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Hydrogen holds the promise of replacing fossil fuels and offers a sustainable pathway for energy generation. However, the large-scale production of hydrogen via the environment friendly electrocatalytic process relies heavily on the performance of electrocatalysts. In this study, we investigate the electrocatalytic performance of graphene nanosheets (GNS), molybdenum disulfide (MoS 2), ruthenium dioxide (RuO 2), and their composites for hydrogen evolution reaction (HER), a novel combination that has not been explored in previous literature. We synthesize the materials using Liquid Phase Exfoliation at 500 and 1000 RPMs for GNS and MoS 2 and via hydrothermal methods for RuO 2 nanosheets and nanoparticles, aiming to exploit synergistic effects for enhanced activity and stability. The synthesized GNS-1000/MoS 2 -1000/RuO 2 -NSs composite demonstrates promising HER results, showcasing a low overpotential of 63 mV and a reduced Tafel slope of 59 mV/dec. This improvement indicates enhanced electron transfer, improved active site dispersion, and increased surface area due to the synergistic effects, which also aids in long-term electrochemical stability. Our study underlines the potential of GNS/MoS 2 /RuO 2 composites, particularly the GNS-1000/MoS 2 -1000/RuO 2 -NSs, in transforming hydrogen production methods and promoting efficient, sustainable energy solutions. The implications of our findings extend the boundaries of materials engineering, edging us closer to a sustainable energy future. • Novel GNS/MoS 2 /RuO 2 catalyst enhances HER with low overpotential and Tafel slope. • Synergistic effects of GNS, MoS 2 , and RuO 2 boost electron transfer in HER. • Cost-effective alternative to platinum catalysts developed for hydrogen production. • Optimized synthesis improves catalytic activity and stability in HER. • Composite catalyst offers potential for sustainable energy applications. [ABSTRACT FROM AUTHOR]

In the search for new advanced 2D materials for technological applications and to expand the research of non‐van der Waals (non‐vdW) 2D electronic devices, this study presents a novel strategy for liquid phase exfoliation (LPE) of non‐vdW Cr2S3 to produce Cr2S3 nanosheets (NSs). By utilizing N‐methyl‐2‐pyrrolidone (NMP), bulk Cr2S3 is separated along the (001) plane, resulting in the formation of NSs with an average thickness of ≈3 nm. Various characterization techniques are applied to the Cr2S3 material before and after LPE. Subsequently, the obtained Cr2S3 NSs are integrated into a photoelectrochemical (PEC)‐type photodetector (PD) to evaluate the photoelectric conversion efficiency under varying conditions. The findings indicate that the developed PD exhibits a distinct self‐powered photodetection capability with a photocurrent (Pph) of 39.5 nA cm−2, a photoresponsivity (Rph) of 622 nA W−1, and a detectivity (D*) of 0.5 × 107 Jones under 350 nm irradiation at 0 V. Moreover, the PD demonstrates rapid response time (0.06 s) and good long‐term stability (over 15 days), thus providing valuable insight for the advancement of non‐vdW Cr2S3‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Ferromagnetic metal Fe3GeTe2 (FGT), whose structure exhibits weak van‐der‐Waals interactions between 5‐atom thick layers, was subjected to liquid‐phase exfoliation (LPE) in N‐methyl pyrrolidone (NMP) to yield a suspension of nanosheets that were separated into several fractions by successive centrifugation at different speeds. Electron microscopy confirmed successful exfoliation of bulk FGT to nanosheets as thin as 6 nm. The ferromagnetic ordering temperature for the nanosheets gradually decreased with the increase in the centrifugation speed used to isolate the 2D material. These nanosheets were resuspended in NMP and treated with an organic acceptor, 7,7,8,8‐tetracyano‐quinodimethane (TCNQ), which led to precipitation of FGT‐TCNQ composite. The formation of the composite material is accompanied by charge transfer from the FGT nanosheets to TCNQ molecules, generating TCNQ⋅− radical anions, as revealed by experimental vibrational spectra and supported by first principles calculations. Remarkably, a substantial increase in magnetic anisotropy was observed, as manifested by the increase in the coercive field from nearly zero in bulk FGT to 1.0 kOe in the exfoliated nanosheets and then to 5.4 kOe in the FGT‐TCNQ composite. The dramatic increase in coercivity of the composite suggests that functionalization with redox‐active molecules provides an appealing pathway to enhancing magnetic properties of 2D materials. [ABSTRACT FROM AUTHOR]

The value of two-dimensional (2D) materials in printed electronics has been gradually explored, and the rheological properties of 2D material dispersions are very different for various printing technologies. Understanding the rheological properties of 2D material dispersions plays a vital role in selecting the optimal manufacturing technology. Inkjet printing is suitable for small nanosheet sizes and low solution viscosity, and it has a significant advantage in developing nanosheet inks because of its masklessness, high efficiency, and high precision. In this work, we selected 2D Ti0.8Co0.2O2 nanosheets, which can be synthesized in large quantities by the liquid phase exfoliation technique; investigated the effects of nanosheet particle size, solution concentration on the rheological properties of the dispersion; and obtained the optimal printing processing method of the dispersion as inkjet printing. The ultrathin Ti0.8Co0.2O2 nanosheet films were prepared by inkjet printing, and their magnetic characteristics were compared with those of Ti0.8Co0.2O2 powder. The films prepared by inkjet printing exhibited long-range ordering, maintaining the nanosheet powders' paramagnetic characteristics. Our work underscored the potential of inkjet printing as a promising method for fabricating precisely controlled thin films using 2D materials, with applications spanning electronics, sensors, and catalysis. [ABSTRACT FROM AUTHOR]

