Ti3C2Tx Nanosheets Research Articles

Enhanced nonlinear optical properties of MXene (Ti3C2Tx) via surface-covalent functionalization with porphyrin

The surface terminations (=O, -OH, and -F) play a key role in determining the physical and chemical properties of MXenes, which have been demonstrated with significant potential in field-effect transistors, humidity sensors, energy storage, and photocatalysis, etc. It is therefore crucial to modify these active functional groups on the surface of MXenes in order to optimize the applicability of these materials. In this study, we introduce a covalent modification strategy to successfully construct a porphyrin-functionalized Ti3C2Tx organic-inorganic nanohybrid (TPP-Ti3C2Tx) by covalently attaching porphyrin molecules to the surface groups on Ti3C2Tx nanosheets for the first time. As revealed by steady-state fluorescence spectra, transient fluorescence spectra, and DFT calculations, the robust covalent bonds between TPP and Ti3C2Tx can effectively promote the photon-induced electron and/or energy transfer within the TPP-Ti3C2Tx nanohybrid. The investigation on the nonlinear optical (NLO) properties of TPP-Ti3C2Tx nanohybrid as well as its precursors, reveals that the TPP-Ti3C2Tx nanohybrid exhibits the highest nonlinear absorption coefficient and the lowest optical limiting threshold among the tested samples at both 532 and 1064 nm, indicating its great potential as a broadband optical limiter for visible and near-infrared wavelengths. This work not only demonstrates the significant promise of covalently-linked TPP-Ti3C2Tx nanohybrid in optical limiting applications but also provides a paradigm for engineering high-performance NLO MXenes-based materials through the covalent modification strategy.

MXene-based nanozymes remodel tumor microenvironment for heterojunction-enhanced sonodynamic and chemodynamic therapy to boost robust cancer immunotherapy

Reactive oxygen species (ROS)-mediated sonodynamic therapy (SDT) holds increasing potential in treating deep-seated tumor owing to the high tissue-penetration depth, but hardly controls remote metastasis. To trigger robust cancer immunotherapy against malignant metastatic cancers, we report the rational construction of Z-scheme heterojunctions through decorating biocompatible Co3O4 nanoparticles with multiple enzyme-like catalytic activities onto Ti3C2Tx nanosheets to realize the augmented SDT and chemodynamic therapy (CDT). The deposition of Co3O4 nanoparticles not only sensitizes the sonodynamic activity of Ti3C2Tx nanosheets owing to the regulation of separation dynamics of electron-hole pairs, but also achieves the cascade amplification of ROS generation through Co2+-mediated Fenton-like reaction, Co3+-facilitated GSH depletion, and catalytic decomposition of endogenous H2O2 to relieve hypoxia. More importantly, the immunosuppressive TME could be reversed by the greatly enhanced ROS levels, ultimately inducing immunogenic cell death that promotes robust systemic immune responses. The heterojunction-enhanced SDT and CDT via Co3O4@Ti3C2Tx could trigger robust cancer immunotherapy, which achieves the eradication of primary tumors and suppression of distant tumors. This work highlights the potential of heterojunction engineering-enhanced SDT and CDT to trigger robust cancer immunotherapy.

Synthesis and Fabrication of Metal Cation Intercalation in Multilayered Ti3C2Tx Composite CNF Electrode for Asymmetric Coin Cell Supercapacitors.

