A carbon nanosphere nanofluid for improving the toughness and thermal properties of epoxy composites.

A carbon nanosphere nanofluid (CNS-nanofluid) was successfully prepared through the non-covalent modification of carbon nanosphere (CNS) with the specific ionic liquid (i.e. [M2070][VBS]) at first. The resulting CNS-nanofluid is a homogeneous and stable fluid with liquid-like behaviour at room temperature, and which shows better dispersion stability in its good solvents and improved processability than the pristine CNS. Subsequently, this CNS-nanofluid was used as a kind of novel functional filler and incorporated into epoxy matrix to prepare the CNS-nanofluid filled epoxy composites (CNS-nanofluid/EP composites). The toughness and thermal properties of those CNS-nanofluid/EP composites were carefully characterized and analysed. And it was found that this CNS-nanofluid could respectively improve the impact toughness and glass transition temperature of the CNS-nanofluid/EP composites to 19.8 kJ m-2and 122.5 °C at the optimum amount, demonstrating that this CNS-nanofluid is a kind of promising functional filler to achieve robust epoxy composites, and thus opening up new possibilities with great significance for epoxy composites in high-performance applications.

Magnetic solid-phase extraction based on carbon nanosphere@Fe3 O4 for enantioselective determination of eight triazole fungicides in water samples.

In this work, a carbon nanosphere decorated by Fe3 O4 nanoparticles was prepared, characterized and used as the magnetic adsorbent. Eight commonly used chiral triazole fungicides, including penconazole, uniconazole, paclobutrazol, triazolone, tebuconazole, hexaconazole, triticonazole and epoxiconazole were extracted from two environmental water samples (river water and lake water) by magnetic solid-phase extraction, followed by the enantiomeric analysis on a Chiralpark IC column coupled with a triple quadrupole mass spectrometry to evaluate their possible stereoselective degradation occurring in the water samples. The possible factors affecting the extraction performance, such as amount of used adsorbents, pH and ionic strength of water solution, types and volumes of desorption solvents were systematically investigated. Under the optimum conditions, extraction yields of eight triazole fungicides were above 80% and the concentration factors were as high as 1000. Method detection and quantification limits for the enantiomers of eight triazole fungicides were in the range of 0.56-6.95 ng/L. Satisfactory accuracy (relative recovery 77.8-93.5%), good intraday precision (RSD 4.3-9.8%) and interday precision (RSD 3.1-7.9%) were also obtained. The developed method provided the simplicity of operation, rapidity and high enrichment factor, which can be used to monitor and evaluate the behavior of the individual enantiomer of chiral triazole fungicides.

Pt-Co nanocluster in hollow carbon nanospheres.

Recently, it has been reported that small Pt/Co bimetallic nanoclusters into hollow carbon spheres (HCS) show outstanding catalytic performances in deriving biomass fuels due to the small particle size and the homogeneous alloying. Thus, the knowledge about the thermal evolution and stability of the nanoclusters into the HCS has a great importance. We have simulated the heating process beyond the melting point for the bare and encapsulated Pt/Co clusters into the HCS with the different sizes of 55, 147, and 309. The different thermodynamic and structural properties of the nanoclusters have also been investigated in this work. Our results show that the nanoclusters are more stable into the HCS than the bare clusters. The melting points of the supported clusters are also higher than the unsupported clusters. The confined nanoclusters have also lower excess energy values than the bare clusters which means that the encapsulation of Pt/Co nanoclusters into the HCS is favorable. The structural investigations show that a core-shell structure cannot be observed for the different supported and unsupported clusters and the initial mixed structure of the different nanoclusters remains also at the melting points. To more investigate this claim, the radial chemical distribution function (RCDF) and radial distribution function (RDF) of the bare and encapsulated clusters have also been calculated and discussed. © 2018 Wiley Periodicals, Inc.

Construction of carbon nanospheres: A rational design based on BS-12 @ LiCl.

