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Over the past several decades infrared (IR) photodetectors have received wide attention due to their important applications. 2D materials, distinguished by their unique electronic structures, ultimate dimensional confinement, and robust light‐matter interactions, provide a promising candidate for fabricating future IR photodetectors. However, there is a lack of reports concerning the practical industrial applications of these 2D photodetectors, despite that some of these 2D photodetectors have demonstrated performance exceeding that of commercial photodetectors. In this work, a case study on 2D Bi2O2Se nanoplate near‐infrared photodetectors from the perspective of practical applications is presented. With the characterization method used for nano detectors, the 2D Bi2O2Se photodetector exhibits a responsivity of 212.5 A W−1, a specific detectivity of 4.99 × 1011 Jones and an external quantum efficiency of 26 887.68% at wavelength of 980 nm, while with the traditional characterization method the photodetector shows a responsivity of 0.13 A W−1 and a specific detectivity of 2.26 × 106 Jones and an external quantum efficiency of 17.87% at wavelength of 900 nm. The Bi2O2Se nanoplate photodetector also presents good passive imaging quality in the near‐infrared wavelength region. These results suggest the great potential of Bi2O2Se nanoplate photodetectors for practical applications. [ABSTRACT FROM AUTHOR]

A transfer-free graphene with high magnetoresistance (MR) and air stability has been synthesized using nickel-catalyzed atmospheric pressure chemical vapor deposition. The Raman spectrum and Raman mapping reveal the monolayer structure of the transfer-free graphene, which has low defect density, high uniformity, and high coverage (>90%). The temperature-dependent (from 5 to 300 K) current–voltage (I–V) and resistance measurements are performed, showing the semiconductor properties of the transfer-free graphene. Moreover, the MR of the transfer-free graphene has been measured over a wide temperature range (5–300 K) under a magnetic field of 0 to 1 T. As a result of the Lorentz force dominating above 30 K, the transfer-free graphene exhibits positive MR values, reaching ∼8.7% at 300 K under a magnetic field (1 Tesla). On the other hand, MR values are negative below 30 K due to the predominance of the weak localization effect. Furthermore, the temperature-dependent MR values of transfer-free graphene are almost identical with and without a vacuum annealing process, indicating that there are low density of defects and impurities after graphene fabrication processes so as to apply in air-stable sensor applications. This study opens avenues to develop 2D nanomaterial-based sensors for commercial applications in future devices. [ABSTRACT FROM AUTHOR]

Hydrogels with high hydrophilicity and excellent biocompatibility have been considered as potential candidates for various applications, including biomimetics, sensors and wearable devices. However, their high water content will lead to poor load-bearing and high friction. Currently, two-dimensional (2D) materials have been widely investigated as promising nanofillers to improve the mechanical and lubrication performances of hydrogels because of their unique physical–chemical properties. On one hand, 2D materials can participate in the cross-linking of hydrogels, leading to enhanced load-bearing capacity and fatigue resistance, etc.; on the other hand, using 2D materials as nanofillers also brings unique biomedical properties. The combination of hydrogels and 2D materials shows bright prospects for bioapplications. This review focusses on the recent development of high-strength and low-friction hydrogels with the addition of 2D nanomaterials. Functional properties and the underlying mechanisms of 2D nanomaterials are firstly overviewed. Subsequently, the mechanical and friction properties of hydrogels with 2D nanomaterials including graphene oxide, black phosphorus, MXenes, boron nitride, and others are summarized in detail. Finally, the current challenges and potential applications of using 2D nanomaterials in hydrogel, as well as future research, are also discussed. [ABSTRACT FROM AUTHOR]

A novel design of an optical refractive index sensor based on surface plasmon resonance (SPR) has been offered in the article. The structure of the sensor is grounded on a Kretschmann configuration which comprises of CaF2 prism, silver (Ag) metal, beryllium oxide (BeO) nanomaterial, Nickel (Ni), and a heterostructure 2D nanomaterial (blue phosphorene/tungsten diselenide; BP/WS2). The analyte has been sensed on the 2D heterostructure material surface to examine the change in refractive index (RI). For prudent examination of the reflectivity of the proposed sensor, the transfer matrix method (TMM) has been employed. The optimization of sensitivity in terms of thickness and number of layers has also been investigated. Electric field intensity enhancement factor and phase interrogation parameters and normalized electric field distribution have also been utilized to validate the resonance angle position and to justify ultrahigh sensitivity. Utilizing the 2D nanomaterials intensifies the sensitivity of the proposed structure up to 401.2° per refractive index unit (deg/RIU). The FoM and detection accuracy (DA) is optimized up to 178.31 RIU−1 and 0.444 deg−1 respectively. The sensor offers a simple and selective structure with efficient cost and thickness. Additionally, the advantage of being real-time, stable, and label-free detection of an analyte sample with a very small amount of sample makes the proposed sensor a competing technology to be fabricated as a sensor chip for commercial applications. [ABSTRACT FROM AUTHOR]

Fluorescent polymers have exciting applications in sensing, imaging, and probes. Agricultural waste is increasingly being used to develop fluorescent nanomaterials due to technology, cost, and waste management advantages. This study developed fluorescent carbon‐based nanomaterials, that is, potassium doped graphene oxide (K‐GO) from Quercus ilex waste and used them to optimize fluorescent epoxy nanocomposites. The resulting nanocomposites showed significant enhancement in tensile strength with only 0.05 wt% of the renewable nanomaterial. The developed fluorescent epoxy nanocomposites have enhanced thermal and mechanical properties and can be used in sensing, imaging, and other applications. Highlights: A greener and easier approach to synthesizing K‐GO from Quercus ilex seeds.Development of fluorescent epoxy composites with K‐GO.Tensile strength is enhanced by adding only 0.05 wt% K‐GO.Thermal stability was improved by adding K‐GO.Developed composites can be applied to sensing and UV‐shielding in the future. [ABSTRACT FROM AUTHOR]