Ti3C2Tx has attracted considerable attention from researchers in energy storage due to its unique structure and beneficial surface functional group characteristics. Recent studies have focused extensively on developing Ti3C2Tx composites to create potential electrode materials for energy storage applications. Carbon nanofiber is often combined with Ti3C2Tx to produce high-performance functional nanocomposites, effectively harnessing the unique properties of Ti3C2Tx nanosheets while ensuring exceptional electrochemical behavior. This work employs an ultrasonication method to prepare a Na-Ti3C2Tx/CNF electrode. Establishing a stable interlayer structure between Ti3C2Tx nanosheets and cationic metal intercalation materials is crucial for expanding the interlayer spacing of Ti3C2Tx and creating multidirectional stable ion transport channels. Consequently, this process exposes more active sites that are accessible to ions. At a current density of 1 A g-1, the resulting Na-Ti3C2Tx/CNF demonstrates an impressive specific capacitance of 680.2 F g-1. Notably, the asymmetric supercapacitor assembled with Na-Ti3C2Tx/CNF as the positive electrode and activated carbon as the negative electrode exhibits remarkable cyclic retention of 83.1% and the Coulombic efficiency of 90.5% after 10,000 cycles at 10 A g-1, a wide voltage window of 1.5 V, a high energy density of 102.5 W h kg-1, and a power density of 2963.7 W kg-1. The fabricated coin cell ASC devices, which include glowing red light-emitting diodes, were demonstrated in practical applications. The optimization strategy for developing Na-Ti3C2Tx/CNF provides essential technical support for integrating Na-Ti3C2Tx/CNF into the next generation of portable and adaptable wearable electrochemical energy storage devices.

Dressing AgNWs with MXenes Nanosheets: Transparent Printed Electrodes Combining High-Conductivity and Tunable Work Function for High-Performance Opto-Electronics.

High-work function transparent electrodes (HWFTEs) are key for establishing Schottky and Ohmic contacts with n-type and p-type semiconductors, respectively. However, the development of printable materials that combine high transmittance, low sheet resistance, and tunable work function remains an outstanding challenge. This work reports a high-performance HWFTE composed of Ag nanowires enveloped conformally by Ti3C2Tx nanosheets (TA), forming a shell-core network structure. The printed TA HWFTEs display an ultrahigh transmittance (>94%) from the deep-ultraviolet (DUV) to the entire visible spectral region, a low sheet resistance (<15 Ωsq-1), and a tunable work function ranging from 4.7 to 6.0eV. The introduction of additional oxygen terminations on the Ti3C2Tx surface generates positive dipoles, which not only increases the work function of the TA HWFTEs but also elevates the TA/Ga2O3 Schottky barrier, resulting in a high self-powered responsivity of 18mAW-1 in Ga2O3 diode DUV photodetectors, as demonstrated via experimental characterizations and theoretical calculations. Furthermore, the TA HWFTEs-based organic light-emitting transistors exhibit exceptional emission brightness of 5020cd m-2, being four-fold greater than that in Au electrodes-based devices. The innovative nano-structure design, work function tuning, and the revealed mechanisms of electrode-semiconductor contact physics constitute a substantial advancement in high-performance optoelectronic technology.

Facile synthesis of hollow Zn-Co-S and Zn-Co-P nanostructures supported on Ti3C2Tx MXene nanosheets for high-performance lithium-ion capacitors

Lithium-ion capacitors (LICs) represent a novel energy storage solution, merging the high energy storage capacity of lithium-ion batteries with the adequate power density of supercapacitors. However, the electrochemical performance of lithium-ion capacitors is notably constrained by the inherent imbalance between the charge storage mechanisms and electrochemical reaction dynamics of their anodes and cathodes. In this study, a dual-shell hollow structured ZnCo2S4 was prepared via a two-step hydrothermal method and compared with spherical ZnCo2P4 prepared by calcination. Subsequently, they were respectively anchored onto two-dimensional Ti3C2Tx nanosheets, which possess abundant surface functional groups, through electrostatic adsorption, forming layered semi-encapsulated framework structures. The introduction of MXene significantly enhances the conductivity of the material, restricts the expansion of ZnCo2S4 and ZnCo2P4 during the Li+ insertion/extraction process, and inhibits their aggregation. Under a three-electrode configuration, ZnCo2S4/Ti3C2Tx exhibits excellent rate performance (1004 C·g−1 at 10 A·g−1) and cycling stability (95 % capacity retention after 5000 cycles at 2 A·g−1). The discharge capacity of the ZnCo2S4/Ti3C2Tx LIB is up to 1360 mAh·g−1 at 0.1 A·g−1, and the discharge capacity of the ZnCo2P4/Ti3C2Tx LIB is 1121 mAh·g−1 at 0.1 A·g−1. As an anode material for LIC, ZnCo2S4/Ti3C2Tx demonstrates excellent specific capacitance and rate performance (105 F·g−1 at 0.5 A·g−1). At a power density of 337.10 W·kg−1, ZnCo2S4/Ti3C2Tx//AC LIC exhibits a significant energy density of 136.25 Wh·kg−1. At a current density of 2 A·g−1, ZnCo2S4/Ti3C2Tx//AC LIC retains 89 % of its capacity after 5000 charge-discharge cycles, demonstrating excellent stability for practical applications. ZnCo2P4/Ti3C2Tx//AC LIC exhibits an energy density of 45.20 Wh·kg−1 at a power density of 623.07 W·kg−1, and after 5000 cycles at 2 A·g−1, its capacity retention rate reaches 80 %. These findings suggest that ZnCo2S4/Ti3C2Tx and ZnCo2P4/Ti3C2Tx composites are promising anode materials for LICs.

