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In this study, an electrospinning method was used to produce highly conductive freestanding carbon nanofibers (CNFs). The freestanding CNFs are compatible with hierarchical growth techniques, such as hydrothermal processes, for the nanostructure engineering of supercapacitor electrodes with enhanced electrochemically active sites. Therefore, the flower-like FeMoO 4 @CNF nanosheets were investigated to improve the electrochemical performance using aqueous and neutral electrolytes (Na 2 SO 4 and K 2 SO 4). The optimized FeMoO 4 @CNF electrode exhibits areal capacitances of 252 and 220 mF·cm−2 at a high current density of 2.5 mA·cm−2 with Na 2 SO 4 and K 2 SO 4 electrolytes, respectively. The wide potential window (1.6 V) of the symmetric supercapacitor delivered maximum energy densities of 22.4 and 19.6 μWh·cm−2 at a power density of 2 mW·cm−2 for Na 2 SO 4 and K 2 SO 4 electrolytes, respectively. [ABSTRACT FROM AUTHOR]

This study presents the development of a facile and sensitive method of analysis for the determination of paracetamol. For this purpose, a boron doped diamond electrode (BDDE) was modified with a composite of carbon nanotubes (CNT), carbon nanofibers (CNF) and carbon black nanoballs (CNB). The voltammetric properties of paracetamol were studied, compared and discussed on unmodified BDDE, CNB/BDDE, CNF/BDDE, CNT/BDDE, CNB@CNF/BDDE, CNF@CNT/BDDE and CNF@CNB@CNT/BDDE. An increase in peak response (Ip) and a dramatic decrease in peak separation (ΔEp) were observed at electrodes in an order from bare BDDE to CNB/BDDE, CNF/BDDE, CNT/BDDE, CNB@CNF/BDDE, CNF@CNT/BDDE and CNF@CNB@CNT/BDDE. This clearly showed that the composite material of CNF@CNB@CNT provided an excellent surface on BDDE leading to a fast electrode reaction of paracetamol. Interestlingly, the amount composite layer on the voltammetry of paracetamol also caused a remarkable decrease in ΔEp and resulted in high electrocatalytic activity. The detection of paracetamol based on the BDDE modified with a composite of CNF@CNB@CNT exhibited stability, excellent selectivity and good sensitivity, with a low detection limit of 0.47±0.002 nM (based on 3sb/m) and wide linear range of 1.5 nM–200 nM. These results demonstrate that CNF@CNB@CNT/BDDE can serve as an ideal voltammetric platform for constructing a paracetamol sensor. The proposed electrochemical platform (CNF@CNB@CNT/BDDE) was also successfully applied for the determination of paracetamol in pharmaceuticals and body fluids. [ABSTRACT FROM AUTHOR]

The optimal fabrication of bead-free polyvinylpyrrolidone (PVP)-based electrospun mats (EMs) with minimum average fiber diameter (~ 0.22 µm) has been carried out using the Taguchi design of experiment (DOE) approach. Hydrated metallic acetate-loaded optimized PVP-based EMs were fabricated from respective colloidal dispersions and were subsequently carbonized to fabricate metal oxide/carbon nanomaterial (MO/CNM)-based active material for electrode application. Thermal, microstructural, and morphological characterizations indicated the presence of significant interactions between metallic salts and the PVP matrix, which in turn facilitated morphology (ID/IG) specific designing of carbon nanomaterial electrodes. The MO/CNM was also subjected to Raman, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) characterization. Carbonized copper acetate-loaded PVP-based EMs (CuO/CNM) exhibited comparatively superior electrochemical performance than carbonized cobalt acetate and nickel acetate-loaded PVP-based EMs (Co3O4/CNM and NiO/CNM). Thus, the study demonstrates the optimal fabrication of metallic salt-loaded mats and the dependence of the electrochemical performance of the carbonaceous nanomaterials on their composition-specific morphological attributes, for designing engineered nanostructured materials for various functional applications such as sensors and energy storage devices. [ABSTRACT FROM AUTHOR]

Experimental studies were focused on decomposition of formic acid over carbon nanofibers (CNF) and carbon nanotubes (CNT) to produce pure hydrogen. These carbon materials were shown to provide decomposition of formic acid to form preferably hydrogen and carbon dioxide. It was established that structural features of carbon nanomaterials affect their activity in the decomposition of formic acid. The specific catalytic activity of CNF (ini) is at least twice as high as that of CNT (ini). The treatment of CNF (NaOH) with an alkali solution of NaOH is shown to improve noticeably both activity and selectivity of the catalytic decomposition of formic acid. The synthesized catalysts were characterized using X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM) and adsorption. It was shown by XPS that the alkali treatment of CNF results in the appearance of C–O–Na fragments on the carbon surface. • CNT and CNF with essentially different structures were synthesized. • The specific catalytic activity of CNF (ini) is at least twice as high as that of CNT (ini). • Alkali-treated CNF have significantly higher catalytic activity in the FA dehydrogenation. • Carbon nanofibers catalyzed FA decomposition to hydrogen and carbon dioxide. • The CNF (NaOH) catalyst is comparable in activity to the 0.2–0.4%Pt/N-graphene catalysts. [ABSTRACT FROM AUTHOR]

Sweat is easily accessible from the human skin's surface. It is secreted by the eccrine glands and contains a wealth of physiological information, including metabolites and electrolytes like glucose and Na ions. Sweat is a particularly useful biofluid because of its easy and non-invasive access, unlike other biofluids, like blood. On the other hand, nanomaterials have started to show promise operation as a competitive substitute for biosensors and molecular sensors throughout the last 10 years. Among the most synthetic nanomaterials that are studied, applied, and discussed, carbon nanomaterials are special. They are desirable candidates for sensor applications because of their many intrinsic electrical, magnetic, and optical characteristics; their chemical diversity and simplicity of manipulation; their biocompatibility; and their effectiveness as a chemically resistant platform. Carbon nanofibers (CNFs), carbon dots (CDs), carbon nanotubes (CNTs), and graphene have been intensively investigated as molecular sensors or as components that can be integrated into devices. In this review, we summarize recent advances in the use of carbon nanomaterials as sweat sensors and consider how they can be utilized to detect a diverse range of analytes in sweat, such as glucose, ions, lactate, cortisol, uric acid, and pH. [ABSTRACT FROM AUTHOR]

Herein, MnO2 nanoflowers are electrodeposited on a self-supported and electroconductive electrode in which 2D Ti3C2Tx nanosheets are encased in carbon nanofibers (MnO2@Ti3C2Tx/CNFs). This improves the conductivity and hydrophilicity of the MnO2 composite electrode. The asymmetric supercapacitor shows a high energy density of 46.4 W h kg−1 and a power density of 4 kW kg−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multifunctional Co 9 S 8 @CNSs/CNFs flexible self-supporting electrode is designed for Sodium-ion batteries. • The advantages of multi-stage structural synergistic composites are illustrated at the electrode scale. • In-depth analysis of electrode electrochemical reaction kinetics and de-/sodiation mechanism. • High sodium storage half-cells and stable full cell capacity with self-supporting electrodes are achieved. Transition metal sulfides (TMSs) are considered as promising anodes for sodium-ion batteries (SIBs) due to their high theoretical capacity and low cost. However, TMSs suffer from massive volume expansion, slow sodium-ion diffusion kinetics, and poor electrical conductivity, which severely restrict their practical application. Herein, we design self-supporting Co 9 S 8 nanoparticles embedded carbon nanosheets/carbon nanofibers (Co 9 S 8 @CNSs/CNFs) as anode materials for SIBs. The electrospun carbon nanofibers (CNFs) provide continuous conductive networks to accelerate the ion and electron diffusion/transport kinetics, while MOFs-derived carbon nanosheets (CNSs) buffer the volume variation of Co 9 S 8 , consequently improving the cycle stability. Benefitting from the unique design and pseudocapacitive features, Co 9 S 8 @CNSs/CNFs deliver a stable capacity of 516 mAh g−1 at 200 mA g−1 and a reversible capacity of 313 mAh g−1 after 1500 cycles at 2 A g−1. Note that, it also displays excellent sodium storage performance when assembled into a full cell. The rational design and excellent electrochemical properties endow Co 9 S 8 @CNSs/CNFs with the potential stepping into commercial SIBs. [ABSTRACT FROM AUTHOR]