Development of Nano-heterostructures based on transition metal chalcogenides is promising strategy to accelerate the catalytic performance for hydrogen evolution reaction (HER) and supercapacitor application. The design and development of non-noble transition metal based catalysts is required for the low-cost, efficient and earth-abundant electrodes for sustainable energy conversion and storage. ReS 2 /CoS heterostructures were synthesized by two step methods involving liquid phase exfoliation of ReS 2 and hydrothermal decoration of CoS. The prepared ReS 2 /CoS heterostructures shows high performance supercapacitor applications with specific capacitance of 663.2 F/g at 2 A/g and 643.1 F/g at scan rate 5 mV/s, showing enhanced redox reaction and number of electrochemically active sites due to synergistic effect and modulated electronic structure. Additionally, ReS 2 /CoS heterostructures shows the superior HER performance in alkaline condition with overpotential of 187 mV at 10 mA/cm2 due to accelerated kinetics, enhanced ECSA and low charge transfer resistance. The ReS 2 /CoS heterostructures shows the stable electrochemical performance for HER for more than 17 h. • This article reports the facile synthesis of ReS 2 /CoS heterostructure catalyst. • Nano-interface engineering facilitates the enhanced HER and supercapacitor performance. • The specific capacitance of 663.2 F/g at 2 A/g and 643.1 F/g at scan rate 5 mV/s are achieved. • Superior HER in alkaline condition with overpotential of 187 mV at 10 mA/cm2 have been achieved. [ABSTRACT FROM AUTHOR]

In this study, a facile and scalable method for synthesizing MoSe2 nanomaterial via a sonication-assisted liquid-phase exfoliation method is proposed. This study shows the successful synthesis of few-layered MoSe2 in various solvents including DI water, ethanol, N-Methyl-2-pyrrolidone (NMP), Dimethylformamide (DMF) and Dimethylsulfoxide (DMSO). The exfoliated nanosheets have remarkably different properties than bulk MoSe2 which were studied using Field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and UV–Vis spectroscopy to investigate their morphology, functional groups, structure and optical properties, respectively. The mean values of the number of layers from an optical extinction spectrum based on the effect of edge and quantum confinement were also calculated. Moreover, the exfoliated material using this method has potential application in energy storage as demonstrated by the electrochemical performance of the bulk and exfoliated materials. • Successful synthesis of the few-layer MoSe2 from bulk MoSe2 using liquid phase exfoliation method in various solvents • The investigation of the effect of solvent on the number of layers and optical properties of MoSe2

Graphene and related two-dimensional materials (2DMs) have shown promise across numerous technology areas including flexible electronics, energy storage and pollution remediation. Research into novel applications of these atomically thin materials relies on access to synthesis techniques for producing 2DMs with suitable quality and quantity. Liquid-phase exfoliation is a mechanochemical approach that can achieve this and produce defect-free nanomaterial dispersions which are compatible for downstream use (e.g. inkjet printing, coatings). Here, using kitchen blenders to deliver shear-driven exfoliation, we develop a range of inexpensive hardware solutions that can allow researchers to synthesise 2DMs using a controllable, sustainable and scalable process. Extensive modifications were necessary as the onboard electronics lack the experimental controls (temperature, speed, characterisation) for scientific research and precision synthesis. The technical aspects (including the many lessons learned) of the modifications are discussed and a simple selection process is proposed for creating bespoke mechanochemical processors for any application in the hope that this encourages experimentation. Specific builds with detailed notes, cost breakdown and associated files are provided in the Open Science Framework (OSF) repository, OpenLPE associated with this article.

The fundamental understanding of the electrochemical transport of ions at the interface of nanoscale materials and its immediate environment lays the foundation to build electrochemical sensors for a wide variety of chemical, biological, and environmental problems. Therefore, enabling an efficient electron transfer from the environment to an atomically thin, two-dimensional material such as graphene and vice versa provides a route to building graphene-based electrochemical sensors. Although many graphene-based electrochemical sensors have been reported in recent years, there have been limitations in designing and manufacturing them to monitor phosphate ions in the environment. This limitation primarily arises from the lack of high-performance printable graphene nanoinks (in terms of their combined electrical conductivity and electrochemical charge transfer properties) as well as complexity in the detection of phosphate ions. Herein, we report the manufacturing of a high-quality graphene nanoink and its use for the first time in fabricating stable and reliable printed phosphate ion electrochemical sensors using a microplotter. These sensors demonstrate a sensitivity of 0.3223 ± 0.025 μA μM–1 cm–2, with a limit of detection (LOD) of 2.2 μM and linear sensing range of 1–600 μM. Moreover, they exhibit high selectivity toward phosphates when tested in the presence of NO3–, CO3–, Cl–, and SO42– interfering ions, affirming their reliability as a sensing platform. Phosphate electrochemical sensing using the proposed printed graphene sensors will pave the way for future development of point-of-care and continuous phosphate monitoring in environmental sensing. [ABSTRACT FROM AUTHOR]

Liquid exfoliation can be considered as a viable approach for the scalable production of 2D materials due to its various benefits, although the polydispersity in the obtained nanosheet size hinders their straightforward incorporation. Size‐separation can help alleviate these concerns, however a correlation between nanosheet size and property needs to be established to bring about size‐specific applicability. Herein, size‐selected aqueous nanosheet dispersions have been obtained via centrifugation‐based protocols, and their chemical activity in the spontaneous reduction of chloroplatinic acid is investigated. Growth of ultrasmall Pt nanoparticles was achieved on nanosheet surfaces without a need for reducing agents, and stark differences in the nanoparticle coverage were observed as a function of nanosheet size. Defects in the nanosheets were probed via Raman spectroscopy, and correlated to the observed size‐activity. Additionally, the effect of reaction temperature during synthesis was investigated. The electrochemical activity of the ultrasmall Pt nanoparticle decorated MoS2 nanosheets was evaluated for the hydrogen evolution reaction, and enhancement in performance was observed with nanosheet size, and nanoparticle decoration density. These findings shine light on the significance of nanosheet size in controlling spontaneous reduction reactions, and provide a deeper insight to intrinsic properties of liquid exfoliated nanosheets. [ABSTRACT FROM AUTHOR]

