MXene Family Research Articles

Prediction of synthesis of ternary-layered double transition metal MAX phases and the possibility of their exfoliation for formation of 2D MXenes

The MXenes family has already demonstrated considerable potential in energy storage, electromagnetic, and electrochemical applications. It is usually created by selectively etching the A layer from the bulk MAX phase. The goal of this work is to broaden the family of MAX phases and examine the possibility of etching them to create a 2D system. Here, we provide a machine learning (ML) approach that is able to accurately predict the relative formation energy (ΔH) on small dataset. From the calculated results, our model shows high prediction accuracy as proved by the RMSE of 0.052 for ΔH. From a dataset of 1320 potential MAX candidates, we predicted 734 MAX phases that could be synthesized by experimental. Moreover, we observed that exfoliating 2D MXenes is more difficult when picking an A atom of S element in the MAX phase, however it is simpler when selecting a group III-A and Ⅳ-A element with a high atomic number. Finally, we identified 75 MXenes candidates with the most potential to be exfoliated from their layered bulk phase. Our machine learning technique can speed up the prediction of possible 2D MXenes while reducing calculation time by more than an order of magnitude.

Surface Plasmons in Two-Dimensional MXenes.

MXenes, a class of layered two-dimensional transition metal carbides and nitrides, exhibit excellent optoelectronic properties and show promise for fields ranging from photonics and communications to energy storage and catalysis. Some members of the MXene family are metallic and exhibit large in-plane conductivity, making them possibly suited for 2D plasmonics. The highly variable chemical structure of MXenes offers a broad chemical space to tune material properties for plasmonic applications, including plasmon-enhanced catalysis, surface-enhanced Raman spectroscopy (SERS), and electromagnetic shielding. However, this synthetic complexity has also presented several roadblocks in the process of moving MXene plasmonics into applications. For example, in the prototypical MXene Ti3C2Tx, there remains disagreement over the bulk plasmon energy and the assignment of a prominent resonance around 1.7 eV. We discuss fundamental models and theories of plasmon physics and apply these models to MXenes in order to clarify some of these problems. We outline the potential for hyperbolic plasmons in MXenes and propose new avenues for MXene photonics research.

Ti3C2Tx-MXene based 2D/3D Ti3C2–TiO2–CuTiO3 heterostructure for enhanced pseudocapacitive performance

Ti3C2Tx MXene family is a promising electrode material for electrochemical energy storage, but it suffers from insufficient pseudocapacitive charge storage because of self-aggregation and oxidation degradation. To resolve the issue, this paper proposes a two-step process for synthesizing oxidation-controlled MXene-derived 2D/3D heterostructures that beneficially utilize oxidation and simultaneously improve conductivity. The first step generates in-situ 3D floral Ti3C2– TiO2 nanoribbons under partial oxidation of MXene. As the second step, further controlled oxidation with Cu ions transforms the 3D floral Ti3C2–TiO2 nanoribbons into 2D/3D Ti3C2–TiO2–CuTiO3 heterostructure. Leveraging the synergistic effects of MXene, TiO2, and CuTiO3, this 2D/3D heterostructure enhances the interlayered spacing, redox-active site concentration and alleviates low conductivity issue associated with TiO2 nanoribbons. At 2 mA/cm2, the proposed 2D/3D Ti3C2–TiO2–CuTiO3 heterostructure achieved a significantly higher capacitance of 599.2 mF/cm2, compared to MXene with a capacitance of 249.16 mF/cm2 and 3D floral Ti3C2–TiO2 nanoribbons with 498.5 mF/cm2. For practical evaluation, an asymmetric supercapacitor (ASC) device (Ti3C2–TiO2–CuTiO3//AC) was fabricated, which exhibited an energy density of 31.1 Wh/kg, power density of 1041.7 W/kg and capacitance retention of 83.7 % after 5000 continuous charging/discharging cycles. It opens new avenues for utilizing controlled oxidation to enhance pseudocapacitive properties.

Pivotal Role of Surface Terminations in MXene Thermodynamic Stability.