Ultrathin 2D nanomaterials with extremely large surface area and unique electrochemical properties are considered excellent electrocatalyst candidates for clean energy conversion and environmental applications. However, it is still challenging to prepare 2D catalysts through a scalable and sustainable process that may become suitable for industrial demands. Here, we reported a facile cyclic synthesis method of ultrathin 2D nanomaterials based on the ionic layer epitaxy. By repeatedly refreshing a surfactant monolayer on the solution surface, free-standing 2.2 nm thick hexagonal Co(OH)2 nanosheets were obtained from the water surface at ambient conditions in multiple cycles. These nanosheets exhibited a consistently high OER performance with an average overpotential of 427.4 ± 5.3 mV at 10 mA cm−2. Remarkably, hexagonal NSs could be obtained from a wide range of precursor concentrations which could enable over 84 cycles of synthesis on the same stock precursor solution. It will shed light on the design of autonomous and sustainable synthesis of 2D nanomaterials for advanced electrocatalysis development toward a clean future.

Advanced electrocatalysts can enable the widespread implementation of clean energy technologies. This paper reviews an emerging class of electrocatalytic materials comprising holey two‐dimensional free‐standing Pt‐group metal (h‐2D‐PGM) nanosheets, which are categorically challenging to synthesize but inherently rich in all the qualities necessary to counter the kinetic and thermodynamic challenges of an electrochemical conversion process with high catalytic efficiency and stability. Although the 2D anisotropic growth of typical nonlayered metal crystals has succeeded and partly improved their atom‐utilization efficiency, regularly distributed in‐planar porosity can further optimize three critical factors that govern efficient electrocatalysis process: mass diffusion, electron transfer, and surface reactivity. However, producing such advanced morphological features within h‐2D‐PGMs is difficult unless they are specially engineered using approaches such as templating or kinetic ramification during 2D growth or controlled etching of preformed 2D‐PGM solids. Therefore, this review highlighting the successful fabrication of various porous PGM nanosheets and their electrocatalytic benefits involving smart nanoscale features could inspire next‐generation scientific and technological innovations toward securing a sustainable energy future. [ABSTRACT FROM AUTHOR]

Hydrogels with high hydrophilicity and excellent biocompatibility have been considered as potential candidates for various applications, including biomimetics, sensors and wearable devices. However, their high water content will lead to poor load-bearing and high friction. Currently, two-dimensional (2D) materials have been widely investigated as promising nanofillers to improve the mechanical and lubrication performances of hydrogels because of their unique physical–chemical properties. On one hand, 2D materials can participate in the cross-linking of hydrogels, leading to enhanced load-bearing capacity and fatigue resistance, etc.; on the other hand, using 2D materials as nanofillers also brings unique biomedical properties. The combination of hydrogels and 2D materials shows bright prospects for bioapplications. This review focusses on the recent development of high-strength and low-friction hydrogels with the addition of 2D nanomaterials. Functional properties and the underlying mechanisms of 2D nanomaterials are firstly overviewed. Subsequently, the mechanical and friction properties of hydrogels with 2D nanomaterials including graphene oxide, black phosphorus, MXenes, boron nitride, and others are summarized in detail. Finally, the current challenges and potential applications of using 2D nanomaterials in hydrogel, as well as future research, are also discussed.

Bone diseases including bone defects, bone infections, osteoarthritis, and bone tumors seriously affect life quality of the patient and bring serious economic burdens to social health management, for which the current clinical treatments bear dissatisfactory therapeutic effects. Biomaterial‐based strategies have been widely applied in the treatment of orthopedic diseases but are still plagued by deficient bioreactivity. With the development of nanotechnology, layered double hydroxides (LDHs) with adjustable metal ion composition and alterable interlayer structure possessing charming physicochemical characteristics, versatile bioactive properties, and excellent drug loading and delivery capabilities arise widespread attention and have achieved considerable achievements for bone disease treatment in the last decade. However, to the authors' best knowledge, no review has comprehensively summarized the advances of LDHs in treating bone disease so far. Herein, the advantages of LDHs for orthopedic disorders treatment are outlined and the corresponding state‐of‐the‐art achievements are summarized for the first time. The potential of LDHs‐based nanocomposites for extended therapeutics for bone diseases is highlighted and perspectives for LDHs‐based scaffold design are proposed for facilitated clinical translation. [ABSTRACT FROM AUTHOR]

Synthetic dyes used in textile and dyeing industries are significantly dangerous to water ecosystems due to their high toxicity and non-biodegradability. Effective removal of dyes from wastewater is now a day a challenging task. Photocatalysis has emerged as a sustainable and eco-friendly technology that uses solar energy to remediate environmental pollution. Enhance photocatalytic activity is a major task towards industrial attractive applications. Tuning photocatalysts activity in the visible region while improving their efficiency involves processes as coupling semiconductors, aligning potential bands, reducing energy gaps, and improving carrier separation. In this study, we synthesized nanotubes based on CeO2 (1D) and nanosheets based on La2Ti2O7 (2D) to form NT-CeO2@La2Ti2O7 heterojunctions via a hydrothermal synthesis route. This approach offers notable advantages as novelty, green chemistry, high yield, efficiency, simple equipment, and intermediate temperature. The NT- CeO2 content in the heterojunctions influenced their catalytic activity, affecting physicochemical characteristics and photocatalytic performance. The 1D-2D NT-CeO2@La2Ti2O7 heterojunctions consisted of CeO2 nanotubes deposited on La2Ti2O7 nanosheets. Characterization techniques including X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Raman spectroscopy, and diffuse reflectance were employed to confirm the junction formation, crystallinity, morphology, and characteristic vibrational modes of the NT- CeO2 @ La2Ti2O7 heterojunction. Photocatalytic tests revealed that the NT-CeO2@La2Ti2O7 heterojunction achieved over ~25% degradation of Rhodamine-B (RhB) within 150 minutes under visible light irradiation from a 150W power LED. The power consumption for RhB degradation using NTCeO2@ La2Ti2O7 heterojunction was superior to previous reports using Xe and Hg lamps in similar systems involving cerium oxide. Furthermore, RhB degradation was dependent on the initial dye concentration, with h+ and O2.- identified as the primary oxidative species responsible for RhB degradation. In summary, this study presents the synthesis of NTCeO2@ La2Ti2O7 heterojunction via the hydrothermal method for visible-light photocatalysis of Rhodamine-B degradation, utilizing the energy in the visible spectrum as a stimulation source. [ABSTRACT FROM AUTHOR]

