Two-dimensional Titanium Carbide Research Articles

Aqueous Electrolyte Asymmetric Supercapacitors Based on the 5-Hydroxyindole Molecule Electrode and MXene with Efficient Energy Storage

It is a suitable tactic to boost energy density, which extends the difference between the redox peak positions of positive and negative electrodes. In this paper, an organic molecular electrode (HIN@rGO) based on 5-hydroxy indole (HIN) non-covalently anchored on graphene is reported, which is used as the positive electrode of asymmetric supercapacitors (ASCs) to enlarge the voltage window. The HIN@rGO-0.5 displays an outstanding specific capacitance of 519 F g–1 at 5 mV s–1 and high capacitance retention of 85.6%, even if the scan rate is increased to 100 mV s–1. What is more, it is observed that the Faraday reactions of HIN@rGO occur in the range of more positive potential. The MXene (Ti3C2Tx) is a two-dimensional titanium carbide, which has been prepared as the counterpart electrode to match the HIN@rGO-0.5. The voltage window of the constructed ASC (HIN@rGO-0.5//Ti3C2Tx) is extended to 1.6 V. The device can deliver an excellent energy density of 32.5 W h kg–1 along with the power density of 640 W kg–1 and show 90.5% of capacitance retention after 10,000 cycles, which is originating from the two electrodes exhibiting a good synergistic matching effect in terms of charge and kinetics during the electrochemical reaction. To verify the application potential, two devices (HIN@rGO-0.5//Ti3C2Tx) connected in series can light up to 58 LEDs.

Two-dimensional titanium carbide MXene produced by ternary cations intercalation via structural control with angstrom-level precision.

Highly effective decontamination of lead is a primary challenge for ecosystem protection and public health. Herein, we report a methodology of ternary cations intercalation to synthesize Ti3C2Tx MXene by structural control with angstrom-level precision through mixed fluorinated salts wet etching-alkalization approach for high-efficient lead adsorption. The successive introduction of lithium, potassium, and sodium ions continuously weakens interaction forces between Ti3C2Tx layers, resulting in achieving fine tailored interlayer distance from 9.8 to 15.9Å. A high density of complexing groups are formed after ternary cations intercalation, which greatly improve the hydrophilicity of Ti3C2Tx to enhance the accessibility and shorten the mass transfer and provide abundant adsorption sites to exhibit strong complexing effects with lead ions. The prepared ternary cations-intercalated Ti3C2Tx nanosheets exhibited a high adsorption capacity (267.2mg/g) toward lead ions and sharply cut down lead concentration from 10 to 0.009mg/L, far below the drinking water standards (0.015mg/L).

An electrochemical sensor for capsaicin based on two-dimensional titanium carbide (MXene)-doped titania-Nafion composite film

Two-dimensional titanium carbide (called MXene) has been utilized to fabricate a highly sensitive electrochemical sensor for the determination of capsaicin. In the present work, Ti3C2Tx MXene was dispersed in the composite solution of sol–gel derived titania and Nafion. The as-prepared MXene-titania-Nafion composite solution was drop-cast on the surface of a glassy carbon (GC) electrode. Due to the electrostatic interaction between positively charged capsaicin at pH 1.0 and negatively charged MXene-titania-Nafion composite film, capsaicin was selectively adsorbed onto the present electrochemical sensor. The introduction of MXene in the titania-Nafion composite film on GC electrode significantly increased the oxidation current of capsaicin compared to that at a bare GC electrode and the titania-Nafion composite-modified GC electrode, which could be attributed to the synergistic effect of Ti3C2Tx MXene and mesoporous titania-Nafion composite film. The experimental parameters affecting the detection capability of capsaicin (i.e., pH, MXene loading amount and accumulation time) were optimized. Using the linear sweep adsorptive stripping voltammetry, the present electrochemical sensor based on the MXene-titania-Nafion composite film can detect capsaicin from 5.0 × 10−8 M to 2.5 × 10−5 M with a detection limit of 2.5 × 10−8 M (S/N = 3). Furthermore, the present electrochemical sensor exhibited good selectivity towards capsaicin against interfering species like glucose and organic acids. Recovery tests for spiked capsaicin in a real pepper sample showed good recoveries. Therefore, the present electrochemical sensor based on the MXene-titania-Nafion composite could be applied to the voltammetric determination of capsaicin in food and pharmaceuticals.

