Ti3C2 Flakes Research Articles

Comprehensive study on catalytic potential of Ti3C2Tx based catalyzer for Dye sensitized solar cells application

Abstract Recently Dye-sensitized solar cells (DSSC) have gained significant research limelight for having exceptional photovoltaic potential. However, DSSC became an underdog solar cell due to the use of an expensive transparent conductive layer (FTO/ITO) along with the use of rare earth element Pt to concoct counter electrode (CE). Thus, an attempt has been made to concoct a Ti3C2-TX MXene-based CE to replace both the transparent conductive layer and CE. Herein, relatively larger with less defective Ti3C2 flakes were produced by the minimally intensive layer delamination method, and physical architecture was investigated by X-ray diffraction (XRD) mapping, Field-emission scanning electron microscope (FE-SEM) and Dynamic light scattering (DLS), respectively. MXene flakes were drop cast on a glass substrate by dispersing it in ethanol, isopropyl alcohol, and deionized water, respectively, and found the least sheet resistance, 14.824 Ω/sq by 4-point probe test, owing to superior adsorption force with the glass substrate. Ethanol solvent facilitates optimum interlamellar spacing to promote fast diffusion and transportation. Further, the study was expanded by introducing it to numerous sintering temperatures to find the best result. The result revealed exceptional sheet resistance of 0.08 Ω/sq for the 120℃ sintered sample, which was encouraged by removing water intercalant and occupying H+. Further, the potential of MXene-based counter electrode’s catalytic activity has been studied through electrochemical impedance spectroscopy, Tafel polarization, and Cyclic voltammogram under iodide and triiodide-based electrolytes. The electrochemical study revealed 120℃ sintered sample superior to 140℃ sintered but comparable to Pt CE. 120℃ sintered Ti3C2-based CE performed exceptional 6.27% power conversion efficiency. Thus, this novel study communicates that Ti3C2-TX is a potential replacement for transparent conductive oxide layer and Pt, frequently used in Dye-sensitized solar cell applications.

The enhanced performance of Li-ion batteries based on Co-MOF/MXene composites

Electrospinning is carried out to fabricate Ti3C2Tx@Co nanocomposite films composed of 2D Ti3C2-encapsulated Co nanoparticles derived from Co-MOF precursors. The unique 1D nanochain structure inherits not only the high electrochemical activity, but also excellent electron and ionic conductivity. The Co nanoparticles with good conductivity and MXene with high electrochemical activity improve the electrochemical properties giving rise to high capacity and good cycling stability. The Ti3C2 flakes partially accommodate the volume changes during Li+ insertion/extraction and the electrospinning technique prevents self-aggregation of Ti3C2 flakes and aggregation of ZIF-67 nanoparticles, consequently producing a larger surface area and more active sites on the flexible anode. As a result, the MXene/Co composite has excellent properties such as a high reversible capacity of 422 mA h g−1 after 500 charging-discharging cycles at a current density of 1 A/g and retained capacity of 177 mA h g−1 at a rate of 5 A/g. The materials and strategy have large potential in commercial energy storage devices.

Bimetallic nickel iron sulfide directly grown on defect-rich Ti3C2 MXene as an efficient bifunctional electrocatalyst for water electrolysis

Water electrolysis has been regarded as ideal method for producing high-purity hydrogen without the generation of environmental pollutants. Accordingly, the development of precious metal-free electrocatalysts that demonstrate high activity for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is essential for practical water electrolysis. Herein, porosity-engineered Ti3C2 MXene is employed as an efficient substrate for a bimetallic Ni-Fe-S electrocatalyst. The porous and defect-rich Ti3C2 (D-Ti3C2) flakes provide metal-like electrical conductivity and large surface area for direct growth of active species. Simultaneously, the Ni-Fe-S nanoparticles, constructed through a strong coupling between NiS2 and (Ni,Fe)S2 solid solution, not only serve as active sites with rich redox properties, but also generate charge transfer channels for electrochemical reactions. Leveraging these advantageous properties, the resulting Ni-Fe-S/D-Ti3C2 electrocatalyst exhibits excellent bifunctional electrocatalytic performance toward both OER and HER. As a result, the symmetric water electrolysis cell using the Ni-Fe-S/D-Ti3C2 requires a low cell voltage of 1.621 V to deliver current density of 10 mA cm−2, and shows stable electrocatalytic performance over 100 h of continuous operation.