Hydrogen is a promising green fuel carrier that can replace fossil fuels; however, its storage is still a challenge. Carbon-based materials with metal catalysts have recently been the focus of research for solid-state hydrogen storage due to their efficacy and low cost. Here, we report on the exfoliation of expanded graphite (EG) through high shear mixing and probe tip sonication methods to form graphene-based nanomaterial ShEG and sEG, respectively. The exfoliation processes were optimized based on electrochemical capacitance measurements. The exfoliated EG was further functionalized with palladium nanoparticles (Pd-NP) for solid-state hydrogen storage. The prepared graphene-based nanomaterials (ShEG and sEG) and the nanocomposites (Pd-ShEG and Pd-sEG) were characterized with various traditional techniques (e.g., SEM, TEM, EDX, XPS, Raman, XRD) and the advanced high-resolution pair distribution function (HRPDF) analysis. Electrochemical hydrogen uptake and release (QH) were measured, showing that the sEG decorated with Pd-NP (Pd-sEG, 31.05 mC cm−2) and ShEG with Pd-NP (Pd-ShEG, 24.54 mC cm−2) had a notable improvement over Pd-NP (9.87 mC cm−2) and the composite of Pd-EG (14.7 mC cm−2). QH showed a strong linear relationship with an effective surface area to volume ratio, indicating nanoparticle size as a determining factor for hydrogen uptake and release. This work is a promising step toward the design of the high-performance solid-state hydrogen storage devices through mechanical exfoliation of the substrate EG to control nanoparticle size and dispersion. [ABSTRACT FROM AUTHOR]

Liquid phase exfoliation (LPE) has emerged as a promising method for the industrial-scale production of graphene. However, one of its critical steps, namely sonication, has faced challenges due to high power consumption and low efficiency, leading to limited applicability in industrial settings. This study introduces a novel, cost-effective microfluidic sonication device designed to significantly reduce power consumption while efficiently assisting the LPE process for graphene production. By coupling a capillary with a buzzer and applying an appropriate electric signal, simulation and particle tracing experiments reveal the generation of robust shear forces resulting from acoustic streaming and cavitation when the capillary end is immersed in the liquid. For the first time, the capillary-based sonication device was effectively utilized for graphene exfoliation in a DMF (N,N-Dimethylformamide) + NaOH liquid phase system. The SEM (Scanning Electron Microscope) and Raman characterization results corroborate the successful exfoliation of 100 nm with thicknesses below 10 nm graphene sheets from graphite flakes using this pioneering device. The values of I 2 D / I G increase after processing, which suggests the exfoliation of graphite flakes into thinner graphene sheets. The vibration-based acoustofluidic effector represents a versatile and scalable miniature device, capable of being employed individually for small-batch production, thereby optimizing the utilization of raw 2D materials, particularly in experimental scenarios. Alternatively, it holds the potential for large-scale manufacturing through extensive parallelization, offering distinct advantages in terms of cost-efficiency and minimal power consumption. [ABSTRACT FROM AUTHOR]

In this work, the excess water-stagnation issue in the high current region in direct methanol fuel cells (DMFCs) is resolved by using atomic precision modulated nitrogen-crafted graphene (NG) in the cathode microporous layer by utilizing simplistic, industrial-expansive and ecological strategy. Few-layer 2D-graphene (∼2–5 nm thickness) is prepared by bath sonication approach from abundant feedstock-graphite and is treated with nitric acid to yield 1.8 wt.% uniformly dispersed nitrogen containing NG. Specifically, 1:4 weight ratio NG:carbon-black (CB) hybrid architecture, displays 0.252 V in 370 mA cm−2 with the peak power density of 93.4 mW cm−2, improving cell power density by 45.6% compared with standard one at 60°C and 1 mol/L methanol/oxygen conditions at ultra-low catalyst loadings and displaying exceptional stability. Atomic insights into NG reveal that interplay between bonding configurations, altered hydrophobic/hydrophilic porosity of graphene (10.6% less wettability from contact angle and 13.1% high electrode porosity measurements) contribute to the better mass-transport-porogenic effect (16.3% high oxygen-permeability), mildly affecting the electron pathway (6.5% reduced in-plane electrical conductivity), overall significantly improving cell performance. Altogether, this work delivers multiple advantages, i.e., the usage of material from facile, sustainable and cost-effective routes, while improving DMFC performance with potential industrial promise. [ABSTRACT FROM AUTHOR]

The value of two-dimensional (2D) materials in printed electronics has been gradually explored, and the rheological properties of 2D material dispersions are very different for various printing technologies. Understanding the rheological properties of 2D material dispersions plays a vital role in selecting the optimal manufacturing technology. Inkjet printing is suitable for small nanosheet sizes and low solution viscosity, and it has a significant advantage in developing nanosheet inks because of its masklessness, high efficiency, and high precision. In this work, we selected 2D Ti0.8Co0.2O2 nanosheets, which can be synthesized in large quantities by the liquid phase exfoliation technique; investigated the effects of nanosheet particle size, solution concentration on the rheological properties of the dispersion; and obtained the optimal printing processing method of the dispersion as inkjet printing. The ultrathin Ti0.8Co0.2O2 nanosheet films were prepared by inkjet printing, and their magnetic characteristics were compared with those of Ti0.8Co0.2O2 powder. The films prepared by inkjet printing exhibited long-range ordering, maintaining the nanosheet powders’ paramagnetic characteristics. Our work underscored the potential of inkjet printing as a promising method for fabricating precisely controlled thin films using 2D materials, with applications spanning electronics, sensors, and catalysis.

Ionic liquids (ILs) are expected to be used as readily available "designer" solvents, characterized by a number of tunable properties that can be obtained by modulating anion and cation combinations and ion chain lengths. Among them, its high ionicity is outstanding in the preparation and property modulation of two-dimensional (2D) materials. In this review, we mainly focus on the ILs-assisted exfoliation of 2D materials towards large-scale as well as functionalization. Meanwhile, electric-field controlled ILs-gating of 2D material systems have shown novel electronic, magnetic, optical and superconducting properties, attracting a broad range of scientific research activities. Moreover, ILs have also been extensively applied in various field practically. We summarize the recent developments of ILs modified 2D material systems from the electrochemical, solar cells and photocatalysis aspects, discuss their advantages and possibilities as "designer solvent". It is believed that the design of ILs accompanying with diverse 2D materials will not only solve several scientific problems but also enrich materials design and engineer of 2D materials. [ABSTRACT FROM AUTHOR]