Abstract Bone diseases including bone defects, bone infections, osteoarthritis, and bone tumors seriously affect life quality of the patient and bring serious economic burdens to social health management, for which the current clinical treatments bear dissatisfactory therapeutic effects. Biomaterial‐based strategies have been widely applied in the treatment of orthopedic diseases but are still plagued by deficient bioreactivity. With the development of nanotechnology, layered double hydroxides (LDHs) with adjustable metal ion composition and alterable interlayer structure possessing charming physicochemical characteristics, versatile bioactive properties, and excellent drug loading and delivery capabilities arise widespread attention and have achieved considerable achievements for bone disease treatment in the last decade. However, to the authors' best knowledge, no review has comprehensively summarized the advances of LDHs in treating bone disease so far. Herein, the advantages of LDHs for orthopedic disorders treatment are outlined and the corresponding state‐of‐the‐art achievements are summarized for the first time. The potential of LDHs‐based nanocomposites for extended therapeutics for bone diseases is highlighted and perspectives for LDHs‐based scaffold design are proposed for facilitated clinical translation.

Abstract Instead of typical household trash, the heavy metal complexes, organic chemicals, and other poisons produced by huge enterprises threaten water systems across the world. In order to protect our drinking water from pollution, we must keep a close eye on the situation. Nanotechnology, specifically two-dimensional (2D) nanomaterials, is used in certain wastewater treatment systems. Graphene, g-C3N4, MoS2, and MXene are just a few examples of emerging 2D nanomaterials that exhibit an extraordinary ratio of surface (m3), providing material consumption, time consumption, and treatment technique for cleaning and observing water. In this post, we'll talk about the ways in which 2D nanomaterials may be tuned to perform certain functions, namely how they can be used for water management. The following is a quick overview of nanostructured materials and its possible use in water management: Also discussed in length are the applications of 2D nanomaterials in water purification, including pollutant adsorption, filtration, disinfection, and photocatalysis. Fluorescence sensors, colorimetric, electrochemical, and field-effect transistors are only some of the devices being studied for their potential use in monitoring water quality using 2D nanomaterials. Utilizing 2D content has its benefits and pitfalls when used to water management. New developments in this fast-expanding business will boost water treatment quality and accessibility in response to rising awareness of the need of clean, fresh water among future generations.

New possibilities for the development of biosensors that are ready to be implemented in the field have emerged thanks to the recent progress of functional nanomaterials and the careful engineering of nanostructures. Two-dimensional (2D) nanomaterials have exceptional physical, chemical, highly anisotropic, chemically active, and mechanical capabilities due to their ultra-thin structures. The diversity of the high surface area, layered topologies, and porosity found in 2D nanomaterials makes them amenable to being engineered with surface characteristics that make it possible for targeted identification. By integrating the distinctive features of several varieties of nanostructures and employing them as scaffolds for bimolecular assemblies, biosensing platforms with improved reliability, selectivity, and sensitivity for the identification of a plethora of analytes can be developed. In this review, we compile a number of approaches to using 2D nanomaterials for biomolecule detection. Subsequently, we summarize the advantages and disadvantages of using 2D nanomaterials in biosensing. Finally, both the opportunities and the challenges that exist within this potentially fruitful subject are discussed. This review will assist readers in understanding the synthesis of 2D nanomaterials, their alteration by enzymes and composite materials, and the implementation of 2D material-based biosensors for efficient bioanalysis and disease diagnosis. [ABSTRACT FROM AUTHOR]

With the fast-pace digitalization evolution in the current generation's lifestyle and the industry revolution, the energy demand has been skyrocketed. Recently, the two-dimensional (2D) bismuth-based nanomaterials emerged as a promising photocatalyst candidate in solar fuel conversion, not only for its exceptional light absorption capability and tunable optical properties, but it also can be synthesized into diverse variety of nanomaterials with different ranges of potential gap and band position to fulfill the potential requirement of wide range of photocatalytic reaction. Yet, the weak light harvesting ability and ultrafast charge recombination has restricted its potential in commercial application. Thus, recent researches have been focusing on tackling these issues by incorporating some modification strategies such as heteroatom doping, vacancy engineering, facet engineering, bismuth rich strategy and heterojunction engineering. Herein, this review article presents the state-of-the-art modifications on 2D bismuth-based parent material, specifically on the relationship between each of the modification strategy on the electronic properties and surface chemistry in achieving boosted photocatalytic performance. In the view of the unique charge interaction between two semiconductors with different dimensions, we systematically discuss the rational heterostructure design from the dimensionality perspective, namely, point-to-face, line-to-face, face-to-face, and bulk-to-face in solar fuel conversion to provide inspiring insights for future interface engineering. Finally, the challenges and the future research outlook in the solar-to-fuel conversion are highlighted to push forward the design of high-performance bismuth-based photocatalyst in realizing commercial-scale solar-to-fuel conversion. [ABSTRACT FROM AUTHOR]

