MXene Nanosheets Research Articles

InVO4-Decorated Ti3C2 MXene for Efficient Photocatalytic Hydrogen Evolution.

The generation of hydrogen through photocatalysis is a fascinating technology for addressing environmental concerns and the energy crisis. Nevertheless, the quest for cost-effective, stable, and efficient photocatalysts in the realm of energy conversion remains a significant challenge. Herein, we designed novel InVO4/Ti3C2 MXene (IVTC) heterostructures by employing acid etching to produce Ti3C2 MXene with an accordion-like morphology, using the hydrothermal technique for the production of orthorhombic InVO4 nanoparticles (NPs), and integrating them through a self-assembly approach. Both field-emission scanning electron microscopy and HRTEM analyses revealed a consistent distribution of InVO4 NPs with an average size of 43.4 nm on both surfaces and between the sheets of Ti3C2 MXene. The intimate interface between the Ti3C2 MXene nanosheet and InVO4 suppressed carrier recombination and promoted charge transfer, thereby boosting photocatalytic H2 production. Under visible light exposure, the rate of hydrogen evolution is enhanced in IVTC heterostructures containing an optimized 10% loading of InVO4, exhibiting over a 3-fold increase compared to pristine InVO4 NPs, maintaining efficiency across four cycles. This research presents a promising method for designing and creating high-efficiency heterostructures possessing excellent visible-light-driven photocatalytic activity for H2 evolution.

In situ grown heterostructures based on MAX-derived TaO2F nanorod and TaC (MXene) nanosheet for high-performance hybrid supercapacitors

Two-dimensional MXene-based interface heterostructures have an undeniable position in the energy storage systems, particularly supercapacitors, due to their unique microstructure and electrochemical properties. However, the selection of materials in heterogeneous structures and the assembly strategy often have often have a significant impact on the properties of heterogeneous structures. This study proposes a in situ grown strategy for constructing TaO2F@TaC nano-heterostructures consisting of one-dimensional TaO2F nanorods combined with two-dimensional TaC nanosheets derived from the precursor MAX phase. The complex etching and growth mechanism from MAX to 1D/2D TaO2F@TaC is reasonably inferred. The construction of TaO2F@TaC nano-heterostructures effectively addresses the issue of MXene to restack and improves the poor conductivity of TaO2F. Density functional theory (DFT) calculations validated the electronic structure and charge distribution at the heterostructure interface, demonstrating its capability for electron conduction and ion transport. Moreover, the hybrid supercapacitor (HSC) based on TaO2F@TaC exhibited superior energy density (153.4 μWh cm−2 at a power density of 222.2 μW cm−2) and excellent cycle stability. The prepared quasi-solid-state supercapacitor (QSC) also shows a capacitance of 457.4 mF cm−2, and retains 99.38 % capacity after 8200 cycles. This work innovatively bypasses the multi-step process of preparing MXene heterostructures and provides a new approach for developing MXene-based electrode materials to enhance the performance of hybrid supercapacitors.

Boron-Doped Ti3C2Tx MXene for Effective and Durable High-Current-Density Ammonia Synthesis.

Ammonia (NH3) synthesis via the nitrate reduction reaction (NO3RR) offers a competitive strategy for nitrogen cycling and carbon neutrality; however, this is hindered by the poor NO3RR performance under high current density. Herein, it is shown that boron-doped Ti3C2Tx MXene nanosheets can highly efficiently catalyze the conversion of NO3RR-to-NH3 at ambient conditions, showing a maximal NH3 Faradic efficiency of 91% with a peak yield rate of 26.2mgh-1mgcat. -1, and robust durability over ten consecutive cycles, all of them are comparable to the best-reported results and exceed those of pristine Ti3C2Tx MXene. More importantly, when tested in a flow cell, the designed catalyst delivers a current density of ‒1000mAcm-2 at a low potential of ‒1.18V versus the reversible hydrogen electrode and maintains a high NH3 selectivity over a wide current density range. Besides, a Zn-nitrate battery with the catalyst as the cathode is assembled, which achieves a power density of 5.24mWcm-2 and a yield rate of 1.15mgh-1mgcat. -1. Theoretical simulations further demonstrate that the boron dopants can optimize the adsorption and activation of NO3RR intermediates, and reduce the potential-determining step barrier, thus leading to an enhanced NH3 selectivity.