Nanocarbons have potential applications in almost all areas of materials science. While we have appreciated the various discoveries and applications of many nanocarbons, we recognize that the field remains challenging in terms of tunability. In this research, we report a new strategy for the self-assembly of surfactant @ salt from the concept of carbon nanostructure design, and introduce the concept of "separator". On the one hand, it allows the core and shell to be formed in one step. On the other hand, it allows the ordered aggregates to remain in their original shape under thermal action. The surface morphology, degree of graphitization, elemental composition and surface chemical state, formation mechanism, and specific luminescent properties of carbon nanomaterials were investigated. TEM reveals that (dodecyldimethyl betaine) BS-12 @ LiCl carbon nanospheres with tunable size (from 55 nm to 70 nm) can be successfully synthesized. Raman and XRD show that the structure of carbon nanospheres has some defects and disordered carbon. XPS and FTIR analyses indicate that the defects present in the carbon nanosphere structure are related to the N and O elements. The detailed growth mechanism shows that the micelle structure in the system can be well adjusted by changing the concentration of surfactant. PL research demonstrates that the synthesized carbon nanospheres have UV luminescent properties. Most importantly, the method can be further developed into a general strategy for self-assembly using a variety of surfactants and "separators" as promising candidates for future practical applications of nanocarbon materials.

N-rich carbon nanosphere as fluorescent nanoprobe for intracellular iron.

Nitrogen rich carbon nanoparticles are known to provide higher fluorescence stokes shift, and thereby are potential candidates for fluorescent sensors. Herein, a facile one-step hydrothermal synthesis is reported for N-rich carbon nanospheres (G-CNS) from caffeine and o-phenylenediamine as precursors. The as-synthesized G-CNS showed high fluorescence with λem at 509 nm, with a highly selective fluorescence turn-off response towards Fe2+/Fe3+, rendering these carbon nanospheres as potential candidates to detect intracellular labile iron pool in live cells. The intracellular labile iron pool in iron-overloaded cells was sensed using the synthesized G-CNS. Mechanistically, the fluorescence quenching via dynamic pathway involves the formation of an excited state charge transfer process, which undergoes non-radiative decay.

Advances on carbon nanomaterials and their applications in medical diagnosis and drug delivery.

Carbon nanomaterials are indispensable due to their unique properties of high electrical conductivity, mechanical strength and thermal stability, which makes them important nanomaterials in biomedical applications and waste management. Limitations of conventional nanomaterials, such as limited surface area, difficulty in fine tuning electrical or thermal properties and poor dispersibility, calls for the development of advanced nanomaterials to overcome such limitations. Commonly, carbon nanomaterials were synthesized by chemical vapor deposition (CVD), laser ablation or arc discharge methods. The advancement in these techniques yielded monodispersed carbon nanotubes (CNTs) and allows p-type and n-type doping to enhance its electrical and catalytic activities. The functionalized CNTs showed exceptional mechanical, electrical and thermal conductivity (3500-5000 W/mK) properties. On the other hand, carbon quantum dots (CQDs) exhibit strong photoluminescence properties with high quantum yield. Carbon nanohorns are another fascinating type of nanomaterial that exhibit a unique structure with high surface area and excellent adsorption properties. These carbon nanomaterials could improve waste management by adsorbing pollutants from water and soil, enabling precise environmental monitoring, while enhancing wastewater treatment and drug delivery systems. Herein, we have discussed the potentials of all these carbon nanomaterials in the context of innovative waste management solutions, fostering cleaner environments and healthier ecosystems for diverse biomedical applications such as biosensing, drug delivery, and environmental monitoring.

Fabrication modulation of lignin-derived carbon nanosphere supported Pd nanoparticle via lignin fractionation for improved catalytic performance in vanillin hydrodeoxygenation.

