MXene Research Articles

Covalently grafting silane coupling agents onto MXene‐reinforced carbon fibers for epoxy composites with improved mechanical properties

AbstractTwo‐dimensional (2D) MXene (MX) and silane coupling agents are increasingly used to modify carbon materials for the fabrication of composite functional materials, which exhibit enhanced electrical, optical, and mechanical properties due to the synergistic effects of both MX and silane. We demonstrate the modification of carbon fibers (CFs) with MX and three different kinds of silane coupling agents, including 3‐aminopropyltriethoxysilane, 3‐glycidyloxypropyldimethoxymethylsilane, and 3‐mercaptopropyltriethoxysilane, which are named as CF‐MX@N, CF‐MX@O, and CF‐MX@S, respectively, and further prepare the CF‐MX@silane/epoxy (EP) composites. The utilized silane coupling agents serve as bridges between MX and CFs, forming CF‐MX@silane composites. Through comparative analysis, it is found that the CF‐MX@S composites form a strong interface phase through covalent bonds, significantly enhancing the interface compatibility and revealing strong interface adhesion. The interfacial shear strength of the molded CF‐MX@S/EP composites increases to 119.7 MPa, with an 173.9% enhancement comparing to unmodified composites. This work can offer useful guidance and reference for selecting appropriate silane coupling agent to modify CFs with 2D materials to form high‐performance composite materials.Highlights Silane coupling agents are used as bridges to graft MXene‐modified CFs The surface modification of CFs is achieved by a simple one‐step approach Excellent interfacial phase is constructed through forming strong covalent bonds Microstructure and failure interface are responsible to interface strengthen.

Novel 2D Layered MXene Nanofluids for Enhancing the Convective Heat Transfer Performance of Double-Pipe Heat Exchangers.

This paper proposes a new class of novel 2D layered structured materials, such as MXene (MX), for the synthesis of innovative nanofluids as coolants to evaluate the convective heat transfer performance of a double-pipe heat exchanger (DPHE). Convective heat transfer experiments were successfully conducted in lab-scale fabricated DPHE using low-concentration MXene nanofluids by varying the volume concentration of MXene nanoparticles (0.01-0.05 vol %) in different base fluids. The influence of the MXene nanofluids on various convective heat transfer parameters, such as LMTD, Nusselt number, heat transfer coefficient, and heat transfer rate without using any inserts in the DPHE was experimentally investigated. The results of the experiments revealed that the heat transfer coefficient and Nusselt number increase with increasing Reynolds number (Re) and concentration of MXene nanoparticles in the base fluids. Maximum enhancement in heat transfer coefficient (126%) was achieved for methanol-based MXene nanofluids at 0.05 vol %. Moreover, the Nusselt number exhibits a maximum enhancement of ∼50% for methanol- and water-based MXene nanofluids. In contrast, the thermal performance factor was also estimated, and it was observed that water- and methanol- based MXene nanofluids showed higher values than castor oil- and silicone oil-based MXene nanofluids. Finally, the LMTD and heat transfer coefficients were successfully validated using Aspen HYSYS 12.1 software.

MXene grafted porous carbon cloth with alumina for high thermal conductivity and EMI shielding effect

Thermal interface material (TIM) has a great potential for efficient heat management and safety of electronic devices. However, achieving high performance polymer-based TIM is still challenging because of its intrinsic thermal conductivity and weak mechanical properties. In particular, electromagnetic interference shielding effect (EMI SE) of polymer-based composites has a great attraction according to electronic devices have become ubiquitous, playing integral roles in everyday life in our increasingly interconnected world. Herein, a porous carbon cloth (CC) for use as a continuous thermally and electrically conductive template is prepared via a freeze-casting method, after which mxene (MX) is chemically grafted onto the CC surface. Then, the as-prepared MX-CC is used along with alumina (AO) to fill a poly vinyl alcohol (PVA) matrix in order to fabricate a thermally conductive film with electromagnetic interference (EMI) shielding properties. The resultant composite demonstrates remarkable characteristics, including an excellent EMI shielding effect of 28 dB, substantial tensile strength of 19 MPa, and impressive out of plane thermal conductivity (3.98 W/mK). When applied to a light-emitting diode (LED), the PVA/MX-CC/AO composite effectively manages heat, thereby resulting in a 49 °C reduction in the operating temperature. Therefore, the composites developed herein hold great promise for improving thermal management in electronic devices.