Two-dimensional molybdenum disulfide (MoS2) is considered as a highly promising anode material for lithium-ion batteries (LIBs) due to its unique layer structure, large plane spacing, and high theoretical specific capacity; however, the overlap of MoS2 nanosheets and inherently low electrical conductivity lead to rapid capacity decay, resulting in poor cycling stability and low multiplicative performance. This severely limits its practical application in LIBs. To overcome the above problems, composite fibers with a core//sheath structure have been designed and fabricated. The sheath moiety of MoS2 nanosheets is uniformly anchored by the hydrothermal treatment of the axial of carbon nanofibers derived from an electrospinning method (CNFs//MoS2). The quantity of the MoS2 nanosheets on the CNFs substrates can be tuned by controlling the amount of utilized thiourea precursor. The influence of the MoS2 nanosheets on the electrochemical properties of the composite fibers has been investigated. The synergistic effect between MoS2 and carbon nanofibers can enhance their electrical conductivity and ionic reversibility as an anode for LIBs. The composite fibers deliver a high reversible capacity of 866.5 mA h g−1 after 200 cycles at a current density of 0.5 A g−1 and maintain a capacity of 703.3 mA h g−1 after a long cycle of 500 charge–discharge processes at 1 A g−1. [ABSTRACT FROM AUTHOR]

The fabrication and functionalization of three-dimensional (3D) MXene are vital for diverse high-performance applications. Herein, the construction of 3D porous MXene architecture and its functionalization with graphene are synchronously implemented by breath figure method. 3D porous rGO/MXene with multi-scale pores is prepared by simply casting the mixture of GO/surfactant and MXene/surfactant solution under humid environment and the subsequent reduction process. The aggregation inhibition of GO and MXene nanosheets at multi-scale caused by surfactant intercalation and the formation of 3D porous structure, as well as the increase in surface area induced by the introduction of GO, enlarged lamellar spacing and multi-scale porous structure endow porous rGO/MXene with excellent electrochemical performance. The synergy of rGO and MXene leads to further improvement in electrochemical property and its stability. Low detection limit, good anti-interference, repeatability, reproducibility, long-range stability and accuracy of actual sample testing are exhibited when porous rGO/MXene is used for electrochemical detection of DA. Furthermore, the electrochemical performance could be controlled via tuning the porous structure and ratio of GO and MXene. This study not only demonstrates the superiority of porous rGO/MXene toward electrochemical sensing, but also proposes a simple and universal method for controllable construction and functionalization of 3D MXene architecture. [ABSTRACT FROM AUTHOR]

MnO2 is an attractive material owing to its high specific capacitance, excellent electrochemical activity, thermal and chemical stability, environmental benignity and broad potential window. However, its poor electrical conductivity limits its performance in supercapacitor applications. The electrical conductivity of MnO2 can be enhanced by making its composites with carbon nanomaterials as these offer superior electrical conductivity and high specific surface area. The present study is a comparative study on the effect of various types of carbon nanomaterials such as carbon nanotubes (CNTs), graphene oxide, thermally reduced graphene oxide, activated carbon and carbon nanofibers on the supercapacitive performance MnO2 electrodes by making composite electrodes. MnO2 was synthesized by a facile chemical reduction method, and calcination was performed at 200 °C to obtain amorphous state. MnO2-based composite electrodes were prepared using 10 wt.% of various carbon nanomaterials. Characterization of different carbon materials was carried out by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and atomic force microscopy. Composite electrodes were prepared by coating mixture, consisting of MnO2, carbon nanomaterials, carbon black and polyvinylidene fluoride on the surface of highly porous Ni foam using a high-speed vacuum planetary centrifugal mixer. Electrochemical characterization of the prepared electrodes was performed by cyclic voltammetry, galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS). GCD revealed that MnO2-CNTs composite electrodes showed maximum specific capacitance (SC) of 330 F/g at 1 A/g current density and areal capacitance of 3.16 F/cm2 with 5–7 mg mass loading of active material in 3 M KOH as an aqueous electrolyte. This SC was ca. 79% higher than pure MnO2 and also higher than previously reported MnO2/CNTs composite electrodes. MnO2-CNTs symmetric supercapacitor device showed excellent SC of 177 F/g at 1 A/g current density with 94% charge retention after 1000 GCD cycles. EIS analysis showed that MnO2-CNTs composite electrode had the lowest charge transfer resistance compared to other electrodes. [ABSTRACT FROM AUTHOR]

Carbon nanostructure materials are becoming of considerable commercial importance, with interest growing rapidly over the decade since the discovery of carbon nanofibers. In this study, a new novel method is introduced to synthesize the carbon nanofibers by gas-phase, where a single-stage microwave-assisted chemical vapour deposition approach is used with ferrocene as a catalyst and acetylene and hydrogen as precursor gases. Hydrogen flow rate plays a significant role in the formation of carbon nanofibers, as being the carrier and reactant gas in the floating catalyst method. The effect of process parameters such as microwave power, radiation time and gas ratio of C 2 H 2 /H 2 was investigated statistically. The carbon nanofibers were characterized using scanning and transmission electron microscopy and thermogravimetric analysis. The analysis revealed that the optimized conditions for carbon nanofibers production were microwave power (1000 W), radiation time (35 min) and acetylene/hydrogen ratio (0.8). The field emission scanning electron microscope and transmission electron microscope analyses revealed that the vertical alignment of carbon nanofibers has tens of microns long with a uniform diameter ranging from 115 to 131 nm. High purity of 93% and a high yield of 12 g of CNFs were obtained. These outcomes indicate that identifying the optimal values for process parameters is important for synthesizing high quality and high CNF yield. [Display omitted] • A new route for synthesis of CNFs usng single stage MA-CVD was discussed. • Optimization of process parameters on production of CNFs using CCD was narrated. • The detailed characterization of CNFs was deliberated. • High purity (93%) and high yield (12 g) of CNFs were obtained. [ABSTRACT FROM AUTHOR]

Coal is a cheap and sustainable precursor for the preparation of fluorescent carbon nanomaterials (FCNMs). Based on the size and morphology, these nanomaterials are classified as carbon quantum dots (CQDs), carbon nanotubes (CNTs), carbon nanofibers (CNFs), carbon nanosheets (CNSs), graphene quantum dots (GQDs), carbon polymer dots (CPDs) etc. The FCNMs have sparked interest because of their distinctive fluorescence, effective catalysis, water solubility, biocompatibility, ease of surface functionalization, cost-effective synthesis, photostability, and other potential benefits for various advanced applications. A substantial percentage of the scientific community has been driven by a strong desire to prepare carbon nanomaterials (CNMs) using environmentally acceptable and low-cost synthesis methods. The precursors used in the preparation of carbon-based nanomaterials are critical to the technology's future success. Most traditional synthesis procedures use high-cost carbon feedstocks like hydrocarbons and graphite, limiting their commercialization. In this review, coal is used as starting material for the synthesis of FCNMs and is applied in various current fields. Highlights : • Coal and its derivatives derived fluorescent carbon nanomaterials are discussed. • Different type of methodology basically top-down and bottom-up for the preparation of fluorescent carbon nanomaterials are described. • The physical and optical properties of fluorescent carbon nanomaterials are discussed. • The origin of fluorescence on coal-based nanomaterials have been discussed. • The multifunctional applications of fluorescent carbon nanomaterials are summarized in detail. • The advantage, challenges and future prospects of fluorescent Carbon Nanomaterials from Coal is discussed. [ABSTRACT FROM AUTHOR]