MXenes, i.e., two-dimensional transition metal carbides and nitrides, have been reported as promising materials for various applications, including energy storage, biomedicine, and electronics. The family of MXenes has proliferated, and the chemical space of synthesized MXenes has expanded to 13 transition metals and a dozen elements in surface terminations. The diverse chemistry of MXenes enables systematical tuning of MXene properties to meet the needs of target applications. However, synthesizing new MXene compositions largely relies on a trial-and-error approach. To overcome it, computational predictions of MXene compositions that are thermodynamically stable are crucial to rationalize experimental efforts. Here, we report a comprehensive computational screening for thermodynamically stable MXenes across 29 transition metals and 11 surface terminations. Density functional theory calculations are employed to compute the energy above the convex energy hull as a descriptor of thermodynamic stability. The results are analyzed to explore factors crucial for determining the thermodynamic stability of MXenes, by which the chemistry of surface terminations is found to play a crucial role. The insights on the chemistry of 998 MXene compositions predicted to be (meta)stable are given to systematically guide further research on MXene synthesis and application.

Comprehensive Insights on MXene-Based TENGs: from Structures, Functions to Applications.

The rapid advancement of triboelectric nanogenerators (TENGs) has introduced a transformative approach to energy harvesting and self-powered sensing in recent years. Nonetheless, the untapped potential of TENGs in practical scenarios necessitates multiple strategies like material selections and structure designs to enhance their output performance. Given the various superior properties, MXenes, a kind of novel 2D materials, have demonstrated great promise in enhancing TENG functionality. Here, this review comprehensively delineates the advantages of incorporating MXenes into TENGs, majoring in six pivotal aspects. First, an overview of TENGs is provided, stating their theoretical foundations, working modes, material considerations, and prevailing challenges. Additionally, the structural characteristics, fabrication methodologies, and family of MXenes, charting their developmental trajectory are highlighted. The selection of MXenes as various functional layers (negative and positive triboelectric layer, electrode layer) while designing TENGs is briefed. Furthermore, the distinctive advantages of MXene-based TENGs and their applications are emphasized. Last, the existing challenges are highlighted, and the future developing directions of MXene-based TENGs are forecasted.

Self-grown carbon nanotubes supported fluorine-free Mo2CTx conductive layers for efficient potassium storage

Mo2CTx is relatively less studied among MXenes family, especially for rechargeable alkali metal ion batteries. Herein, a systematic investigation has been conducted to unlock its potential as electrode materials in potassium-ion battery (PIBs), including innovative fluorine-free synthesis strategy, construction of heterostructure, and exploration of suitable electrolyte systems. Firstly, Cetyltriethylammnonium bromide (CTAB)-assisted etching route was provided to fabricate high-quality multilayer Mo2CTx with expanded interlayer space (C-Mo2CTx). The as-obtained C-Mo2CTx demonstrates a large specific capacity of 200 mAh g−1over 300 cycles in potassium-ion battery, surpassing the HF etched counterparts (F-Mo2CTx) by about 300 %. Afterwards, Zeolitic Imidazolate Frameworks (ZIF-67) derived Co, N-codoped carbon nanotubes (Co@NCNTs) were homogenously grown on the surface of Mo2CTx, working as embedding spacer to open the stacked Mo2CTx conductive layers (Mo2CTx-Co@NCNTs). Mo2CTx-Co@NCNTs electrode represents stable reversible capacity of 280 mA h g−1 over 300 cycles. The highly conductive matrix constructed by the strong bond between CNTs arrays and Mo2CTx conductive layer could provide numerous K-ion-diffusion pathways, and buffer volume strain and facilitate electron transfer. The present work proves the potential of Mo2CTx in PIBs and gives the systematic research methodologies on Mo2CTx-based materials in alkali metal ion storage.

Tuning the hole transporting layer using the NiO@X2C (X = W or Mo) composites for polymer solar cells and X-ray detectors

In this paper, we showcased the augmentation in power conversion efficiency (PCE) and photodetectivity of bulk heterojunction (BHJ) organic solar cells and photodetectors through the integration of functionalized metal carbides interacted NiO composites with PEDOT:PSS as a hole transport (HT) material. The 2D metal carbides (Mo2C and W2C), quintessential representatives of the MXenes family, integrated NiO were synthesized and employed to tune the HT in BHJ solar cells and photodetectors. These materials exhibit exceptional electronic conductivity, high mobility, enhanced electron extraction, excellent optical transparency, and desirable mechanical properties, rendering them as ideal candidates for enhancing the performance of BHJ devices. The constructed devices with NiO@Mo2C and NiO@W2C blended PEDOT:PSS HT achieved a PCE of ∼7.49 % and ∼8.32 %, representing the ∼28 % and ∼43 % improvement, respectively compared to the PCE obtained with the pure PEDOT:PSS active layer (PCE = 5.86 %). Additionally, the photodetector utilizing the NiO@Mo2C and NiO@W2C blended PEDOT:PSS HT demonstrated a maximum sensitivity of 2.25 and 2.62 mA/Gy·cm² better than the pure HT under X-ray irradiation. This work suggests the integration of 2D metal carbides integrated NiO into the HT as a promising approach to enhance the efficiency of BHJ devices.