Stabilizing atomic Co on 2D ordered mesoporous carbon sandwiched MXene for peroxymonosulfate activation: Enhanced performance and electron-transfer mechanism

In this study, a dual-carrier catalyst is designed for efficient Fenton-like catalysis following non-radical electron-transfer process (ETP). By using 2D mesoporous carbon sandwiched MXene (MCSMx) nanosheets as dual functional substrates, Co single atoms (Co-SA) were confined within MCSMx (CoSA/MCSMx), in which the coordinated Co-N4 sites in highly ordered mesoporous channels (∼10 nm) facilitated the adsorption of peroxymonosulfate (PMS), while the excellent conductivity of MXene as the substrate enhanced the transport of electron. The unique design of Co-SA anchored on dual carriers endows the CoSA/MCSMx with excellent PMS adsorption and rapid electron transfer, achieved nearly 100 % ETP pathway for bisphenol A (BPA) removal and highly selective degradation towards electron-rich pollutants. Moreover, the ETP-induced polymerization transfer reaction of BPA was discovered in the catalytic system, resulting in total organic carbon (TOC) removal ratios of up to 72 %. This work provides new insights into the rational design ETP-based systems for the efficient removal of organic pollutants.

Highly conductive Ti3C2 MXene-supported CoAl-layered double hydroxide nanosheets for ultrasensitive electrochemical detection of organophosphate pesticide fenitrothion.

A novel electrochemical method is presented for ultrasensitive detection of the organophosphate pesticide (OPP) fenitrothion by using Ti3C2 MXene/CoAl-LDH nanocomposite as the electrode modifier. The Ti3C2 MXene/CoAl-LDH nanocomposite is synthesized by growing CoAl-LDH in situ on MXene nanosheets. The combination of two ultrathin 2D materials provides more active sites, larger specific surface area, superior adsorption properties, and better electrical conductivity, which leads to rapid electron-transfer and mass-transfer between the substrate electrode and analytes when it is acted as the electrochemical sensing material. In addition, through the chelation of phosphate groups with the Ti defect sites enriched in MXene, OPP is adsorbed on the electrode. Consequently, the corresponding modified electrode gives rise to a wide linear response range of 0.03 ~ 120μmol/L for the differential pulse voltammetry detection of fenitrothion with a low detection limit of 5.8nmol/L (3σ). The method offers good repeatability, stability, selectivity, and practicability for real samples. This strategy provides a reference platform for the electrochemical monitoring of trace OPPs residue by using MXene/LDH-based nanocomposites.

Defects introducing and heterostructures engineering synergistically constructing active sites for achieving stable and fast ion transport in sodium-ion batteries

Bronze phase TiO2 (TiO2(B)) has attracted significant interest as potential anode materials for sodium-ion batteries (SIBs) due to its distinctive open tunnel structure, offering abundant insertion sites for Na+-ions. However, the practical application has been hindered by its poor electrical conductivity and insufficient Na+ diffusion kinetics. Herein, we propose a novel strategy that integrates defect introducing and heterostructures engineering to enhance the performance of TiO2(B) anode. Specifically, we aim to induce oxygen vacancies (OVs) into TiO2(B) through N-doping and in-situ growth on MXenes nanosheets, thereby fabricating N-doped TiO2(B)/MXenes (N-TiO-MX) heterostructures. This strategy leverages the synergistic effects of OVs and N-atoms, along with the formation of heterointerfaces, to effectively reduce the bandgap, increase the number of Na+-ion storage sites, and shorten ion diffusion distances. The robust coupling between TiO2(B) and MXenes ensures the structural integrity of N-TiO-MX heterostructures. Consequently, the N-TiO-MX exhibits a high specific capacity of 211.3 mAh g−1 at 0.1 A g−1 after 400 cycles and superior cycling stability with 163.1 mAh g−1 after 1000 cycles at 1.0 A g−1. The study provides unique insights for designing heterostructure materials to achieve high capacity and excellent fast-charging capability.