Originating from the hexagonal arrangement of magnetic ions in the presence of strong spin orbit coupling, α -RuCl3 is considered as model system for the Kitaev-Heisenberg model. While the magnetic properties of α -RuCl3 have been studied in bulk single crystals or micromechanically-exfoliated nanosheets, little is known about the nanosheets' properties after exfoliation by techniques suitable for mass production such as liquid phase exfoliation (LPE). Here, we demonstrate sonication-assisted LPE on α -RuCl3 single crystals in an inert atmosphere. Coupled with centrifugation-based size selection techniques, the accessible size- and thickness range is quantified by statistical atomic force microscopy. Individual nanosheets obtained after centrifugation-based size selection are subjected to transmission electron microscopy to confirm their structural integrity after the exfoliation. The results are combined with bulk characterisation methods, including Raman and x-ray photoelectron spectroscopy, and powder diffraction experiments to evaluate the structural integrity of the nanosheets. We report changes of the magnetic properties of the nanomaterial with nanosheet size, as well as photospectroscopic metrics for the material concentration and average layer number. Finally, a quantitative analysis on environmental effects on the nanomaterial integrity is performed based on time and temperature dependent absorbance spectroscopy revealing a relatively slow decay (half-life of ∼2000 h at 20 °C), albeit with low activation energies of 6–20 kJ mol−1. [ABSTRACT FROM AUTHOR]

Originating from the hexagonal arrangement of magnetic ions in the presence of strong spin orbit coupling, α -RuCl3 is considered as model system for the Kitaev-Heisenberg model. While the magnetic properties of α -RuCl3 have been studied in bulk single crystals or micromechanically-exfoliated nanosheets, little is known about the nanosheets' properties after exfoliation by techniques suitable for mass production such as liquid phase exfoliation (LPE). Here, we demonstrate sonication-assisted LPE on α -RuCl3 single crystals in an inert atmosphere. Coupled with centrifugation-based size selection techniques, the accessible size- and thickness range is quantified by statistical atomic force microscopy. Individual nanosheets obtained after centrifugation-based size selection are subjected to transmission electron microscopy to confirm their structural integrity after the exfoliation. The results are combined with bulk characterisation methods, including Raman and x-ray photoelectron spectroscopy, and powder diffraction experiments to evaluate the structural integrity of the nanosheets. We report changes of the magnetic properties of the nanomaterial with nanosheet size, as well as photospectroscopic metrics for the material concentration and average layer number. Finally, a quantitative analysis on environmental effects on the nanomaterial integrity is performed based on time and temperature dependent absorbance spectroscopy revealing a relatively slow decay (half-life of ∼2000 h at 20 °C), albeit with low activation energies of 6–20 kJ mol−1. [ABSTRACT FROM AUTHOR]

Carbon‐based materials, such as graphene oxide and reduced graphene oxide membranes have been recently used to fabricate ultrathin, high‐flux, and energy‐efficient membranes for ionic and molecular sieving in aqueous solution. However, these membranes appeared rather unstable during long‐term operation in water with a tendency to swell over time. Membranes produced from pristine, stable, layered graphene materials may overcome these limitations while providing high‐level performance. In this paper, an efficient and "green" strategy is proposed to fabricate µm‐thick, graphene‐based laminates by liquid phase exfoliation in Cyrene and vacuum filtration on a PVDF support. The membranes appear structurally robust and mechanically stable, even after 90 days of operation in water. In ion transport studies, the membranes show size selection (>3.3 Å) and anion‐selectivity via the positively charged nanochannels forming the graphene laminate. In antibiotic (tetracycline) diffusion studies under dynamic conditions, the membrane achieve rejection rates higher than 95%. Sizable antibacterial properties are demonstrated in contact method tests with Staphylococcus aureus and Escherichia coli bacteria. Overall, these "green" graphene‐based membranes represent a viable option for future water management applications. [ABSTRACT FROM AUTHOR]

The graphene sheets were aqueous processed via simple method liquid phase exfoliation. Sodium perylene-3, 4, 9, 10-tetracarboxylate (NaPTCA) were used as surfactant to assist the exfoliation process. The purpose of this research is to investigate the impact of NaPTCA concentration on the yield of liquid phase exfoliation of graphite to graphene sheets. The degree of exfoliation was found to be greatly influenced upon the concentration of NaPTCA surfactant. 1.0 mgmL-1 was identified as the optimal NaPTCA concentration as the graphene produced had a distinct x-ray diffraction crystallinity, scanning electron microscopic image features, high concentration of graphene dispersion (0.154 mgmL-1) and high conductivity values (751.88 Sm-1) in 2-probe electrical measurements, all of which comparison are much favourably with typical values obtained for multi-layer graphene. Hence, this simple approach for liquid-phase graphite exfoliation provides decent potential for mass production of high-quality graphene for a wide range of applications in energy storage, optical, and electronic areas.

Industrial applications of nanomaterials require large-scale production methods, such as liquid phase exfoliation (LPE). Regarding this, it is imperative to characterize the obtained materials to tailor parameters such as exfoliation medium, duration, and mechanical energy source to the desired applications. This work presents results of statistical analyses of talc flakes obtained by LPE in four different media. Talc is a phyllosilicate that can be exfoliated into nanoflakes with great mechanical properties. Sodium cholate at two different concentrations (below and at the critical micelar concentration), butanone, and Triton-X100 were employed as exfoliation medium for talc. Using recent published statistical analysis methods based on atomic force microscopy images of thousands of flakes, the shape and size distribution of nanotalc obtained using the four different media are compared. This comparison highlights the strengths and weaknesses of the media tested and hopefully will facilitate the choice of the medium for applications that have specific requirements.

Although easily scalable, the production of graphene nanoplatelets (GNP) by the means of liquid‐phase exfoliation of graphite flakes (GF) remains an energy‐ and time‐intensive process. In this work, we demonstrate that significant time and energy can be saved in GNP production when employing expanded graphite (EG) in a surfactant‐assisted liquid phase exfoliation process. Owing to its increased interlayer distance, the exfoliation of EG can be accomplished in a much shorter time (<30 min) compared to GF (approximately 7 h in the present case). Moreover, the energy required for the EG exfoliation is close to 80‐fold lower than that for GF exfoliation. Monitoring of the mean lateral dimension, specific surface area, and graphite flake‐to‐GNP transition during exfoliation was performed experimentally using several analytical techniques. The EG‐derived GNPs are produced much faster and require less energy for exfoliation compared to GF, thus making it a more efficient alternative technique. [ABSTRACT FROM AUTHOR]