Currently, lightweight wearable energy storage devices are in great demand owing to their use in wearable electronics and energy-efficient electric vehicles. Freestanding carbon nanofibers replace the need for metal substrates while providing a rapid electrical network owing to their excellent electrical properties. Bimetallic oxides with multivalent oxidation states facilitate the rapid transfer of electrolytic ions owing to efficient Faradaic reactions, thereby enhancing the overall energy storage capability. In this study, CoOx@CNF was derived from ZIF-67 (zeolitic-imidazolate framework) @PAN-2MI fibers that were stabilized in air at 280°C and then annealed in argon at 900°C. Subsequently, Co was seeded on the annealed CoOx@CNF and subjected to a hydrothermal process in sodium molybdate dihydrate solution to grow CoMoO4 nanosheets, eventually forming bimetallic CoMoO4@CNF. The concentration of sodium molybdate solution was varied to determine the optimal growth conditions for CoMoO4 nanosheets. The energy density of the optimal bimetallic CoMoO4@CNF sample was 166.5 μWh cm-2 at a power density of 200 μW cm-2; this represented a nearly twofold increase compared to that of the single metallic CoOx@CNF. Powering humidity sensors using only one CoMoO4@CNF supercapacitor was demonstrated. The optimal sample remained stable during long-term galvanostatic charge and discharge cycles ( N cyc = 30,000) and retained 100% of its specific capacitance. [ABSTRACT FROM AUTHOR]

Physical mixing of monofunctional noble metal catalysts, such as Pt/C or Ru/IrO 2 , increases the commercial cost and stability risk of electrodes. Therefore, it is desirable to develop a multifunctional electrocatalyst for zinc-air batteries and integrated electrolytic devices. To develop an effective way to fabricate high-performance multifunctional electrocatalysts by modifying advanced nanostructures, a coaxial electrospinning approach with in-situ synthesis and subsequent carbonization was used to construct a highly integrated three-function catalyst composed of graphitic carbon-encapsulated cobalt nanoparticles embedded into one-dimensional (1D) porous hollow carbon nanofibers (CoNC-HCNFs). Under the synergistic effect of the active material and the advanced nanostructure, the as-prepared CoNC-HCNFs demonstrated an operating overpotential of 186 mV (10 mA cm−2) for the hydrogen evolution reaction (HER), a half-wave potential of 0.83 V (vs. RHE at 10 mA cm−2) for the oxygen reduction reaction (ORR), and a potential of 1.58 V (10 mA cm−2) for the oxygen evolution reaction (OER). With their exceptional multifunctional activities, two CoNC–HCNF-based aqueous zinc-air batteries (ZABs) in series could drive an alkaline water electrolyzer for splitting water. Furthermore, due to the superior mechanical flexibility and rechargeability of the solid-state ZAB, it has great application prospects in powering portable and wearable electronics. This research is expected to offer inspiration for the development of other excellent MOF-based hollow carbon nanofibers and to enable them to be adopted more widely in electrochemical energy conversion and energy storage. [Display omitted] • Porous hollow carbon nanofibers embedded with Co nanoparticles were fabricated. • The hollow structure was prepared via coaxial electrospinning and hydrolyzation. • The CoNC-HCNFs catalysts exhibit the multifunctional activity of ORR, OER and HER. [ABSTRACT FROM AUTHOR]

Utilizing 1D and 2D carbon nanomaterials to develop resilient and strong multifunctional composites has been a common theme in the field of nanomaterials in the past two decades. This theme is partly driven by the strong bonds between carbon atoms and the variety in bonding which translates into a wide variety of carbon nanomaterial types. It was once envisioned that CNT yarns would replace carbon fibers (CFs), an industry's gold standard for load bearing. However, the dream of developing super-strong materials based on carbon nanomaterials is yet to be fulfilled. In this paper, we have systematically reviewed the strength, fracture and failure mechanisms of 1D, including carbon nanotubes and carbon nanofibers, and 2D carbon materials, mainly graphene. For any physical quantity including strength, the measured values and the measurement techniques/protocols are inherently coupled. Therefore, the experimental approaches and the reported mechanical properties are reviewed together to assist with a better understanding of the true and engineering mechanical properties. The factors which limit strength and cause failure, especially the inevitable defects commonly observed in both 1D and 2D carbon nanomaterials, are discussed. Afterwards, the mixed dimensional carbon nanomaterials , where the 1D nanomaterials are used as reinforcement of 2D materials, is discussed towards developing super-tough structural materials. At the end, potential future research directions on carbon nanomaterials for load bearing is briefly discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

A series of core-triple-shelled GCNF/PANI/NCO nanostructures have been fabricated via a facile strategy. Taking full advantage of the free-standing architecture of graphene-coated electrospun carbon nanofibers (GCNF), high conductivity and flexibility of the polyaniline (PANI) layers, and abundant active sites of nickel carbonate hydroxide (Ni 2 (CO 3)(OH) 2) nanosheets, the optimal electrode exhibits a high specific capacitance of 1565F g−1 at 1 A/g, which exceeds almost all of the reported nickel carbonate hydroxide-based electrodes in literatures. A hybrid supercapacitor delivers a high energy density of 35.4 Wh kg−1@750 W kg−1 and a long cycle lifespan. This strategy enables the controllable synthesis of core-triple-shelled hierarchical materials applicable to diverse electrochemical applications. [Display omitted] • We prepared the core-triple-shelled GCNF/PANI/NCO fiber-based films via a new route. • The optimal electrode exhibits high electrochemical properties via joint actions. • A hybrid supercapacitor displays large specific capacities and high energy density. • This strategy provides a new way to synthesize other core-triple-shelled materials. Designing novel efficient electrode materials with controlled hierarchical structure and composition for advanced supercapacitors remains a great challenge. Herein, a core-triple-shelled hierarchical GCNF/PANI/NCO nanostructure has been designed and fabricated by sequential growth of the conductive polyaniline (PANI) layers and nickel carbonate hydroxide (Ni 2 (CO 3)(OH) 2) nanosheets on the graphene-coated electrospun carbon nanofibers (GCNF) via a facile wet-chemical strategy. Taking full advantage of the free-standing architecture of graphene-coated electrospun carbon nanofibers, high conductivity and flexibility of the PANI layers, and abundant active sites of Ni 2 (CO 3)(OH) 2 nanosheets, the optimal GCNF/PANI/NCO (2 h) electrode exhibits a high specific capacitance of 1565F g−1 at 1 A/g and enhanced rate capability, which are higher than those of the GCNF, GCNF/PANI, and GCNF/NCO (2 h) electrodes at the same situation, and also exceeds most of the reported nickel carbonate hydroxide-based electrodes in literature. The superior performance should be mainly ascribed to the collaborative contribution of each component. Moreover, a self-assembled GCNF/PANI/NCO//AC hybrid supercapacitor delivers a high energy density of 35.4 Wh kg−1@750 W kg−1 and a long cycle lifespan. This strategy enables the controllable synthesis of core-triple-shelled hierarchical materials applicable to advanced electrochemical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Potassium-ion batteries (PIBs) have attracted enormous attention due to the increasing lithium battery cost, but their development is still in the pre-mature stage due to the limited selection of electrodes. Herein, a free-standing current-collector-integrated electrode, composed of mixed-phase WS 2 nanosheets with nitrogen-doped multichannel carbon nanofibers (N -MCNFs) membrane, is reported for high-performance potassium ion batteries anode. Benefiting the unique multichannel carbon nanostructure as a current collector-integrated electrode as well as mixed-phase lamellar structure WS 2 for enhanced potassium ion entry, the 1T/2H-WS 2 / N -MCNFs hybrid current-collector-free anode delivers an outstanding areal capacity of 2.88 mAh cm−2 (corresponding to 411 mAh/g based on the mass of both electrode and current collector) at a current of 0.7 mA cm−2 as well as long-term cycling stability for over 1000 cycles at a high current of 14 mA cm−2, surpassing the current state-of-art PIB anode. It is believed that our findings based on the high energy current collector integrated electrode at high mass loading would boost future research on practical metal ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Potassium-ion batteries (PIBs) have attracted enormous attention due to the increasing lithium battery cost, but their development is still in the pre-mature stage due to the limited selection of electrodes. Herein, a free-standing current-collector-integrated electrode, composed of mixed-phase WS 2 nanosheets with nitrogen-doped multichannel carbon nanofibers (N -MCNFs) membrane, is reported for high-performance potassium ion batteries anode. Benefiting the unique multichannel carbon nanostructure as a current collector-integrated electrode as well as mixed-phase lamellar structure WS 2 for enhanced potassium ion entry, the 1T/2H-WS 2 / N -MCNFs hybrid current-collector-free anode delivers an outstanding areal capacity of 2.88 mAh cm−2 (corresponding to 411 mAh/g based on the mass of both electrode and current collector) at a current of 0.7 mA cm−2 as well as long-term cycling stability for over 1000 cycles at a high current of 14 mA cm−2, surpassing the current state-of-art PIB anode. It is believed that our findings based on the high energy current collector integrated electrode at high mass loading would boost future research on practical metal ion batteries. [ABSTRACT FROM AUTHOR]