Shear‐Rheological‐Assisted MXene Dispersion in Epoxy Resin for Efficient Electromagnetic Absorption

AbstractMXenes, a burgeoning family of 2D materials with high conductivity and large specific surface area, are ideal electromagnetic absorbing materials. However, the ample polar functional groups lead to poor dispersion in the non‐polar matrix, limiting its application in non‐polar‐polymer‐based composites. With the help of the shear rheological properties of SiO2, the conflict is resolved here by directly dispersing MXene aqueous dispersion into the non‐polar resin. Water is locked dynamically through SiO2 nanoparticles among the MXene@SiO2 nanosheets, suppressing MXene's self‐restacking and aggregation in the resin matrix. Therefore, the fabrication of uniform MXene/non‐polar polymer composites is achieved. Meanwhile, this method allows different nanoparticles (Fe3O4, etc.) to be evenly dispersed among the MXene nanosheets to further improve the composites' electromagnetic parameters. The as‐prepared composites achieve remarkable absorbing performance with a low MXene concentration (≤5 wt.‰). The SMEP‐h achieves the maximum reflection loss value of over 60 dB at 12 GHz (at the thickness of 2.15 mm), and the SMEP‐F possesses a broad effective absorbing bandwidth of over 6.18 GHz (at the thickness of 1.75 mm). The shear‐rheological‐assisted MXene dispersion method in the non‐polar matrix paves an avenue for the design of outstanding MXene‐based electromagnetic absorbing composites.

0D/2D CuCo2O4/Ti3C2 hybrid nanostructure as anodic nanocatalyst for direct power generation in fuel cells: Investigating annealing temperature and synergetic effect

In the present work, CuCo2O4 nanoparticles, CuCo2O4/Ti3C2, CuO/Ti3C2, and Co3O4/Ti3C2 hybrid nanostructures were synthesized. Various characterization and electrochemical methods were used to investigate the effect of annealing temperature on the catalytic properties. Based on the results, the hybrid of Ti3C2 MXene nanosheets with CuCo2O4 nanoparticles improved the active surface area and kinetics of electron transfer. The annealing temperature through affecting the crystalline structure, leads to a change in the electrocatalytic performance of nanostructures. On the other, the CuCo2O4/Ti3C2 hybrid nanostructure shows better performance than the single metal oxides (CuO and Co3O4) due to the synergistic effect of Cu and Co. Therefore, CuCo2O4/Ti3C2(200) hybrid nanostructure can be used as an efficient nanocatalyst in the electrooxidation process of alcohols in fuel cells due to its higher electrochemical surface area, higher current density (42 mA cm−2) and better stability (83.3 %) compared to other structures.

Potassium Ion-Assisted Self-Assembled MXene-K-CNT Composite as High-Quality Sulfur-Loaded Hosts for Lithium-Sulfur Batteries.

We successfully synthesized hybrid MXene-K-CNT composites composed of alkalized two-dimensional (2D) metal carbide and carbon nanotubes (CNTs), which were employed as host materials for lithium-sulfur (Li-S) battery cathodes. The unique three-dimensional (3D) intercalated structure through electrostatic interactions by K+ ions in conjunction with the scaffolding effect provided by CNTs effectively inhibited the self-stacking of MXene nanosheets, resulting in an enhanced specific surface area (SSA) and ion transport capability. Moreover, the addition of CNTs and in situ-grown TiO2 considerably improved the conductivity of the cathode material. K+ ion etching created a more hierarchical porous structure in MXene, which further enhanced the SSA. The 3D framework effectively confined S embedded between nanosheet layers and suppressed volume changes of the cathode composite during charging/discharging processes. This combination of CNTs and alkalized nanosheets functioned as a physical and chemical dual adsorption system for lithium polysulfides (LiPSs). When subjected to a high current at 1.0C, S@MXene-K-0.5CNT with S-loaded of 1.2 mg cm-2 had an initial capacity of 919.6 mAh g-1 and capacity decay rate of merely 0.052% per cycle after 1000 cycles. Moreover, S@MXene-K-0.5CNT maintained good cycling stability even at a high current of up to 5.0C. These impressive results highlight the potential of alkalized 2D MXene nanosheets intercalated with CNTs as highly promising cathode materials for Li-S batteries. The study findings also have prospects for the development of next-generation Li-S batteries with high energy density and prolonged lifespans.

