aerogels, known for their low density and high porosity, have garnered significant attention in this regard. However, developing a lightweight multifunctional aerogel that combines exceptional thermal and mechanical properties through a straightforward and time-efficient method remains a significant challenge. Herein, a facile and universal approach is developed for the preparation of Kevlar/hexagonal boron nitride (h-BN) aerogels, in which a spin-assisted method is applied to create robust microribbons and further accelerate solvent displacement. The resulting microribbon scaffold, with its entangled nanofiber-nanosheet morphologies, exhibits sufficient strength to prevent volume shrinkage during drying, thereby allowing precise control over aerogel density. The porous hybrid aerogels, featuring controllable geometric characteristics and tailored densities ranging from 6.9 to 100 mg cm-3, can be successfully fabricated. These aerogels exhibit excellent thermal insulation properties, and the thermal conductivities of the as-prepared KBX aerogels have a wide distribution in the range of 0.0269-0.0450 W m-1 k-1. The thermal stability of the hybrid aerogels is enhanced to 566 °C. Moreover, the resulting hybrid aerogels exhibit an ultrahigh bearing ratio, supporting more than 2000 times their own weight while maintaining stable structural integrity. These aerogels also demonstrate high compressive strength, hydrophobicity, and excellent sorption performance for various oils and solvents. Additionally, the oil-saturated aerogels can be easily recovered through heat treatment or combustion in air. The features endow hybrid Kevlar/h-BN aerogels with significant potential for applications in thermal management, environmental protection, and neutron protection.

Triple Regulations via Fe Redox Boosting Nitrate Reduction to Ammonia at Industrial Current Densities.

Electrochemical nitrate reduction reaction (NO3-RR) has promising prospects for green synthesis of ammonia and environmental remediation. However, the performance of catalysts at high current density usually suffers from the high energy barrier for the nitrate (NO3-) to nitrite (NO2-) and the competitive hydrogen evolution. Herein, we proposed a two-step relay mechanism through spontaneous redox reaction followed electrochemical reaction by introducing low-valence Fe species into Ni2P nanosheets to significantly enhance the NO3-RR performance at industrial current density. The existence of low-valence Fe species bypasses the NO3- to NO2- step through the spontaneous redox with NO3- to produce NO2- and Fe2O3, regulates the electronic structure of Ni2P to reduce the barrier of NO2- to NH3, thirdly prohibits the hydrogen evolution by consuming the excess active hydrogen through reduction of Fe2O3 to recover low-valence Fe species. The triple regulations via Fe redox during the two-step relay reactions guarantee the Fe-Ni2P@NF high ammonia yield of 120.1 mg h-1 cm-2 with Faraday efficiency of more than 90% over a wide potential window and a long-term stability of more than 130 h at ~1000 mA cm-2. This work provides a new strategy to realize the design and synthesis of nitrate reduction electrocatalysts at high current densities.

Cationic covalent organic framework nanosheets as the coating layer of commercial separator for high-efficiency lithium-sulfur batteries.

Ion-selective separators, are crucial and in high demand for maximizing the performance of lithium-sulfur (Li-S) batteries, which can conduct lithium ions while efficiently blocking polysulfides. However, commercial separators cannot effectively block the shuttle of polysulfides after multiple cycles due to their large porosity and easy dissolution, resulting in a reduced battery life. Herein, a covalent organic framework nanosheets (CON) ion-coated separator is prepared on the commercial separator. Due to the smaller pore size of CON-TFSI compared to polysulfides, the CON-TFSI modified separator can effectively block the polysulfide from migrating across the separator. By incorporating this innovative functional layer, Li-S batteries demonstrate outstanding performance. In a Li-S battery featuring a sulfur loading of 0.6 mg/cm2, it attains an initial discharge specific capacity of up to 891.9 mA h g-1, and exhibits the capacity retention of 54.6 % after 500 cycles at a current density of 0.2 C. This work offers a fresh perspective on the advancement of high-performance membranes for Li-S batteries.

Dipole field as charge-transfer bridge between Cu atomic clusters/PtCu alloy nanocubes and nitrogen-rich C3N5 for superior photocatalytic hydrogen evolution.