Liquid phase exfoliation (LPE) has been used for the successful fabrication of nanosheets from a large number of van der Waals materials. While this allows to study fundamental changes of material properties’ associated with reduced dimensions, it also changes the chemistry of many materials due to a significant increase of the effective surface area, often accompanied with enhanced reactivity and accelerated oxidation. To prevent material decomposition, LPE and processing in inert atmosphere have been developed, which enables the preparation of pristine nanomaterials, and to systematically study compositional changes over time for different storage conditions. Here, we demonstrate the inert exfoliation of the oxidation-sensitive van der Waals crystal, CrTe3. The pristine nanomaterial was purified and size-selected by centrifugation, nanosheet dimensions in the fractions quantified by atomic force microscopy and studied by Raman, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX) and photo spectroscopic measurements. We find a dependence of the relative intensities of the CrTe3 Raman modes on the propagation direction of the incident light, which prevents a correlation of the Raman spectral profile to the nanosheet dimensions. XPS and EDX reveal that the contribution of surface oxides to the spectra is reduced after exfoliation compared to the bulk material. Further, the decomposition mechanism of the nanosheets was studied by time-dependent extinction measurements after water titration experiments to initially dry solvents, which suggest that water plays a significant role in the material decomposition.

One of the most critical challenges for commercialization of sodium-ion battery (SIB) is to develop carbon anodes with high capacity and good rate performance. Graphene would be an excellent SIB anode candidate due to its success in various kinds of batteries. Liquid-phase exfoliation (LPE) method is an inexpensive, facile and potentially scalable method to produce less-defected graphene sheets. In this work, we developed an improved, dispersant-assisted LPE method to produce graphene composite materials from raw graphite with high yield and better quality for SIB anode. Here, bacterial cellulose (BC) was used as a green dispersant/stabilizer for LPE, a "spacer" for anti-restacking, as well as a carbon precursor in the composite. As a result, the carbonized BC (CBC)/LPE graphene (LEGr) presented improved performance compared to composite with graphene prepared by Hummers method. It exhibited a specific capacity of 233 mAh g−1 at a current density of 20 mA g−1, and 157 mAh g−1 after 200 cycles at a high current density of 100 mA g−1 with capacity retention rate of 87.73%. This method not only provides new insight in graphene composites preparation, but also takes a new step in the exploration of anode materials for sodium-ion batteriesSIBs. [ABSTRACT FROM AUTHOR]

ZnO/graphene nanocomposites were prepared using a facile approach. Graphene nanosheets were prepared by ultrasonication-based liquid phase exfoliation of graphite powder in a low boiling point organic solvent, 1,2-Dichloroethane, for the preparation of ZnO/graphene nanocomposites. Structural properties of the synthesized ZnO/graphene nanocomposites were studied through powder XRD and micro-Raman analysis. The characteristic Raman active modes of ZnO and graphene present in the micro-Raman spectra ensured the formation of ZnO/graphene nanocomposite and it is inferred that the graphene sheets in the composites were few layers in nature. Increasing the concentration of graphene influenced the surface morphology of the ZnO nanoparticles and a flower shape ZnO was formed on the graphene nanosheets of the composite with high graphene concentration. The efficiencies of the samples for the photocatalytic degradation of Methylene Blue dye under sunlight irradiation were investigated and 97% degradation efficiency was observed. The stability of the nanocomposites was evaluated by performing five cycles, and 92% degradation efficiency was maintained. The observed results were compared with that of ZnO/graphene composite derived from other methods. [ABSTRACT FROM AUTHOR]

Antimonene has attracted much attention due to its excellent properties such as high carrier mobility, excellent thermoelectric performance and high stability. In order to verify its theoretical advantages, a large number of experimental studies have been carried out and its applications explored. This paper mainly introduces the experimental preparation of antimonene by mechanical exfoliation, liquid phase exfoliation and epitaxial growth, summarizes the advantages and disadvantages of each method, and describes the applications of antimonene in sensor, battery, medicine and laser. Finally, prospects have been made to the future applications of antimonene in photoelectric field. [ABSTRACT FROM AUTHOR]

The present article involves a liquid phase exfoliation technique to synthesize SnSe nanosheets. These nanosheets are deposited on an ITO glass substrate to make a thin film via an electrophoretic deposition (EPD) technique. Through the use of energy-dispersive X-ray analysis (EDAX), the cleanliness and chemical compositions of the film are examined. The surface topography of the deposited film is carried out by scanning electron microscopy (SEM). The orthorhombic crystal structure of SnSe thin film is verified by X-ray diffraction (XRD) analysis. The optical gap energy and absorbance profiles also exhibit a morphology-dependent response, as measured by ultraviolet–visible (UV–vis) spectroscopy. The Photoresponse performance of SnSe thin film-based PEC-type photodetector was carried out under illumination of poly and monochromatic wavelengths. SnSe nanosheet-based photodetector showed a maximum photocurrent of 14.50 μA under polychromatic light of intensity 100 mW/cm2, at zero bias. This study demonstrates how the Requirement for TMC semiconductors in optoelectronic devices increases due to their exceptional photoresponse performance. • SnSe nanosheets were successfully produced via DVT, liquid phase exfoliation, and electrophoretic deposition. • Characterization revealed an orthorhombic lattice structure with controlled lateral widths, indicating potential in electronics and optoelectronics. • At zero bias, SnSe nanosheet-based electrodes demonstrated a peak photocurrent of 14.50 μA under polychromatic light (100 mW/cm2). • The PEC photodetector had an IPCE of 38.28 % and a photoresponsivity of 145 mA/W, indicating fast photo-switching capability for photodetection applications. [ABSTRACT FROM AUTHOR]

This work illustrates the production of highly electrochemically active graphene by liquid phase exfoliation technique for ultrasensitive electrochemical sensors. An airless high-pressure spray technique was designed to exfoliate bulk natural graphite into nm-scaled flakes (referred as HP50). Transmission electron microscopy, Raman and X-ray photoelectron spectroscopy studies reveal that the HP50 sample has a mixed structure composed of amorphous carbon and a few-layer graphene fraction with high amount of edge plane defects. The HP50 flakes are drop cast on glassy carbon electrodes to test the simultaneous and selective electrochemical detection of hydrogen peroxide, ascorbic acid, and dopamine. In cyclic voltammetry measurements, hydrogen peroxide reduces at −0.2 V vs Ag/AgCl (1 M), while ascorbic acid and dopamine oxidize at 0.1 V vs Ag/AgCl (1 M) and 0.3 V vs Ag/AgCl (1 M), respectively. Linear sweep voltammetry demonstrates high sensitivity (164, 739, and 3357 μA mM−1 cm−2) and low limit of detection (15, 1.7, and 2.1 μM) for the three analytes, respectively. Interference studies confirm a high sensitivity and selectivity towards the different chemical species. The HP50-based multianalyte sensors are also tested against different environmental and commercial samples, illustrating their viability in practical applications. [Display omitted] • Graphene-based flakes are produced by airless high-pressure spray exfoliation. • The hybrid flakes are made of amorphous carbon and few-layer graphene. • High-density edge-plane defects translates into high electrochemical activity. • As electrode material they allow simultaneous and selective electrochemical sensing. • Interference studies confirm high performance vs H 2 O 2 , ascorbic acid and dopamine. [ABSTRACT FROM AUTHOR]