Two-dimensional titanium carbide (MXene)-supported Pt3Ti intermetallic compound catalysts for efficient room-temperature oxidative removal of gaseous formaldehyde

The potential of reactive metal–support interactions has been investigated using platinum (Pt) and a two-dimensional titanium carbide (Ti3C2 [MXene]) support to achieve the full conversion of formaldehyde (FA: XFA) into carbon dioxide (CO2) at room temperature (RT) through the formation of a Pt3Ti intermetallic compound. The RT steady-state oxidation reaction rate (mol/g/h) of FA increased in the following order: 2% Pt/Ti3C2 (0.020) < 0.1% Pt/Ti3C2-R (0.054) < 1% Pt/Ti3C2-R (0.058) < 2% Pt/Ti3C2-R (0.061: turnover frequency of approximately 60 mmolFA/molO/s). The Pt3Ti formed in situ during reduction pre-treatment (R) enhanced catalytic activity, and 2% Pt/Ti3C2-R achieved significant resistance to moisture by maintaining 100% XFA at a relative humidity of 0%–90%. In situ diffuse reflectance infrared Fourier-transform spectroscopy revealed the formation of dioxymethylene, formate, and carbon monoxide as the reaction intermediates of FA oxidation. According to the density functional theory simulations, the carbonyl bond (C=O) of FA appears to be activated through chemisorption on Pt3Ti (adsorption of oxygen and carbon atoms (in C=O) on the Pt and titanium sites of Pt3Ti, respectively) to generate CO2 through reaction with active oxygen species formed by the decomposition of molecular oxygen on the Pt/Ti sites. In terms of the normalized reaction rate, 0.1 Pt/Ti3C2-R (0.55 mol/g/h [bulk Pt, wt.%]–1) appears to be one of the best-performing Pt catalysts reported for FA oxidation at RT.

Antibacterial, antifungal, and anticancer potential of two-dimensional Ti3C2Tx MXene

Here, we explored the antimicrobial and anticancer potential of two-dimensional titanium carbide (Ti3C2Tx) MXene. Several gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterococcus faecalis, Shigella flexneri, Salmonella typhimurium, and Proteus vulgaris), gram-positive bacteria (Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, and Enterococcus faecalis), and fungi (Candida albicans, Candida krusei, Candida parapsilosis, Candida acuminatus, and Epidermophyton floccosum) were examined for antimicrobial activity of Ti3C2Tx. Anticancer activity of Ti3C2Tx was determined in human lung (A549) and breast (MCF7) cancer cells along with their normal counterparts (IMR90 and MCF10A). Results demonstrated that Ti3C2Tx exhibits significant antimicrobial activity against all selected microbes. In bacteria, B. subtilis and E. coli were most sensitive while S. epidermidis was least sensitive against Ti3C2Tx. Among fungi, E. floccosum was most vulnerable while C. Candida krusei was least vulnerable toward Ti3C2Tx exposure. Moreover, Ti3C2Tx exhibited dose-dependent cytotoxicity in both types of cancer (A549 and MCF7) cells. Importantly, Ti3C2Tx did not cause cytotoxicity to normal cells (IMR90 and MCF10A). This study warrants further research on the application of 2D Ti3C2Tx nanosheets in medicine.