• Ultralow-concentration emulsion-based ink (5.882 mg mL−1) of MXene was prepared due to the enhanced binding of MXene and GO by ODA. • The MX/rGO architectures with macroscopic (hierarchical lattice) and microscopic (porous) structure were constructed by DIW technology. • The synergistic effect of macroscopic (hierarchical lattice) and microscopic (porous) structure enables 3D MX/rGO architectures to achieve high sensitivity (166.957 kPa−1), wide sensing range (∼100 kPa), and excellent cyclic stability (10500 cycles). 3D direct ink writing technology based on two-dimensional (2D) MXene nanomaterial inks receives attention in the field of pressure sensing for simplicity of fabrication, programmable geometry with controllable function and performance. However, it is still a huge challenge to print excellent macro-structure with ultralow-concentration MXene inks, attributed to its weak gelation ability. Herein, we construct a MXene/reduced graphene oxide (MX/rGO) architecture (0.012 g cm−3) with macroscopic (hierarchical lattice) and microscopic (porous) structure by using ultralow-concentration emulsion-based inks of MXene (5.882 mg mL−1). The introduction of octadecylamine enhances the bonding between the MXene and GO, significantly improving the gelation ability of the ink with low-concentration 2D nanomaterials. More importantly, the MX/rGO pressure sensor achieves a high sensitivity (166.957 kPa−1), wide sensing range (0.028∼100 kPa), and excellent cyclic stability (10500 cycles) due to its 3D hierarchical lattice porous structure. These sensing capabilities enable the sensor to detect various human motions, such as pulse beating, vocal cord vibration, facial expressions, different joint movements and pressure distribution. Undoubtedly, this work provides a broad development prospect for the customized flexible pressure sensors based on MXene ink 3D printing technology. [ABSTRACT FROM AUTHOR]

By using the first principles calculations, we study the structural and electronic properties of zinc oxide (ZnO) bilayers. Initial ZnO bilayer has a planar structure, which is different from bulk ZnO. Another kind of twist ZnO bilayer is designed by rotating 60° on the basis of ZnO bilayer structure with a Zn/O atom as the axis. Both the bilayers have stable structure and high symmetry. As the interlayer distance increases, the interaction of the upper and the lower layers will weaken in both the bilayers. It is Zn atom but not O atom that plays a key role in the interlayer interaction, which has been confirmed by Mulliken charge and density of states results. The band gap of the bilayers can be tuned by translation motion, and ZnO twist bilayer shows a better performance than the initial bilayer in this study. Combining the two factors (interlayer distance and twist angle), ZnO bilayers are very hopeful to be utilized in 3D joints of nanoelectronic devices. Our results provide a detailed understanding of the structural and electronic properties of ZnO bilayers and help to predict the performance of ZnO-based two-dimensional nanoelectronics and nanocomposites. The band gap of the bilayers can be tuned by translation motion, and ZnO twist bilayer shows a better performance than the initial bilayer in this study. [ABSTRACT FROM AUTHOR]

New possibilities for the development of biosensors that are ready to be implemented in the field have emerged thanks to the recent progress of functional nanomaterials and the careful engineering of nanostructures. Two-dimensional (2D) nanomaterials have exceptional physical, chemical, highly anisotropic, chemically active, and mechanical capabilities due to their ultra-thin structures. The diversity of the high surface area, layered topologies, and porosity found in 2D nanomaterials makes them amenable to being engineered with surface characteristics that make it possible for targeted identification. By integrating the distinctive features of several varieties of nanostructures and employing them as scaffolds for bimolecular assemblies, biosensing platforms with improved reliability, selectivity, and sensitivity for the identification of a plethora of analytes can be developed. In this review, we compile a number of approaches to using 2D nanomaterials for biomolecule detection. Subsequently, we summarize the advantages and disadvantages of using 2D nanomaterials in biosensing. Finally, both the opportunities and the challenges that exist within this potentially fruitful subject are discussed. This review will assist readers in understanding the synthesis of 2D nanomaterials, their alteration by enzymes and composite materials, and the implementation of 2D material-based biosensors for efficient bioanalysis and disease diagnosis.

Two-dimensional (2D) nanomaterials have attracted much attention for lubrication enhancement of grease. It is difficult to disperse nanosheets in viscous grease and the lubrication performances of grease under harsh conditions urgently need to be improved. In this study, the 2D talc nanosheets are modified by a silane coupling agent with the assistance of high-energy ball milling, which can stably disperse in grease. The thickness and size of the talc nanosheet are about 20 nm and 2 µm. The silane coupling agent is successfully grafted on the surface of talc. Using the modified-talc nanosheet, the coefficient of friction and wear depth can be reduced by 40% and 66% under high temperature (150 °C) and high load (3.5 GPa), respectively. The enhancement of the lubrication and anti-wear performance is attributed to the boundary adsorbed tribofilm of talc achieving a repairing effect of the friction interfaces, the repairing effect of talc on the friction interfaces. This work provides green, economical guidance for developing natural lubricant additives and has great potential in sustainable lubrication. [ABSTRACT FROM AUTHOR]

In recent years, antibiotic-resistant bacterial strains have spread rapidly and widely around the world. New antibacterial drugs have emerged to develop. With the development of biological nanotechnology, two-dimensional nanomaterials have become a very promising alternative for the treatment of antibiotic-resistant bacteria. Based on the recent literature, the structural features and antibacterial applications of graphene materials (GMs), transition-metal dichalcogedes (TMDs), layered double hydroxides (LDHs) and MXenes were elaborated, the antibacterial mechanisms of those materials were discussed, such as physical/mechanical damage, lipid extraction, oxidative stress, and photothermal/photodynamic effects,etc. Finally, the antibacterial research progress and challenges of two-dimensional nanomaterials were prospected:(1) 2D materials has a unique space structure and excellent biocompatibility, so it can be used as an ideal carrier for antibacterial drugs; (2) the material has photodynamic and photothermal bactericidal effects, so it has a strong potential to cure local skin infections; (3) it can be made into antibacterial coatings to achieve simple in-situ disinfection applying to sterile medical equipment in the future.

