MXene Nanosheets Research Articles

Photocatalytic degradation of malachite Green dye using Ti3C2 MXene nanosheets decorated with Fe3O4 NPs under visible light irradiation

Photocatalytic degradation of malachite Green dye using Ti3C2 MXene nanosheets decorated with Fe3O4 NPs under visible light irradiation

Co single-atom-embedded MXene nanosheets as catalytic UF membrane instant water purification with fouling resistant performance

Two-dimensional (2D) catalytic ultrafiltration membranes, tightly assembled with MXene (Ti3C2Tx) lamellae and significantly dispersed Co single atoms (∼ 2.4 wt%), were prepared by a simple solvothermal and low-temperature reduction method. The Co-MXene membrane overcomes the conventional trade-off between selectivity and permeability, and demonstrated an instant water purification (100 % carbamazepine degradation within 240 ms) and a high membrane permeability (∼900 LMH/bar). It has been confirmed that coordinatively unsaturated Co-N1O2 accelerated electron transfer and activated the formation of 1O2 and high-valent Co-oxo species. Nano-confinement channels assembled by the small-sized lamellae facilitated the transport of water molecules. A stable treatment performance with natural surface water was achieved at 3000 L/m2. Good anti-fouling capabilities were also demonstrated with a 96 % alleviation of membrane fouling in the presence of Pseudomonas aeruginosa. These comprehensive mechanistic investigations and stable performances provide a valuable basis for preparing SACs-catalyzed membranes with highly dispersed single atoms and high permeability.

Surface functionalized porous MXene (Ti3C2Tx)/Polyethyleneimine membrane for efficient osmotic energy conversion

The development of ion-selective membranes is crucial for achieving efficient osmotic power conversion in reverse electrodialysis system. However, balancing ion selectivity and ion permeability in membranes remains a challenge, limiting improvements in energy conversion efficiency for practical applications. In this study, we develop efficient cation exchange membranes by integrating versatile aromatic hydroxyl groups with MXene nanosheets and polyethyleneimine (PEI) into their lamellar structure. This approach holds promise for achieving non-swelling, high selectivity, and enhanced power density for osmotic energy conversion. The abundance positive surface charge within PEI molecules, combined with the 2D sub-nanochannels of MXene nanosheets, facilitates the biomimetic replication of channel size, chemical groups, and adjustable charge density in the resulting membranes. The fabrication of these membranes is easily achieved through simple hydrothermal, functionalization, and surface-charged techniques, suggesting promising scalability. These membranes exhibit remarkable stability against swelling in aqueous solutions for up to 25 days and demonstrate a high selectivity of 0.95 and a superior output power density of 18.3 W/m2 in artificial river water and seawater.

Multistage rigid and flexible structure-decorated basalt fibers for epoxy resin composites with synergistically enhanced strength and toughness

In this study, we report the construction of a multistage rigid and flexible structure using boron nitride (BN) and MXene (MX, Ti3C2Tx) nanosheets through the conjugation with (3-aminopropyl) triethoxysilane (APTES). The created structure is further utilized to modify basalt fibers (BFs) to obtain BF/epoxy resin (BF/EP) composites via a simple coating process. The rigid two-dimensional materials (2DMs), BN and MX, significantly enhance the roughness of the BF surface, while the silane (APTES) acts as a flexible bridge for linking BFs, BN, and MX. Consequently, the constructed multistage rigid and flexible structure synergistically enhances the strength and toughness of the composite through effective mechanical interlocking, chemical bonding, and multistage energy dissipation. Meanwhile, this complex structure prevents the stress concentration and promotes uniform stress transfer between BFs and EP. This study provides a promising strategy to construct an effective interface layer and achieve high-performance BF/EP composites by introducing 2DMs and a silane linker.

Translocation of Ti2CO2 MXene monolayer through the cell membranes.