Designing a Ti3C2Tx MXene with long-term antioxidant stability for high-performance anti-corrosion coatings

Two-dimensional titanium carbide (Ti3C2Tx) MXene has many distinctive advantages, including high conductivity, energy-storing, catalysis, etc. In particular, its accordion-like lamellar structure could provide excellent barrier properties to corrosive agents, which exhibit potential application value for anti-corrosion coatings. However, the problem that MXenes are susceptible to oxidative degradation in an aggressive environment limits its further application in the field of corrosion prevention. Herein, in our work for the first time, an effective method was developed for protecting sensitive Ti3C2Tx MXene against oxidation by imidazolium salt modification (I-Ti3C2Tx), which considerably increased MXene antioxidant stability. The crystalline structure of I-Ti3C2Tx remained unaltered in an aqueous solution for 30 days and kept the lamellar structure for a long period. Simultaneously, 1.0 wt% I-Ti3C2Tx/EP could provide excellent anti-corrosion protection. A new synergistic mechanism for improving antioxidant stability and anti-corrosion property of I-Ti3C2Tx/EP coatings was developed and clarified based on the free radical scavenging ability of imidazolium ions and the chemical characteristics of MXene.

Positive resolution of the wound-healing response in lens epithelial cells by Ti3C2T x MXene coatings for use in accommodative intraocular lens devices

Cataract surgery removes the diseased lens of the eye replacing it with an intraocular lens, restoring visual acuity. However, accommodation, the lens’ ability to provide dynamic change in focus, is lost. A number of accommodative intraocular lens (AIOL) designs have been considered although none have provided a truly effective clinical AIOL. Two-dimensional titanium carbide (Ti3C2T x ) MXene has been used as a transparent conductive electrode within an AIOL feasibility study. Nevertheless, the potential for Ti3C2T x to repress excessive inflammation and promote wound healing following cataract surgery has not been considered. Cataract surgery can trigger chronic inflammation and epithelial-mesenchymal transition (EMT) in residual lens epithelial cells (LECs), producing a fibrotic mass across the posterior capsule known as posterior capsule opacification (PCO). With a large surface area and capacity for surface functionalisation, MXene has properties enabling a dual purpose AIOL design with an additional therapeutic role in the repression of pathways leading to PCO development. In this study, Ti3C2T x MXene was investigated to determine its impact on pathways leading to chronic inflammation and EMT using an in vitro LECs model. Ti3C2T x MXene was synthesised and characterised using UV-vis spectroscopy, dynamic light scattering and scanning electron microscopy. Changes in markers linked to inflammation and EMT in Ti3C2T x -treated LECs were measured using enzyme linked immunosorbent assays, quantitative polymerase chain reaction, scratch assay, RNA sequencing for whole-cell gene expression profiling and lipidomics analysis. Ti3C2T x significantly reduced the expression of pro-inflammatory cytokines by interleukin 1 beta primed LECs and did not advocate EMT, promoting a positive resolution of the wound healing response. This study supports the role of Ti3C2T x within an AIOL design with the potential to repress key developmental pathways leading to PCO.

Alkanolamine intercalation assisted liquid phase exfoliation of titanium carbide MXene nanosheets for highly efficient photocatalytic CO2 reduction

Two-dimensional titanium carbide (Ti3C2Tx) MXene nanosheets have been widely concerned due to its abundant surface functional groups, high conductivity, excellent photoelectrochemical properties and thermal conductivity. Nevertheless, it is still a challenge for the mass production of high-quality Ti3C2Tx MXene nanosheets. Herein, the bulk Ti3C2Tx MXene powders were stripped into monolayer or few layer nanosheets in propylene carbonate through liquid-phase exfoliation strategy assisted via alkanolamine as intercalators. It is shown that the stripping yield is up to 59.3 %, which is the recorded value for the delamination of Ti3C2Tx MXene nanosheets from bulk Ti3C2Tx MXene powder, and 62.2 % of nanosheets are monolayer. The ability of hydrogen bond donor and molecular size of alkanolamine have important effects on the yield. Moreover, Ti3C2Tx MXene nanosheets have been employed as catalysts in the photocatalytic CO2 reduction. The yield of CO is 149.7 μmol g-1h−1, which is about five times that of bulk Ti3C2Tx MXene powder. This work paves the way for the mass production of MXene nanosheets with high activity photocatalysis.