Utilizing spontaneous polarization field to harness charge transfer kinetics is a promising strategy to boost photocatalytic performance. Herein, a novel Cu atom clusters/PtCu alloy nanocubes coloaded on nitrogen-rich triazole-based C3N5 (PtCu-C3N5) with dipole field was constructed through facile photo-deposition and impregnation method. The dipole field-drive spontaneous polarization in C3N5 acts as a charge-transfer bridge to promote directional electron migration from C3N5 to Cu atom clusters/PtCu alloy. Through the synergistic effects between Cu atom clusters, PtCu alloy and dipole field in C3N5, the optimized Pt2Cu3-C3N5 achieved a record-high performance with H2 formation rate of 4090.4 µmol g-1 h-1 under visible light, about 154.4-fold increase compared with pristine C3N5 (26.5 µmol g-1 h-1). Moreover, the apparent quantum efficiency was up to 25.33 % at 320 nm, which is greatly superior than most previous related-works. The directional charge transfer mechanism was analyzed in detail through various characterizations and DFT calculations. This work offers a novel pathway to construct high-efficiency multi-metal photocatalysts for solar energy conversion.

Induced Circularly Polarized Luminescence From 0D Quantum Dots by 2D Chiral Nanosheets.

Materials with circularly polarized luminescence (CPL) exhibit great application potential in biological scenes such as cell imaging, optical probes, etc. However, most developed materials are non-aqueous and toxic, which seriously restricts their compatibility with the life systems. Thus, it is necessary to explore a water-based CPL system with high biocompatibility so that to promote the biologic application process. Herein, a facile and efficient route to achieve the CPL properties of a functional aqueous solution is demonstrated by the combination of 0D quantum dots (QDs) and 2D chiral nanosheets. Benefited by the specific absorption ability of nanosheets for left/right-handed CPL, the QDs adsorbed onto the surface of nanosheets through hydrogen bond interactions showed apparent CPL features. In addition, this system has a good extensibility as the CPL property can be effectively regulated by changing the kind of emissive QDs. More importantly, this water-based nano-composite with facile fabrication process (one-step mixing) is suitable for the real applications, which is undoubtedly beneficial for the further progress of functional CPL materials.

Two-Dimensional Atomically Thin Piezoelectric Nanosheets for Efficient Pyroptosis-Dominated Sonopiezoelectric Cancer Therapy.

Sonopiezocatalytic therapy is an emerging therapeutic strategy that utilizes ultrasound irradiation to activate piezoelectric materials, inducing polarization and energy band bending to facilitate the generation of reactive oxygen species (ROS). However, the efficient generation of ROS is hindered by the long distance of charge migration from the bulk to the material surface. Herein, atomically thin Bi2O2(OH)(NO3) (AT-BON) nanosheets are rationally engineered through disrupting the weaker hydrogen bonds within the [OH] and [NO3] layer in the bulk material. The ultrathin structure of AT-BON piezocatalytic nanosheets shortens the migration distance of carriers, expands the specific surface area, and accelerates the charge transfer efficiency, showcasing a natural advantage in ROS generation. Importantly, the non-centrosymmetric polar crystal structure grants the nanosheets the ability to separate electron-hole pairs. Under ultrasonic mechanical stress, Bi2O2(OH)(NO3) nanosheets with the remarkable piezoelectric feature exhibit the desirable in vivo antineoplastic outcomes in both breast cancer model and liver cancer model. Especially, the AT-BON-induced ROS bursts lead to the activation of the Caspase-1-driven pyroptosis pathway. This study highlights the beneficial impact of bulk material thinning on enhancing ROS generation efficiency and anti-cancer effects.

Simultaneously Flame Retarding and Toughening of Epoxy Resin Composites Based on Two-Dimensional Polyhedral Oligomeric Silsesquioxane/Polyoxometalate Supramolecular Nanocrystals with Ultralow Loading.