Nanoparticle-based therapies represent a cutting-edge direction in medical research. Ti2CO2 MXene is a novel two-dimensional transition metal carbide with a high surface area and reactivity, making it suitable for biomedical applications due to its biocompatibility. In biomedicine, Ti2CO2 MXene is particularly used in photothermal therapy, where its ability to absorb light and convert it into heat can be utilized to target and destroy cancer cells. The study of how temperature influences the interaction between nanoparticles and cell membranes is a critical aspect of this field. Our study conducts a thorough coarse-grained molecular dynamics analysis of a Ti2CO2 MXene nanosheet interacting with a phosphatidylcholine (POPC) membrane under various thermal conditions and nanosheet orientations. We show that the hydrophilic nature of the nanosheet presents a substantial barrier to membrane penetration and an increase in temperature significantly enhances the permeability of the membrane, thereby facilitating the migration of the MXene nanoparticles across it. The peak force required to translocate the nanosheet through the membrane decreases e.g., from 2150 pN at 300 kelvin to 1450 pN at 370 kelvin indicating significant reduction in resistance at higher temperatures. The study also highlights the critical role of the nanosheets' spatial orientation in cellular uptake. Our research underscores the importance of the application of MXenes for nanomedical and photothermal therapy purposes.

Architecting Ni3Se4-NiSe2-Co3O4 Triple-Interface Heterostructure on MXene Nanosheets for Boosting Water Splitting by Electronic Modulation and Interface Effects.

Strategically engineering electrocatalysts with optimized interfacial electronic architectures and accelerated reaction dynamics is pivotal for augmenting hydrogen generation via alkaline water electrolysis on an industrial scale. Herein, a novel triple-interface heterostructure Ni3Se4-NiSe2-Co3O4 nanoarrays are designed anchored on Ti3C2Tx MXene (Ni3Se4-NiSe2-Co3O4/MXene) with significant work function difference (ΔΦ) as bifunctional electrocatalysts for water electrolysis. Theoretical calculations combined with experiments uncover the pivotal role of the interface-induced electric field in steering charge redistribution, which in turn modulates the adsorption and desorption kinetics of reaction intermediates. Furthermore, the synergistic interaction between Ni3Se4-NiSe2-Co3O4 and Ti3C2Tx MXene nanosheets endows the hybrids with a large electrochemical surface area, abundantly active sites, and high conductivity. Thus, Ni3Se4-NiSe2-Co3O4/MXene manifests exceptional catalytic prowess for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In addition, the Ni3Se4-NiSe2-Co3O4/MXene electrocatalyst in the water electrolyzer delivers excellent performance and maintains commendable stability beyond 100h of electrocatalytic operation.

Forthright synthesis of titanium-based MXene nanosheets for bio-synaptic device applications: A novel approach

Recent advances in two-dimensional materials have highlighted the outstanding electrical and chemical properties of titanium-based MXene (Ti3C2Tx), which has attracted intensive research attention. Despite its considerable potential, the integration of MXene into fully functional devices has been limited. This study employs titanium-based MXene, synthesized in-situ through a simplified etching method, to construct memristive devices tailored towards bio-synaptic applications. The Ti3C2Tx material was fabricated following comprehensive analyses of its structural, morphological, and compositional characteristics, which confirmed its high crystallinity and suitability for integration into the device. The fabricated memristive devices exhibited considerable potential as non-volatile memory elements, exhibiting stable bipolar resistive switching through robust testing of up to 1000 cycles and retention capabilities that surpassed 5000 s. Electrical characterization of these devices revealed an ON/OFF ratio of approximately >103. Notably, charge transport within these devices was governed by Ohmic and square law conduction, which was essential to their RS behavior. The promising outcomes from this study not only confirm the potential of 2D MXene in memory device applications but also pave the way for their use in advanced computing systems, including neuromorphic computing that mimics neurological architectures. The findings suggest potential applications for MXene in bio-synaptic systems, sensor integration, and biomedical applications. Furthermore, MXene could enable the development of novel types of electronic devices that combine biological and synthetic materials. As a result, electronic devices may become more efficient and compact, featuring improved performance and capabilities.

Two-dimensional MXene Nanosheets and their Composites for Antibacterial Textiles: Current Trends and Future Prospects

Abstract: As a novel two-dimensional (2D) nanosheet (NS), MXene has attracted attention in antibacterial applications due to its excellent high surface area, remarkable hydrophilicity, strong flexibility, and excellent antibacterial properties. This review intends to provide valuable insight into the further development of antibacterial MXenes and their composite materials. In this paper, we review the antibacterial mechanisms of MXenes and their composite materials and summarize the research progress of antibacterial finishing fabrics, fibers and dressings based on MXene NSs. Due to the rich oxygen-containing groups, 2D MXene NSs and its composites exhibited significant antibacterial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis so they have been widely used in antibacterial textiles including finishing fabrics, fibers, and dressings. 2D MXene NSs have showed some antibacterial properties based on cell experiments or blood tests. The antibacterial mechanisms mainly include physical sterilization and chemical oxidative stress sterilization. The future direction of antibacterial textiles based on MXenes was proposed.