High performance Cu/SAC305 solder low temperature bonding using Ti3C2 MXene interlayer

Ti3C2 MXene (MX) was introduced as the interlayer between the Cu film and Sn-3.0Ag-0.5Cu (SAC) solder to inhibit the overgrowth of intermetallic compounds (IMCs) at the bonding interface of Cu and SAC solder. The Cu-MX-SAC bonding was fabricated at 160 °C for 6 mins under a load of 10 MPa. Compared with Cu-SAC bonding, after 72 h aging, the average thickness of the IMCs layer in the Cu-MX-SAC structure is about 47 % thinner. As aging time increases, the diffusion rate of Cu atoms is limited due to the introduction of MXene interlayer, and the growth of IMCs in the Cu-MX-SAC structure is controlled by volume diffusion. For the Cu-MX-SAC solder bonding, after prolonged aging, the shear strength increases, and contact resistance at the bonding interface is almost no change compared with Cu-SAC solder bonding.

In-situ grown ternary metal hydroxides@3D oriented crumpled V2C MXene sheets for improved electrocatalytic oxygen evolution reaction

High valence multi transition metal hydroxides are greatly enriched with OER redox active sites due to strong synergy of heteroatomic nuclei. The efficiency of these redox active sites could be efficiently improved by coupling with highly conductive substrate. The advanced three-dimensional (3D) architecture and hydrophilic terminal functionalities of MXene (MX) considerably enhance the maximum utilization rate of anchored redox active sites by triggering the direct growth of these at MX substrate. Here-in, the freeze-dried 3D network of crumpled Vanadium-Carbide (V2C) MX sheets regulates the crystallization of in-situ grown NiFeCr multi transition metal hydroxides on MX scaffold through co-precipitation process. The XPS results suggest a synergistic chemical interaction of 3D MX scaffold with NiFeCr that modifies the electronic structure of the composite ensuring reduced charge transfer resistance. Besides, as found in FESEM morphological investigation, the well-dispersed NiFeCr multi-transition metal hydroxides are immobilized on open pores like structure of V2C-MX facilitate thoroughly accessible active sites. As a result, the NiFeCr@3D V2C-MX composite has shown an excellent electrocatalytic activity with an overpotential of 410 mV at a current density of 200 mA cm−2, Tafel slope of 100 mV dec in 1M KOH. Besides, the significant interaction between metallic centers and MXene support prevent detachment or agglomeration of active centers providing maximum interaction with the electrolytic ions, quick ionic OH− transportation, speedy and stable electron transfer channels thus ensure the long-term stability of NV-5MX during 53 h continuous operation of OER. Furthermore, we have utilized a more accurate value of half-cell standard reduction potential of the Hg/HgO electrode in the Nernst equation to represent all test voltages and to determine the overpotential values. In essence, this study features a facile approach for the confined growth of multi transition metal hydroxides in the presence of morphologically unique 3D crumpled V2C MXene architectures. Consequently, the increased OER reaction kinetics and improved stability of the synthesized composites are potentially due to synergistic interplay between well dispersed active sites and the conductive substrate.

Controlling electrospun nanofibers surface morphology using relative humidity for enhancing triboelectric nanogenerator performance

We employ an electrospinning technique to precisely modulate nanofibers diameter by varying humidity, impacting surface morphology, roughness and frictional contact-area of triboelectric materials. This leads to an augmentation of surface charge density, promoting generation of surface charges on triboelectric materials. MXene (MX) and cellulose acetate (CA) form an effective pairing, with optimized sample CA-40_MX-40 at 40 % RH displaying five-fold increase in voltage compared to CA-20_MX-20. This sample achieves a peak power density of 2351.1 mW/m2 at 106 Ω, capable of powering LEDs. These findings introduce a viable fabrication technique to manipulate surface roughness, promising significant avenue for sustainable high-performance TENGs.