Facile fabrication of carbon fiber skeleton structure of MoS2 supported on 2D MXene composite with highly efficient and stable hydrogen evolution reaction

Development of advanced electrocatalytic materials is the crucial technology in electrolytic water to produce clean hydrogen energy. Herein, we have developed a highly efficient and stable hydrogen evolution reaction (HER) electrocatalyst MoS2/Ti3C2@CNFs hybrid material, which obtained by sulfur vapor assisted graphitization of Mo/Ti3C2@PAN precursor. Conductive Ti3C2 MXene and carbon nanofiber (CNFs) were applied to construct the “plane-line” skeleton structure to effectively prevent the stacking of Ti3C2 flakes, increase the loading content of MoS2, enlarge the exposure active edge sites of MoS2 and accelerate charger transfer of MoS2. MoS2/Ti3C2@CNFs exhibits excellent electrocatalytic activity and high stability in HER compared to pure MoS2 and MoS2/Ti3C2 nanostructure. The excellent performance of MoS2/Ti3C2@CNFs in HER is attributed to the special characteristics of the skeleton structure and the strong interface coupling between MoS2 and Ti3C2 MXene. Our findings provide a viable approach for designing advanced nanostructures for catalysis, electronic devices, and other potential applications.

Rational design of Ti3C2/carbon nanotubes/MnCo2S4 electrodes for symmetric supercapacitors with high energy storage

The enhancement of electrochemical performance of supercapacitors with high-energy storage is largely determined by the selective electrode materials and their rational structural design. In this paper, we fabricated Ti3C2/CNTs/MnCo2S4 composite electrodes by electrostatic self-assembly between positively charged multiwalled carbon nanotubes (CNTs) and negatively charged Ti3C2, followed by subsequent anchoring of bimetallic sulphide MnCo2S4 nanoparticles to Ti3C2/CNTs hybrid via a two-step hydrothermal method. All the Ti3C2/CNTs/MnCo2S4 composite electrodes exhibit enhanced specific capacitance comparing with the pure Ti3C2 electrodes. The optimized Ti3C2/CNTs/MnCo2S4 electrode shows paramount gravimetric capacitance (Cs) (823 F/g at a current density of 1A/g), high rate retention (63.5% of specific capacitance retains when current density increases from 1 to 5A/g), and excellent cycling stability (94.09% after 5000 charging and discharging cycles). These improved electrochemical performances are mainly attributed to the synergistic effect of high specific capacitance from the pseudocapative material of MnCo2S4, remarkable conductivity of Ti3C2 and CNTs, and the micro-/nano-porous structures constructed by stacking Ti3C2 flakes with CNTs. Moreover, the as-synthesized Ti3C2/CNTs/MnCo2S4 electrode-based symmetric supercapacitor demonstrates a high energy density of 49.5 Wh/kg at a power density of 350 W/kg, suggesting that the electrochemical performance of Ti3C2-based supercapacitors can be substantially boosted by rational design and modification of Ti3C2 electrodes with MnCo2S4 and multilayer CNTs.

MXene-encapsulated hollow Fe3O4 nanochains embedded in N-doped carbon nanofibers with dual electronic pathways as flexible anodes for high-performance Li-ion batteries.

Fe3O4 is one of the promising anode materials in Li-ion batteries and a potential alternative to graphite due to the high specific capacity, natural abundance, environmental benignity, non-flammability, and better safety. Nevertheless, the sluggish intrinsic reaction kinetics and huge volume variation severely limit the reversible capacity and cycling life. In order to overcome these hurdles and enhance the cycling life of Fe3O4, a one-dimensional (1D) nanochain structure composed of 2D Ti3C2-encapsulated hollow Fe3O4 nanospheres homogeneously embedded in N-doped carbon nanofibers (Fe3O4@MXene/CNFs) is designed and demonstrated as a high-performance anode in Li-ion batteries. The distinctive 1D nanochain structure not only inherits the high electrochemical activity of Fe3O4, but also exhibits excellent electron and ion conductivity. The Ti3C2 layer on the Fe3O4 hollow nanospheres forms the primary electron transport pathway and the N-doped carbon nanofiber network provides the secondary transport pathway. At the same time, Ti3C2 flakes partially accommodate the large volume change of Fe3O4 during Li+ insertion/extraction. Density functional theory (DFT) calculations demonstrate that the Fe3O4@MXene/CNFs electrode can efficiently enhance the adsorption of Li+ to promote Li+ storage. As a result of the electrospinning process, self-restacking of Ti3C2 flakes and aggregation of Fe3O4 nanospheres can be prevented resulting in a larger surface area and more accessible active sites on the flexible anode. The Fe3O4@MXene/CNFs anode has remarkable electrochemical properties at high current densities. For example, a reversible capacity of 806 mA h g-1 can be achieved at 2 A g-1 even after 500 cycles, corresponding to an area specific capacity of 1.612 mA h cm-2 at 4 mA cm-2 and a capacity as high as 613 mA h g-1 is retained at 5 A g-1, corresponding to an area capacity of 1.226 mA h cm-2 at 10 mA cm-2. The results indicate that the Fe3O4@MXene/CNFs anode has excellent properties for Li-ion storage.