Carbon matrix NiFeP/C nanoparticles anchored on Ti3C2Tx nanosheets as heterostructure high-performance anode for lithium-ion batteries

Engineered micro-nano heterogeneous architectures for transition metal phosphide (TMPs) anode materials in lithium-ion batteries (LIBs) provide multifunctional active components. These components synergistically interact to address pivotal challenges of pronounced volume expansion and sluggish reaction kinetics within the electrode. Consequently, this engineering design approach significantly enhances the overall battery performance. In this study, a self-assembled approach is employed to integrate hybridized NiFe-PBA nanocubes with two-dimensional (2D) monolayer MXene (Ti3C2Tx), producing a heterostructured NiFeP/C@Ti3C2Tx composite. In this meticulously engineered architecture, the interface between the outer MXene layer and NiFeP embedded within the carbon matrix exhibits several distinct superiorities, such as rapid interfacial ion migration, multidirectional migration pathways, and strong spatial adaptability. The resulting non-uniform phase structure effectively mitigates electrode expansion and enhances electronic conductivity. Consequently, the NiFeP/C@Ti3C2Tx-15 composite demonstrates distinct performance advantages over NiFeP/C without MXene. The composite achieves a specific capacity of 689.4 mAh g⁻¹ at 200 mA g⁻¹ over 300 cycles, double that of NiFeP/C. Furthermore, density functional theory (DFT) calculations validate the electronic conductivity facilitated by the heterointerface between MXene and NiFeP, substantiating the strategic significance of the heterostructure in advancing high-performance anode materials for lithium-ion batteries.

Microwave-assisted hydrothermal synthesis of highly dispersed cerium–zirconium solid solution on Ti3C2Tx nanosheets as an efficient decontamination towards sulfur mustard simulants

The microwave-assisted hydrothermal method has facilitated the straightforward and efficient production of nanoscale CexZr1-xO2/Ti3C2Tx composites. This technique has greatly shortened the synthesis time several hours required by conventional hydrothermal method to merely 10minutes. Due to the unique mechanism of microwave-hydrothermal synthesis, composites with excellent crystallinity, uniform particle size, and superior degradation capabilities can be obtained without calcination. Our investigation systematically explores the influence of various factors including mineralizer concentration, dispersant types, synthesis duration, cerium-to-zirconium ratio, as well as MXene content on the material properties. Optimal degradation of 2-chloroethyl ethyl sulfide, sulfur mustard simulants, is achieved using PEG1000 as the dispersant, a cerium-to-zirconium ratio of 1:2, along with 15mL of MXene, resulting in a remarkably short half-life of only 6.5min. Furthermore, it is confirmed that the incorporation of cerium atoms into ZrO2 lattice, forming a solid solution that is deposited onto the interlayer and surface of Ti3C2Tx nanosheets, with the composite particles measuring approximately 5.01nm. The reduced size and increased specific surface area, coupled with the synergistic effects of oxygen vacancies and acid-base sites, ultimately contribute to the hydrolysis and elimination reactions occurring on 2-CEES. This research offers fresh perspectives on the development of novel materials for the degradation of chemical warfare agents.