Aqueous based nano lubricants with 0.1 wt% of MoS2 could reduce the coefficient friction, wear scar diameter and wear depth significantly providing pathways for recycle, sustainable and economical solutions for lubricant and engineering industries. [Display omitted] • A sustainable, economical and abundant natural surfactant "Sapindius Mukrossi" as non-ionic surfactant for MoS 2 nanosheets exfoliation. • Highly concentrated MoS 2 nanosheets (∼1.23 mg/ml), Yield of 33 % with recycling, an average lateral length () and number of layers () of ∼ 150 nm and ∼ 8 layers. • Compared to pure water, MoS 2 nanosheets (0.1 wt%) in water led to effective reductions in the COF between stainless steel balls and wear scar diameter of ∼ 75 % and ∼ 65 %. • ∼94 % reduction in wear depth was observed compared to pure water for the 0.1 wt% MoS 2 nanosheets, formation of stable tribo-films and demonstrated for hydro lubricant applications. From the outlook of energy saving and environmental protection, the development of eco-friendly and green lubricants without compromising their lubrication performance has become a global agenda. Nevertheless, water-based lubricants suffer from low lubricity and weak load-bearing capacity, making them unsuitable for various industrial applications. Herein, using liquid-phase exfoliation, bulk MoS 2 layers are delaminated into atomically thin nanosheets and stabilized in a water medium by a natural surfactant, Sapindius Mukrossi (SM). A natural SM surfactant consisting of 10 % –12 % saponin molecules has a hydrophobic tail aglycone and hydrophilic head glycone molecules that provide steric repulsive forces against the aggregation of exfoliated MoS 2 nanosheets. Optimization of the surfactant concentration in water led to highly concentrated MoS 2 nanosheets (∼1.23 mg/ml in a single step) with an average lateral length () and number of layers () of ∼ 150 nm and ∼ 8 layers, respectively. Owing to its high concentration and few-layers, MoS 2 nanosheets based aqueous dispersion was directly tested for aqueous lubricant applications. Compared to pure water, MoS 2 nanosheets (0.1 wt%) in water led to effective reductions in the coefficient of friction and wear scar diameter of ∼ 75 % and ∼ 65 %, respectively. Wear depth ∼ 15 µm on SS ball is reduced to ∼ 1 µm when 0.1 wt% of MoS 2 nanosheets-SM surfactant dispersion under similar testing conditions. Post-mortem analysis suggested that the stable formation of protective tribo-film on the worn surfaces of steel surface that were tested at different intervals (1-210-400 Days) leads to an effective sliding under load. To demonstrate the practicality of this dispersion, SM surfactant stabilized MoS 2 nanosheets was used as a dielectric lubricant fluid in a wire EDM for advanced metal-cutting fluid applications. [ABSTRACT FROM AUTHOR]

Hydrogen is a promising green fuel carrier that can replace fossil fuels; however, its storage is still a challenge. Carbon-based materials with metal catalysts have recently been the focus of research for solid-state hydrogen storage due to their efficacy and low cost. Here, we report on the exfoliation of expanded graphite (EG) through high shear mixing and probe tip sonication methods to form graphene-based nanomaterial ShEG and sEG, respectively. The exfoliation processes were optimized based on electrochemical capacitance measurements. The exfoliated EG was further functionalized with palladium nanoparticles (Pd-NP) for solid-state hydrogen storage. The prepared graphene-based nanomaterials (ShEG and sEG) and the nanocomposites (Pd-ShEG and Pd-sEG) were characterized with various traditional techniques (e.g., SEM, TEM, EDX, XPS, Raman, XRD) and the advanced high-resolution pair distribution function (HRPDF) analysis. Electrochemical hydrogen uptake and release (QH) were measured, showing that the sEG decorated with Pd-NP (Pd-sEG, 31.05 mC cm−2) and ShEG with Pd-NP (Pd-ShEG, 24.54 mC cm−2) had a notable improvement over Pd-NP (9.87 mC cm−2) and the composite of Pd-EG (14.7 mC cm−2). QH showed a strong linear relationship with an effective surface area to volume ratio, indicating nanoparticle size as a determining factor for hydrogen uptake and release. This work is a promising step toward the design of the high-performance solid-state hydrogen storage devices through mechanical exfoliation of the substrate EG to control nanoparticle size and dispersion.

Here, we report the exfoliation of bulk MoS2 (molybdenum disulfide) into few-layer nanosheets and then prepared nanocomposite films (MoS2-PEO) with poly(ethylene oxide) as the host. We observed nonpolar or polarity independent bistable resistive switching memory in two-terminal devices with indium tin oxide and aluminum (Al) as bottom and top electrodes, respectively. In both bipolar and unipolar operations, it is observed that the biasing direction controls the current conduction mechanism. When the positive bias is applied at the top Al electrode, the low resistance state (LRS) conduction is ohmic type. But in the opposite biasing condition, LRS conduction is space charge controlled. The current–voltage characteristics of bipolar and unipolar switching are distinctly different in terms of their RESET process. In bipolar, the RESET process is very sharp, whereas in unipolar operation it is staggered and step-wise. [ABSTRACT FROM AUTHOR]