The fabrication and design of carbon-based hierarchical structures with tailored nano-architectures have attracted the enormous attention of the materials science community due to their exceptional chemical and physical properties. The collective control of nano-objects, in terms of their dimensionality, orientation and size, is of paramount importance to expand the implementation of carbon nanomaterials across a large variety of applications. In this context, porous anodic alumina (PAA) has become an attractive template where the pore morphologies can be straightforwardly modulated. The synthesis of diverse carbon nanomaterials can be performed using PAA templates, such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), and nanodiamonds, or can act as support for other carbon allotropes such as graphene and other carbon nanoforms. However, the successful growth of carbon nanomaterials within ordered PAA templates typically requires a series of stages involving the template fabrication, nanostructure growth and finally an etching or electrode metallization steps, which all encounter different challenges towards a nanodevice fabrication. The present review article describes the advantages and challenges associated with the fabrication of carbon materials in PAA based materials and aims to give a renewed momentum to this topic within the materials science community by providing an exhaustive overview of the current synthesis approaches and the most relevant applications based on PAA/Carbon nanostructures materials. Finally, the perspective and opportunities in the field are presented. [ABSTRACT FROM AUTHOR]

The development of advanced coal-based functional nanomaterials is of great significance for clean and effective utilization of coal resources. Herein, we report novel coal-based ultra-fine carbon nanosheets (UCNSs) prepared by chemical oxidation of bituminous coal with a high yield of 40.0 wt%. UCNSs show a lamellar size of 10–20 nm, mainly composed of 63.5 at.% carbon, 5.1 at.% nitrogen, and 31.4 at.% oxygen. The structural merits of suitable size distribution, enriched functional groups, and highly conjugated core enable the UCNSs showing a tri-functional reinforcement for carbon nanofibers prepared by electrospinning and carbonization. Thanks to the strong cross-linking effect and formation of entire conductive networks, the UCNS-embedded carbon nanofiber fabrics show 32.6 and 1.5 times improved mechanical strength and electrical conductivity, respectively, than the one without UCNSs. What's more, the exposed edges of UCNSs act as active sites for ultrafast capacitive energy storage, leading to the free-standing fabric with significantly improved capacitance and rate performance (191.2 F g−1 at 1 A g−1, 113.5 F g−1 at 50 A g−1) for aqueous supercapacitors. This work may provide a new thought for high-efficient and high-value-added utilization of coal resources. Ultra-fine carbon nanosheets with a high yield of 40.0 wt% were prepared through liquid-phase oxidation of bituminous coal, showing tri-functional (mechanical/electrical/electrochemical) reinforcement for carbon nanofiber fabrics. [Display omitted] • Ultra-fine carbon nanosheets with a high yield of 40 wt% were prepared from coal. • The inlaid UCNSs show tri-functional reinforcement for carbon nanofiber fabrics. • Exposed edges enable an ultra-fast pseudocapacitive energy storage ability. [ABSTRACT FROM AUTHOR]

Cyclodextrins and nanomaterials are widely used in the achievement of powerful platforms in supramolecular chemistry and nanotechnology. The relatively hydrophobic internal cavity of the CDs selectively retains molecules having the proper geometry, while the hydrophilic exterior allows CDs to improve the dispersibility and molecular recognition. The nanomaterials provide higher surface area, good conductivity, and electrocatalytic effect. The use of nanomaterials and CDs in electrochemical sensors' design allows the development of a large variety of devices, explaining the increasing number of papers in the last years that are discussed in this review. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials are the major and fastest growing area of nanotechnology. Their exceptional properties find application in numerous sectors of the economy. However, their large-scale production with adequate quality is still an open problem. In the present work, the advances obtained in the development of the submerged arc discharge technology for the production of carbon nanostructures in the Nanosciences Group of CEADEN are presented. We also report the implementation of methods for the safety evaluation of the in vitro use of carbon nanostructures synthesized using this method. [ABSTRACT FROM AUTHOR]

The rapid advancement of electrical and telecommunication facilities has resulted in increasing requirements for the development of electromagnetic interference (EMI) shielding composites. Accordingly, an experimental study was conducted to evaluate the EMI shielding performance of carbon nanomaterial (CNM)-embedded carbon-fiber-reinforced polymer (CFRP) or glass-fiber-reinforced polymer (GFRP) composites. Nine combinations of CNMs and carbon or glass fibers were used to fabricate the composites. The synergistic effects of CNMs on the EMI shielding performance were systematically investigated. The results indicated that plate-type CNMs (i.e., graphene and graphite nanoplatelets) have more prominent effects than fiber-type CNMs (carbon nanofibers). The composites fabricated with CFRP afforded higher EMI shielding than the GFRP-based composites. Among the eighteen samples, 3% CNT-GNP in CFRP composites, which included plate-typed CNM, exhibited the best EMI shielding performances, showing 38.6 dB at 0.7 GHz. This study helps understand the shielding performance of CNM-embedded CFRP and GFRP composites in electrical and telecommunication facilities. [ABSTRACT FROM AUTHOR]

The nitrogen-doped carbon nanofiber absorber (MnO 2 @HNCFs) filled with MnO 2 nanoparticles/nanosheets is constructed through layer-by-layer coating assisted by vacuum carbonization and etching. The MnO 2 nanoparticles/nanosheets filled in the hollow carbon fibers make the material exhibit a hierarchical porous structure, and reduce the density of the material as well. MnO 2 @HNCFs show excellent microwave absorbing properties, with a minimum reflection loss (RL min) of −48.87 dB@14.9 GHz at a low loading of 10%, and the thickness is 2.5 mm. The corresponding effective absorption bandwidth (EAB) is 6.2 GHz, covering the entire Ku-band. When the thickness is adjusted to 2.8 mm, the EAB is up to 7.8 GHz and the RL min is −32.17 dB. The EAB is 5.7 GHz at 3.4 mm, covering the X-band, and the RL min is −30.62 dB. Through the comparison of the absorbing properties of materials, it is proved that the construction of porous structures can effectively enhance the absorbing properties, which provides a solid argument for the claim that multiple reflection can enhance the electromagnetic wave loss. This work is of great significance to the construction of porous structure microwave absorbing materials, and provides a new idea for the design of lightweight microwave absorbing materials. [Display omitted] • The nitrogen-doped carbon nanofiber absorber MnO 2 @HNCFs is first constructed. • MnO 2 @HNCFs have large specific surface and abundant pores. • The RL min and EAB of MnO 2 @HNCFs are −48.87 dB and 6.2 GHz with a loading of 10%. • The loss mechanism of MnO 2 @HNCFs is clarified. [ABSTRACT FROM AUTHOR]