Nano-lignin presents great potential in advanced carbon materials preparation since it integrates the advantages of nanomaterials as well the preferable properties of lignin (e.g. high carbon content and highly aromatic structure). Herein, lignin-derived carbon nanosphere supported Pd catalysts (Pd@LCNS) were prepared via a two-step carbonization of Pd2+ adsorbed lignin nanospheres (LNS) and applied in vanillin hydrodeoxygenation. The effect lignin heterogeneity on the synthesis of Pd@LCNS as well as its catalytic performance was further investigated through the synthesis of Pd@LCNS using three lignin fractions with different molecular weight. The results showed that the three Pd@LCNSs exhibited significant differences in the morphology of both carbon support and Pd nanoparticles. Pd@LCNS-3 prepared from high molecular weight lignin fraction (L-3) presented stable carbon nanosphere support with the smallest particle size (∼150 nm) and the highest Pd loading amount (3.78 %) with the smallest Pd NPs size (∼1.6 nm). Therefore, Pd@LCNS-3 displayed superior catalytic activity for vanillin hydrodeoxygenation (99.34 % of vanillin conversion and 99.47 % of 2-methoxy-4-methylphenol selectivity) at 90 °C without H2. Consequently, this work provides a sustainable strategy to prepare uniformly dispersed lignin-based carbon-supported Pd catalyst using high molecular weight lignin as the feedstock and further demonstrate its superior applicability in the selective transfer hydrogenation of vanillin.

A Fe2(SO4)3-assisted approach towards green synthesis of cuttlefish ink-derived carbon nanospheres for high-performance supercapacitors.

The conversion of renewable biomass resources into advanced electrode materials through green, simple, and economical methods has become an important research direction in energy storage. In this study, Fe-decorated N/S-codoped porous carbon nanospheres have been successfully fabricated from cuttlefish ink through Fe2(SO4)3-assisted hydrothermal carbonization coupled with heat treatment. The effects of Fe2(SO4)3 dosage on the structure, chemical composition, and capacitive property of carbon nanospheres were investigated. Herein, environmentally friendly Fe2(SO4)3 plays a multifunctional role as the graphitization catalyst, dopant, and morphology-regulating agent. Benefitting from the moderate graphitization degree, great heteroatom content and hierarchical porous structure, the prepared carbon nanospheres exhibit high specific capacitance (311.9 F g-1 at a current density of 0.5 A g-1), good rate capability (19.1% decrease in specific capacitance as current density increases from 0.5 to 10 A g-1), and ideal cycling stability (94.3% capacitance retention after 5000 cycles). In addition, the symmetric supercapacitor assembled with the carbon nanosphere electrodes achieves an energy density of 9.7 Wh kg-1 at a power density of 0.25 kW kg-1 and maintains 91.3% capacitance after 10,000 cycles. The desirable electrochemical performance of cuttlefish ink-derived carbon nanosphere material makes it a potential electrode candidate for supercapacitors.

Novel and sustainable green sulfur-doped carbon nanospheres via hydrothermal process for Cd (II) ion removal.

Herein, the synthesis, characterization, and adsorption performance of a novel green sulfur-doped carbon nanosphere (S-CNs) is studied to eliminate Cd (II) ions from water effectively. S-CNs were characterized using different techniques including Raman spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), , Brunauer-Emmett-Teller (BET) specific surface area analysis and Fourier transform infrared spectrophotometry (FT-IR), were performed. The efficient adsorption of the Cd (II) ions onto S-CNs strongly depended on pH, initial concentration of Cd (II) ions, S-CNs dosage, and temperature. Four isotherm models (Langmuir, Freundlich, Temkin & Redlich Peterson) were tested for modeling. Out of four, Langmuir showed more applicability than the other three models, with a Qmax value of 242.72 mg/g. Kinetic modeling studies suggest a superior fit of the obtained experimental data with the Elovich equation (linear) and pseudo-second-order (non-linear) rather than other linear and non-linear models. Data obtained from thermodynamic modeling indicates that using S-CNs for Cd (II) ions adsorption is a spontaneous and endothermic . The current work recommends using better and recyclable S-CNs to uptake excess Cd (II) ions.