Elevating energy storage performance of bismuth antimonate coupled with MXene and graphitic nanofibers in advanced supercapacitors

Improving the electrochemical performance of metal oxide-based materials for energy storage devices often involves employing key strategies, including the deliberate modification of composition through composite formation and the application of structural engineering techniques. Herein, we have synthesized bismuth antimonate (BiSbO4) and ternary structure is constructed by integrating Graphitic Nanofiber (GNF) and MXene (MX) via a facile hydrothermal method. The synergistic effect of the well-defined structure, coupled with the excellent electrical conductivity facilitated by the MXene and GNF networks, significantly contributes to the outstanding energy and power density. The unblocked ion and electron channels within its hierarchical structure enhances the material's performance as a battery-type cathode for supercapacitors. This work reports a notable specific capacitance of 819 F g−1 at 1 A g−1 and an impressive durability, with 94% capacity retention after 5000 charge/discharge cycles in a three-electrode system. Furthermore, an asymmetric supercapacitor device BSO–GF–MX‖AC is fabricated with activated carbon as negative electrode, which delivered superior energy density 46 Wh kg−1 at power density 750 W kg−1 and retains 90.6% of initial capacitance. This study provides a promising strategy for fabricating ternary composite-based electrodes, offering a pathway to assemble high-performance and cost-effective energy storage devices.

Highly thermally conductive and EMI shielding composite fabricated via free‐radical polymerization of poly acrylic acid assisted by expanded graphite with liquid metal‐grafted MXene

AbstractPolymer composites offer numerous benefits, including low cost, easy processability, and diverse applications. In this work, we fabricated a composite material with high thermal conductivity and electromagnetic interference (EMI) shielding performance using EGaIn, a liquid metal (referred to as LM in this paper), MXene (MX), and expanded graphite (EG) as multifunctional fillers, along with polyacrylic acid (PAA). LM was used to exfoliate MX under the effect of shear force, which not only reduced the size of MX but also increased the aspect ratio of the 2D‐structured MX. MX was filled into the pores of EG to make a heat transfer path, thereby enhancing its thermal conductivity, mechanical properties, and EMI SE properties. LM served as the initiator of free‐radical polymerization to convert acrylic acid (AA) into PAA. Finally, the LMMX/EG/PAA composite was hot‐pressed to make the heat‐transfer path dense. As a result, the LMMX/EG/PAA composite exhibited a thermal conductivity of 1.88 W/m·K and an EMI shielding effect of 52 dB.

Preparation of cyclodextrin polymer-functionalized polyaniline/MXene composites for high-performance supercapacitor.

Controlled aggregation is of great significance in designing nanodevices with high electrochemical performance. In this study, an in situ aggregation strategy with cyclodextrin polymer (CDP) was employed to prepare polyaniline (PANI)/MXene (MX) composites. MXene served as a two-dimensional structure template. Due to supramolecular interactions, CDP could be controllably modified with PANI layers, effectively preventing the self-polymerization of PANI. As a result, this integration facilitated a more uniform growth of PANI on MXene and further improved the capacitance performance of CDP-MX/PA. In a three-electrode system, the specific capacitance of MX/PA at 1 A g-1 was 460.8 F g-1, which increased to 523.8 F g-1 after CDP-induced growth. CDP-MX/PA exhibited a high energy density of 27.7 W h kg-1 at a power density of 700 W kg-1. This suggests that the synthetic strategy employed in this study holds promise in providing robust support for the preparation of high-performance energy-storage device.

Engineering Photo-Cross-Linkable MXene-Based Hydrogels: Durable Conductive Biomaterials for Electroactive Tissues and Interfaces.