Harnessing Holey MXene/Graphene Oxide Heterostructure to Maximize Ion Channels in Lamellar Film for High-Performance Capacitive Deionization.

2D Ti3C2Tx MXene-based film electrodes with metallic conductivity and high pseudo-capacitance are of considerable interest in cutting-edge research of capacitive deionization (CDI). Further advancement in practical use is however impeded by their intrinsic limitations, e.g., tortuous ion diffusion pathway of layered stacking, vulnerable chemical stability, and swelling-prone nature of hydrophilic MXene nanosheet in aqueous environment. Herein, a nanoporous 2D/2D heterostructure strategy is established to leverage both merits of holey MXene (HMX) and holey graphene oxide (HGO) nanosheets, which optimize ion transport shortcuts, alleviate common restacking issues, and improve film's mechanical and chemical stability. In this design, the nanosized in-plane holes in both handpicked building blocks build up ion diffusion shortcuts in the composite laminates to accelerate the transport and storage of ions. As a direct outcome, the HMX/rHGO films exhibit remarkable desalination capacity of 57.91mg g-1 and long-term stability in 500mgL-1 NaCl solution at 1.2V. Moreover, molecular dynamics simulations and ex situ wide angle X-ray scattering jointly demonstrate that the conductive 2D/2D networks and ultra-short ion diffusion channels play critical roles in the ion intercalation/deintercalation process of HMX/rHGO films. The study paves an alternative design concept of freestanding CDI electrodes with superior ion transport efficiency.

Stretchable Piezoresistive Pressure Sensor Array with Sophisticated Sensitivity, Strain-Insensitivity, and Reproducibility.

This study delves into the development of a novel 10 by 10 sensor array featuring 100 pressure sensor pixels, achieving remarkable sensitivity up to 888.79kPa-1, through the innovative design of sensor structure. The critical challenge of strain sensitivity inherent is addressed in stretchable piezoresistive pressure sensors, a domain that has seen significant interest due to their potential for practical applications. This approach involves synthesizing and electrospinning polybutadiene-urethane (PBU), a reversible cross-linking polymer, subsequently coated with MXene nanosheets to create a conductive fabric. This fabrication technique strategically enhances sensor sensitivity by minimizing initial current values and incorporating semi-cylindrical electrodes with Ag nanowires (AgNWs) selectively coated for optimal conductivity. The application of a pre-strain method to electrode construction ensures strain immunity, preserving the sensor's electrical properties under expansion. The sensor array demonstrated remarkable sensitivity by consistently detecting even subtle airflow from an air gun in a wind sensing test, while a novel deep learning methodology significantly enhanced the long-term sensing accuracy of polymer-based stretchable mechanical sensors, marking a major advancement in sensor technology. This research presents a significant step forward in enhancing the reliability and performance of stretchable piezoresistive pressure sensors, offering a comprehensive solution to their current limitations.