[Display omitted] • Nanozymatic activity of silicene for H2O2 and dopamine detection. • External electric potential has reduced the detection time significantly. • The second method was 20 times faster than the first. • LODs for H2O2 and dopamine was 3.11 μM and 2.21 μM, respectively. Silicene is a material that is largely studied via theoretical models. In the practical world, lengthy incubation times and poor sensitivity of colorimetric detection methods have limited their implementation. This paper transforms silicene's theoretical advantages into practical applications, presenting it as a tangible solution for significantly improving colorimetric biosensing. More specifically, this paper presents a pivotal breakthrough by not only documenting the remarkable nanozymatic activity of silicene in oxidizing 3,3′,5,5′-Tetramethylbenzidine (TMB) with hydrogen peroxide (H 2 O 2), but also leveraging silicene's inherent electronic properties to enhance the speed and precision of the peroxidase reaction, thereby improving its performance and advancing applicability. Two detection mechanisms were tested to observe the influence of silicene's electronic scope; one in the absence and the other in the presence of an externally supplied electric potential. Both were successful in the detection of H 2 O 2 and dopamine. The latter proved to be more favorable as it not only shortened the incubation time from 30 min to 1.5 min but also exhibited lower Limit of Detection (LOD) values. To demonstrate, for dopamine, in a concentration range of 0 – 10 μM, the LOD was 4.13 μM without the electric potential and 2.21 μM with the electric potential. Similarly, in a second concentration range, the LOD values were 37.81 μM and 34.94 μM, respectively. Kinetic profiles indicated the superior affinity silicene has for TMB and H 2 O 2. A selectivity test also indicated that the method has excellent selectivity towards dopamine. [ABSTRACT FROM AUTHOR]

The current two-dimensional (2D) material based NH 3 sensors generally suffer from low response values and sluggish recovery dynamics, which is resulted from their inferior conductivity. Herein, high conductivity (0.045 S/m) of 2D hydrogen substituted graphyne (HsGY) nanosheets are successfully synthesized employing aqueous/organic interface method and using them for the first time for the detection of NH 3 at room temperature. The resultant gas sensing performance shows that the 2D HsGY nanosheets exhibit a high gas response value (4.9) to 100 ppm NH 3 and fast recovery time (108 s) at the room temperature. The NH 3 gas sensing mechanism is discussed by utilizing density functional theory (DFT) calculations. The present study provides novel gas sensing material for the development of high-performance room temperature NH 3 sensors. This study successfully synthesized two-dimensional hydrogen substituted graphyne (HsGY) nanosheets using an aqueous/organic interface method and applied them for the detection of NH 3 at room temperature for the first time. HsGY nanosheets exhibit excellent sensing performance towards NH 3 , due to their high conductivity and continuous thin gauze like morphology, which facilitates gas transport. [Display omitted] [ABSTRACT FROM AUTHOR]

Most anticancer drugs with broad toxicities are systematically administrated to cancer patients and their distribution in tumors is extremely low owing to hypoxia, which compromises the therapeutic efficacies of these cancer drugs. Consequently, a preponderant proportion of cancer drugs is distributed in off-target-healthy tissues, which often causes severe adverse effects. Precision cancer therapy without overdosing patients with drugs remains one of the most challenging issues in cancer therapy. Here, a novel concept of nanopoxia is presented, which is a tumor-hypoxia-based photodynamic nanoplatform for the release of therapeutic agents to achieve precision cancer therapy. Under tumor hypoxia, exposure of tumors to laser irradiation induces the fracture of polymer outer shell and produces anticancer reactive oxygen species, and switches 2D antimonene (Sb) nanomaterials to cytotoxic trivalent antimony to synergistically kill tumors. In preclinical cancer models, delivery of Sb nanomaterials to mice virtually ablates tumor growth without producing any detectable adverse effects. Mechanistically, the tumor hypoxiatriggered generation of trivalent antimony displays direct damaging effects on cancer cells and suppression of tumor angiogenesis. Together, the study provides a proof-of-concept of hypoxia-based precision cancer therapy by developing a novel nanoplatform that offers multifarious mechanisms of cancer eradication. [ABSTRACT FROM AUTHOR]

Abstract Electrochemical water splitting driven by renewable energy-derived electricity is considered as the most promising pathway for delivering clean and sustainable hydrogen production. The key to achieving an efficient water splitting process is developing highly active electrocatalysts. Two-dimensional (2D) nanomaterials hold great promise in the electrocatalysis field due to their unique physicochemical properties. Some of them are not active enough because of the poor intrinsic activity, low density of active sites or low electrical conductivity. Some are inert for electrocatalytic reactions, but are able to work as the functional substrates for hybrid electrocatalysts. Thus, tremendous strategies have been developed to modulate the physicochemical and electronic properties of 2D nanomaterial-based electrocatalysts, and to make full use of the functionalities of functional 2D nanomaterial substrates to achieve fast catalytic reaction kinetics. In this review, the recent progress on the well-established design strategies for the 2D nanomaterials-based electrocatalysts is highlighted. The perspectives on the current challenges and future development of 2D electrocatalysts are addressed.

Highly active and low-cost co-catalysts have a positive effect on the enhancement of solar H 2 production. Here, we employ two-dimensional (2D) MBene as a noble-metal-free co-catalyst to boost semiconductor for photocatalytic H 2 production. MoB MBene is a 2D nanoboride, which is directly made from MoAlB by a facile hydrothermal etching and manual scraping off process. The as-synthesized MoB MBene with purity >95 wt % is treated by ultrasonic cell pulverization to obtain ultrathin 2D MoB MBene nanosheets (∼0.61 nm) and integrated with CdS via an electrostatic interaction strategy. The CdS/MoB composites exhibit an ultrahigh photocatalytic H 2 production activity of 16,892 μmol g -1 h -1 under visible light, surpassing that of pure CdS by an exciting factor of ≈1135%. Theoretical calculations and various measurements account for the high performance in terms of Gibbs free energy, work functions, and photoelectrochemical properties. This work discovers the huge potential of these promising 2D MBene family materials as high-efficiency and low-cost co-catalysts for photocatalytic H 2 production.