Silica-Ti3C2Tx MXene Nanoarchitectures with Simultaneous Adsorption and Photothermal Properties.

Layered Ti3C2Tx MXene has been successfully intercalated and exfoliated with the simultaneous generation of a 3D silica network by treating its cationic surfactant intercalation compound (MXene-CTAB) with an alkoxysilane (TMOS), resulting in a MXene-silica nanoarchitecture, which has high porosity and specific surface area, together with the intrinsic properties of MXene (e.g., photothermal response). The ability of these innovative MXene silica materials to induce thermal activation reactions of previously adsorbed compounds is demonstrated here using NIR laser irradiation. For this purpose, the pinacol rearrangement reaction has been selected as a first model example, testing the effectiveness of NIR laser-assisted photothermal irradiation in these processes. This work shows that Ti3C2Tx-based nanoarchitectures open new avenues for applications that rely on the combined properties inherent to their integrated nanocomponents, which could be extended to the broader MXene family.

3D Printable Mxene for Chemoresistive Sensing

The demand for smaller microenvironments in modern electronics has prompted a search for new solutions, with the MXene (Mn+1XnTx) family emerging as a strong candidate due to its unique properties. This research focuses on incorporating microelectronics into micropatterned structures using cost-effective methods, opening up possibilities for smart devices and microsystems. The study details the synthesis and processing of titanium carbide (Ti3AlC2)-based MXene nanoparticles, with a novel in situ etching method to create multi-layered MXene (Ti3C2Tx) nanosheets. Water-based Ti3C2Tx inks in various concentrations were examined, and 3D printing was used to create micropatterned MXene layers with anisotropic electrical properties and energy storage potential, making them promising for 3D printable devices.

(Invited) Insights into the Electrocatalytic Behavior of Mxenes

The continued rise in global energy consumption, along with the associated environmental hazards, pose a significant risk to our society’s infrastructure unless the main source is changed. Electrocatalysis involving hydrogen evolution reaction (HER), nitrogen reduction reaction (NRR), and oxygen reduction reaction (ORR), provide a pathway for energy storage and conversion due to their enhanced environmental friendliness and efficient energy input compared to their thermocatalytic counterparts. Currently, the state-of-the-art electrocatalysts suffer from scarcity and high cost. MXenes, a novel family of two-dimensional (2D) transition metal carbide and nitride materials, show potential as cost-efficient and highly abundant electrocatalysts with limited knowledge on their electrocatalytic mechanisms. This is especially true when considering the often-overlooked nitride family of MXenes. Herein, we investigate the electrocatalytic performance of a Ti2N nitride MXene under different electrocatalytic conditions. The effect of surface phenomena is investigated through manipulation of the surface passivation layer, as evidenced by Raman and Fourier-transform infrared (FTIR) spectroscopies, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Successful decoupling of the bulk and surface phenomena is achieved through Raman laser power attenuation. Under acidic medium, the surface reactivity towards HER is poor but the bulk reactivity for NRR is favored, making it an optimal NRR catalyst. Under alkaline medium, the surface reactivity of the pristine Ti2N MXene for ORR is high, but also leads to surface passivation and thus hinders the electrocatalytic activity. Overall, these results provide fundamental insights into future optimization strategies of the Ti2N nitride MXene, along with other MXene electrocatalysts, towards electrocatalytic applications.

Effects of Concentration and Surface Termination on the Workfunction of Ti3C2X2 MXene (X=F,Cl,O,OH)