Cross-linked amorphous potassium titanate Nanobelts/Titanium carbide MXene nanoarchitectonics for efficient sodium storage at low temperature

One of the major challenges to improving the performance of sodium-ion batteries at low temperatures is to develop effective anode materials with novel structures and fast reaction kinetics. Currently, converting electrode materials from the crystalline to amorphous state is an effective approach to fabricate the electrode material with high sodium storage performance. Herein, a three-dimensional (3D) cross-linked heterostructure with one-dimensional (1D) amorphous potassium titanate (KTiOx) nanobelts in-situ grown on two-dimensional (2D) titanium carbide (Ti2CTx) nanosheets (a-KTiOx/Ti2CTx) was fabricated through alkalization of the multilayered Ti2CTx MXene, which exhibits remarkable sodium storage performance at both room and low temperatures. The heterostructure prepared by the combination of 1D amorphous nanobelts and 2D conductive nanosheets enables efficient strain alleviation in the electrode, a high capacitive contribution to charge storage, rapid ionic diffusion kinetics, and robust electrode integrity, thus enhancing the sodium storage performance. In particular, reversible capacities of 221.9, 144.2 and 112.6 mAh/g can be achieved at 0.1 A/g after 100 cycles at 25, 0 and −25 °C, respectively. This study provides significant insights into the construction of MXene-based electrode materials for sodium storage at low temperatures.

Preparation of Three-Dimensional MF/Ti3C2Tx/PmPD by Interfacial Polymerization for Efficient Hexavalent Chromium Removal.

Heavy metal pollution is a serious threat to human health and the ecological environment, but adsorption technology based on nano adsorbents can effectively treat the crisis. However, due to the nanoscale effect, nano adsorbents have some crucial shortcomings, such as recycling difficulty and the loss of nanoparticles, which seriously limit their application. The feasible assembly of nano adsorbents is an accessible technology in urgent need of a breakthrough. In this study, three-dimensional (3D) adsorbent (MF/Ti3C2Tx/PmPD) with excellent performance and favorable recyclability was prepared by interfacial polymerization with melamine foam (MF) as the framework, two-dimensional (2D) titanium carbide (Ti3C2Tx) as the bridge and Poly (m-Phenylenediamine) (PmPD) as the active nano component. The morphology, structure, mechanical property of MF/Ti3C2Tx/PmPD and reference MF/PmPD were investigated through a scanning electron microscope (SEM), Fourier transformed infrared spectra (FT-IR), Raman scattering spectra and a pressure-stress test, respectively. Owning to the regulation of Ti3C2Tx on the morphology and structure of PmPD, MF/Ti3C2Tx/PmPD showed excellent adsorption capacity (352.15 mg/g) and favorable cycling performance. R–P and pseudo-second-order kinetics models could well describe the adsorption phenomenon, indicating that the adsorption process involved a composite process of single-layer and multi-layer adsorption and was dominated by chemical adsorption. In this research, the preparation mechanism of MF/Ti3C2Tx/PmPD and the adsorption process of Cr(VI) were systematically investigated, which provided a feasible approach for the feasible assembly and application of nano adsorbents in the environmental field.

Ultralarge Flakes of Ti3C2Tx MXene via Soft Delamination.