We outline the interaction of two-dimensional nanomaterial and cell barriers and their potential applications in major diseases. This paper aims to provide insights into the subsequent development of new smart nanomaterials capable of transport within cells. [Display omitted] The cell membrane serves as a barrier against the free entry of foreign substances into the cell. Limited by factors such as solubility and targeting, it is difficult for some drugs to pass through the cell membrane barrier and exert the expected therapeutic effect. Two-dimensional nanomaterial (2D NM) has the advantages of high drug loading capacity, flexible modification, and multimodal combination therapy, making them a novel drug delivery vehicle for drug membrane attachment and intracellular transport. By modulating the surface properties of nanocarriers, it is capable of carrying drugs to break through the cell membrane barrier and achieve precise treatment. In this review, we review the classification of various common 2D NMs, the primary parameters affecting their adhesion to cell membranes, and the uptake mechanisms of intracellular transport. Furthermore, we discuss the therapeutic potential of 2D NMs for several major disorders. We anticipate this review will deepen researchers' understanding of the interaction of 2D NM drug carriers with cell membrane barriers, and provide insights for the subsequent development of novel intelligent nanomaterials capable of intracellular transport. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) nanomaterials have attracted much attention for lubrication enhancement of grease. It is difficult to disperse nanosheets in viscous grease and the lubrication performances of grease under harsh conditions urgently need to be improved. In this study, the 2D talc nanosheets are modified by a silane coupling agent with the assistance of high-energy ball milling, which can stably disperse in grease. The thickness and size of the talc nanosheet are about 20 nm and 2 µm. The silane coupling agent is successfully grafted on the surface of talc. Using the modified-talc nanosheet, the coefficient of friction and wear depth can be reduced by 40% and 66% under high temperature (150 °C) and high load (3.5 GPa), respectively. The enhancement of the lubrication and anti-wear performance is attributed to the boundary adsorbed tribofilm of talc achieving a repairing effect of the friction interfaces, the repairing effect of talc on the friction interfaces. This work provides green, economical guidance for developing natural lubricant additives and has great potential in sustainable lubrication.

MXene as a new type of metal carbide was used as a nanoadsorbent for the removal of toxic arsenic species from water. It was prepared by etching the Ti3C2Al powders in HF solution. The final product was (2D) titanium carbide nanosheet. The prepared MXene exhibited high sorption capacities and fast kinetics for As(III) removal from water. It provided an efficient removal performance for As(III) with a capacity of 2.8 mg/g, higher than most of the commercial adsorbents. The residual concentration of As in water is far below the standard limit set by World Health Organization for drinking water at 10 µg/L. Using steered molecular dynamics simulation, the global minimum energy between arsenic and MXene surface was found to be of 7.1 kJ/mol. The arsenic adsorption data with MXene fits very well the pseudo-second-order model with a coefficient of determination being close to unity. The second-order rate constant was (k2) found to be 25.38 g/mgh and adsorption capacity was found to be 0.241 mg/g. Furthermore, MXene nanosheets were also discovered to remove other contaminants, such as Cr(VI), Ba(II) and Pb(II) from water. These significantly expand the potential applications of 2D Ti3C2Tx nanosheets in water treatment due to their well-defined morphology, which holds promising industrial advantages. [ABSTRACT FROM AUTHOR]

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Electrochemical water splitting driven by renewable energy-derived electricity is considered as the most promising pathway for delivering clean and sustainable hydrogen production. The key to achieving an efficient water splitting process is developing highly active electrocatalysts. Two-dimensional (2D) nanomaterials hold great promise in the electrocatalysis field due to their unique physicochemical properties. Some of them are not active enough because of the poor intrinsic activity, low density of active sites or low electrical conductivity. Some are inert for electrocatalytic reactions, but are able to work as the functional substrates for hybrid electrocatalysts. Thus, tremendous strategies have been developed to modulate the physicochemical and electronic properties of 2D nanomaterial-based electrocatalysts, and to make full use of the functionalities of functional 2D nanomaterial substrates to achieve fast catalytic reaction kinetics. In this review, the recent progress on the well-established design strategies for the 2D nanomaterials-based electrocatalysts is highlighted. The perspectives on the current challenges and future development of 2D electrocatalysts are addressed. [ABSTRACT FROM AUTHOR]

Two-dimensional porous graphitic carbon nitride (g-C3N4) nanosheets were synthesized by low-cost and direct thermal oxidation. Porous g-C3N4 assembled with graphene oxide (GO) was immobilized on a glassy carbon electrode. The sensor was applied to simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) with high performance. Cyclic voltammetry and differential pulse voltammetry were used to investigate electrochemical and electrocatalytic properties. The results indicate that the electrochemical sensor possesses high specific surface area, hierarchical pore structure and excellent signal response to AA, DA and UA. The oxidation potentials are well separated at around 0.15, 0.34 and 0.46 V for AA, DA and UA respectively. The determination limits for AA, DA and UA are 3.7 μM, 0.07 μM and 0.43 μM, respectively. The sensor was applied to tracking the three analytes in spiked serum samples with recovery 95.1~105.5% and relation standard deviations of less than 5%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Key features and challenges of polyaniline (PANI)-based adsorbents are summarized; • Mechanisms of adsorption/desorption on PANI-based adsorbents are discussed; • Roles of low-cost materials and 2D nanosheets in PANI-based adsorbents are highlighted; • We offer perspectives and future directions in developing PANI-based adsorbents. Access to clean water and sanitization is crucial to all life on Earth, and has been listed among the United Nations Sustainable Development Goals. Adsorption is a simple and economical technology for water purification. However, conventional adsorbents, such as zeolites, biochar, activated carbon and clay minerals, have some limitations, particularly their unsatisfactory adsorption efficiencies. Polyaniline (PANI), a stable conducting polymer with facile synthesis, nitrogen-rich functional groups, and tuneable morphology, is a promising candidate for adsorbing various pollutants. This review attempts to critically assess PANI-based adsorbents in terms of their advantages, disadvantages, and separation mechanisms in pollutant removal. Low-cost natural and waste materials, and emerging ultrathin 2D nanosheets can also be promising adsorbents. We highlight the significant roles of low-cost materials as well as emerging 2D nanosheets in enhancing the performance of PANI-based adsorbents. Combining PANI-based adsorbents and low-cost materials or 2D nanosheets can not only address the challenges of PANI-based adsorbents (e.g., low surface areas and thus low adsorption efficiencies), but also employ the synergistic effects of these adsorptive materials. As a result, the PANI-based hybrid adsorbents have enhanced functionality, and improved pollutant removal performance. Finally, we offer insightful perspectives and future research directions in developing PANI-based adsorbents with low-cost and 2D materials. [ABSTRACT FROM AUTHOR]