For industrial practical applications, it is difficult to simultaneously endow epoxy resin (EP) composites with superior flame retardancy, smoke suppression, toughness, and low-dielectric constants. Herein, unique polyhedral oligomeric silsesquioxane/polyoxometalate (POM(Mo)-POSS(ibu-Li)) nanosheets were synthesized via a simple one-pot method using laboratory-made lithium-containing hepta-isobutyl-POSS (ibu-Li-POSS) and the low-cost industrial chromogenic agent H3PMo12O40 as raw materials. The incorporation of 2 wt % POM(Mo)-POSS(ibu-Li) nanoflakes into EP significantly enhanced the compatibility between nanoadditives and the EP matrix. Compared with EP, the flexural and impact strengths increased by 36.2 and 78.2%, respectively. Therefore, POM(Mo)-POSS(ibu-Li) has significant advantages in enhancing the toughness of EP compared with existing flame retardants. The dielectric constant and loss were apparently reduced to meet the increasing requirements of EP-type electronic packaging materials and components. Notably, the synthesized POM(Mo)-POSS(ibu-Li) contained various flame-retardant and smoke-suppression elements such as P, Mo, and Si. The ultralow loading (2 wt %) of POM(Mo)-POSS(ibu-Li) significantly reduced the peak heat release rate, peak of smoke production rate, and CO production rate by 43.9, 40.6, and 65.8%, respectively. Meanwhile, the value of LOI increased directly from 24.0% for EP to 30.2% and passed the V-0 rating in the UL-94 test. However, incorporating 5 wt % POSS derivatives into EP alone to ensure that the prepared composites pass the V-0 rating of the UL-94 test has always been an extraordinarily difficult problem. Therefore, the dilemmas of poor dielectric properties, inherent flammability, and brittleness of EP were completely overcome through the successful application of POM(Mo)-POSS(ibu-Li) supramolecular nanosheets.

Copper tannate nanosheets-embedded multifunctional coating for antifouling and photothermal bactericidal applications.

Implant-associated infections (IAIs), triggered by pathogenic bacteria, are a leading cause of implant failure. The design of functionalized coatings on biomedical materials is crucial to address IAIs. Herein, a multifunctional coating with good antifouling effect and antibacterial photothermal therapy (aPTT) performance was developed. The copper tannate nanosheets (CuTA NSs) were formed via coordination bonding of Cu2+ ions and tannic acid (TA). The CuTA NSs were then integrated into the TA and poly(ethylene glycol) (PEG) network to form the TCP coating for deposition on the titanium (Ti) substrates via surface adhesion of TA and gravitational effect. The resulting Ti-TCP substrate exhibited good antifouling property, reactive oxygen species (ROS) scavenging capability and cytocompatibility. The TCP coating exhibited antifouling efficacy in conjunction with aPTT, curtailing the surface adhesion and biofilm formation of pathogens, such as Staphylococcus aureus and Escherichia coli. Notably, the Ti-TCP substrate also exhibited the ability to prevent bacterial infection in vivo in a subcutaneous implantation model. The present work demonstrated a promising approach in designing high-performance antifouling and photothermal bactericidal coatings to combat IAIs.

One-Step Synthesis of Heterostructured Mo@MoO2 Nanosheets for High-Performance Supercapacitors with Long Cycling Life and High Rate Capability.

Supercapacitors have gained increased attention in recent years due to their significant role in energy storage devices; their impact largely depends on the electrode material. The diversity of energy storage mechanisms means that various electrode materials can provide unique benefits for specific applications, highlighting the growing trend towards nanocomposite electrodes. Typically, these nanocomposite electrodes combine pseudocapacitive materials with carbon-based materials to form heterogeneous structural composites, often requiring complex multi-step preparation processes. This study introduces a straightforward approach to fabricate a non-carbon-based Mo@MoO2 nanosheet composite electrode using a one-step thermal evaporating vapor deposition (TEVD) method. This novel electrode features Mo at the core and MoO2 as the shell and demonstrates exceptional electrochemical performance. Specifically, at a current density of 1 A g-1, it achieves a storage capacity of 205.1 F g-1, maintaining virtually unchanged capacity after 10,000 charge-discharge cycles at 2 A g-1. The outstanding long-cycle stability is ascribed to the vertical two-dimensional geometry, the superior conductivity, and pseudocapacitance of the Mo@MoO2 core-shell nanosheets. These attributes significantly improve the electrode's charge storage capacity, charge transfer speed, and structural integrity during the cycling process. The development of the one-step grown Mo@MoO2 nanosheets offers a promising way for the advancement of high-performance, non-carbon-based supercapacitor nanocomposite electrodes.

Synthesis and characterization of fluorinated graphene oxide nanosheets derived from Lissachatina fulica snail mucus and their biomedical applications.

The modern nanomedicine incorporates the multimodal treatments into a single formulation, offering innovative cancer therapy options. Nanosheets function as carriers, altering the solubility, biodistribution, and effectiveness of medicinal compounds, resulting in more efficient cancer treatments and reduced side effects. The non-toxic nature of fluorinated graphene oxide (FGO) nanosheets and their potential applications in medication delivery, medical diagnostics, and biomedicine distinguish them from others. Leveraging the unique properties of Lissachatina fulica snail mucus (LfSM), FGO nanosheets were developed to reveal the novel characteristics. Consequently, LfSM was utilized to create non-toxic, environmentally friendly, and long-lasting FGO nanosheets. Ultraviolet-visible (UV-vis) spectroscopy revealed a prominent absorbance peak at 235 nm. The characterization of the synthesized FGO nanosheets involved X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), and atomic force microscopy (AFM) analyses. The antimicrobial activity data demonstrated a broad spectrum of antibacterial effects against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The cytotoxicity efficacy of LfSM-FGO nanosheets against pancreatic cancer cell line (PANC1) showed promising results at low concentrations. The study suggests that FGO nanosheets made from LfSM could serve as alternate factors for in biomedical applications in the future.