Two-dimensional (2D) titanium carbide MXene (Ti3C2Tx) has attracted significant attention due to its combination of properties and great promise for various applications. The size of the 2D sheets is a critical parameter affecting multiple properties of assembled films, fibers and 3D structures. The increased lateral size of MXene flakes can benefit not only their assemblies by improving the interflake contacts and alignment but also fundamental studies at the individual flake level, allowing for facile patterning and investigation of intrinsic physical properties of MXenes. Increasing the average size of the parent MAX phase is one of the strategies previously used to increase the flake size of the resultant MXene. Here, we show that the protocol used for the next step of the synthesis procedure, delamination of multilayer MXene into individual nanosheets, significantly affects the lateral size of the resultant flakes. We developed a soft delamination approach, which prevents fracture of flakes and preserves their size. Combining this approach with the large-grain Ti3AlC2 MAX phase precursor, we achieved individual flakes of up to 40 μm in lateral size. These flakes can be used for patterning multiple contacts and fabrication of field-effect transistors for multiprobe electrical characterization and other measurements. These findings indicate the importance of controlling the delamination process in order to achieve large MXene flakes and improve properties of MXene-based materials and devices.

Smart Low-temperature responsive fire alarm based on MXene/Graphene oxide film with wireless transmission: Remote real-time luminosity detection

Early fire alarms working at the pre-combustion stage have a promising future to achieve more efficient and intelligent fire management. Herein, a graphene oxide (GO)-based film is provided by introducing two-dimensional conductive titanium carbide (MXene) as a bridge to implement low-temperature alert and coupled with a small self-designed wireless signal conversion device to improve its intelligence. The fire-warning film fabricated by a facile formulation can shorten the response time to 1 s, showing the ultrafast sensitive ability at 250 ºC. Moreover, the warning signal transmission contains the warning message on a computer monitor and precise real-time fire luminosity value on a local and remote computer monitor via the associated luminosity sensor. This work further shortens response time at lower response temperatures, showing improved sensitivity ability. Intriguingly, a luminosity sensor is firstly introduced, fully realizing the combination between signal transmission of fire alarm and the Internet era. This work can also provide theoretical guidance for next-generation smart low-temperature fire alarms.

Application of MXene as a new generation of highly conductive coating materials for electromembrane-surrounded solid-phase microextraction

Abstract For the first time, highly conductive thickly layered two-dimensional titanium carbide (MXene) was applied as a new coating agent for electromembrane-surrounded solid-phase microextraction (SPME) of triadimenol and iprodione as two model analytes. Preparation of the desired coated electrode was carried out using electrophoretic deposition of MXene on the surface of platinum electrode. Characterization of the prepared coated electrode was conducted using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The coated electrode was located inside a hollow fiber membrane impregnated by 2-nitrophenyl octyl ether as the supported liquid membrane (SLM), while an aqueous solution was injected inside the hollow fiber lumen. Separation and quantification of the analytes were carried out using a gas chromatography instrument equipped with mass spectrometric detection. The effective parameters of the microextraction procedure comprising pHs of sample solution and the acceptor phase, composition of the SLM, extraction time, and the applied voltage were optimized using one-variable at-a-time method. Under the optimal conditions, the calibration curves of the analytes were linear (R 2 &gt; 0.9973) in the range of 0.3–250.0 and 0.5–250.0 ng mL−1 for triadimenol and iprodione, respectively. The limit of detections was determined to be 0.10 and 0.15 ng mL−1 for triadimenol and iprodione, respectively. Repeatability and reproducibility of the method were evaluated by the calculation of intra-day and inter-day relative standard deviations (%). The applicability of the method was evaluated by quantitative analysis of the model analytes in environmental water samples. Relative recoveries in the range of 87.31–102.7% confirmed that the prepared coated electrode can be considered a reliable option in electromembrane-surrounded SPME techniques.