Rapid and Scalable Synthesis of In2O3‐Decorated MXene Nanosheets for High‐Performance Flexible Broadband Photodetectorss

AbstractA promising flexible photodetector based on hybrid nanocomposites of 2D MXene and In2O3 nanoparticles (NPs) has been developed, demonstrating excellent ultraviolet (UV) light responsivity. In this work, In2O3‐decorated MXene nanosheets (In2O3MX) are synthesized via a simple one‐step sonochemical method using ultrasonication, rapidly producing the composites in a short time. The synthesized material shows efficacy across broadband wavelengths (UV, Vis, NIR). Notably, the photodetector using In2O3MX exhibits a responsivity (R) of 121.6 A W−1 and a specific detectivity (D*) of 106.4 × 10¹⁰ Jones in the UV range, and confirming enhanced electrical properties and the feasibility of low‐voltage detection with tau plots. Additionally, the electrical and optical characteristics remain unchanged after bending the device up to 10,000 times with a bending radius of 6.0 mm, highlighting its suitability for flexible optoelectronic applications. Overall, this study introduces a novel approach to the simple synthesis of 2D MXene nanocomposites and provides valuable insights into the development of flexible photodetectors using these materials.

Energy-efficient synthesis of Ti3C2Tx MXene for electromagnetic shielding

Traditional methods for synthesizing two-dimensional Ti3C2Tx MXenes such as hydrofluoric acid (HF) or LiF/HCl based etching can be time-consuming, complex, and often result in low yields. They generally involve multi-step processes involving >40 h of preparation time that can expose the materials to harsh conditions. In this study, we demonstrate a rapid single-step microwave (MW) synthesis method that significantly reduces production time to 90 min, achieving a 90 % yield and cutting energy consumption by 75 %. For the first time, synchrotron x-ray pair distribution function (PDF) analysis conducted on MW-synthesized MXene (MW-Ti3C2Tx) indicates greater structural fidelity in local atomic ordering, indicating high-quality which is comparable to conventionally synthesized counterparts (CO-Ti3C2Tx). This method achieves similar or greater structural quality in less time while also enhancing electromagnetic interference shielding (EMI SE) performance. A 15 μm MW-Ti3C2Tx film demonstrated an impressive EMI SE of ∼67 dB in the X-band, compared to the ∼63 dB achieved by CO-Ti3C2Tx. The enhanced EMI SE performance is attributed to the presence of fluorine terminations, which provide oxidation resistance, increased conductivity and improved absorption of EM waves. The MW-induced shocks during irradiation not only help remove O2/OH groups, preventing oxidation, but also tunes the functional groups, enhancing charge transport and effective EM wave attenuation. The MW synthesis method presents a fast, efficient, and scalable approach for producing high-quality MXene nanosheets, paving the way for advancements in EMI shielding and other applications.

2D MXene Nanosheets with ROS Scavenging Ability Effectively Delay Osteoarthritis Progression.

MXenes nanosheets with high conductivity, hydrophilicity, and excellent reactive oxygen species (ROS) scavenging ability have shown promise in treating various degenerative diseases correlated with abnormal ROS accumulation. Herein, the therapeutic potential of Ti3C2Tx nanosheets, which is the most widely investigated MXene material, in delaying osteoarthritis (OA) progression is demonstrated. In vitro experiments indicate the strong ROS scavenging capacity of Ti3C2Tx nanosheets and their acceptable biocompatibility. Ti3C2Tx nanosheets effectively protect chondrocytes from cell death induced by oxidative stress. In addition, Ti3C2Tx nanosheets demonstrate a prominent anti-inflammatory effect and the ability to restore homeostasis between anabolic activities and catabolic activities in chondrocytes. Furthermore, RNA sequencing reveals the potential mechanism underlying the Ti3C2Tx nanosheet-mediated therapeutic effect. Finally, the in vivo curative effect of Ti3C2Tx nanosheets is verified using a rat OA model. Histological staining and immunohistochemical analyses indicate that Ti3C2Tx nanosheets effectively ameliorate OA progression. Conclusively, the in vitro and in vivo experiments suggest that Ti3C2Tx nanosheets could be a promising and effective option for OA treatment.