Light-cured conductive hydrogels have attracted immense interest in the regeneration of electroactive tissues and bioelectronic interfaces. Despite the unique properties of MXene (MX), its light-blocking effect in the range of 300-600 nm hinders the efficient cross-linking of photocurable hydrogels. In this study, we investigated the photo-cross-linking process of MX-gelatin methacrylate (GelMa) composites with different types of photoinitiators and MX concentrations to prepare biocompatible, injectable, conductive, and photocurable composite hydrogels. The examined photoinitiators were Eosin Y, Irgacure 2959 (Type I), and lithium phenyl-2,4,6-trimethylbenzoyl phosphinate (Type II). The light-blocking effect of MX strongly affected the thickness, pore structure, swelling ratio, degradation, and mechanical properties of the light-cured hydrogels. Uniform distribution of MX in the hydrogel matrix was achieved at concentrations up to 0.04 wt % but the film thickness and curing times varied depending on the type of photoinitiator. It was feasible to prepare thin films (0.5 mm) by employing Type I photoinitiators under a relatively long light irradiation (4-5 min) while thick films with centimeter sizes could be rapidly cured by using Type II photoinitiator (<60 s). The mechanical properties, including elastic modulus, toughness, and stress to break for the Type II hydrogels were significantly superior (up to 300%) to those of Type I hydrogels depending on the MX concentration. The swelling ratio was also remarkably higher (648-1274%). A conductivity of about 1 mS/cm was attained at 0.1 mg/mL MX for the composite hydrogel cured by the Type I photoinitiator. In vitro cytocompatibility assays determined that the hydrogels promoted cell viability, metabolic activity, and robust proliferation of C2C12 myoblasts, which indicated their potential to support muscle cell growth during myogenesis. The developed photocurable GelMa-MX hydrogels have the potential to serve as bioactive and conductive scaffolds to modulate cellular functions and for tissue-device interfacing.

Boosted Charge-Transfer behavior for ultrafast Zn storage by constructing intrinsic heterojunction of ammonium vanadate nanoribbons coupling with interlaminar MXenes nanosheets

Ammonium vanadate (NH4V4O10, NHVO) is one of the most promising cathode materials for aqueous zinc-ion batteries (ZIBs) owing to its inherent large interplanar spacing, highly reversible electrochemical reaction mechanism and admirable specific capacity. However, the fragile interlayer structure and sluggish electron transport behavior generally cause tardy electrochemical reaction kinetics and result in poor cycling stability and rate capabilities. In this work, a novel intrinsic heterojunction cathode (NHVO@MX) of NHVO nanoribbons coupling with inserted Mxenes (MX) nanosheets is rationally constructed on a flexible carbon cloth substrate for wearable ZIB applications. The intercalated MX nanosheets not only serve as the spacer to isolate the NHVO interlayers as well as efficiently accelerate electron and ion transport behaviors, hence preserving the numerous exposed active areas required for rich and rapid Zn storage. Most impressively, it presents the lowest charge-transfer barrier among all the reported vanadate-based materials induced by the interlaminar MX nanosheets, demonstrated by both experimental measurement and theoretical calculation. As a result, the as-prepared heterojunction cathode delivers high specific capacity of 437 mAh·g−1, excellent rate capability and ultralong cycling life (over 2000 cycles). Therefore, manufacturing the heterojunction laminar cathode with incorporated MX can be considered a prospective strategy for next-generation advanced ZIBs.

MAX, MXene, or MX: What Are They and Which One Is Better?

The fast ever-growing interest in transition metal carbonitrides (MXenes) for energy and catalysis is undermined by the undesirable multi-surficial terminations, which severely limit their applications. In contrast, considering the intriguing and tunable electronic structure, rich surface active sites, and high thermal durability, termination-free MXene (MX) hosts a huge possibility for catalysis. As such, recent advances in the evolution from MAX to MXene, and then to MX are overviewed and compared briefly, before concentrating on the unique future of MX in multi-heterogeneous catalysis. This work also looks beyond the fundamental properties of MX and discusses the potential of such materials for applications in multi-electron redox reactions. It is convinced that the potential success of MX in future catalysis is promising. Further extension toward high entropy and single-atom modifications will consolidate the leading position of MX in catalysis.

Highly Permeable Sulfonated Polydopamine Integrated MXene Membranes for Efficient Surfactant-Stabilized Oil-in-Water Separation.