Titanium carbide (Ti3C2), belonging to the MXene family, has become a focal point of research due to its exceptional electronic and structural properties. As a two-dimensional transition metal carbide, Ti3C2 exhibits promising potential in a variety of applications, ranging from electronic devices to energy storage. Among the key parameters influencing its electronic behavior, the work function plays a pivotal role. This study aims to elucidate the intricate relationship between concentration, surface termination, and the work function of Ti3C2X2 through first-principles density functional theory (DFT) calculations. First-principles DFT calculations were employed to investigate the electronic structure of Ti3C2X2, focusing on the influence of varying concentrations of surface functional groups. Hydroxyl (-OH), oxygen (-O), chlorine (-Cl), and fluoride (-F) terminations were specifically chosen as representative functional groups for their prevalence in experimental studies and potential technological applications. These calculations provide a quantum-level understanding of the electronic properties and behaviors of Ti3C2 under different surface conditions. Our results indicate a notable sensitivity of the work function of Ti3C2 to changes in both concentration and the type of surface termination. The presence of functional groups induces charge redistribution within the MXene layers, significantly impacting the overall electronic landscape. The variation in charge distribution directly correlates with changes in the work function, illustrating the dynamic nature of Ti3C2 in response to surface modifications. Furthermore, an in-depth analysis of the correlation between concentration, surface termination, and the energetics of charge transfer at the Ti3C2 surface provides valuable insights. The interplay between these factors reveals intricate mechanisms that govern the observed variations in the work function. The concentration-dependent charge transfer at the surface serves as a key determinant, emphasizing the importance of carefully tailoring the composition to achieve desired electronic properties. The understanding gained from this study has significant implications for the tailored design and utilization of Ti3C2 in various technological applications. By manipulating concentration and surface termination, researchers and engineers can fine-tune the work function to meet specific requirements in electronic devices, sensors, and energy storage systems. This level of control over electronic properties enhances the versatility and applicability of Ti3C2 in emerging technologies. In conclusion, our investigation highlights the critical roles of concentration and surface termination in modulating the work function of Ti3C2. The pronounced sensitivity of this parameter to surface modifications underscores the need for a comprehensive understanding of the underlying electronic mechanisms. By elucidating the interplay between concentration, surface termination, and charge transfer, this study provides valuable insights that pave the way for the strategic design and implementation of Ti3C2 in advanced technological applications. The ability to fine-tune electronic properties opens new avenues for exploiting the full potential of Ti3C2 in diverse fields, driving innovation and progress in materials science and technology.

γ-Radiation-induced in-situ formation of TiC/MXene nanocomposites for superior electromagnetic wave absorption

The layered structure of two-dimensional transition metal carbides/nitrides (MXenes) is potentially conducive to efficient electromagnetic wave absorption (EWA). However, Ti3C2Tx MXene typically encounters challenges with a narrow effective absorption bandwidth (EAB) due to impedance mismatch caused by its inherent high conductivity. This study employed γ-radiation to induce the in-situ formation of TiC/MXene nanocomposites for EWA. The radiation preparation process is carried out under reducing conditions at ambient temperature and pressure, effectively minimizing the risk of MXene oxidation while preserving its original layered structure. The resultant intercalated structure, featuring in-situ formed TiC nanoparticles embedded within the Ti3C2Tx MXene layers, facilitates the integration of layered conductive networks with abundant spatial gaps and multiple heterojunction interfaces. Leveraging these structural and chemical advantages, the composite demonstrates enhanced EWA capabilities. At a 50 wt% irradiated MXene loading, the material achieves an EAB of 6.08 GHz at 1.55 mm thickness and a minimum reflection loss (RLmin) of −51.1 dB at 3.95 mm. Compared to conventional composite fabrication methods, γ-radiation offers a more environmentally sustainable, efficient, and scalable approach. This research opens up a new avenue for exploiting the MXene family in EWA applications.

Synthesis, physico-chemical characterization, DFT simulation, and field electron behaviour of 2D layered Ti3C2Tx MXene nanosheets

Nanostructures of Ti3C2Tx, one of the members of the MXenes family, have been successfully prepared by chemical etching of Al from Ti3AlC2 (MAX phase) using Hydrofluoric Acid (HF) for various etching durations at room temperature. The phase, morphological, structural, and chemical analysis was performed using XRD, FESEM, TEM, Raman, and x-ray photoelectron spectroscopy. The surface morphology of as-synthesized Ti3C2Tx (MXene) phase is characterized by stacks of layered sheets like structures. Field electron emission (FEE) behaviour was investigated at the base pressure of 1 × 10−8 mbar. The pristine Ti3AlC2 (MAX) and Ti3C2Tx (MXene) nanosheets emitters showed values of turn-on field (defined at current density ∼ 1 μA cm−2) as 4.18 and 1.67 V μm−1, respectively. Furthermore, maximum emission current density of ∼ 825 μA cm−2 was extracted from the MXene nanosheets emitter at an applied field of 3.60 V μm−1, in contrast to ∼71 μA cm−2 drawn at 7.31 V μm−1 from the pristine MAX emitter. The MXene nanosheets emitter exhibited good emission current stabilities at pre-set values ∼ 10 and 100 μA over 3 h duration. Work function values of the MAX and MXene nanosheets emitters were measured using a retarding field analyzer, and found to be 4.4 and 3.6 eV, respectively. Extensive ab-initio simulations have been performed to provide structural and electronic properties, as well as for estimating the work function of Ti3C2 layered material. The estimated electronic density of states revealed its metallic character. The improved FEE performance exhibited by the 2D layered Ti3C2Tx (MXene) nanosheets emitter is attributed to its unique morphology characterized by high aspect ratio, metallic electronic properties and relatively lower work function.