Multiple Heterointerfaces and Heterostructure Engineering in MXene@Co-P-S Hybrids Promote High-Performance Sodium-Ion Half/Full Batteries.

In this paper, heterogeneous cobalt phosphosulfide (Co4S3/Co2P) nanocrystals anchoring on few-layered MXene nanosheets (MXene@Co4S3/Co2P) were prepared by in situ growth and the subsequent high-temperature phosphorization/sulfidation processes. Thanks to the synergistic effect and the abundant phase interfaces of Co4S3, Co2P, and MXene, the electron transfer and Na+ diffusion processes were greatly accelerated. Meanwhile, the high electrical conductivity of MXene nanosheets and the heterogeneous structure of Co4S3/Co2P effectively avoided the MXene restacking and the agglomeration of phosphosulfide particles, thus mitigating volumetric expansion during charging and discharging. The results show that the MXene@Co4S3/Co2P heterostructure presents good rate capability (251.08 mAh g-1 at 1 A g-1) and excellent cycling stability (198.69 mAh g-1 after 407 cycles at 5 A g-1). Finally, the storage mechanism of Na+ in the heterostructure and the multistep phase transition reaction were determined by ex situ X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS) analyses. This study provides a new perspective on the formation of metal phosphosulfide and MXene hybrids with multiple heterointerfaces as well as demonstrates MXene@Co4S3/Co2P composites as the promising anode material in sodium-ion batteries.

Synergetic enhancement of wear resistance of polyimide coatings through the integration of MoS2 nanoflowers and MXene nanosheets

Composite nano-lubricating fillers have attracted much attention due to their excellent synergistic effect. In this study, MoS2 nanoflowers composed of two-dimensional nanosheets were synthesized by precise control of hydrothermal conditions. Using the "bridging" effect of dopamine, the flower-like MoS2 was assembled with MXene to form a unique compound filler. This distinctive structure perfectly retained the shape of the MoS2 flower. The impacts of compound fillers on the thermodynamic, mechanistic, and frictional properties of polyimide (PI) coatings were scrutinized. The formation of the compound fillers between MXene and MoS2 effectively improve the interface compatibility of individual materials in the PI matrix. The compound fillers can enhance the thermodynamic stability and mechanical properties of PI. It is noteworthy that the frictional coefficient of the PI/(MoS2:MXene = 4:6) compound coating decreased by 47.2 %, and the attrition rate reduced by 98.5 % compared to the pure PI coating. The compound lubricating filler prepared by the combination of two types of two-dimensional lubrication fillers has an important application prospect in the field of wear resistance of polymer materials.

High-Performance Red Transparent Quantum Dot Light-Emitting Diodes via Fully Solution-Processed MXene/Ag NWs Top Electrode.

The integration of high-performance transparent top electrodes with the functional layers of transparent quantum dot light-emitting diodes (T-QLEDs) poses a notable challenge. This study presents a composite transparent top electrode composed of MXene and Ag NWs. The composite electrode demonstrates exceptional transparency (84.6% at 620 nm) and low sheet resistance (16.07 Ω sq-1), rendering it suitable for integration into T-QLEDs. The inclusion of MXene nanosheets in the composite electrode serves a dual role: adjusting the work function to enhance electron injection efficiency and enhancing the interface between Ag NWs and the emissive layer, thereby mitigating the common issue of interfacial resistance in conventional transparent electrodes. This strategic amalgamation results in notable improvements in device performance, yielding a maximum current efficiency of 23.12 cd A-1, an external quantum efficiency of 13.98%, and a brightness of 21,015 cd m-2. These performance metrics surpass those achieved by T-LEDs employing pristine Ag NW electrodes. This study offers valuable insights into T-QLED device advancement and provides a promising approach for transparent electrode fabrication in optoelectronic applications.