Renewable synthesis of MoO3 nanosheets via low temperature phase transition for supercapacitor application.

2D transition metal oxides have created revolution in the field of supercapacitors due to their fabulous electrochemical performance and stability. Molybdenum trioxides (MoO3) are one of the most prominent solid-state materials employed in energy storage applications. In this present work, we report a non-laborious physical vapor deposition (PVD) and ultrasonic extraction (USE) followed by vacuum assisted solvothermal treatment (VST) route (DEST), to produce 2D MoO3 nanosheets, without any complex equipment requirements. Phase transition in MoO3 is often achieved at very high temperatures by other reported works. But our well-thought-out, robust approach led to a phase transition from one phase to another phase, for e.g., hexagonal (h-MoO3) to orthorhombic (α-MoO3) structure at very low temperature (90 °C), using a green solvent (H2O) and renewable energy. This was achieved by implementing the concept of oxygen vacancy defects and solvolysis. The synthesized 2D nanomaterials were investigated for electrochemical performance as supercapacitor electrode materials. The α-MoO3 electrode material has shown supreme capacitance (256 Fg-1) than its counterpart h-MoO3 and mixed phases (h and α) of MoO3 (< 50 Fg-1). Thus, this work opens up a new possibility to synthesize electrocapacitive 2D MoO3 nanosheets in an eco-friendly and energy efficient way; hence can contribute in renewable circular economy.

Synthesis and Anisotropic Memristive Behavior of Borophene Nanosheets.

Neuromorphic computing, marked by its parallel computational abilities and low power usage, has become pivotal in advancing artificial intelligence. However, the advancement of neuromorphic computing has faced significant obstacles due to the performance limitations of traditional memory devices struggling with high power consumption and limited reliability. Two-dimensional (2D) materials have been extensively investigated as high-performance memristive materials, but they are often restricted by fixed memristive properties, which complicate circuit design and limit flexibility. Here, we report that multilayer borophene nanosheets represent a breakthrough material, displaying anisotropic variable memristive properties. The nanosheets, comprising semiconductor α'-4H-borophene sheets and metal ß12-borophene sheets, have been synthesized on aluminum foil surface through chemical vapor deposition (CVD) method. The multilayer borophene nanosheets exhibit volatile memory behavior in the vertical direction and non-volatile memory behavior in the planar direction. This innovative class of 2D nanosheets not only overcomes the limitations of conventional memory devices but also expands the potential applications of borophene-based memories in information storage and in-memory computing.

2D Differential Metallic Immunopotentiators Drive High Diversity and Capability of Antigen-specific Immunity Against Tumor.

The therapeutic efficacy of vaccines for treating cancers in clinics remains limited. Here, a rationally designed cancer vaccine by placing immunogenically differential and clinically approved aluminum (Al) or manganese (Mn) in a 2D nanosheet (NS) architecture together with antigens is reported. Structurally optimal NS with a high molar ratio of Mn to Al (MANS-H) features distinctive immune modulation, markedly promoting the influx of heterogeneous innate immune cells at the injection site. Stimulation of multiple subsets of dendritic cells (DCs) significantly increases the levels, subtypes, and functionalities of antigen-specific T cells. MANS-H demonstrates even greater effectiveness in the production of antigen-specific antibodies than the commercial adjuvant (Alhydrogel) by priming T helper (Th)2 cells rather than T follicular helper (Tfh) cells. Beyond humoral immunity, MANS-H evokes high frequencies of antigen-specific Th1 and CD8+ cell immunity, which are comparable with Quil-A that is widely used in veterinary vaccines. Immunized mice with MANS-H adjuvanted vaccines exert strong potency in tumor regression by promoting effector T cells infiltrating at tumor and overcoming tumor resistance in multiple highly aggressive tumor models. The engineered immunogen with an intriguing NS architecture and safe immunopotentiators offers the next clinical advance in cancer immunotherapy.