Adsorption properties and mechanism of zinc acrylic carbon nanosphere aggregates for perfluorooctanoic acid from aqueous solution.

This study found that the cross-linkable zinc acrylic nanosphere aggregates (NAs) as precursors were successfully prepared by a simple one-step synthesis route, and Zn,O dopped-carbon nanocomposites were obtained through temperature-controllable engineering, which showed excellent adsorption capacities for perfluorooctanoic acid (PFOA). A series of experiments were performed to investigate and compare carbon materials for the efficient removal of PFOA. The maximum adsorption capacities of PFOA absorbed on carbon nanospheres aggregates (CNAs) were calculated by the Langmuir (360.98 mg/g) and Sips models (309.65 mg/g). The kinetic model indicated there was chemical adsorption and physical adsorption in the adsorption process. Van der Waals force and electrostatic interactions might be the dominant mechanism of the adsorption process. Additionally, pore-filling also played a role in the adsorption process. Furthermore, the adsorption efficiency was still above 90% after five cycles. The selective adsorption ability was tested through various pollutants (metal ions and dye solutions) absorbed by the CNAs. Our results proved that carbon nanosphere aggregates (CNAs) are expected to be outstanding adsorption materials for the decontamination of PFOA from wastewater.

Ratiometric Fluorescent Detection of Ultrasound-Regulated ATP Release: An Ultrasound-Resistant Cu,N-Doped Carbon Nanosphere.

Focused ultrasound, as a protocol of cancer therapy, might induce extracellular adenosine triphosphate (ATP) release, which could enhance cancer immunotherapy and be monitored as a therapeutic marker. To achieve an ATP-detecting probe resistant to ultrasound irradiation, we constructed a Cu/N-doped carbon nanosphere (CNS), which has two fluorescence (FL) emissions at 438 and 578 nm to detect ultrasound-regulated ATP release. The addition of ATP to Cu/N-doped CNS was conducted to recover the FL intensity at 438 nm, where ATP enhanced the FL intensity probably via intramolecular charge transfer (ICT) primarily and hydrogen-bond-induced emission (HBIE) secondarily. The ratiometric probe was sensitive to detect micro ATP (0.2-0.6 µM) with the limit of detection (LOD) of 0.068 µM. The detection of ultrasound-regulated ATP release by Cu,N-CNS/RhB showed that ATP release was enhanced by the long-pulsed ultrasound irradiation at 1.1 MHz (+37%, p < 0.01) and reduced by the short-pulsed ultrasound irradiation at 5 MHz (-78%, p < 0.001). Moreover, no significant difference in ATP release was detected between the control group and the dual-frequency ultrasound irradiation group (+4%). It is consistent with the results of ATP detection by the ATP-kit. Besides, all-ATP detection was developed to prove that the CNS had ultrasound-resistant properties, which means it could bear the irradiation of focused ultrasound in different patterns and detect all-ATP in real time. In the study, the ultrasound-resistant probe has the advantages of simple preparation, high specificity, low limit of detection, good biocompatibility, and cell imaging ability. It has great potential to act as a multifunctional ultrasound theranostic agent for simultaneous ultrasound therapy, ATP detection, and monitoring.

Facile Strategy to Prepare Poly(ionic liquid)-Coated Solid Polymer Electrolytes through Layer-by-Layer Assembly.