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

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

Unveiling the potential: Asymmetric supercapacitors with conductive polymers/Ti3C2Tx/Ni3S4 electrodes deliver high energy densities

Ti3C2Tx is considered a promising electrode material for supercapacitors due to its fast electronic properties, excellent hydrophilicity and mechanical properties. However, severe Ti3C2Tx nanosheet stacking reduces the exposed active sites and hinders the ion diffusion of Ti3C2Tx, leading to poor electrochemical performance. Here, we report a strategy for doping of Ti3C2Tx, in which the Ni3S4 and conducting polymer (CP) were selected as doping agent for Ti3C2Tx, and it is expected that metal sulfide and CP can overcome the defects of Ti3C2Tx. In this work, the conducting polymers were as polyaniline (PANI), polypyrrole (PPY) and poly(3,4-ethylenedioxythiophene) (PEDOT). As a result, the prepared composites exhibit superior multiplicative capacity with a capacitance of 2502 F g-1 (PANI/Ti3C2Tx/Ni3S4), 2440 F g-1 (PPY/Ti3C2Tx/Ni3S4), and 2620 F g-1 (PEDOT/Ti3C2Tx/Ni3S4), respectively. In addition, CP/Ti3C2Tx/Ni3S4// AC asymmetric supercapacitors were assembled with energy densities of 60.2 (PANI/Ti3C2Tx/Ni3S4), 86.7 (PPY/Ti3C2Tx/Ni3S4), and 53.4 (PEDOT/Ti3C2Tx//Ni3S4) Wh kg-1 at 1,500 W kg-1, respectively. This work develops a simple way to prepare the porous Ti3C2Tx film for supercapacitors with excellent electrochemical performance.

In Situ Construction of Crumpled Ti3C2Tx Nanosheets Confined S-Doping Red Phosphorus by Ti-O-P Bonds for LIBs Anode with Enhanced Electrochemical Performance.

Red phosphorus (RP) with a high theoretical specific capacity (2596 mA h g-1) and a moderate lithiation potential (∼0.7 V vs Li+/Li) holds promise as an anode material for lithium-ion batteries (LIBs), which still confronts discernible challenges, including low electrical conductivity, substantial volumetric expansion of 300%, and the shuttle effect induced by soluble lithium polyphosphide (LixPPs). Here, S-NRP@Ti3C2Tx composites were in situ prepared through a phosphorus-amine-based method, wherein S-doped red phosphorus nanoparticles (S-NRP) grew and anchored on the crumpled Ti3C2Tx nanosheets via Ti-O-P bonds, constructing a three-dimensional porous structure which provides fast channels for ion and electron transport and effectively buffers the volume expansion of RP. Interestingly, based on the results of adsorption experiments of polyphosphate and DFT calculation, Ti3C2Tx with abundant oxygen functional groups delivers a strong chemical adsorption effect on LixPPs, thus suppressing the shuttle effect and reducing irreversible capacity loss. Furthermore, S-doping improved the conductivity of red phosphorus nanoparticles, facilitating Li-P redox kinetics. Hence, the S-NRP@Ti3C2Tx anode demonstrates outstanding rate performance (1824 and 1090 mA h g-1 at 0.2 and 4.0 A g-1, respectively) and superior cycling performance (1401 mAh g-1 after 500 cycles at 2.0 A g-1).

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

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

Intercalation of multilayered Ti3C2Txelectrode doped with vanadium for highly sensitive electrochemical detection of dopamine in biological samples.

Theelectrochemical detection characteristics of the layered Ti3C2Tx materialwere enhanced by modifying its surface. Ti3C2Tx is used as the Ti - F chemical bond weakens with increasing pH levels. Ti3C2Tx is alkalinized by KOH, and F is substituted for - OH. The surface hydroxyl groups can be eliminated by intercalating K+. This study elaborates on the hydrothermal production of vanadium-doped layered Ti3C2Tx nanosheets intercalated with K+. Thedevelopment of a sensitive dopamine electrochemical sensor is outlinedby intercalating a vanadium-doped multilayered K+ Ti3C2Tx electrode. The chemical, surface, and structural composition of the synthesized electrode for dopamine detection was investigated and confirmed. The sensor exhibits a linear range (1-10 µM), a low detection limit (8.4 nM), and a high sensitivity of 2.746 µAµM-1cm-2 under optimal electrochemical testing conditions. The sensor also demonstrates exceptional anti-interference capabilities and stability. The sensor was applied todetection of dopamine in (spiked) rat brains, human serum, and urine samples. This study introduces a novel approach by utilizing K+ intercalation of vanadium-doped Ti3C2Tx-based electrochemical sensors and an innovative method for dopamine detection. The dopamine detection revealed the potential of (V0.05) K+ Ti3C2Tx-GCE for practical application in pharmaceutical sample analysis.