MXene is an incredibly promising two-dimensional material with immense potential to serve as a high-performing separating or barrier layer to develop advanced membranes. Despite the significant progress made in MXene membranes, two major challenges still exist: (i) effectively stacking MXene nanosheets into defect-free membranes and (ii) the high fouling tendency of MXene-based membranes. To address these issues, we employed sulfonated polydopamine (SPD), which simultaneously serves as a binding agent to promote the compact assembling of Ti3C2Tx MXenes (MX) nanosheets and improves the antifouling properties of the resulting sulfonated polydopamine-functionalized MX (SPDMX) membranes. The SPDMX membrane was tested for challenging surfactant-stabilized oil-in-water separation with an impressive efficiency of 98%. Moreover, an ultrahigh permeability of 1620 LMH/bar was also achieved. The sulfonation of PD helps in improving the antifouling characteristics of SPDMX by developing a strong hydration layer and enhancing the oleophobicity of the membrane. The underwater SPDMX membrane appeared superoleophobic with an oil contact angle of 153°, whereas the ceramic membrane exhibited an oil contact angle of 137°. The SPDMX membranes showed an improved flux recovery (31%) compared to the nonsulfonated counterpart. This work highlights the appropriate functionalization of MXene as a promising approach to developing MXene membranes with high permeation flux and better antifouling characteristics for oily wastewater treatment.

Enhanced termination of zinc and cadmium ions from wastewater employing plain and chitosan-modified mxenes: synthesis, characterization, and adsorption performance

Zinc and cadmium pollutants cause a significant environmental effect that cannot be ignored. Due to their considerable amount in an aqueous environment, industries are seeking suitable adsorbents that are environmentally friendly and inexpensive for removing metals from wastewater before disposing of them in surface waters. This research employed original MXene (MX) and chitosan-modified MXene (CSMX) to extract zinc (Zn(II)) and cadmium (Cd(II)) metal ions from water-based solutions. The composite material produced was analyzed using techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The effects of contact duration, pH of the solution, and initial concentration of metal ions on the adsorption process of Zn(II) and Cd(II) onto both MX and CSMX composites were investigated. MX and prepared CSMX composite presented a high adsorption capacity for both studied heavy metals, which were 91.55 and 73.82 mg/g for Zn(II) and Cd(II) onto MX, 106.84 and 93.07 mg/g for Cd(II) and Zn(II) onto CSMX composite, respectively. Furthermore, the maximum competitive adsorption capacities for Zn(II) onto MX and CSMX composites are 77.29 and 93.47 mg/g, and for are Cd(II) 60.30 and 79.66 mg/g, respectively. Hence, the removal capacities for both single and competitive metal ions were superior to CSMX composite. However, the adsorption capacities after five successive regeneration sequences were only dropped by 13.2% for Zn(II) and 17.4% for Cd(II) onto the CSMX composite compared to the first cycle. These results confirm that both metals could be efficiently terminated from wastewater, which makes the prepared CSMX composite a favorable candidate adsorbent in practical applications.

Swelling-induced deformation electronic signal of MXene hydrogel for cancer detection

A reactive-oxygen-species-responsive (ROS-responsive) conductive hydrogel sensor is developed for cancer detection using degradable TiO2/MXene-integrated polymer dots (PD-MX/TiO2) that could generate heat and control conductivity. During contact between hydrogel and H2O2, the loaded MXene (MX) is oxidized, resulting in formation of TiO2 and a change in MX dimensional conformation, conductivity, and light-to-heat generation. Interestingly, the presence of visible light accelerates this process owing to photocatalytic properties of TiO2. Furthermore, the resistivity of hydrogel changes from 27.5 to 72.0 and 48.1 kΩ after H2O2 treatment and visible-light irradiation, respectively. The hydrogel exhibits a distinct resistance signal during its deformation at x, y, and z axes of the three-dimensional axis, with a mean signal of 22.2%, 15.3%, and 7.2%, respectively. The in vitro analysis of cancer cells displays a distinguishable detection result for CHO-K1, HeLa, and PC-3, exhibiting electrical resistance of 62.9, 123.8, and 121.7 kΩ, respectively. Furthermore, light-to-heat conversion in the PD-MX/TiO2 Hydrogel decreases to 9.7 °C (HeLa) and 9.7 °C (PC-3) compare to that of the normal cells (17.3 °C). It is demonstrated that the hydrogel could be used for direct diagnosis when linked with a wireless apparatus, thus facilitating accurate and rapid evaluation of cancer microenvironment.