Assessment of Tribological Properties of Ti3C2 as a Water-Based Lubricant Additive.

Water-based lubrication has attracted remarkable interest due to its environmental and economic advantages. However, practical applications of water-based lubrication are often limited, mainly because of low viscosity and corrosivity. The use of additives has been proposed to overcome these limitations. In this work, the tribological characteristics of titanium carbide (Ti3C2) MXenes, as additives for water-based lubrication, were systematically investigated for contact sliding between stainless steel under various normal forces and Ti3C2 concentrations. Both friction and wear were found to decrease with increasing Ti3C2 concentration up to 5 wt%, and then increased when the concentration was larger than 5 wt%. The results suggest that Ti3C2 flakes hindered direct contact, particularly at the edges of the contact interfaces. It was further shown that the agglomeration of Ti3C2 flakes may have reduced the hindering when an excessive amount of Ti3C2 (e.g., 7 wt%) was applied. The decreases in the friction coefficient and wear rate with 5 wt% of Ti3C2 concentration w approximately 20% and 48%, respectively. The outcomes of this work may be helpful in gaining a better understanding of the tribological properties of Ti3C2 as a feasible water-based lubrication additive.

Maximizing ion accessibility in MXene-knotted carbon nanotube composite electrodes for high-rate electrochemical energy storage

Improving the accessibility of ions in the electrodes of electrochemical energy storage devices is vital for charge storage and rate performance. In particular, the kinetics of ion transport in organic electrolytes is slow, especially at low operating temperatures. Herein, we report a new type of MXene-carbon nanotube (CNT) composite electrode that maximizes ion accessibility resulting in exceptional rate performance at low temperatures. The improved ion transport at low temperatures is made possible by breaking the conventional horizontal alignment of the two-dimensional layers of the MXene Ti3C2 by using specially designed knotted CNTs. The large, knot-like structures in the knotted CNTs prevent the usual restacking of the Ti3C2 flakes and create fast ion transport pathways. The MXene-knotted CNT composite electrodes achieve high capacitance (up to 130 F g−1 (276 F cm−3)) in organic electrolytes with high capacitance retention over a wide scan rate range of 10 mV s−1 to 10 V s−1. This study is also the first report utilizing MXene-based supercapacitors at low temperatures (down to −60 °C).

Interface coupling in FeOOH/MXene heterojunction for highly reversible lithium-ion storage

Recently, MXene coupling with active nanomaterials show considerable potential for energy storage applications. However, the complicated fabrication of MXene-based composites and their low Li+ storage reversibility impede the further application for lithium-ion batteries. Herein, as a proof of concept, a novel architecture of β-FeOOH quantum dots grafted on Ti3C2 flakes has been realized via a one-step facile immersion method. The crumple Ti3C2 MXene in the synthetic hybrids functions as a favorable matrix to load FeOOH dots due to its open framework, superior electrical conductivity, and low energy barrier of Li+ diffusion. In virtue of the strong interfacial interactions of the formed heterojunctions between alkali-Ti3C2 matrix and FeOOH, the hybrid enables the enhanced kinetics of charge transfer and stable interfacial structure. Consequently, the FeOOH@3D-MX electrode exhibits superior high-rate capability (286.1 mAh g−1 at 10 A g−1) and particularly durable lithium-ion storage with no capacity decay over 500 cycles (572.3 mAh g−1 after 500 cycles at 500 mA g−1). The enhanced Li+ storage mechanism of FeOOH/MXene heterostructures is also evidenced by density functional theory calculations and kinetics analyses. This work exploits a facile strategy to build high-performance anode composite and paves the way to exploring their energy storage mechanisms.

Using a Self-Assembled Two-Dimensional MXene-Based Catalyst (2D-Ni@Ti3C2) to Enhance Hydrogen Storage Properties of MgH2.