Microporous tungsten oxide spheres coupled with Ti3C2Txnanosheets for high-volumetric capacitance supercapacitors.

In the contemporary landscape of technological advancements, the burgeoning demand for portable electronics and flexible wearable devices has necessitated the development of energy storage systems with superior volumetric performance. Tungsten oxide (WO3), known for its high density and theoretical capacitance, is a promising electrode material for supercapacitors. However, low conductivity and poor cycling stability are still the key bottlenecks for its application. Herein, a novel composite comprising hollow porous WO3 spheres (HPWS) derived by template method was electrostatic self-assembled on the surface of the Ti3C2Tx nanosheets. The resulting electrodes exhibited ultra-high volumetric capacitance of 1930 F cm-3 at 1 A g-1 and rate capability of 46% at 50 A g-1, attributed to enhanced ion accessibility from microporous structure and electron transport from conductive network of Ti3C2Tx even at a high packing density of 3.86 g cm-3. Utilizing HPWS/Ti3C2Tx as the negative electrode and porous carbon as the positive electrode, the assembled asymmetric supercapacitor achieved an energy density of 31 Wh kg-1 at a power density of 650 W kg-1 with over 107% capacitance retention after 5000 cycles. This work provides a promising approach for developing next-generation supercapacitors with ultra-high volumetric capacitance.

Confinement synthesis of few-layer MXene-cobalt@N-doped carbon and its application for electrochemical sensing

Herein, the few-layer Ti3C2Tx nanosheets loaded zeolitic imidazolate framework-67 nanoplates (Ti3C2Tx-ZIF-67) with a unique structure has been synthesized by surfactant control method, and then is employed as the core of precursor. A thin layer of polydopamine as the shell of precursor covered Ti3C2Tx-ZIF-67 forms a micro-nano reactor, leading to the confinement carbonization process. Consequently, a novel sensing material that few-layer Ti3C2Tx nanosheets loaded Co nanoparticles coated N-doped carbon (Ti3C2Tx-Co@NC) is obtained for the non-enzymatic determination of glucose. Owing to the impressive structure, the established glucose sensor based on Ti3C2Tx-Co@NC/glassy carbon electrode exhibits 0.5–100.0 μM of linear detection range and 66.8 nM of detection limit, which tends to detect low concentration of glucose. The synergistic few-layer Ti3C2Tx nanosheets, Co nanoparticles and NC are considered through a series of control experiments. First, few-layer Ti3C2Tx nanosheets provide a good transport channel for electron transfer, resulting in the lower steric hindrance. Second, Co nanoparticles provide active centers for the electrochemical detection. Third, N-doped carbon with conductivity and hydrophilia plays the role of stabilizing material structure to prevent the fragmentation of Ti3C2Tx and the agglomeration of Co nanoparticles. Such work proposes a confined strategy to develop MXene-ZIF-67-derived nanocomposite with high-performance structure.

Graphene-Wrapped Magnetic Multichamber Ti3C2Tx Spheres for Stable Broadband Microwave Absorption.