Energy storage is the process of storing previously generated energy for future usage in order to meet energy demands. The need for high-power density energy storage materials is growing across the board. The high ionic transport, superior electronic conductivity, rapid ion diffusion, high current tolerance, etc. are few among the numerous factors that can be considered the versatilities of nanomaterials. This makes the nanomaterials suitable for energy storage applications. According to the allied market research, the global nanotechnology in energy industry was estimated at $139.7 million in 2020 and is anticipated to hit $384.8 million by 2030, registering a compound annual growth rate (CAGR) of 10.7% from 2021 to 2030. The extraordinary and improved properties of carbon-based nanomaterials and their tunable surface chemistry authorize them to be used in design of competent high-energy and high-power energy storage devices. Recent research and future progress focus on effective usage of low-dimensional carbon-based nanomaterials for energy conversion and storage systems. In particular, versatile carbon nanomaterials with multifunctional capabilities have attracted incredible attention in different types of batteries, solar cells, fuel cells, supercapacitors, and other energy storage devices. Engineering the carbon-based nanomaterials with efficient energy storage and remarkable conversion ability embraces the promise of creating a new path for their future development. This article reviews the role of few carbon-based nanomaterials in efficiently increasing the competence and dependability of energy storage applications. [ABSTRACT FROM AUTHOR]

Hydrogen has attracted wide attention in the field of new energy, triggering a comprehensive study of hydrogen production, storage and application. This paper mainly studies the hydrogen storage capacity of magnesium-based materials with nanostructure. The reversible hydrogen capacity of Mg-based hydrogen storage materials can reach 7.6 wt%, but due to its poor kinetic and thermodynamic properties, its hydrogen storage performance is not as good as other hydrogen storage materials. In order to reduce the desorption temperature of materials, many studies have been carried out. Alloying, nanostructure and adding catalyst are feasible methods to improve the properties of Mg-based hydrogen storage alloys. By adding catalyst and alloy with other transition elements, the dehydrogenation temperature of magnesium-based materials has been reduced to less than 200 °C. The hydrogen storage of magnesium-based alloys has been practically applied. • High-energy ball milling and plasma ball milling can generate in-situ nanophases. • MOFs provides a highly controllable and intrinsically ordered environment. • Nanoconfinement effect improves the Mg alloy hydrogen storage properties. • Carbon nanofibers or carbon nanotube load transition metal act as a catalyst. [ABSTRACT FROM AUTHOR]

Nanomaterials are chemical compounds or substances which are moderately produced and used. Nanomaterials are engineered to reveal novel properties of nanocells that contrast with related non-visible substances, such as expanded consistency, conductivity or synthetic reaction. Topological indexes are quantities related to molecules that capture the harmony of molecular structures and give scientifically related properties, such as: viscosity, boiling point, radius of gravity, and so on. Their demands in genetics, chemistry, physics and nanoscience are infinite. The molecular topology of such compounds would be clarify by the quantitative structure properties relationship (QSPR) and quantitative structure activity relationship (QSAR). Two carbon nanosheet structures such as V C 5 C 7 and H C 5 C 7 have been discussed in this article. We also computed ev-degree and ve-degree based topological indices of these structures. [ABSTRACT FROM AUTHOR]

Developing high-performing and scalable electrode materials for supercapacitors and batteries has been of tremendous interest for the world's forthcoming clean and renewable energy transition. As a versatile material, Two-dimensional graphitic carbon nitride (g-CN) has been utilized in electrochemical energy storage (EES) applications due to its nitrogen-rich adsorption sites, cost-effective production, and tunable electronic structure. The electrochemical performance of pristine g-CN has been boosted by forming hybrid architectures with highly conductive carbon-based materials, such as graphene, reduced graphene oxide, carbon nanofibers, carbon nanotubes, and beyond (e.g., MXene). Using such heterogeneous compositions for EES applications has significantly increased in recent years. This study reviews the g-CN/carbon nanomaterial (CNM) hybrids, considering the dimensionality in nanomaterials, and underscores the influence of the material's dimensionality and the synthesis/fabrication routes. The effect of structural and physicochemical changes on the electrode's electrochemical performance after hybridization is presented comparatively. Besides, the comprehensive review outlines challenges and future improvements in g-CN/CNM hybrid materials for outstanding developments in energy storage systems. [Display omitted] • Graphitic carbon nitride (g-CN)/carbon nanomaterial (CNM) hybrids are reviewed for supercapacitor and battery applications. • The impact of the CNM-type on the hybrid electrode's performance is examined through a chemical and physical perspective. • An overview of how hybrid electrode synthesis affects ion/electron transport, surface area, and porosity is provided. • Design-oriented control of the physicochemical properties for enhanced electrochemical performance is exemplified. • g-CN/CNM nanoarchitectures are emphasized as electrode materials with the potential for easy scalability. [ABSTRACT FROM AUTHOR]

In this review, the research progress of various kinds of nanomaterials for high performance of electrochemical HMI sensors were summarized in detail. The synthesis strategies, advantages, performance and challenges of the various nanomaterials for application in electrochemical HMI sensors are discussed. [Display omitted] • Deep insights into nanomaterials-based electrochemical HMI sensors were discussed. • Recent advances of electrochemical HMI sensing modified nanomaterials are reviewed. • The design ideas, innovations and merits of the modified materials were discussed. • Remaining challenges and prospects of the modified nanomaterials were presented. As one of the main pollutants, heavy metal ions can accumulate in the human body and cause a cascade of damage. Electrochemical sensors provide great prospects for tracing heavy metal ions because of their properties of high sensitivity, low detection limits and fast response. Electrode surface modification materials play a key role in enhancing the performance of electrochemical sensors. Herein, we summarize in detail the recent work on electrochemical sensors modified by carbon nanomaterials (graphene and its derivatives, carbon nanofibers and carbon nanotubes), metal nanomaterials (gold, silver, bismuth and iron), complexes (MOFs, ZIFs and MXenes) and their composites for the detection of heavy metal ions (mainly include Cd(II), Hg(II), Pb(II), As(III), Cu(II) and Zn(II)) in food and water. The synthetic strategies, mechanisms, innovations, advantages, challenges and prospects of various electrode modification nanomaterials for the detection of heavy metal ions in food and water are discussed. [ABSTRACT FROM AUTHOR]

Metal oxide semiconductors (MOSs) are widely utilized in the gas-sensing field owing to their superior gas sensing performances. Herein, a hierarchical nanostructure consisting of Bi 2 MoO 6 nanosheets (NSs) assembled on LaFeO 3 nanofibers (NFs) was successfully synthesized by combining an electrospinning with a solvothermal method. The full study of the sensing performances was conducted by manufacturing commercial gas sensors based on Bi 2 MoO 6 /LaFeO 3 hierarchical nanostructure in order to showcase its potential application in gas sensing. The results show that the sensor based on Bi 2 MoO 6 /LaFeO 3 hierarchical nanostructure exhibits excellent HCHO gas sensing performances including a high response (R a /R g = 36.5), a superior selectivity and a short recovery time (τ rec = 20 s). Additionally, sensors based on Bi 2 MoO 6 NSs and LaFeO 3 NFs were also respectively fabricated to measure HCHO gas sensing performances in order to elucidate the sensing mechanism and structural superiority of the Bi 2 MoO 6 /LaFeO 3 hierarchical nanostructure. The increased capability of detecting HCHO gas can be attributed to the n-p heterostructure formed within the Bi 2 MoO 6 /LaFeO 3 hierarchical nanostructure. The findings in this work can contribute to the realization to enhance the sensing performances by designing n-p heterostructure in gas sensing material. [Display omitted] • A 1D Bi 2 MoO 6 /LaFeO 3 n-p type hierarchical nanostructure is designed and synthesized. • The novel hierarchical nanostructure displays excellent HCHO gas sensing performance. • Heterostructure and 1D nanofibrous structure jointly promote the sensing performance. • Superb sensing performances come from the synergies among designed favorable factors. • Sensing mechanism and structural merits of hierarchical nanostructure are advanced. [ABSTRACT FROM AUTHOR]