Observation of band gap enhancement and green–yellow emission of thermally stable MXene nanosheets

The known two-dimensional material MXene comprises carbide, carbonitride, and nitride. MXene processes are hydrophilic in addition to high electrical conductivity, thermal conductivity, flexibility, Young’s modulus, fracture toughness, etc. The present work synthesizes a thermodynamically stable titanium-based MXene using HF etchant at low temperatures. Also, the paper manifests how the functional group affects the conducting nature of MXene. The structural properties of synthesized MXene are examined using XRD patterns, where the shift in the (002) arises. This indicates the successful formation of MXene. The electron microscopy of MXene is done using FESEM and HRTEM, which shows the layered structure of MXene thickness ranging from 5nm to 8nm along with EDX spectra showing the pure form of MXene with F, O and OH as the termination groups which is further confirmed by Raman spectroscopy and FTIR spectroscopy. The optical behavior is then examined using UV–Vis spectroscopy, and a large bandgap of symmetric MXene is observed, i.e., 1.1eV, due to the addition of a functional group at the surface of the MXene nanosheet. This demonstrates the semiconducting nature of MXene and the small particle size. Photoluminescence (PL) and Zeta-potential were also used to analyze the excellent stability of MXene after the material was confirmed, and the results indicate the green–yellow emission of the material. This prudent the thermally-stable MXene over the period both before and after 20 days. The electrical properties were then examined through current–voltage measurement, which predict the semiconducting nature of MXene. Consequently, the material can be used in numerous energy and optoelectronic applications.

Regulating integral alignment of magnetic MXene nanosheets in layered composites to achieve high-effective electromagnetic wave absorption

The integral structure design is equally crucial to the regulation of electromagnetic components in microwave absorbing materials. In this work, magnetic MXene/polyvinylidene fluoride composites with integral nacre-like structure were prepared by successive hot-pressing process to realize the layered arrangement of Ni anchored MXene (Ni@MXene). The order degree of Ni@MXene from random to orientation can be adjusted by gradually changing compression ratio. Interestingly, increasing the orientation degree of Ni@MXene effectively improves the dielectric constant, minimal reflection loss (RLmin) and effective absorption bandwidth (EAB) of the layered composites. This is attributed to the improved loss ability by increasing the contact areas between Ni@MXene and vertically incident electromagnetic waves, inducing multiple scattering/reflection effect, and the formation of localized conductive pathways. As a result, the layered composite with optimal layered structure delivers the best electromagnetic microwave absorption performance with a RLmin of −69.8 dB and an EAB of 4.77 GHz. Besides, increasing the orientation degree can also optimize the mechanical properties of the layered composites, with the maximum tensile strength and toughness of 32.6 MPa and 115.0 MJ m−3, respectively. Therefore, this work proves the adjustability of absorption performance by changing the distribution of absorbents, and integrates the structure and function for microwave absorption materials.

High‐Performance Zn2+‐Crosslinked MXene Fibers for Versatile Flexible Electronics

AbstractThe advent of flexible electronics has prompted the development of functional fibers with superior mechanical and electrical properties. MXenes, a novel family of 2D functional materials, have a variety of potential applications in flexible electronics. Herein, wet‐spinning is employed to continuously assemble Ti3C2Tx MXene liquid crystals into macroscopic fibers. Meanwhile, Zn2+ is introduced into the fiber to eliminate the electrostatic repulsion between the MXene nanosheets and enhance interlayer interactions and sheet alignment. The as‐obtained MXene fibers have strong mechanical strength (150.7 MPa), high electrical conductivity (3637.9 S cm−1), and good flexibility that facilitates weaving and knotting, making them suitable for fabric‐like flexible devices. The sound pressure sensors are woven from MXene fibers, which feature quick response time (286 ms) and recovery time (642 ms), ultra‐high sensitivity (280.2 kPa−1), and a low detection limit (0.1 Pa). Sound detection and recording are achieved using this sensor. MXene fibers as wearable thermal management devices are also demonstrated, exhibiting fast Joule thermal responses and good cycling stability.