Two-dimensional transition metal carbides/nitrides (MXenes) have aroused widespread interest in the field of microwave absorption because of their unique layered structures. However, the inherent aggregation, poor impedance matching, and low chemical stability of MXenes inevitably obstruct their practical applications. Herein, a multichamber Fe3O4/Ti3C2Tx@reduced graphene oxide (FT@RGO) hierarchical structure was constructed through self-assembly and sacrificial template strategies where the Ti3C2Tx nanosheets were assembled into hollow microspheres that were decorated with Fe3O4 nanospheres and wrapped by RGO nanosheets. The massive heterointerfaces and interior cavities favor enhanced microwave absorption performance via interfacial polarization, multiple scattering/reflections, and dielectric-magnetic synergistic effects. Consequently, the synthesized ultralight FT@RGO foam (0.009 g/cm3) presents superior microwave absorption ability with the minimum reflection loss of -50.5 dB at the matching thickness of 2.5 mm and effective absorption bandwidth of 8.0 GHz covering the frequency range of 10.0-18.0 GHz at the thickness of 2 mm. Furthermore, the encapsulation of hollow Ti3C2Tx spheres by RGO nanosheets avoids direct contact with external air, which considerably improves the stability of Ti3C2Tx and ensures the long-term application of FT@RGO foam in a conventional environment. This work provides a reference for the structural design of MXene-based materials as broadband and durable microwave absorbers.

Bio-inspired fabrication of chitosan/PEO/Ti3C2Tx 2D MXene nanosheets supported palladium composite nanofiber catalysts via electrospinning

In this study, novel chitosan/polyethylene oxide/Ti3C2Tx 2D MXene nanosheets (CS/PEO/Ti3C2Tx) nanofibers were successfully prepared by a continuous electrospinning process. During the electrospinning process, induced by the syringe tip capillary effects and electric field force, the Ti3C2Tx nanosheets were aligned along the direction of the nanofiber formation to occur a highly oriented structure. This well-ordered arrangement of the inorganic Ti3C2Tx nanosheets within the organic polymer matrix nanofiber was similar with nacre-like ‘brick-and-motar’ structure to some extent, resulting in a marked increase in thermal stability and mechanical properties of the resultant CS/PEO/Ti3C2Tx nanofiber. As 4 wt% of Ti3C2Tx nanosheets loaded, the highest tensile strength of the CS/PEO/Ti3C2Tx nanofiber mats was achieved as 31.7 MPa, about two times that of neat CS/PEO nanofibers. Uniformly dispersed Pd nanoparticles in size of about 1.6 nm have been successfully immobilized on the composite nanofiber with a solution impregnation process. With a loading as low as 0.2 mol% of Pd, the resultant Pd@CS/PEO/Ti3C2Tx composite nanofiber catalysts were highly active for both Heck and Sonogashira coupling reactions with broad reactants application scope, and could be recycled 15 runs without significant loss of activities.

Boosting Zinc‐Ion Storage Capability in Longitudinally Aligned MXene Arrays with Microchannel Architecture

AbstractFlexible Zn2+ ion hybrid capacitors (ZHCs) will play a crucial role in developing next‐generation wearable products, which demand portability, durability, and environmental adaptability. To further meet these requirements, Ti3C2Tx MXene with exceptional conductivity and robust mechanical properties can be utilized as cathodes, except for challenges such as the dense stacking of Ti3C2Tx nanosheets. In this study, a novel MXene cathode architecture has been developed with the facilitation of an ice template, which creates longitudinally aligned Ti3C2Tx arrays with microchannels. The introduction of hydrochloric acid to the Ti3C2Tx slurry induces a crumpled morphology, increasing active sites and enhancing ion transport with expanded interlayer spacing. Interestingly, experimental results and COMSOL simulations verify that the cathode structure also has effective impacts on the Zn anode with a weakened ion concentration gradient and suppressed dendrite formation. Consequently, the ZHCs exhibit enhanced electrochemical performance with excellent rate performance and long‐term cycling stability (enduring over 50 000 cycles at 5 A g−1) and further deliver a reliable low‐temperature operation by applying an anti‐freezing electrolyte. Moreover, flexible ZHCs assembled with gel electrolytes demonstrate excellent flexibility, improved rate performance, and mechanical stability, making them well‐suited for flexible electronics that power flexible LED panels.