Due to the unique geometric characteristics and electronic structure of hierarchical 3D nanosheets, they show excellent electron migration rate, ultra‐high specific surface area, and reliable structural stability. Therefore, 3D nanosheets have great application prospects in the field of electrochemical energy storage. Supercapacitor has attracted extensive attention in recent years due to its merits of fast charge and discharge, long cycle life, safety, and stability. Flexibility, miniaturization, and intelligent integration are the development direction of supercapacitor energy storage devices. The emerging 3D printing technology, especially the ink direct writing mode, has greatly improved the design ability and control accuracy of device microstructures. Based on the research progress of 3D graphene nanosheets and 3D MXene nanosheets in the early stage of the authors' or other teams, this paper proposes to use advanced 3D printing technology to realize the design of flexible all solid‐state supercapacitors by using 3D nanosheets active materials with high specific capacitance. The design methods of interdigital electrodes, multilayer skeleton electrodes and fiber electrodes by 3D printing technology and the performance evaluation of flexible supercapacitor are systematically analyzed. This perspective review aims to provide new conception and theoretical guidance for the design, preparation, and performance optimization of 3D nanosheets‐built materials by 3D printing for the practical application of flexible all‐solid‐state supercapacitor in the future. [ABSTRACT FROM AUTHOR]

Gynecologic cancers are one of the main health concerns of women throughout the world, and the early diagnosis and effective therapy of gynecologic cancers will be particularly important for the survival of female patients. As a current hotspot, carbon nanomaterials have attracted tremendous interest in tumor theranostics, and their application in gynecologic cancers has also been developed rapidly with great achievements in recent years. This Overview Article summarizes the latest progress in the application of diverse carbon nanomaterials (e.g., graphenes, carbon nanotubes, mesoporous carbon, carbon dots, etc.) and their derivatives in the sensing, imaging, drug delivery, and therapy of different gynecologic cancers. Important research contributions are highlighted in terms of the relationships among the fabrication strategies, architectural features, and action mechanisms for the diagnosis and therapy of gynecologic cancers. The current challenges and future strategies are discussed from the viewpoint of the real clinical application of carbon-based nanomedicines in gynecologic cancers. It is anticipated that this review will attract more attention toward the development and application of carbon nanomaterials for the theranostics of gynecologic cancers. [ABSTRACT FROM AUTHOR]

[Display omitted] With the increasing energy and environmental crisis, exploring convenient and general strategies for constructing of highly active, stable, and cost-effective bifunctional electrocatalysts for overall water splitting are exceedingly desirable yet still challenging. Herein, 3D hierarchical mesoporous cobalt phosphide embedded N-doped carbon nanoflowers (CoP@NCNFs) are successfully constructed with ultrathin nanosheets by phosphating of the cobalt coordination polymer nanoflowers (CoCPNFs). By virtue of their unique architecture and particular composition, the obtained CoP@NCNFs reveal extraordinary performance with ultralow overpotentials and small Tafel slopes for both OER (291 mV at 10 mA cm−2; 75 mV dec−1) and HER (166 mV at 10 mA cm−2; 76 mV dec−1) in alkaline medium. In particular, CoP@NCNFs can act as both anode and cathode to perform overall water splitting, and the assembled device only needs a cell voltage as low as 1.59 V to achieve the current density of 10 mA cm−2. Simultaneously, the CoP@NCNFs also exhibit admirable durability (at least 15 h) throughout the water splitting process. These remarkable electrocatalytic performances could be attributed to the synergistic effect of highly active CoP NPs and conductive mesoporous N-doped carbon nanosheets, which effectively improved the surface contact between catalyst and electrolyte, mass diffusion, and stability. [ABSTRACT FROM AUTHOR]

Nanotechnology is a novel approach to dermatologic treatment. Nanomaterials are materials typically defined as less than 100 nm in size. As this size approaches molecular dimensions, the chemical and physical properties vastly change due to a relative increase in surface area to volume ratio. Unique and altered properties ensue, such as carbon becoming an electrical conductant in the nano form, and glass becoming a liquid. The interaction of nanoparticles with biota likewise changes. Novel therapeutics may be possible with the use of nanomaterials. Advantages of nanoparticles include the ability to overcome microbial resistance and potentially induce immunomodulatory effects. Engineered nanomaterials or the development of nano-therapeutics with photo-induced antibacterial propensity and immunomodulatory activities has the potential to open new prospects for the treatment of ubiquitous cutaneous diseases, such as acne vulgaris. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) has emerged as a sustainable energy carrier capable of replacing/complementing the global carbon-based energy matrix. Although studies in this area have often focused on the fundamental understanding of catalytic processes and the demonstration of their activities towards different strategies, much effort is still needed to develop high-performance technologies and advanced materials to accomplish widespread utilization. The main goal of this review is to discuss the recent contributions in the H2 production field by employing nanomaterials with well-defined and controllable physicochemical features. Nanoengineering approaches at the sub-nano or atomic scale are especially interesting, as they allow us to unravel how activity varies as a function of these parameters (shape, size, composition, structure, electronic, and support interaction) and obtain insights into structure–performance relationships in the field of H2 production, allowing not only the optimization of performances but also enabling the rational design of nanocatalysts with desired activities and selectivity for H2 production. Herein, we start with a brief description of preparing such materials, emphasizing the importance of accomplishing the physicochemical control of nanostructures. The review finally culminates in the leading technologies for H2 production, identifying the promising applications of controlled nanomaterials. [ABSTRACT FROM AUTHOR]

Catalytic conversion of biomass and waste into chemicals and fuels is gaining interest to reach a circular economy. Here, we review carbon-based and carbon-supported nanocatalysts for biomass conversion with focus on catalyst types and synthesis, optimization, mechanisms and three-dimension catalytic structures. Catalystic materials include amorphous carbon, graphene, graphene oxide, carbon nanotubes and carbon nanofibers. [ABSTRACT FROM AUTHOR]

Nanomaterial science is a particularly important research field in modern science and technology, which has attracted wide attention and research from all walks of life since its inception and has formed a relatively perfect category of science and technology. The purpose of this paper is to explore the application of carbon nanocomposite sensing and functional magnetic nanomaterial in the sports industry and their biosecurity research. This paper first discusses the research progress of nanocomposite in biosecurity and concludes that chemical modification can reduce the negative biological effects of nanomaterial, then puts forward the research methods on nanocomposite in the sports industry, and then selects nanosilver composites to explore and study the effects of different particle sizes and concentrations on the antibacterial properties of Aspergillus and test and characterize the properties of nanocomposite. The stability of nanocomposite modification electrodes is also explored. The results show that nanosilver has excellent bactericidal effects on both AF293 and Gra04. In particular, 8.08 × 10 − 5 mol/L and 4.03 × 10 − 5 mol/L nanosilver has a bacteriological rate of 100%, indicating that the growth of all fungal spores can be completely inhibited, and when the content of 10 wt% is found, the thermal conductivity of PHBE-MWNT pressure-sensitive composite materials is achieved 0.6975 W/(m-K), 1.8 times the MWNT pressure-sensitive glue, higher than the pure pressure-sensitive glue about 255%. [ABSTRACT FROM AUTHOR]

The microstructure, electrical and electrochemical properties of MXene/aromatic poly(ether amide) (PEA)‐derived hybrid carbon nanofibers (HCNFs) as high‐performance free‐standing supercapacitor electrode materials are reported. For this purpose, a series of HCNFs are fabricated by sequential methods of electrospinning of PEA solutions, dip‐coating (1–10 cycles) of as‐spun PEA nanofibers into MXene aqueous dispersion, and heat‐treatment of MXene‐coated PEA nanofibers for carbonization. The structural analyses of HCNFs reveal that MXene nanosheets are uniformly deposited on PEA‐derived and nitrogen self‐doped CNFs and that they are accumulated with increasing the number of dip‐coating cycles. Accordingly, the electrical conductivity increases from 3.94 S cm−1 for PEA‐derived neat CNF to 15.74 S cm−1 for HCNF10 (10 dip‐coating cycles) due to the increase in the content of electrically conductive MXene nanosheets. On the other hand, the electrochemical performance is measured to be the highest in HCNF7 (7 dip‐coating cycles) owing to a trade‐off effect of ion barrier function and high electrical conductivity of MXene nanosheets to porous CNF webs. For a symmetric supercapacitor setup of two self‐standing HCNF7 electrodes, outstanding electrochemical properties of specific capacitance of 66.7–179.3 F g−1, power density of 1000–10 000 W kg−1, and energy density of 52.7–91.2 Wh kg−1 are attained at current densities of 1–10 A g−1. [ABSTRACT FROM AUTHOR]