Thermal transports in the MXenes family: Opportunities and challenges

Thermal transports in the MXenes family: Opportunities and challenges

Recent Advances in Non-Ti MXenes: Synthesis, Properties, and Novel Applications.

One of the most fascinating 2D nanomaterials (NMs) ever found is various members of MXene family. Among them, the titanium-based MXenes, with more than 70% of publication-related investigations, are comparatively well studied, producing fundamental foundation for the 2D MXene family members with flexible properties, familiar with a variety of advanced novel technological applications. Nonetheless, there are still more candidates among transitional metals (TMs) that can function as MXene NMs in ways that go well beyond those that are now recognized. Systematized details of the preparations, characteristics, limitations, significant discoveries, and uses of the novel M-based MXenes (M-MXenes), where M stands for non-Ti TMs (M=Sc, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, W, and Lu), are given. The exceptional qualities of the 2D non-Ti MXene outperform standard Ti-MXene in several applications. There is many advancement in top-down as well as bottom-up production of MXenes family members, which allows for exact control of the M-characteristics MXene NMs to contain cutting-edge applications. This study offers a systematic evaluation of existing research, covering everything in producing complex M-MXenes from primary limitations to the characterization and selection of their applications in accordance with their novel features. The development of double metal combinations, extension of additional metal candidates beyond group-(III-VI)B family, and subsequent development of the 2D TM carbide/TMs nitride/TM carbonitrides to 2D metal boride family are also included in this overview. The possibilities and further recommendations for the way of non-Ti MXene NMs are in the synthesis of NMs will discuss in detail in this critical evaluation.

Highly selective oxidation of biomass-derived alcohols and aromatic alcohols to aldehydes over Ti3C2-TiO2 nanocomposites under visible light

Ti3C2Tx is a two-dimensional (2D) material belonging to the MXenes family. It has a unique combination of functional features that make it appropriate for a wide range of fascinating applications, including supercapacitors, batteries, strain sensors, photocatalysis, and more. In this study, we report a synthesis of Ti3C2-TiO2 nanocomposites with tight interfacial contact that has been successfully fabricated by in situ development of TiO2 nanoparticles (NPs) on the surface of Ti3C2Tx nanosheets (NSs) via a simple and cost-effective hydrothermal process. The catalysts are well characterized by various sophisticated techniques, including X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), Brunauer-Emmett-Teller (BET), CHI660E electrochemical workstation, and HRTEM. The photocatalytic performance of pure Ti3C2Tx, Ti3C2-TiO2 (MT1), and Ti3C2-TiO2 (MT5) nanocomposites was evaluated by highly selective photo-oxidation of biomass-derived furfuryl alcohol (FA), cinnamyl alcohol, vanillin alcohol, and various aromatic alcohols to the corresponding aldehyde with >99% selectivity for all the alcohol substrates under visible light (385–740 nm). Photocatalytic oxidation results revealed that Ti3C2-TiO2 (MT5) has superior photocatalytic activity than Ti3C2-TiO2 (MT1) and pure Ti3C2Tx NSs. The exceptional photocatalytic activity was attributed to the composite's unique morphology and characteristics.

Temperature Evolution of Composition, Thermal, Electrical and Magnetic Properties of Ti3C2Tx-MXene.