The inability of solid polymer electrolytes to preserve strong mechanical strength with high ionic conductivity hinders the commercialization of lithium metal batteries (LMBs). The success of fabricating layer-by-layer (LbL)-assembled electrolytes has realized the application of flexible solid polymer electrolytes in electrochemical devices. Here, we demonstrate a rational strategy to construct solid electrolytes coated with multiple ultrathin layers of polyanions (poly(sodium 4-styrenesulfonate)) and polycations (linear poly(1-butyl-3-(4-vinylbenzyl)-1H-imidazolium chloride) (BVIC)/linear poly(PEG4-VIC)/SiO2-g-poly(PEG4-VIC)) using an LbL assembly method. Poly(ionic liquid) backbones and PEG side groups are employed to facilitate the transport of lithium ions via the segmental motion of the macromolecular matrix. The fabricated free-standing membranes exhibited good ionic conductivities of 9.03-10 × 10-4 S cm-1. Furthermore, a Li/LiFePO4 cell assembled with the LbL-membrane electrolytes exhibits an initial high discharge capacity of 143-158 mAhg-1 at 60 °C with high columbic efficiency. This approach, which combines polymer synthesis and LbL self-assembly, is an effective and facile route to fabricate solid polymer electrolyte membranes with superior ionic conductivity and mechanical robustness, which are useful for electrochemical devices and high-voltage battery applications.

Solar-Light-Responsive Zinc-Air Battery with Self-Regulated Charge-Discharge Performance based on Photothermal Effect.

It is extremely challenging to significantly increase the voltaic efficiency, power density, and cycle stability of a Zn-air battery by just adjusting the catalytic performance of the cathode with nanometers/atomistic engineering because of the restriction of thermodynamic equilibrium potential. Herein, inspired by solar batteries, the S-atom-bridged FeNi particles and N-doped hollow carbon nanosphere composite configuration (FeNi-S,N-HCS) is presented as a prototype of muti-functional air electrode material (intrinsic electrocatalytic function and additional photothermal function) for designing photoresponsive all-solid-state Zn-air batteries (PR-ZABs) based on the photothermal effect. The local temperature of the FeNi-S,N-HCS electrode can well respond to the stimuli of sunlight irradiation because of their superior photothermal effect. As expected, under illumination, the power density of the as-fabricated PR-ZABs based on the FeNi-S,N-HCS electrode can be improved from 77 mW cm-2 to 126 mW cm-2. Simultaneously, charge voltage can be dramatically reduced, and cycle lifetime is also prolonged under illumination, because of the expedited electrocatalytic kinetics, the increased electrical conductivity, and the accelerated desorption rate of O2 bubbles from the electrode. By exerting the intrinsic electrocatalytic and photothermal efficiency of the electrode materials, this research paves new ways to improve battery performance from kinetic and thermodynamic perspectives.

Hollow porous carbon nanospheres containing polar cobalt sulfide (Co9S8) nanocrystals as electrocatalytic interlayers for the reutilization of polysulfide in lithium-sulfur batteries.

HYPOTHESIS: The introduction of functional interlayers for efficient anchoring of lithium polysulfides has received significant attention worldwide. EXPERIMENTS: A facile wet-chemical method was adopted to obtain hollow porous carbon nanospheres (HPCNSs) impregnated with metallic and polar cobalt sulfide (Co9S8) nanocrystals (abbreviated as "Co9S8@HPCNS"). The prepared nanocrystals were employed as electrocatalytic interlayers via separator coating for the efficient capture and reutilization of polysulfide species in Li-S batteries. The HPCNSs were synthesized via the polymerization method followed by carbonization and template removal. The Co9S8 nanocrystals were impregnated inside the HPCNSs, followed by heat treatment in a reducing atmosphere. FINDINGS: The porous structure of the CNS enables the efficient percolation of the electrolyte, in addition to accommodating unwanted volume fluctuations during redox processes. Furthermore, the metallic Co9S8 nanocrystals improve the electronic conductivity and enhance the polarity of the CNS towards the polysulfide. Correspondingly, the Li-S cells featuring Co9S8@HPCNS as electrocatalytic interlayers and regular sulfur (S) electrodes display improved electrochemical performance such as reasonable rate performance and prolonged cycling stability at different current rates (0.1, 0.5, and 1.0 C). Therefore, we anticipate that the rational design strategy proposed herein will provide significant insights into the synthesis of advanced materials for various energy storage applications.