Creating multilayer-structured polystyrene composites for enhanced fire safety and electromagnetic shielding

Two-dimensional (2D) titanium carbide (Ti3C2Tx) with high electrical conductivity and large active surfaces has attracted extensive attention in recent years. Here, in order to address the fire safety and poor electromagnetic shielding performance of polystyrene (PS), a highly effective cetyltrimethyl ammonium bromide-multi-wall carbon nanotubes@Ti3C2Tx (C-MWCNT@Ti3C2Tx) bilayer was deposited on PS sphere to achieve PS@C-MWCNT@Ti3C2Tx (PCT) composites for improving its fire safety and electromagnetic shielding performances. In addition, Ti3C2Tx and γ-propyl-trimethoxysilane (KH550) were adopted to modify silicon wrapped ammonium polyphosphate (SiAPP-NH2@Ti3C2Tx) via the microencapsulation strategy. Finally, the SiAPP-NH2@Ti3C2Tx was incorporated into PCT composites to fabricate excellent fire-resistant PS composites, i.e. PCTS. The obtained results demonstrated that Ti3C2Tx not only promoted the thermal stability and fire safety but also enhanced the electromagnetic shielding performance of PS. For instance, the PS composite with three number of C-MWCNT@Ti3C2Tx bilayers (PCTS3) exhibited dramatically lowest the peak of heat release rate (528 kW/m2) and highest electromagnetic shielding effectiveness value (11 dB), indicative of the excellent flame retardant and considerable electromagnetic shielding properties. This work sheds light on the design of multifunctional multi-layer structured polymer composites.

Constructing titanium carbide MXene/reduced graphene oxide superlattice heterostructure via electrostatic self-assembly for high-performance capacitive deionization

Capacitive deionization has attracted wide concern on accountof its high energy efficiency, low manufacturing cost and environmental friendliness. Nevertheless, the development of capacitive deionization is still impeded because of the scarcity of suitable electrode materials with superior performance. Herein, we successfully prepared the two-dimensional (2D) titanium carbide (Ti3C2Tx) MXene/ reduced graphene oxide (rGO) superlattice heterostructure by a facile electrostatic self-assembly strategy and systematically investigated its performance as capacitive deionized electrode materials. The unique 2D/2D superlattice heterostructure not only effectively alleviates the self-stacking problem of Ti3C2Tx MXene nanosheets, but also endows the heterostructure with superior conductivity and fast ion diffusion rate. As a result, the MXene/rGO superlattice heterostructure exhibits an outstanding salt (Na+) adsorption capacity (48 mg g−1) at 1.2 V significantly superior to pristine Ti3C2Tx MXene nanosheets, along with outstanding long-term cycling performance. Furthermore, the mechanism involved was elucidated through comprehensive characterizations. Therefore, this study offers a new pathway for designing high-performance electrode materials for capacitive deionization.

Regulated layer spacing and functional surface group of MXene film by hexamethylenetetramine for high-performance supercapacitors

Two-dimensional titanium carbide (MXene) has attracted a wide attention for its fast charging and discharging ability as an electrode for supercapacitors. Tremendous efforts have been dedicated to further optimize the electrochemical performance of MXene by adjusting the interlayer spacing and surface functional groups. Here, hexamethylenetetramine (HMT) molecules are used as an intercalation agent to enlarge the layer spacing of MXene nanosheets and regulate their electronic structure by the partial replacement of the surface functional groups (F, O and OH) with N elements via the carbonization temperature at 300 °C. The as-prepared N-doped MXene film exhibits the excellent flexibility, appropriate layer spacing and high electrical conductivity, which can be used directly as supercapacitor electrode materials. It delivers the excellent rate performance with a specific capacitance of 193 F g−1 at 2000 mV s−1. In addition, the assembled asymmetric supercapacitor with N-doped graphene aerogel, delivers a high energy density of 26.22 W h kg−1 at a power density of 899 W kg−1, and the capacitance retention of 92.1 % after 25,000 discharging/charging cycles, indicating the excellent application prospect.