MXenes are a family of two-dimensional nanomaterials. Titanium carbide MXene (Ti3C2Tx-MXene), reported in 2011, is the first inorganic compound reported among the MXene family. In the present work, we report on the study of the composition and various physical properties of Ti3C2Tx-MXene nanomaterial, as well as their temperature evolution, to consider MXenes for space applications. X-ray diffraction, thermal analysis and mass spectroscopy measurements confirmed the structure and terminating groups of the MXene surface, revealing a predominant single OH layer character. The temperature dependence of the specific heat shows a Debye-like character in the measured range of 2 K-300 K with a linear part below 10 K, characteristic of conduction electrons of metallic materials. The electron density of states (DOS) calculations for Ti3C2OH-MXene reveal a significant DOS value at the Fermi level, with a large slope, confirming its metallic character, which is consistent with the experimental findings. The temperature dependence of electrical resistivity of the MXene samples was tested for a wide temperature range (3 K-350 K) and shows a decrease on lowering temperature with an upturn at low temperatures, where negative magnetoresistance is observed. The magnetoresistance versus field is approximately linear and increases its magnitude with decreasing temperature. The magnetization curves are straight lines with temperature-independent positive slopes, indicating Pauli paramagnetism due to conduction electrons.

Fabrication strategies, applications and prospects of MXene titanium nitride (Tin+1NnTx): A mini review

MXenes, as promising two-dimensional (2D) transition metal carbides or nitrides, are a promising new family of 2D materials. MXenes have superior electrical conductivity, a unique accordion-like structure, excellent mechanical properties and abundant surface termination, which make them the preferred material for the ever-growing market of energy storage, adsorption, gas sensing and other fields. As one of the typical representatives of the MXene family, Tin+1NnTx MXene is notable due to its high conductivity, high specific capacitance, high catalytic activity and low precursor cost compared to other MXenes and can be used for clean energy storage and catalysis applications. However, relatively little is currently known about the MXene Tin+1NnTx, and a special review on the synthesis, properties, and applications of Tin+1NnTx has not been reported to date. Herein, we overview and introduce the synthesis progress, application and properties of MXene Tin+1NnTx. The major problems and bottlenecks are objectively dissected and evaluated. In addition, future viewpoints and research opportunities are presented for the development of advanced MXene and MXene-based materials.

Solid lubrication performance of multi-layered V2CTx coatings

MXenes induce excellent wear resistance under solid lubrication due to their distinctive surface chemistry, easy-to-shear ability, and capability to form low-friction and wear-resistant tribofilms. However, beyond the extensively studied Ti3C2Tx, other promising members of the MXene family remain largely underexplored. Therefore, we spray-coated multi-layer vanadium carbide (V2CTx) coatings (thickness ∼10.8 μm) on steel substrates and studied their tribological performance for prolonged times (10,000 cycles) using a reciprocating ball-on-disk tribometer with acting contact pressure of 445 MPa in ambient conditions. Results show that V2CTx-coated substrates demonstrate an 8-fold reduction in friction (COF of 0.11) and a 10-fold wear rate reduction (1.405 × 10−6 mm3 N−1 m−1). High-resolution materials characterization confirmed that the remarkable tribological performance of these coatings can be traced back to the formation of protective films on the substrate (tribofilm) and counterbody (transferfilm) consisting of contact pressure and frictional heat-induced degraded, deformed, exfoliated V2CTx nanosheets, nanocrystalline oxides, and amorphous carbon debris. This work fully elucidates the tribological potential of V2CTx, which is of utmost relevance for designing high-performance lubricating materials. Our work has assessed the performance of multi-layer V2CTx (M2XTx) due to its remarkable thermal stability, low molecular weight, good mechanical properties, and high interlayer spacing, thus serving as an entry point into diverse MXene compositions, including M4X3Tx (V4C3Tx).

A water transfer printing method for contact lenses surface 2D MXene modification to resist bacterial infection and inflammation.

Contact lenses (CLs) are prone to adhesion and invasion by pollutants and pathogenic bacteria, leading to infection and inflammatory diseases. However, the functionalization of CL (biological functions such as anti-fouling, antibacterial, and anti-inflammatory) and maintaining its transparency still face great challenges. In this work, as a member of the MXenes family, vanadium carbide (V2C) is modified onto CL via a water transfer printing method after the formation of a tightly arranged uniform film at the water surface under the action of the Marangoni effect. The coating interface is stable owing to the electrostatic forces. The V2C-modified CL (V2C@CL) maintains optical clarity while providing good biocompatibility, strong antioxidant properties, and anti-inflammatory activities. In vitro antibacterial experiments indicate that V2C@CL shows excellent performance in bacterial anti-adhesion, sterilization, and anti-biofilm formation. Last, V2C@CL displays notable advantages of bacteria elimination and inflammation removal in infectious keratitis treatment.