Organic-Inorganic Hybrid Interfaces Enable the Preparation of Nitrogen-Doped Hollow Carbon Nanospheres as High-Performance Anodes for Lithium and Potassium-Ion Batteries.

An abundant hollow nanostructure is crucial for fast Li+ and K+ diffusion paths and sufficient electrolyte penetration, which creates a highly conductive network for ionic and electronic transport. In this study, we successfully developed a molecular-bridge-linked, organic-inorganic hybrid interface that enables the preparation of in situ nitrogen-doped hollow carbon nanospheres. Moreover, the prepared HCNSs, with high nitrogen content of up to 10.4%, feature homogeneous and regular morphologies. The resulting HCNSs exhibit excellent lithium and potassium storage properties when used as electrode materials. Specifically, the HCNS-800 electrode demonstrates a stable reversible discharge capacity of 642 mA h g-1 at 1000 mA g-1 after 500 cycles for LIBs. Similarly, the electrode maintains a discharge capacity of 205 mA h g-1 at 100 mA g-1 after 500 cycles for KIBs. Moreover, when coupled with a high-mass-loading LiFePO4 cathode to design full cells, the HCNS-800‖LiFePO4 cells provide a specific discharge capacity of 139 mA h g-1 at 0.1 C. These results indicate that the HCNS electrode has promising potential for use in high-energy and environmentally sustainable lithium-based and potassium-based batteries.

Atomically Dispersed Pd-N1C3 Sites on a Nitrogen-Doped Carbon Nanosphere for Semi-hydrogenation of Acetylene.

Rationally designing efficient catalysts for semi-hydrogenation of acetylene is significant but challenging. Herein, Pd isolated single-atom sites (ISAS) on a covalent-organic-framework (COF)-derived nanosphere (Pd-ISAS/CN) are synthesized by a COF-absorption-pyrolysis strategy. This synthetic strategy is also applicable for Pt and Ru ISAS catalysts, demonstrating that it is a general method to synthesize noble-metal ISAS on COF-derived carbon materials. Pd-ISAS/CN exhibits outstanding reactivity and high selectivity for semi-hydrogenation of acetylene, with 92% conversion of acetylene, 80% selectivity toward ethylene at 100 °C, and corresponding activity is as high as 712 molacetylene molmetal-1 h-1. Extended X-ray absorption fine structure (EXAFS) measurement and density functional theory (DFT) calculation reveal the Pd-N1C3 sites from Pd-ISAS/CN efficiently boost the reactivity for semi-hydrogenation of acetylene. This work will bring inspiration to rationally design noble-metal-based ISAS catalysts derived from COF materials and boost catalytic performance by optimizing the coordination environment of catalytic sites.

Thermal Conductivity Enhancement of Atomic Layer Deposition Surface-Modified Carbon Nanosphere and Carbon Nanopowder Nanofluids.

In this paper, we present a study on thermal conductivity and viscosity of nanofluids containing novel atomic layer deposition surface-modified carbon nanosphere (ALD-CNS) and carbon nanopowder (ALD-CNP) core-shell nanocomposites. The nanocomposites were produced by atomic layer deposition of amorphous TiO2. The nanostructures were characterised by scanning (SEM) and transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, thermogravimetry/differential thermal analysis (TG/DTA) and X-ray powder diffraction (XRD). High-concentration, stable nanofluids were prepared with 1.5, 1.0 and 0.5 vol% nanoparticle content. The thermal conductivity and viscosity of the nanofluids were measured, and their stability was evaluated with Zeta potential measurements. The ALD-CNS enhanced the thermal conductivity of the 1:5 ethanol:water mixture by 4.6% with a 1.5 vol% concentration, and the viscosity increased by 37.5%. The ALD-CNS increased the thermal conductivity of ethylene-glycol by 10.8, whereas the viscosity increased by 15.9%. The use of a surfactant was unnecessary due to the ALD-deposited TiO2 layer.