A film stripping method that allows for liquid phase exfoliation assisted by spin coating polymethyl methacrylate has been investigated, resulting in a two‐inch hexagonal boron nitride (hBN) film to be fully stripped and then transferred. A number of key factors that can influence the stripping and the transferring process of the films grown by sputtering have been systematically analyzed, including different solutions, different concentration of solution and different thickness of films. The morphology and properties of the hBN films before and after stripping have been characterized. The band edge absorption peak of the transferred film is 229 nm and the corresponding optical band gap is 5.50 eV. Such transferred hBN films have been fabricated into transparent resistive switching devices on indium‐tin‐oxide glass, demonstrating a constant resistance window of ≈102 even under different applied voltages. This work systematically studies the stripping process, characterizes the transferred films, and explores the application in the field of resistance switching, which lay a foundation for the further application of hBN materials in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Liquid phase exfoliation (LPE) has emerged as a promising method for the industrial-scale production of graphene. However, one of its critical steps, namely sonication, has faced challenges due to high power consumption and low efficiency, leading to limited applicability in industrial settings. This study introduces a novel, cost-effective microfluidic sonication device designed to significantly reduce power consumption while efficiently assisting the LPE process for graphene production. By coupling a capillary with a buzzer and applying an appropriate electric signal, simulation and particle tracing experiments reveal the generation of robust shear forces resulting from acoustic streaming and cavitation when the capillary end is immersed in the liquid. For the first time, the capillary-based sonication device was effectively utilized for graphene exfoliation in a DMF (N,N-Dimethylformamide) + NaOH liquid phase system. The SEM (Scanning Electron Microscope) and Raman characterization results corroborate the successful exfoliation of 100 nm with thicknesses below 10 nm graphene sheets from graphite flakes using this pioneering device. The values of I2D/IG increase after processing, which suggests the exfoliation of graphite flakes into thinner graphene sheets. The vibration-based acoustofluidic effector represents a versatile and scalable miniature device, capable of being employed individually for small-batch production, thereby optimizing the utilization of raw 2D materials, particularly in experimental scenarios. Alternatively, it holds the potential for large-scale manufacturing through extensive parallelization, offering distinct advantages in terms of cost-efficiency and minimal power consumption.

Recently, the 1D ternary transition metal chalcogenide Nb2Pd3Se8 has been reported as a promising channel material for the field‐effect transistors (FETs) with high performance transport behavior. Its structural characteristic of weak van der Waals (vdW) forces between unit ribbons allows for the isolation of high quality Nb2Pd3Se8 nanowires from the bulk crystal that are similar to typical layered 2D materials. This study reports on the liquid phase exfoliation (LPE) of 1D vdW Nb2Pd3Se8 to predict the optimal solvent in terms of the total surface tension and polar/dispersive component ratio. Among the various test solvents, N‐methyl‐2‐pyrrolidone and dimethylformamide are found to be the best solvents for the exfoliation and stabilization of the Nb2Pd3Se8 nanowires due to their well‐matched total surface tensions and polar/dispersive component ratios. Additionally, FETs are fabricated on the LPE‐processed Nb2Pd3Se8 nanowires, and the charge transport behavior is characterized at room temperature. The FETs exhibit n‐type characteristics with an Ion/Ioff ratio and field‐effect mobility up to ≈103 and 15 cm2 V−1 s−1. This study on the LPE of novel Nb2Pd3Se8 nanowires is an important step toward various practical applications in nanoelectronics. [ABSTRACT FROM AUTHOR]

NiTe2 thin films have been considered promising candidates for transparent electrodes due to their high electrical conductivity and 2-dimensional (2D) layered structure. The transparency of 2D thin films with layered structure can be further improved by the exfoliation process. In the process, the increase in electrical resistance should be minimized by maintaining electrical continuity in the thin film. In this study, the mixing ratio of ethanol, acetone, and DI water in the solvent for the liquid-phase exfoliation (LPE) process was optimized to achieve high transmittance while suppressing the increase in electrical resistance. We prepared three solvents by varying the mixing ratio (ethanol:acetone:DI water = 2:4:4, 3:3:4, and 4:2:4). In the three mixed solvents, NiTe2 thin films were removed by two mechanisms: separation from the substrate and layer-by-layer exfoliation. Some of the NiTe2 grains were separated from the glass substrate in the early stage of the LPE process, and layer-by-layer exfoliation became the major mechanism when LPE proceeded longer than 6 h in the three solvents. Among the three solvents, the one with a 3:3:4 ratio more effectively suppressed the increase in electrical resistance during the separation of the NiTe2 thin film. The separation of NiTe2 grains provided an advantageous condition for layer-by-layer exfoliation. Additionally, the similarity of the polarization and dispersion ratio of 3-3-4 with the one of NiTe2 accelerated layer-by-layer exfoliation. The optimized solvent of 3-3-4 improved the transmittance of the NiTe2 thin film from 59.6% to 68.4% after the 8-h LPE process. [ABSTRACT FROM AUTHOR]

• Turbostratic graphene via ultrasonic-assisted liquid phase exfoliation. • 3.2 mg/ml graphene concentration via a green mixed solvent strategy. • Preparation of PANI/G nanocomposites with varying amounts of aniline. • The highest specific capacitance of 126.16 mF/cm2 at 1 mA/cm2. • Device with maximum energy density of 0.29 Wh/kg and power density of 72.72 W/kg. In the present work, a green high-yielding method for the preparation of graphene is introduced via ultrasonic-assisted liquid phase exfoliation (LPE) of graphite in a green solvent medium, since the common preparation method of graphene via graphite oxide is hazardous. A high concentration of 3.2 mg/ml graphene is achieved here in a comparatively short duration of 3 h ultrasonication. By using a mixed solvents strategy (acetophenone and isopropyl alcohol, 1:19 V/V), surface energy requirements needed for the exfoliation of graphite are satisfied here with acetophenone, where isopropyl alcohol further facilitated the exfoliation via non-conventional CH-π and OH-π interactions. Turbostratic graphene in high-yield (16 %) in a simple means of ultrasonic assisted LPE is the added attraction of the present procedure. The less-defective structure of graphene, its few-layered turbostratic nature, and edge functionalization of the sheets are evident from the material characterization via Raman spectroscopy, XRD, TEM-SAED, and XPS analyses. Here, we report a combination of the attractive conducting polymer polyaniline (PANI) with the as-prepared graphene for supercapacitor applications, where the PANI/graphene nanocomposites with different aniline concentrations (PANI1.125/G, PANI4.5/G, and PANI9/G) have been prepared via in-situ polymerization of aniline in the graphene dispersion. The structure and morphology of the nanocomposites are investigated using different characterization techniques which revealed that the molecular structure of the PANI is retained in the nanocomposites even with a strong interaction with graphene. FESEM and TEM images revealed the good coverage of graphene sheets with PANI that limit the volume change of PANI during the repeated charge-discharge processes. Electrochemical studies showed that PANI4.5/G has the highest specific capacitance of 126.16 mF/cm2 at a current density of 1 mA/cm2, resulting from the perfect combination of the pseudocapacitance behavior of the PANI along with the electrical double layer capacitance of graphene. A symmetric supercapacitor device is also fabricated with PANI4.5/G, which showed the highest areal capacitance of 116.38 mF/cm2 similar to that with three-electrode studies and also good cycling stability with 87 % capacitance retention in the specific capacitance after 6000 cycles. It also exhibited an energy density of 16 µWh/cm2 (0.29 Wh/kg) and a power density of 3.99 mW/cm2 (72.72 W/kg). [ABSTRACT FROM AUTHOR]