Influence of binder and solvents on the electrochemical performance of screen-printed MXene electrodes

The present study is concerned with the use of binders and solvents in fabricating MXene electrodes, which play a vital role in influencing supercapacitive performance. The electrodes were prepared by screen printing MXene on flexible stainless steel mesh (FSSM) substrate, which is a straightforward, efficient, and cost-effective approach. The influence of binder and solvent on the electrochemical performance was investigated by fabricating them with and without using a binder i.e. only organic solvents ethanol and n-methyl-2-pyrrolidone (NMP). The electrode with the binder is abbreviated as MX-B@FSSM and was prepared with the composition of acetylene black conducting material, polyvinylidene fluoride (PVDF) polymer binder, and MXene (MX) as active material. While electrodes without binder were prepared by a slurry of MXene using organic solvent ethanol and NMP and are abbreviated as MX-E@FSSM and MX-N@FSSM, respectively. The electrochemical performance of these MX-B@FSSM, MX-E@FSSM and MX-N@FSSM electrodes was examined by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy. The influence of the binder altered the electrochemical performance. The samples MX-B@FSSM, MX-E@FSSM, and MX-N@FSSM show the specific capacitance of 35.60, 490.80, and 339.6 F g−1, respectively at 2 mA cm−2 current density. The MX-E@FSSM electrode exhibited marginally the best electrochemical performance. Furthermore, MnO2/MXene//MX-E asymmetric supercapacitor device exhibits 252 F g−1 specific capacitance at 35.2 Wh kg−1 energy density demonstrating a promising electrode for the supercapacitor.

Sodium-alginate-laden MXene and MOF systems and their composite hydrogel beads for batch and fixed-bed adsorption of naproxen with electrochemical regeneration

Sodium alginate (SA)-laden two-dimensional (2D) Ti3C2Tx MXene (MX) and MIL-101(Fe) (a type of metal–organic framework (MOF)) composites were prepared and used for the removal of naproxen (NPX), following the adsorption and electrochemical regeneration processes. The fixed-bed adsorption column studies were also conducted to study the process of removal of NPX by hydrogels. The number of interactions via which the MX-embedded SA (MX@SA) could adsorb NPX was higher than the number of pathways associated with NPX adsorption on the MIL-101(Fe)-embedded SA (MIL-101(Fe)@SA), and the MX and MIL-101(Fe) composite embedded SA (MX/MIL-101(Fe)@SA). The optimum parameters for the electrochemical regeneration process were determined: charge passed and current density values were 169.3 C g−1 and 10 mA cm−2, respectively, for MX@SA, and the charge passed and current density values were 16.7 C g−1 and 5 mA cm−2, respectively, for both MIL-101(Fe)@SA and MX/MIL-101(Fe)@SA. These parameters enabled excellent regeneration, consistent over multiple adsorption and electrochemical regeneration cycles. The mechanism for the regeneration of the materials was proposed that the regeneration of MX@SA and MIL-101(Fe)@SA involved the indirect electrooxidation process in the presence of OH radicals, and the regeneration of MX/MIL-101(Fe)@SA involved the indirect oxidation process in the presence of active chlorine species.

Highly Conductive Cellulose Strain Sensor with Excellent Negative Resistance Variation and Joule Heating Property