Comparative Study of Carbon Nanosphere and Carbon Nanopowder on Viscosity and Thermal Conductivity of Nanofluids.

A comparative research on stability, viscosity (µ), and thermal conductivity (k) of carbon nanosphere (CNS) and carbon nanopowder (CNP) nanofluids was performed. CNS was synthesized by the hydrothermal method, while CNP was provided by the manufacturer. Stable nanofluids at high concentrations 0.5, 1.0, and 1.5 vol% were prepared successfully. The properties of CNS and CNP nanoparticles were analyzed with Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area (SBET), X-ray powder diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), and energy dispersive X-ray analysis (EDX). The CNP nanofluids have the highest k enhancement of 10.61% for 1.5 vol% concentration compared to the base fluid, while the CNS does not make the thermal conductivity of nanofluids (knf) significantly higher. The studied nanofluids were Newtonian. The relative µ of CNS and CNP nanofluids was 1.04 and 1.07 at 0.5 vol% concentration and 30 °C. These results can be explained by the different sizes and crystallinity of the used nanoparticles.

Bioinspired Metal-Free Fluorescent Carbon Nanozyme with Dual Catalytic Activity to Confront Cellular Oxidative Damage.

Development of metal-free, recyclable enzyme mimics is challenging and requires key chemical modifications at the molecular level. Here, nitrilotriacetic acid-functionalized carbon nanospheres (LC-CNS@NTA) were prepared from the nitrogen-rich weed Lantana camara (LC) using a simple hydrothermal reaction condition. Transmission electron microscopy (TEM) studies revealed size of ∼160 ± 20 nm for LC-CNS@NTA whereas, the same showed fluorescence emission at ∼520 nm with a ∼63% quantum yield. Furthermore, LC-CNS@NTA showed strong peroxidase (Pxrd) activity toward a wide range of substrate viz., H2O2, 3,3',5,5'-tetramethylbenzidine, and o-phenylenediamine with Km and Vmax values of ∼257 µM and 1.06 µM/s, 282 µM and 1.47 µM/s, and 270.8 µM and 1.647 µM/s, respectively. Interestingly, this also showed catalase (CAT) activity against H2O2 with Km and Vmax values of ∼0.374 µM and 1.87 µM/s, respectively. It was observed that LC-CNS@NTA could effectively reduce the oxidative stress-induced cytotoxicity of HEK293 cells via retention of mitochondrial membrane potential, prevention of lipid peroxidation and DNA damage. It was further found that LC-CNS@NTA-treated cells showed reduced level of intracellular protein carbonylation and protein aggregation. The finding of the present study is expected to pave the path for designing engineered metal-free carbon nanozyme with dual enzyme mimic activity.

Orientated VSe2 nanoparticles anchored on N-doped hollow carbon sphere for high-stable aqueous energy application.

Transition metal dichalcogenides (TMDs) have been considered as the promising energy storage materials due to their unique crystalline structure. In this work, the VSe2 nanoparticles are vertically anchored on N-doping carbon (NC) hollow nanosphere (VSe2@NC) for aqueous energy application. The electrochemical measurements indicate that the VSe2@NC electrode exhibits outstanding electrochemical properties with high specific capacitance and excellent cycling life. Moreover, the asymmetric supercapacitor was assembled by using VSe2@NC cathode and activated carbon anode. It shows high energy density of 85.41 Wh Kg-1 at a power density of 701.99 W Kg-1, and high-stable cycling performance of 90% retention after 2000 cycles. The superior properties are attributed to the particular hollow structure design, which accommodates both the high specific capacity of VSe2 and the desired electrical conductivity of N-doping carbon sphere template.