Mussel-inspired polydopamine (PDA)-grafted 2D-Ti3C2 MXene nanosheets tailored ZnAl-layered double hydroxides (LDH); Toward designing a smart self-healing epoxy composite coating

The constant challenge of corrosion significantly compromises the durability and functionality of metal substrates, propelling the demand for advanced protective solutions. This study introduces a novel smart epoxy coating system modified with a three-component nanocomposite integrating polydopamine (PDA)-modified Ti3C2 MXene with ZnAl-layered double hydroxides (LDH), intercalated with phosphate (P) and glutamate (Gl) ions as corrosion inhibitors. The innovative approach leverages the synergistic impacts of barrier protection, ion exchangeability, and self-healing capabilities to offer superior anti-corrosion performance. In the solution phase, the EIS results revealed a notable increase in resistance values, with MPLG samples exhibiting a 2.45-fold and MPLP samples a 2.17-fold enhancement compared to the blank specimen after 96 h of immersion. Furthermore, the data obtained from EIS demonstrated a significant enhancement in the barrier effects of the epoxy coating upon the addition of MPLG and MPLP. This enhancement was evidenced by a significant increase in the impedance values, which were observed to be 103-fold higher following a prolonged immersion period of 140 days. The self-healing properties, confirmed through EIS, FE-SEM, and EDX/Mapping analyses, indicated the formation of a stable corrosion-protective layer over the damaged areas, thus providing active protection. Adhesion assessments further underscored the coatings' durability, with MPLG and MPLP samples demonstrating minimal delamination. Collectively, these findings emphasize the potential of the proposed PDA-modified MXene@ZnAl-LDH nanocomposite as a multifaceted solution to corrosion challenges, promising significant advancements in the longevity and reliability of coated metal surfaces.

Tannic Acid-Enabled Antioxidant and Stretchable MXene/Silk Strain Sensors for Diving Training Healthcare.

MXene-based conductive hydrogels hold significant promise as epidermal sensors, yet their susceptibility to oxidation represents a formidable limitation. This study addresses this challenge by incorporating MXene into a tannic acid (TA) cross-linked silk fibroin matrix. The resulting conductive hydrogel (denoted as e-dive) exhibits favorable characteristics such as adjustable mechanical properties, self-healing capabilities (both mechanically and electrically), and strong underwater adhesion. The existence of a percolation network of MXene within the nanocomposites guarantees good electrical conductivity. Importantly, the surface interaction of MXene nanosheets with the hydrophobic moiety from TA substantially reduced moisture and oxygen interactions with MXene, thereby effectively mitigating MXene oxidation within hydrogel matrices. This preservation of the electrical characteristics ensures prolonged functional stability. Furthermore, the e-dive demonstrates inherent antibacterial properties, making it suitable for use in underwater environments where bacterial contamination is a concern. The utilization of this advanced e-dive system extends to the correction of diving postures and the facilitation of underwater healthcare and security alerts. Our study presents a robust methodology for enhancing the stability of MXene-based conductive hydrogel electronics, thereby expanding their scope of potential applications.

Synergic effect between La-MOF and MXene: Revolutionizing TPU with improved mechanical strength and fire safety

Two-dimensional MXene nanosheets with lamellar structure and high specific surface area are considered promising flame retardants for polymers. However, MXene easily accumulates in polymer materials, resulting in the impairment of their mechanical properties. Metal-organic frameworks (MOFs) not only address this issue effectively but also improve compatibility with polymer materials due to their organic components. In this work, lanthanide rare-earth MOF (La-MOF) were successfully grown in-situ on the MXene surface to prepare hybrid flame retardants (La-MOF@MXene), then added to thermoplastic polyurethane (TPU). The La-MOF suppressed the accumulation of MXene in TPU, and the synergistic effect between them improved the fire safety and mechanical strength of TPU composites. The peak heat release rate of the TPU composites with the addition of 3 wt% La-MOF@MXene was 473.3 kW/m2, which represented a 49.4 % decrease compared to that of pure TPU. Besides, due to the synergic properties of MXene and La-MOF, La-MOF@MXene further reduced total smoke, CO2, and CO of TPU composites in fires. Moreover, with the addition of 3.0 wt% La-MOF@MXene, the tensile strength and elongation at break of TPU composites dramatically improved to 42.4 MPa and 686 %, respectively. Therefore, this study provides a novel paradigm for preparing hybrid flame retardants that can improve the fire safety and mechanical properties of TPU composites, exhibiting broad application prospects.