The rational design of a wearable strain sensor with heating property has attracted great interest. In this study, a flexible conductivity hierarchical cellulose strain sensor (MX@Ag@CY) with heating property was fabricated via in situ formation of silver nanoparticles (Ags) on cotton yarn (CY) and subsequent dip-coating with MXene (MX). Ags coupled with MX coating endowed the cotton yarn with a high conductivity, where the resistance of the optimized composite MX@Ag0.47@CY was about 22 Ω/cm. Compared with the previously reported strain sensors, the woven MX@Ag0.47@CY fabric strain sensor showed a distinctive negative resistance variation, wherein it showed an enhanced conductivity with the increased strain owing to its unique architecture. The woven MX@Ag0.47@CY fabric strain sensor exhibited a repeatable response and displayed long-term stability in the strain range of 0–55%. In addition, the strain sensor demonstrated great detectability on large-scale human movements when directly attached to the elbow, wrist, or knee. Furthermore, when MX@Ag0.47@CY served as a heater (at an applied DC voltage of 6 V), it presented high heating temperature (92.4 °C), homogeneous temperature distribution, low operation voltage (1–6 V), and excellent thermal stability even under strain.

Comparative radiosensitization efficiency assessment of graphene oxide and Ti3C2 MXene as 2D carbon-based nanoparticles against breast cancer cells: characterization, toxicity and mechanisms

The efficacy of two carbon-based nanomaterials, graphene oxide (GO) and Ti3C2 MXene (MX), on the radiosensitivity of the breast cancer cells (BCCs) was investigated using clinical x-ray irradiation. The prepared GO and MX nanoparticles (NPs) were firstly characterized utilizing Fourier transform infrared, ultraviolet–visible, atomic force microscopy and transmission electron microscopy techniques and subsequently assessed in terms of their radiobiological properties. The results of the cell toxicity assay indicated that neither NPs exhibited significant cytotoxicity after 48 h incubation with BCC up to 50 µg ml−1 concentration without irradiation. The cell internalization results showed an approximately equivalent cellular uptake for both NPs after 6 h incubation with BCC. Our comparative studies with radiotherapy demonstrated that both NPs substantially increased cell proliferation inhibition and cell apoptosis of BCC under x-ray irradiation when compared to BCC treated with irradiation alone. Additionally, the 2ʹ,7ʹ-dichlorofluorescin diacetate flow cytometry results and fluorescent microscopy images revealed that both NPs remarkably increased the level of intracellular reactive oxygen species (ROS) generation in BCC under x-ray irradiation. The MX nanosheets exhibited superior radiosensitization efficiency than GO under x-ray irradiation due to its higher level of intracellular ROS generation (MX = 75.2% and GO = 65.2%). Clonogenic cell survival assay and extracted radiobiological parameters revealed that both NPs in combination with x-ray irradiation induced more lethal damage and less sublethal damage to BCC. Generally, the obtained results demonstrate that the MX NPs, as a stronger radiosensitizer than GO, could be a promising candidate for enhancing the effectiveness of radiotherapy in breast cancer treatment.

A facile method for synthesizing MOF derived ZnCo2O4 particles on MXene nanosheets as a novel anode material for high performance hybrid supercapacitors

MXene (MX) is a capable material for future generation supercapacitor devices. But, the attraction between active functional groups and hydrogen bonds on the surface of MX make the interlayer agglomerate obviously. In this work, we present a ZnCo-MOF (ZCM) derived ZnCo2O4 (ZCO) particles to adsorb on the (MX) nanosheets and form a mesoporous structure which may provide the flexible ion diffusion pathways. The as obtained MXene@ZnCo2O4 (MX@ZCO) composite is investigated using XRD, XPS, HRTEM, FESEM, and nitrogen adsorption and desorption isotherm analysis. The ZCO particles not only provide activation sites for free movement of charges but also help to avoid the agglomeration of MX nanosheets. Benefitted from this novel composite structure, MX@ZCO holds a great specific capacity of 260 mAh g−1 at the current density of 1 mA g−1. Further, the MX@ZCO electrode exhibits a good cyclic stability of 78.9% even after 5000 cycles at the current density of 10 mA g−1, which can be ascribed to excellent electronic conductivity and short ion transport path. Furthermore, the fabricated aqueous HSC device with MX@ZCO/NF as a positive electrode and AC/NF as a negative electrode revealed a high energy density of 63.8 Wh kg−1 at power density of 3512.2 W kg−1, along with the outstanding capacitance retention of 91.3% even after 15,000 GCD cycles. This work offers an excellent approach for the preparation of MX and ZCO composite material as an electrode for hybrid supercapacitors.