The demand for alternative energy sources from non-recyclable waste materials will be a hot research topic in future industries. This interest is primarily due to the ability to harness energy from waste materials, the provision of localized power solutions, and the promotion of efficient power conversation. In this respect, Microbial Fuel Cells (MFC) represent new energy sources possessing unique qualities for many applications. MFC generates power by utilising exoelectrogens forming the biofilm on the surface of the anode. Since in the MFC, wastewater is primarily converted into protons and electrons at the anode surface, where biofilms typically develop, the anode becomes the most vital component. Consequently, significant research has been conducted on anode material to improve MFC performance. The present review focuses on different aspects of the MFC, including a comprehensive summary of the recent developments in the field of MFCs, including a state-of-the-art literature review based on a bibliometric analysis using keywords, a description of the mechanism and operational principle of MFC, applications and a summary of current research perspectives including the use of carbon nanotubes, graphene, graphitic carbon nitride, MXene, and their nanocomposites as anode materials with stable power density performance. Lastly, we present the challenges and future perspectives regarding the continued development of MFC anode materials, culminating in overall conclusions related to MFC research. [Display omitted] • Emerging 2D nanomaterials as potential anode modifications for MFC are presented. • Nanocomposites of CNTs, Graphene, Graphitic carbon nitride, and MXene are described. • Nanomaterials for improving the maximum power density of MFC are highlighted. • Limitations and applications of bio-anode fabrication materials are summarised. [ABSTRACT FROM AUTHOR]

In this study, a new green synthesis method for two-dimensional (2D) copper nanosheets is developed using methylsulfonylmethane (DMSO2). The chemical composition and light absorption of 2D copper nanosheets are also studied. A new green method is mainly to utilize DMSO2, which is environmentally friendly enough to be considered a food-grade chemical, unlike the conventional method using toxic chemicals, such as ammonia and hydrazine (N2H4). With a reducing agent, the aggregation of uncertain copper products was produced in the absence of DMSO2, while 2D copper nanosheets were formed in the presence of DMSO2. The optimum concentration of DMSO2 as a surfactant was determined to be 2 M, resulting in large surface areas with regular edges. FTIR spectrum confirmed C–H bonding from DMSO2 used to synthesize 2D copper nanosheets. The light absorption peak was revealed at 800 nm in the UV–vis spectrum. This proposed new green method not only has a simpler process than the conventional methods, such as hydrothermal method and chemical bath deposition, but also substitutes toxic chemicals with DMSO2. 2D copper nanosheets can be used for various applications, including conductive filler or ink in the flexible electronics and laser photonics fields.

Here, tris(hydroxymethyl)aminomethane (i.e., Tris) is reported to be an effective protecting agent to stabilize 2D nanomaterials in water for various enhanced applications. As demonstrated, molybdenum sulfide (MoS2) nanosheets are first exfoliated from MoS2 bulk under a low-energy sonication in the assistance of protein bovine serum albumin (BSA), and then BSA molecules are replaced with Tris to stabilize the exfoliated MoS2 nanosheets. The Tris-stabilized MoS2 nanosheets have a robust dispersibility to resist long-term storage (e.g., 2.5 years), high temperature (e.g., 220 °C), and high speed centrifugation (e.g., 12 000 rpm). Furthermore, they also exhibit high biocompatibility and promising photothermal effect, which provide a better performance in photothermal therapy for inhibiting the growth of tumor. In addition, the surface Tris molecules readily introduce the grafting of polydopamine on MoS2 nanosheets to form a universal platform for coating of other functional polymers on nanosheets. Overall, this work not only brings more opportunities to exploit the outstanding applications of 2D nanomaterials, but also suggests a new and effective route to prepare the composite of nanosheets and functional polymers for their synergistic properties. [ABSTRACT FROM AUTHOR]

In an era of graphene-based nanomaterials as the most widely studied two-dimensional (2D) materials for enhanced performance of devices and systems in solar energy conversion applications, molybdenum disulfide (MoS2) stands out as a promising alternative 2D material with excellent properties. This review first examined various methods for MoS2 synthesis. It, then, summarized the unique structure and properties of MoS2 nanosheets. Finally, it presented the latest advances in the use of MoS2 nanosheets for important solar energy applications, including solar thermal water purification, photocatalytic process, and photoelectrocatalytic process. [ABSTRACT FROM AUTHOR]

Abstract We demonstrate a facile hydrothermal synthesis of the interconnected porous NiCo 2 O 4 nanosheets for hybrid supercapacitor applications. The as-synthesized NiCo 2 O 4 nanosheets show a high specific capacitance of 3137 F g−1 at a current density of 2 A g−1, which is much greater than 1916 and 1251 F g−1 of Co 3 O 4 and NiO, respectively. Interestingly, the total specific capacitance of the NiCo 2 O 4 is almost close to the sum of the specific capacitance of the NiO and Co 3 O 4. Furthermore, a hybrid supercapacitor is configured with the NiCo 2 O 4 nanosheets and the nitrogen- and sulfur-codoped reduced graphene oxide as the positive and negative electrodes, respectively. This hybrid supercapacitor delivers a maximum energy density of 33.64 W h kg−1 at a power density of 1196 W kg−1 and excellent long-term cyclic stability over 12,000 charge/discharge cycles at the enlarged voltage window of 1.5 V. The remarkable supercapacitive performances of the hybrid device are attributed to the interconnected porous structure of NiCo 2 O 4 nanosheets and three-dimensional continuous macropores of codoped reduced graphene oxides. Graphical abstract Image 1 Highlights • The interconnected porous NiCo 2 O 4 nanosheets are synthesized. • The NiCo 2 O 4 shows high capacitances of 3137 and 2420 F g−1 at 2 and 20 A g−1. • The HSC consists of NiCo 2 O 4 nanosheets and 3D N,S-rGO. • The HSC delivers a maximum energy density of 33.64 W h kg−1. • The HSC exhibits the outstanding cyclic stability and Coulombic efficiency. [ABSTRACT FROM AUTHOR]