Novel fluorine-functionalized Ti3C2Tx/TiO2 hybrid coatings with enhanced weatherability, antifouling, and interfacial anticorrosion performances

As a valuable symbol of human cultural heritage, bronze inevitably endures varying degrees of corrosion due to environmental change. Thus, developing an efficient protective coating for bronze is crucial to ensure bronze relics receive more protection. Herein, a multifunctional organic-inorganic hybrid composite coating of 1 H,1 H,2 H,2 H-Perfluorodecyltriethoxysilane (PFDTES), Ti3C2Tx nanosheets and TiO2 nanoparticles (PFDTES@Ti3C2Tx/TiO2) are successfully prepared and coated the bronze, which exhibits excellent anti-corrosion, weathering stability and superhydrophobicity. The superhydrophobicity of coating is derived from introducing a low surface energy C-F bond. Furthermore, the corrosion protection ability can be improved by the barrier effect of Ti3C2Tx nanosheets, and TiO2 nanoparticles can enhance the weathering stability of coatings by providing exceptional abrasion resistance and ultraviolet (UV) resistance capabilities. Morphological examination, X-ray photoelectron spectroscopy, an accelerated aging test, and electrochemical measurements, among other methods, were used to research the protective effect and anticorrosion performance of organic-inorganic hybrid coatings. It can be found that the composite coatings have a large water contact angle (153°) and form a superhydrophobic surface. Furthermore, electrochemical results show that the superhydrophobic PFDTES@Ti3C2Tx/TiO2 coating has a higher low-frequency impedance modulus and lower current density than the uncoated substrate, indicating enhanced corrosion resistance. Based on solid and liquid pollutant tests, the PFDTES@Ti3C2Tx/TiO2 coatings also showed good self-cleaning and antifouling properties. And coating maintained good transparency without changing the bronze color and appearance. In conclusion, the superhydrophobic PFDTES@Ti3C2Tx/TiO2 composite coating has potential applications in the field of bronze protection.

MOF-derived ZnCo2O4 @ Ti3C2TX nanosheet with high microwave absorption

Abstract Electromagnetic wave absorbing (EWA) materials have a wide application in military technology, so it is necessary to develop EWA materials with lightweight, and wide absorption bandwidth and strong absorption. Novel two-dimensional material (MXene) with high dielectric constant property and unique structure has attracted extensive focus in microwave absorption. However, the high conductivity of MXene limits its application in microwave absorption. In this work, ZnCO2O4 nanoparticles were obtained via a hydrothermal method and subsequent heat treatment. Then it was anchored on MXene nanosheets. The effective absorption bandwidth (EAB) of the ZnCO2O4@Ti3C2Tx is 4.77GHz at 1.5mm thickness. Composites show great potential in the field of designing a new generation of efficient and lightweight microwave absorbers, which are expected to be used in various EWA applications.

Nitrogen-doping engineering in two-dimensional transition-metal carbides for electrochemical hydrogen evolution

Developing electrocatalysts with the trade-off between overall electrocatalytic performance and economic cost towards hydrogen evolution reaction (HER) is crucial for producing green hydrogen fuels. Although theoretical studies have reported the potential of two-dimensional (2D) MXenes for the HER, their electrocatalytic performance is still unsatisfactory for the particular application due to their low intrinsic active and MXene stacking. To address this problem, we herein modify the electronic structure and increase the interlayer spacing between 2D Ti3C2Tx MXenes through ammonia (NH3)-assisted hydrothermal approach. The effect of synthesis temperature on the nitrogen doping mechanism and electrochemical behaviors for the HER is systemically explored. As a result, the nitrogen (N)-doped Ti3C2Tx MXene fabricated at 160 °C exhibits the highest HER activity among all 2D N-doped Ti3C2Tx nanosheets with the overpotential/Tafel slope of 186.91 mVRHE/115.94 mVRHE dec−1 in an acidic solution. Due to the synergistic contribution of nitrogen, the N-doped Ti3C2Tx-160 °C has mass activity of 337.95 mA mg−1 at 0.3 VRHE, being 27.50-fold higher than that of pristine Ti3C2Tx. This work indicated that heteroatom doping is a facile but efficient approach for modulating the electronic structure and intrinsic activity of MXene-based materials for electrochemical reactions.