This document is a special issue of the journal Nanomaterials, focusing on the fabrication and characterization of nanostructured carbon electrodes for energy storage systems. The issue includes five papers that discuss the development and performance of various nanostructured carbon materials, such as carbon nanofibers, graphene, and bio-derived carbons, in lithium-ion batteries, sodium-ion batteries, and supercapacitors. The papers highlight the use of different techniques and materials to improve the electrochemical performance of these electrodes. Overall, this special issue provides valuable insights into the design of high-performance electrodes and offers potential references for future research in this field. [Extracted from the article]

The rational design of catalysts with low cost, high efficient and robust stability toward oxygen evolution reaction (OER) is greatly desired but remains a formidable challenge. In this work, a one-pot, spatially confined strategy was reported to fabricate ultrathin NiFe layered double hydroxide (NiFe-LDH) nanosheets interconnected by ultrafine, strong carbon nanofibers (CNFs) network. The as-fabricated NiFe-LDH/CNFs catalyst exhibits enhanced OER catalytic activity in terms of low overpotential of 230 mV to obtain an OER current density of 10 mA cm−2 and very small Tafel slope of 34 mV dec−1, outperforming pure NiFe-LDH nanosheets assembly, commercial RuO 2 , and most non-noble metal catalysts ever reported. It also delivers an excellent structural and electrocatalytic stability upon the long-term OER operation at a large current of 30 mA cm−2 for 40 h. Furthermore, the cell assembled by using NiFe-LDH/CNFs and commercial Pt/C as anode (+) and cathode (−) ((+)NiFe-LDH/CNFs||Pt/C(−)) only requires a potential of 1.50 V to deliver the water splitting current of 10 mA cm−2, 130 mV lower than that of (+)RuO 2 ||Pt/C(−) couple, demonstrating great potential for applications in cost-efficient water splitting devices. An advanced electrocatalyst was developed by a facile, spatially confined strategy to grow ultrathin NiFe-LDH nanosheets within carbon nanofibers (CNFs), which exhibits excellent catalytic activity for oxygen evolution reaction with a low overpotential of 230 mV at 10 mA cm−2 and Tafel slope of 34 mV dec−1. [Display omitted] • Nanohybrid catalyst comprising NiFe-LDH and carbon nanofibers was prepared. • Carbon nanofibers own merits of low-cost, eco-friendliness and easy-fabrication. • Carbon nanofibers improve the conductivity and dispersity of LDHs. • The hybrid catalyst exhibits excellent catalytic activity and stability to OER. [ABSTRACT FROM AUTHOR]

Nanocatalysts, as a part of nanotechnology, have been seen very useful for various fileds of applications capturing a large contribution of the world market. Indeed, several unsolved issues of catalysts have been reconsidered by employing the new nanocatalysts including single core metal atoms and ions with surrounding holes. Moreover, it was expected that the future of catalytic reactions, especially those organic ones, will deal with the nanocatalyst applications. To this aim, the features of catalytic nanoparticles and magnetic nanocatalysts regarding evaluation of their advantages and applications in organic reactions were investigated in this work. Developments of catalytic nanoparticles and magnetic nanocatalysts were discussed in this work regarding the novel applications of such materials at the nanoscale for approaching advantageous features. Increased availability, activity, and stability are very important for applications of the catalysts in various organic reactions. Therefore, it is a must to discuss features of such nanocatalytic systems to provide more information about their advantages and even disadvantages of their applications. [ABSTRACT FROM AUTHOR]

Herein, a rational design of SnS2 nanosheets confined into bubble‐like carbon nanoreactors anchored on N,S doped carbon nanofibers (SnS2@C/CNF) is proposed to prepare the self‐standing electrodes, which provides tunable void space on carbon fibers for the first time by introducing hollow carbon nanoreactors. The SnS2@C/CNF provides the stable support with greatly enhanced ion and electron transport, alleviates aggregation and volume expansion of SnS2 nanosheets, and promotes the formation of abundant exposed edges and active sites. The volume balance between SnS2 nanosheets and hollow carbon nanoreactors is reached to accommodate the expansion of SnS2 during cycles by controlling the thickness of SnO2 shells, which achieves the best space utilization. The doping of N,S elements enhances the wettability of the carbon nanofiber matrix to electrolyte and Li ions and further improves the electrical conductivity of the whole electrode. Thus, the SnS2@C/CNF benefits greatly in structural stability and pseudocapacitive capacity for improved lithium/sodium storage performance. As a result of these improvements, the self‐standing SnS2@C/CNF film electrodes exhibit the highly stable capacity of 964.8 and 767.6 mAh g−1 at 0.2 A g−1, and excellent capacity retention of 87.4% and 82.4% after 1000 cycles at high current density for lithium‐ion batteries and sodium‐ion batteries, respectively. [ABSTRACT FROM AUTHOR]

Nanotechnology is one of the most emerging fields of research within recent decades and is based upon the exploitation of nano-sized materials (e.g., nanoparticles, nanotubes, nanomembranes, nanowires, nanofibers and so on) in various operational fields. Nanomaterials have multiple advantages, including high stability, target selectivity, and plasticity. Diverse biotic (e.g., Capsid of viruses and algae) and abiotic (e.g., Carbon, silver, gold and etc.) materials can be utilized in the synthesis process of nanomaterials. "Nanobiotechnology" is the combination of nanotechnology and biotechnology disciplines. Nano-based approaches are developed to improve the traditional biotechnological methods and overcome their limitations, such as the side effects caused by conventional therapies. Several studies have reported that nanobiotechnology has remarkably enhanced the efficiency of various techniques, including drug delivery, water and soil remediation, and enzymatic processes. In this review, techniques that benefit the most from nano-biotechnological approaches, are categorized into four major fields: medical, industrial, agricultural, and environmental. [ABSTRACT FROM AUTHOR]

This work was devoted to a search for effective catalysts for the processing of chlorine-substituted hydrocarbons to obtain carbon nanomaterials. A series of porous (1–x)Ni–xW nanoalloys with tungsten concentrations from 0.5 to 10 wt % was synthesized by a coprecipitation method. All of the samples were single-phase solid solutions based on a face-centered cubic (fcc) lattice of nickel and had a spongy structure. The kinetics of carbon erosion of bulk (1–x)Ni–xW alloys in the course of interaction with a reaction atmosphere containing 1,2-dichloroethane vapor at 600°C was studied. This process was accompanied by rapid disintegration of the alloys with the formation of active particles for the growth of carbon nanofibers (CNFs). The addition of tungsten led to an increase in the activity of nickel in the synthesis of CNFs by 10–70%. The highest yield of CNFs for 2 h of reaction (29.8 g/gNi) was observed with a Ni–W alloy (4 wt %). The structural and morphological features of the resulting carbon product were investigated. Electron-microscopic data indicated the formation of carbon filaments with a pronounced segmented structure. Raman spectroscopy data revealed that the addition of tungsten decreased the fraction of amorphous carbon in the product. According to the data of low-temperature nitrogen adsorption, the specific surface area of the carbon nanomaterial was 300–400 m2/g. [ABSTRACT FROM AUTHOR]

[Display omitted] • A non-noble-metal based novel SERS substrate-porous carbon film/WO 3-x nanosheets was developed; • Detection limit of 10-7 M with the Raman enhancement factor of 106 was achieved on the optical substrate. • A deep leaning method was used to accurately analyze the Raman spectra of flavonoids of quercetin, 3-hydroxyflavone and flavone. • Quercetin can be accurately detected by the fully convolutional network, and lowest detectable concentration of 10-5 M was achieved. The Surface-enhanced Raman scattering (SERS) is an attractive optical detecting method with high sensitivity and detectivity, however challenges on large-area signal uniformity and complex spectra analysis methods always retards its wide application. Herein, a highly sensitive and uniform SERS detection strategy supported by porous carbon film/WO 3-x nanosheets (PorC/WO 3-x) based noble-metal-free SERS substrate and deep learning algorithm are reported. Experimentally, the PorC/WO 3-x substrate was prepared by high-temperature annealing the PorC/WO 3 films under the argon atmosphere. The defect density of the WO 3 was controlled by tuning the reducing reaction time during the annealing process. The SERS performance was evaluated by using R6G as the Raman reporter, it showed that the SERS intensity obtained on the substrate with the optimal annealing time of 3 h was about 8 times as high as that obtained on the PorC/WO 3 substrate without annealing treatment. And detection limit of 10-7 M and Raman enhancement factor of 106 could be achieved. Moreover, the above optimal SERS substrate was utilized to detect flavonoids of quercetin, 3-hydroxyflavone and flavone, and a deep learning algorithms was incorporated to identify the quercetin. It revealed that quercetin can be accurately detected within the above flavonoids, and lowest detectable concentration of 10-5 M can be achieved. [ABSTRACT FROM AUTHOR]