Platinum nanowires/MXene nanosheets/porous carbon ternary nanocomposites for in situ monitoring of dopamine released from neuronal cells

Dopamine is an important neurotransmitter in the body and closely related to many neurodegenerative diseases. Therefore, the detection of dopamine is of great significance for the diagnosis and treatment of diseases, screening of drugs and unraveling of relevant pathogenic mechanisms. However, the low concentration of dopamine in the body and the complexity of the matrix make the accurate detection of dopamine challenging. Herein, an electrochemical sensor is constructed based on ternary nanocomposites consisting of one-dimensional Pt nanowires, two-dimensional MXene nanosheets, and three-dimensional porous carbon. The Pt nanowires exhibit excellent catalytic activity due to the abundant grain boundaries and highly undercoordinated atoms; MXene nanosheets not only facilitate the growth of Pt nanowires, but also enhance the electrical conductivity and hydrophilicity; and the porous carbon helps induce significant adsorption of dopamine on the electrode surface. In electrochemical tests, the ternary nanocomposite-based sensor achieves an ultra-sensitive detection of dopamine (S/N = 3) with a low limit of detection (LOD) of 28 nM, satisfactory selectivity and excellent stability. Furthermore, the sensor can be used for the detection of dopamine in serum and in situ monitoring of dopamine release from PC12 cells. Such a highly sensitive nanocomposite sensor can be exploited for in situ monitoring of important neurotransmitters at the cellular level, which is of great significance for related drug screening and mechanistic studies.

High‐Performance MXene/Carbon Nanotube Electrochemical Actuators for Biomimetic Soft Robotic Applications

AbstractIonic electrochemical actuators, which convert electrical energy into mechanical energy through electrochemical‐induced ion migration, show great potential in biomimetic soft robots. However, their applications are still limited due to the influence of the electrode materials and actuator performance. Here, an MXene/carbon nanotube (CNT) heterostructural electrode‐based ionic actuator is developed and realizes dexterous touch manipulation mimicking humans. In this MXene/CNT heterostructure, one‐dimensional CNTs are chemically interconnected into layered two‐dimensional MXene nanosheets, increasing their interlayer spacing, promoting mechanical stability, and enhancing specific surface area, which facilitates the ion migration and storage as well as electrochemical actuation. Accordingly, the MXene/CNT actuator can output excellent mechanical deformation under 2.5 V voltage, including large peak‐to‐peak deformation (displacement 24 mm, strain 1.54%), wide frequency response (0.1–15 Hz), large force (5 mN) and good cycling stability. The actuators can be used to construct artificial fingers to achieve gentle, multi‐point, variable frequency, and synergistic touching on fragile smartphone screens, including pressing a phone number to make a call and tapping an electronic drum. Especially, this finger can tap the drum at a high frequency (13 Hz), exceeding the tapping frequency that real human fingers can reach, which demonstrates its prospect in human‐computer interaction.

Leveraging doping strategies and interface engineering to enhance catalytic transformation of lithium polysulfides for high-performance lithium-sulfur batteries

The commercialization of lithium-sulfur (Li–S) batteries has faced challenges due to the shuttle effect of soluble intermediate polysulfides and the sluggish kinetics of sulfur redox reactions. In this study, a synergistic catalyst medium was developed as a high-performance sulfur cathode material for Li–S batteries. Termed A/R-TiO2@ Ni-N-MXene, this sulfur cathode material features an in-situ derived anatase–rutile homojunction of TiO2 nanoparticles on Ni-N dual-atom-doped MXene nanosheets. Using in-situ transmission electron microscopy (TEM) technique, we observed the growth process of the homojunction for the first time confirming that homojunctions facilitated charge transfer, while dual-atom doping offered abundant active sites for anchoring and converting soluble polysulfides. Theoretical calculations and experiments showed that these synergistic effects effectively mitigated the shuttle effect, leading to improved cycling performance of Li–S batteries. After 500 cycles at a 1C rate, Li–S batteries using A/R-TiO2@Ni-N-MXene as cathode materials exhibited stable and highly reversible capacity with a capacity decay of only 0.056 % per cycle. Even after 150 cycles at a 0.1C rate, a high-capacity retention rate of 62.8 % was achieved. Additionally, efficient sulfur utilization was observed, with 1280.76 mA h/g at 0.1C, 694.24 mA h/g at 1C, alongside a sulfur loading of 1.5–2 mg/cm2. The effective strategy based on homojunctions showcases promise for designing high-performance Li–S batteries.