• A novel Nanobubbles -assisted liquid phase exfoliation method is proposed. • Nanobubbles can enhance cavitation phenomenon during the exfoliation process. • Highly concentrated graphene solutions were produced within 300 min. In this study, we propose a novel method utilizing nanobubbles (NBs) to assist in liquid phase exfoliation. The size, thickness, and number of layers of the resulting graphene solution were characterized and quantified. A highly concentrated graphene solution was achieved through ultrasonic processing in deionized (DI) water, without the need for any surfactant. The observed increase in yield can be attributed to the heightened cavitation within the NBs solution. This study presents a sustainable and cost-effective approach for the large-scale production of graphene, aligning with green and eco-friendly principles. [ABSTRACT FROM AUTHOR]

Graphene, in spite of exceptional physio-chemical properties, still faces great limitations in its use and industrial scale-up as highly selective membranes (enhanced ratio of proton conductivity to fuel cross-over) in liquid alcohol fuel cells (LAFCs), due to complexity and high cost of prevailing production methods. To resolve these issues, a facile, low-cost and eco-friendly approach of liquid phase exfoliation (bath sonication) of graphite to obtain graphene and spray depositing the prepared graphene flakes, above anode catalyst layer (near the membrane in the membrane electrode assembly (MEA)) as barrier layer at different weight percentages relative to the base membrane Nafion 115 was utilized in this work. The 5 wt.% nano-graphene layer raises 1 M methanol/oxygen fuel cell power density by 38% to 91 mW·cm−2, compared to standard membrane electrode assembly (MEA) performance of 63 mW·cm−2, owing to less methanol crossover with mild decrease in proton conductivity, showing negligible voltage decays over 20 h of operation at 50 mA·cm−2. Overall, this work opens three prominent favorable prospects: exploring the usage of nano-materials prepared by liquid phase exfoliation approach, their effective usage in ion-transport membrane region of MEA and enhancing fuel cell power performance. [ABSTRACT FROM AUTHOR]

Two-dimensional (2 D) materials have emerged as important part of high-performance polymer nanocomposites, thanks to their immaculate and tunable properties. Layered double hydroxides (LDHs), in particular, have received much attention in the polymer industry as multifunctional fillers for polyolefins and vinyl polymers. Highly exfoliated boron nitride nanosheets (BNNSs) have been a reliable partner for polyesters and polyamides, especially as thermal conductivity fillers. In this article, we have critically reviewed the latest developments in the field of polymer nanocomposites based on 2 D materials, with special emphasis on liquid phase exfoliated LDHs and BNNSs. Liquid phase exfoliation delivers few-layered or even monolayered nanosheets, and further structural modifications or surface functionalizations of these nanosheets result in better compatibility with the polymer matrix. Trace amounts of the exfoliated 2 D nanofillers can significantly alter the crystallization kinetics, mechanical properties, thermal stability, thermal conductivity and flame-retardant properties of polymers. Through this review, we aim to track down some of the important contributions in this area along with our own works, and this article is expected to fertilize considerable progress in this field. [ABSTRACT FROM AUTHOR]

Chemical sensors based on solution‐processed 2D nanomaterials represent an extremely attractive approach toward scalable and low‐cost devices. Through the implementation of real‐time impedance spectroscopy and development of a three‐element circuit model, redox exfoliated MoS2 nanoflakes demonstrate an ultrasensitive empirical detection limit of NO2 gas at 1 ppb, with an extrapolated ultimate detection limit approaching 63 ppt. This sensor construct reveals a more than three orders of magnitude improvement from conventional direct current sensing approaches as the traditionally dominant interflake interactions are bypassed in favor of selectively extracting intraflake doping effects. This same approach allows for an all solution‐processed, flexible 2D sensor to be fabricated on a polyimide substrate using a combination of graphene contacts and drop‐casted MoS2 nanoflakes, exhibiting similar sensitivity limits. Finally, a thermal annealing strategy is used to explore the tunability of the nanoflake interactions and subsequent circuit model fit, with a demonstrated sensitivity improvement of 2× with thermal annealing at 200 °C. [ABSTRACT FROM AUTHOR]

Ultrasonic-Assisted Liquid Phase Exfoliation (UALPE) is considered one of the most promising approaches for the scale-up of graphene production. The process is based on the isolation and stabilization of layers of 2D materials, such as graphene: the selection of a proper stabilizing/exfoliating agent is crucial to achieve a stable Few-Layers-Graphene (FLG) dispersion. In the present work we propose the use of alkali lignin (AL) as a polymeric stabilizing agent for the rapid (≤ 3 hours) synthesis of FLG. Sonication time and graphite-to-lignin (Gr/AL) ratios were investigated as the primary operational parameters to identify the optimal working conditions. Spectroscopical characterization of the samples were employed to assess the quality of the synthesized material: the analysis of the Raman and XPS spectra provided insight on the number of layers and the nature of the limited defects introduced with the exfoliation procedure.Low-defectivity FLG was obtained at Gr/AL = 8 and a sonication time of 3 hours. Furthermore, Scanning Electron Microscopy and Dynamic Light Scattering were performed to investigate the size of the exfoliated flakes (∼ 400 nm). The procedure proposed represents a rapid route for the synthesis of FLG, which will be further explored for composites in chemiresistive devices.