Tin monosulfide (SnS), recognized for its exceptional electrochemical properties, cost-effectiveness, and environmental sustainability, has emerged as a promising anode material for sodium-ion batteries. However, it suffers from significant volume expansion and limited electrical conductivity. Herein, an NC@SnS nanocomposite featuring SnS nanosheets directly grown on nitrogen-doped porous carbon fibers has been synthesized, showing a reversible capacity of 471 mAh g−1 at 1 A g−1 for sodium storage. The full cell containing Na 3 V 2 (PO 4) 3 and NC@SnS achieved a specific energy density of 114 Wh kg−1, highlighting its potential applicability for advanced electrochemical energy storage systems. The enhanced sodium storage performance indicates that the structural design of the composite material has a broad prospect for improving the application of electrode materials. N-doped carbon nanofiber-supported SnS nanosheets were synthesized by multi-step method. The as-prepared sample showed an ordered nanoarray structure which provided void space to buffer volume change, while the carbon scaffold offered high electronic conductivity. The nanocomposite demonstrated high reversible capacity and long cycle life for sodium storage. [Display omitted] • A multi-step approach to produce carbon nanofibers supported SnS nanosheets. • The carbon backbone offers high electronic conductivity. • The nanosheet array provides large amount of space for volume variation buffering. • The sample exhibits high capacity and long cycle life for sodium storage. [ABSTRACT FROM AUTHOR]

Alkali-activated materials are sustainable low-carbon cementitious materials with a promising future as an alternative to cementitious materials. Industrial solid waste can be consumed substantially in preparing alkali-activated materials, which are energy-efficient and environmentally friendly. Nanotechnology and nanomaterials play a crucial part in enhancing the properties of alkali-activated materials at the micro-scale. Based on their geometric dimensions, nanomaterials can be classified into different dimensional categories: zero, one, two, and three dimensions. Through systematic literature research and data statistics, this work reviews the analysis of the regularity and mechanism by which nanomaterials of different dimensions (0-dimensional, 1-dimensional, and 2-dimensional) influence the workability, rheology, physico-mechanical, durability, and volume stability of alkali-activated materials. In conclusion, nanomaterials' dispersion methods in alkali-activated materials can be classified as dry and wet dispersion (dispersion in water or activator). In addition, the method of dispersion has an impact on the performance of nanomaterials. The properties of alkali-activated materials paste relate to nanomaterial activity, dimension, morphology, and dosage. Nanomaterials in different dimensions have distinct structural and performance advantages that can significantly enhance alkali-activated materials' physical, mechanical, and durability properties and endow them with various functionalities (refractory, photocatalysis, electrical conductivity, etc.). Nanomaterial modification and enhancement technology have great potential for application in alkali-activated material property optimization. [Display omitted] • Based on geometric dimensions, nanomaterials are 0, 1, 2, and 3 dimensional (D). • Different-dimensional nanomaterials both have identical and differing characteristics. • Studies on alkali-activated materials modified with nanomaterials (0,1,2-D) are reviewed. • Nanomaterials have excellent modification effects on alkali-activated materials. • Nanomaterial-modification technology has excellent potential for alkali-activated materials. [ABSTRACT FROM AUTHOR]

Interfacial configuration of heterostructured photocatalysts to boost photocarrier separation and transfer is immensely beneficial to acquire great photocatalytic efficiency. Herein, a well-structured Mo 2 C/C/BiOI heterostructure containing different weight ratios Mo 2 C instead of noble metal was successfully prepared, where the inter-modified carbon nanosheets subserve as a connective to generate a perfect interface contact between Mo 2 C and BiOI. The photocatalytic performances of the photocatalysts were appraised by the degradation of indigo carmine and reduction of 4-nitroaniline under visible-light elucidation. The nanocomposite containing 7 % by weight of Mo 2 C/C showed the highest photocatalytic efficiency by eliminating 99.4 % of indigo carmine and 99.8 % of 4-nitroaniline within 75 min and 13 min, respectively. The boosted photocatalytic activity is attributed to the synergistic interaction between Mo 2 C/C and BiOI and the all-solid-state Z mechanism, where conductive carbon nanoparticles as an efficient electron mediator enable rapid photocarrier transfer and separation between Mo 2 C and BiOI. This study accentuates that Mo 2 C/C-based all-solid-state Z-scheme heterojunction nanocomposites are hopeful candidate photocatalysts for environmental applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• The NiFe-LDH nanosheets grow on the carbon nanofibers via an in-situ conversion strategy. • The CNF@NiFe-LDH interlayer can effectively restrict the diffusion of polysulfides. • The CNF@NiFe-LDH interlayer cells exhibit good cyclic and rate performances. • High initial discharge capacity of 799 mAh g−1 at 1 C with a low decay ratio of 0.045 % per-cycle over 500 cycles. To solve the shuttle effect of polysulfides and sluggish reaction kinetics in Li-S batteries, a functional interlayer added between the cathode and separator has been proven to be a very effective means. The pleasing interlayer is usually formed by the conductive skeleton and active components that have polysulfide adsorption and catalytic conversion abilities. In this paper, an electrospinning method assisted with in-site growth strategy has been developed to design a hierarchical functional film with NiFe-LDH nanosheets anchored on carbon nanofibers (CNF@NiFe-LDH). Structural characterizations and electrochemical measurements have been taken to indicate that the CNF@NiFe-LDH interlayer can effectively restrict the diffusion of polysulfides and accelerate the redox kinetics. [ABSTRACT FROM AUTHOR]

• Provide a detailed analysis of the various types of carbon-based catalysts employed for CO 2 reduction from an experimental design perspective. • Present a comprehensive understanding of the recent theoretical advancements in electrochemical CO 2 RR, involving adsorbent geometric structure, electrocatalytic mechanisms, and intrinsic descriptor. • Explore the general design strategies of carbon-based catalysts to achieve efficient CO 2 conversion. • Evaluate the challenges and opportunities associated with carbon-based catalysts for CO 2 reduction. The rational design of nanostructured carbon-based materials has emerged as a crucial research area due to their significant impact on the electrochemical CO 2 reduction reaction (CO 2 RR). This process converts carbon dioxide gas into value-added chemical products, such as formate, CO, or other fuels. A variety of carbon-based electrocatalysts, including non-metallic doped carbon materials (e.g., N-doped carbon nanofibers, N-doped diamonds), metal-macroring materials (e.g., metal-porphyrins, metal-phthalocyanines, and metal-corroles), and M−N−C typical materials (Fe-N-C, Co-N-C, and Ni-N-C), have exhibited promising results as efficient catalysts for CO 2 RR. In this review, we discuss recent advances in the rational design of nanostructured carbon-based materials for CO 2 RR using both experimental and theoretical approaches. These include the design and synthesis of morphology-tunable carbon-based materials and heteroatom doping. Furthermore, we delve into the catalytic mechanisms of CO 2 electrochemical reduction on carbon-based materials, encompassing surface reactions, geometric effects, and electronic effects. These findings contribute to the development of intrinsic descriptors for establishing the volcano relationship with catalytic performance. Finally, we highlight the challenges and future directions in the field of CO 2 RR, stressing the importance of gaining a better understanding of the complex structure–function relationships in carbon-based materials and the development of efficient and sustainable CO 2 RR processes for industrial applications. [ABSTRACT FROM AUTHOR]