Ionic covalent organic framework-MXene heterojunction constructed by electrostatic interaction for stable electrocatalytic hydrogen generation

Constructing stable electrocatalysts by pyrolysis-free technique is an important topic in hydrogen-evolution reaction (HER) for water splitting reactions. Covalent organic frameworks (COFs), an emerging class of porous materials, offer ideal candidates owing to their abundant active sites and unique structures. Herein, a novel pyrolysis-free heterostructure was constructed using electrostatic interactions between an ionic COF (JUC-628) and Ti3C2Tx (MXene) nanosheets, which exhibits an impressively low overpotential of 137 mV at 10 mA cm−2 and excellent catalytic activity and stability for five days operation under alkaline conditions. Theoretical calculations depict that the formation of a stable heterostructure between MXene nanosheets and JUC-628 is the critical factor underlying the outstanding catalytic performance. Moreover, the optimized catalyst showed superior hydrogen-evolution capability in alkaline seawater electrolysis, highlighting the first successful application of a COF-based catalyst for hydrogen production from seawater electrolysis. As a leading covalent organic porous material–based catalyst for HER, as a proof of concept, this study represents a novel strategy to construct efficient electrocatalysts by COFs directly without the pyrolysis technique.

Enhancing CO2/CH4 separation performance in PIM-1 based MXene nanosheets mixed matrix membranes

This study presents an approach by integrating MXene nanosheets (Ti2C3Tx) into polymer of intrinsic microporosity (PIM-1) matrix to develop mixed matrix membranes (MMMs) for biogas upgrading. Different concentrations (1–5 wt%) of MXene were incorporated into PIM-1, and the resulting materials were characterized to 1H NMR, FTIR, XRD, TGA, nitrogen adsorption, SEM and EDS to assess their physicochemical properties. The research focused on evaluating the gas separation performance, particularly CO2/CH4 separation, as well as the aging behavior of the MMMs. The incorporating of MXene nanosheets significantly enhanced the CO2 permeability and selectivity of PIM-1 by enhancing gas solubility and diffusivity. The most promising results were observed at 5 wt% filler loading, achieving a 13.5 CO2/CH4 separation selectivity at 7652 Barrer of CO2 permeability. In all membranes with aging time (60 days), there was a decrease in CO2 permeability and a slight increase in CO2/CH4 selectivity, observing that the introduction of MXene slightly mitigates the physical aging process in the PIM-1 polymer. Additionally, the permeability tests revealed higher CO2 permeability and (CO2/CH4) selectivity values for mixed gases compared to single gases. Overall, the study highlights the potential of MXene/PIM-1 MMMs as effective materials for CO2/CH4 separation, outperforming pristine PIM-1.

Plasmonic molybdenum carbide MXene nanosheets for highly efficient and stable perovskite solar cells

Besides the excellent metallic electrical conductivity, high carrier mobility, and high optical transmittance, the two-dimensional MXenes exhibiting impressive optical and plasmonic properties have been explored to photodiodes. However, their potential use of surface plasmons oscillating in perovskite solar cells has not been studied. Herein, we incorporate, for the first time, Mo2CTx MXene nanosheets with characteristic plasmonic absorption in the whole visible region into the perovskite active layer. First, the presence of Mo2CTx nanosheets in the perovskite film increases the perovskite grain size due to the decreased growth rate and passivation of the defects around the grain boundaries through strong interaction with undercoordinated Pb2+. Furthermore, with the help of the localized surface plasmon resonance effect of Mo2CTx nanosheets, the exciton binding energy in the perovskite absorber is reduced, which suggests the efficient exciton dissociation and enhanced charge separation. Consequently, Mo2CTx nanosheets based perovskite solar cell device exhibits a champion power conversion efficiency (PCE) of 24.05 %. It is worth noting that the unencapsulated devices demonstrate considerably improved stability, maintaining about 89.25 % of the initial PCE after aging in air for 3000 h. This fascinating strategy provides more opportunities of the functional MXene materials for the perovskite optoelectronics.