Ultrafine Aramid Nanofiber-Assisted Large-Area Dense Stacking of MXene Films for Electromagnetic Interference Shielding and Multisource Thermal Conversion.

Polymers are often used as adhesives to improve the mechanical properties of flexible electromagnetic interference (EMI) shielding layered films, but the introduction of these insulating adhesives inevitably reduces the EMI performance. Herein, ultrafine aramid nanofibers (UANF) with a diameter of only 2.44 nm were used as the binder to effectively infiltrate and minimize the insulating gaps in MXene films, for balancing the EMI shielding and mechanical properties. Combining the evaporation-induced scalable assembly assisted by blade coating, flexible large-scale MXene/UANF films with highly aligned and compact MXene stacking are successfully fabricated. Compared with the conventional ANF with a larger diameter of 7.05 nm, the UANF-reinforced MXene film exhibits a "brick-mortar" structure with higher orientation and compacter stacking MXene nanosheets, thus showing the higher mechanical properties, electrical conductivity, and EMI shielding performance. By optimizing MXene content, the MXene/UANF film can achieve the optimal tensile strength of 156.9 MPa, a toughness of 2.9 MJ m-3, satisfactory EMI shielding effectiveness (EMI SE) of 40.7 dB, and specific EMI SE (SSE/t) of 22782.4 dB cm2/g). Moreover, the composite film exhibits multisource thermal conversion functions including Joule heating and photothermal conversion. Therefore, the multifunctional MXene/UANF EMI shielding film with flexibility, foldability, and robust mechanical properties shows the practical potential in complex application environments.

Facile Preparation of MXene Decorated PANI/Lignosulfonate Nanocomposite Film Electrodes for Electrochemical Supercapacitors

AbstractMXenes are a large family of two‐dimensional transition‐metal carbides, nitrides, and carbonitrides with large surface area and metal conductivity. They have not been widely used as electrodes in the field of supercapacitors because of their low specific capacity, poor chemical stability, and tendency towards self‐stacking. Herein, a three‐component nanocomposite film electrode has been successfully achieved, consisting of MXene nanosheets, polyaniline (PANI), and lignosulfonate (LGS). The PANI‐LGS nanocomposite was prepared through the oxidative polymerization of PANI in the presence of LGS, and then MXene decorated PANI/LGS (labeled as MPL) nanocomposite films were facilely self‐assembled via a vacuum‐assisted filtration by using the dispersion. Compared with pure PANI and PANI‐LGS, the MPL nanocomposite film electrode possesses better conductivity, showing a high specific capacitance of 559 F/g at a scan rate of 5 mV/s and a capacity retention rate of 92.2 % after 1000 cycles at a current density of 10 A/g. This study demonstrates that the doping of LGS and MXene can significantly improve the electrochemical performance of PANI‐based composite materials. Thus, the convenient preparation and excellent electrochemical performance of MPL show great potentials in the application of high‐performance electrodes for supercapacitors.

Ultrastrong MXene film induced by sequential bridging with liquid metal.

Assembling titanium carbide (Ti3C2Tx) MXene nanosheets into macroscopic films presents challenges, including voids, low orientation degree, and weak interfacial interactions, which reduce mechanical performance. We demonstrate an ultrastrong macroscopic MXene film using liquid metal (LM) and bacterial cellulose (BC) to sequentially bridge MXene nanosheets (an LBM film), achieving a tensile strength of 908.4 megapascals. A layer-by-layer approach using repeated cycles of blade coating improves the orientation degree to 0.935 in the LBM film, while a LM with good deformability reduces voids into porosity of 5.4%. The interfacial interactions are enhanced by the hydrogen bonding from BC and the coordination bonding with LM, which improves the stress-transfer efficiency. Sequential bridging provides an avenue for assembling other two-dimensional nanosheets into high-performance materials.