Highly-sensitive fire alarm system based on cellulose paper with low-temperature response and wireless signal conversion

Highly sensitive smart sensors for early fire detection with remote warning capabilities are urgently required to improve the fire safety of combustible materials in diverse applications. The highly-sensitive fire alarm can detect fire situation within a short time quickly when a fire disaster is about to occur, which is conducive to achieve fire tuned. Herein, a novel fire alarm is designed by using flame-retardant cellulose paper loaded with graphene oxide (GO) and two-dimensional titanium carbide (Ti3C2, MXene). Owing to the excellent temperature dependent electrical resistance switching effect of GO, it acts as an electrical insulator at room temperature and becomes electrically conductive at high temperature. During a fire incident, the partial oxygen-containing groups on GO will undergo complete removal, which results in the conductivity transformation.Besides the use of GO feature, this work also introduces conductive MXene to enhance fire detection speed and warning at low temperature, especially below 300 {\deg}C. The designed flame-retardant fire alarm is sensitive enough to detect fire incident, showing a response time of 2 s at 250 {\deg}C, which is calculated by a novel and quantifiable technique. More importantly, the designed fire alarm sensor is coupled to a wireless communication interface to conveniently transmit fire signal remotely. Therefore, when an abnormal temperature is detected, the signal is wirelessly transmitted to a liquid crystal display (LCD) screen when displays a message such as "FIRE DANGER". The designed smart fire alarm paper is promising for use as a smart wallpaper for interior house decoration and other applications requiring early fire detection and warning.

Enhancing Electric Double Layer Capacitance of Two-Dimensional Titanium Carbide (MXene) with Facile Synthesis and Accentuated Properties

Enhancing Electric Double Layer Capacitance of Two-Dimensional Titanium Carbide (MXene) with Facile Synthesis and Accentuated Properties

Mechanically and environmentally robust composite nanofibers with embedded MXene for wearable shielding of electromagnetic wave

Flexible materials based on two-dimensional titanium carbides (MXene) exhibit great potential for electromagnetic interference (EMI) shielding applications. However, MXene base EMI shielding materials usually cannot possess combined favorable properties of high strength, environmental stability and air permeability, which can inhibit practical implementations as wearable components. Herein, newly designed EMI shielding Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite fabric with MXene embedded in nanofibers have been prepared by one-step electrospinning technique. The highly hydrophobic composite fabric shows excellent specific EMI shielding effectiveness of 160 dB/mm, which remains unchanged when exposed in acidic, alkali or saline solutions for 10 days due to the polymer matrix protection. Moreover, the embedded MXene can greatly enhance the strength and modulus of the fabric. The ultimate strength of the highly flexible composite can reach as high as20 MPa, which is 33% higher compared with untreated PVDF-HFP fabric. Our study could allow us to implement MXene based EMI shielding materials for more practical applications.

A molecularly imprinted electrochemical sensor based on cationic intercalated two-dimensional titanium carbide nanosheets for sensitive and selective detection of triclosan in food samples

An advanced molecularly imprinted electrochemical sensor (MIECS) based on two-dimensional materials MXene was developed for determination of triclosan (TCS) in food samples for the first time. Two-dimensional titanium carbide (Ti3C2Tx) were introduced to improve electrochemical response of the MIECS. K+ ions were spontaneously inserted into Ti3C2Tx nanosheets to form K+-Ti3C2Tx by soaking in alkali solution, thus improving the sensitivity of the sensor. Molecularly imprinted polymers (MIP) were prepared by electropolymerization of para aminobenzoic acid (p-ABA), which can specifically recognize TCS. Under optimal conditions, the linear relationship between the current intensity and TCS concentration was obtained from 10 nmol L−1 to 50 μmol L−1 with a low detection limit of 1.18 nmol L−1. The proposed MIECS showed good repeatability for detecting TCS at a concentration of 500 nmol L−1 solution by preparing five parallel modified electrodes, with a relative standard deviation (RSD) of 3.42%. At the spiked concentration levels of 0.05, 0.1, 0.5 mg L−1/mg kg−1, the recoveries range of TCS in peach juice, onions and fish samples were 86.38%–95.52%. The proposed MIECS combining the advantages of Ti3C2Tx and MIP exhibited good sensitivity and selectivity, providing strategy of utilizing MXenes in the construction of electrochemical sensing platform and holding great promise in the field of food safety.