Abstract Determination of hepatotoxic drugs is critical for both clinical diagnosis and quantity control of their pharmaceutical formulations. In this work, a facile and sensitive sensor based on MXene modified screen-printed electrode (MXene/SPE) has been developed for detection of acetaminophen (ACOP) and isoniazid (INZ), which are two commonly used drugs but might induce liver damage in certain circumstances. MXene showed excellent electrocatalytic activity toward the oxidation of ACOP and INZ compared with bare SPE in 0.1 M H 2 SO 4 , and the separated oxidation peak potentials ensured simultaneous detection of the targets with wide linear ranges from 0.25 to 2000 μM for ACOP and 0.1–4.6 mM for INZ. The detection limits of ACOP and INZ were 0.048 μM and 0.064 mM, respectively. (S/N = 3). MXene/SPE exhibits good stability, reproducibility and repeatability, and the method has been successfully applied for detection of ACOP and INZ in their pharmaceutical and biological samples with satisfactory recovery. Highlights • The first report on combining accordion-like Ti 3 C 2 T x with SPE for acetaminophen and isoniazid electrochemical detection. • MXene using as signal amplification matrix shows good electrocatalysis towards both targets. • SPE/MXene features facile preparation, low reagent consumption and cost effectiveness. • Simultaneous assay of ACOP and INZ can be taken with fast response, good accuracy, good anti-interference and practicability. [ABSTRACT FROM AUTHOR]

Abstract In this work, ultrathin Ti 3 C 2 -MXene nanosheets were synthesized by minimally intensive layer delamination methods, and uniformly functionalized with aminosilane (f -Ti 3 C 2 -MXene) to provide a covalent binding for the immobilized bio-receptor (anti-CEA) for label free, ultrasensitive detection of cancer biomarker (carcinoembryonic antigen, CEA). The effect of different redox probes on the electrochemical behavior of f -Ti 3 C 2 -MXene was investigated and found that hexaammineruthenium ([Ru(NH 3) 6 ]3+) is the preferable redox probe for biosensing. The fabricated biofunctionalized Ti 3 C 2 -MXene exhibits a linear detection range of 0.0001–2000 ng mL−1 with sensitivity of 37.9 µA ng−1 mL cm−2 per decade. The wider linear detection range of our f -Ti 3 C 2 -MXene is not only higher than previously reported pristine 2D nanomaterials, but is even comparable to other hybrid 2D nanomaterials. We believe that this work opens a new window for development of MXene-based highly sensitive DNA, aptamer, enzyme, antibody, and cell based biosensors, and could be further used in drug delivery application. Highlights • Two-dimensional Ti 3 C 2 -MXene nanosheets were synthesized by the MILD method. • Single/few layered MXene nanosheets were functionalized via APTES (f- Ti 3 C 2 -MXene). • The electrochemical behavior of f- Ti 3 C 2 -MXene was explored. • f- Ti 3 C 2 -MXene was biofunctionalized for electrochemical detection of CEA. • It exhibits a wide linear detection range of 0.0001–2000 ng mL−1. [ABSTRACT FROM AUTHOR]

Recently, two-dimensional (2D) nanomaterials have been investigated extensively in the field of nonlinear photonics. Cr 2 Te 3 , which is one of the 2D transition metal chalcogenides, has garnered attention in the field of spintronics and optoelectronics because of its fascinating magnetic and optical properties. Despite its potential in optoelectronics, Cr 2 Te 3 has rarely been studied in the field of nonlinear photonics. This study investigates the nonlinear optical responses of nanoscale-layered Cr 2 Te 3 films grown by physical vapor deposition at telecommunication wavelengths. A large nonlinear absorption coefficient of –(1.43 ± 0.06) × 105 cm/GW and a nonlinear refractive index of –1.22 ± 0.04 cm2/GW at 1560 nm obtained through Z-scan measurements indicate that the Cr 2 Te 3 film shows saturable absorption and self-defocusing properties at telecommunication wavelengths. Density functional theory calculation show that Cr 2 Te 3 is suitable for broadband optical device. The potential of the nanoscale-layered Cr 2 Te 3 film as a base medium for a nonlinear optical switch was evaluated by fabricating a saturable absorption mirror (SAM). Stable Q-switched pulses with a maximum repetition rate of 33.35 kHz and minimum temporal width of 2.62 μs were readily achieved from a fiber laser cavity incorporating the SAM. • Optical nonlinearities of PVD-grown 2D stacked Cr 2 Te 3 were studied. • Cr 2 Te 3 properties are superior and/or comparable to those of popular 2D materials. • A Cr 2 Te 3 -film-based saturable absorption mirror was fabricated successfully. • The saturable absorption mirror was successfully used for fiber laser Q-switching. [ABSTRACT FROM AUTHOR]

Borophene, a two-dimensional (2D) monolayer of elemental boron, has emerged as an intriguing material with superior characteristics including outstanding electronic, optical, chemical, mechanical, and catalytic properties. Due to superior properties, borophene has shown great prospects for a variety of novel applications in the field of energy storage devices, supercapacitors, sensors, and healthcare devices. This review provides an overview of various synthesis techniques to produce borophene nanostructures. Additionally, different simulation approaches have been discussed for studying the structural, electronic, and sensing properties of borophene and its composites. Besides synthesis, this review focuses on exploring the structural and morphological characteristics of borophene materials. Moreover, the uses of 2D borophene in gas sensing, humidity sensing, as well as other chemical sensing have been discussed. Lastly, the current challenges and prospects of this promising 2D nanomaterial have been extensively addressed. [Display omitted] [ABSTRACT FROM AUTHOR]