In this work, we report the remarkable catalytic effects of a novel Ti3C2 MXene-based catalyst (Ni@Ti-MX), which was prepared via self-assembling of Ni nanoparticles onto the surface of exfoliated Ti3C2 nanosheets. The resultant Ni@Ti-MX catalyst, characterized by ultradispersed Ni nanoparticles being anchored on the monolayer Ti3C2 flakes, was introduced into MgH2 through ball milling. In situ transmission electron microscopy (TEM) analysis revealed that a synergetic catalytic effect of multiphase components (Mg2Ni, TiO2, metallic Ti, etc.) derived in the MgH2 + Ni@Ti-MX composite exhibits remarkable improvements in the hydrogen sorption kinetics of MgH2. In particular, the MgH2 + Ni@Ti-MX composite can absorb 5.4 wt % H2 in 25 s at 125 °C and release 5.2 wt % H2 in 15 min at 250 °C. Interestingly, it can uptake 4 wt % H2 in 5 h even at room temperature. Furthermore, the dehydrogenation peak temperature of the MgH2 + Ni@Ti-MX composite is about 221 °C, which is 50 and 122 °C lower than that of MgH2 + Ti-MX and MgH2, respectively. The excellent hydrogen sorption properties of the MgH2 + Ni@Ti-MX composite are primarily attributed to the peculiar core-shell nanostructured MgH2@Mg2NiH4 hybrid materials and the interfacial coupling effects from different catalyst-matrix interfaces. The results obtained in this study demonstrate that using self-assembling of transition-metal elements on two-dimensional (2D) materials as a catalyst is a promising approach to enhance the hydrogen storage properties of MgH2.

In Situ Formation of Multiple Schottky Barriers in a Ti3C2 MXene Film and its Application in Highly Sensitive Gas Sensors

AbstractThe main gas‐sensing mechanisms of 2D materials are surface charge transfer by analytes and Schottky barrier (SB) modulation at the interface between the metallic and semiconducting surfaces. In particular, dramatic differences in the gas‐sensing performances of 2D materials originate from SB modulation. However, SB sites typically exist only at the interface between the semiconducting channel material and the metal electrode. Herein, in situ formed multiple SBs in a single gas‐sensing channel are demonstrated, which are derived from the heterojunction of metallic Ti3C2 and semiconducting TiO2. In stark contrast with previous techniques, edge‐oxidized Ti3C2 flakes are synthesized by solution oxidation, allowing the uniform formation of TiO2 crystals on all flakes that comprise the gas sensing channel. Oxidized colloidal solutions are subjected to vacuum filtration to automatically form SB sites at the multiple inter‐flake junctions in both the outer surface and inner bulk regions of the film. The TiO2/Ti3C2 composite sensor shows 13.7 times higher NO2 sensitivity as compared with pristine Ti3C2 MXene, while the responses of the reducing gases are almost unchanged. The results suggest a new strategy for improving gas‐sensing performance by maximizing the density of SB sites through a simple method.

Engineering of 2D Ti3C2 MXene Surface Charge and Its Influence on Biological Properties.

Current trends in the field of MXenes emphasize the importance of controlling their surface features for successful application in biotechnological areas. The ability to stabilize the surface properties of MXenes has been demonstrated here through surface charge engineering. It was thus determined how changing the surface charges of two-dimensional (2D) Ti3C2 MXene phase flakes using cationic polymeric poly-L-lysine (PLL) molecules affects the colloidal and biological properties of the resulting hybrid 2D nanomaterial. Electrostatic adsorption of PLL on the surface of delaminated 2D Ti3C2 flakes occurs efficiently, leads to changing an MXene’s negative surface charge toward a positive value, which can also be effectively managed through pH changes. Analysis of bioactive properties revealed additional antibacterial functionality of the developed 2D Ti3C2/PLL MXene flakes concerning Escherichia. coli Gram-negative bacteria cells. A reduction of two orders of magnitude of viable cells was achieved at a concentration of 200 mg L−1. The in vitro analysis also showed lowered toxicity in the concentration range up to 375 mg L−1. The presented study demonstrates a feasible approach to control surface properties of 2D Ti3C2 MXene flakes through surface charge engineering which was also verified in vitro for usage in biotechnology or nanomedicine applications.

On tuning the cytotoxicity of Ti3C2 (MXene) flakes to cancerous and benign cells by post-delamination surface modifications

Despite intensive research on the application of two-dimensional (2D) materials, including MXenes, in nanomedicine, the knowledge concerning the mechanisms responsible for their observed bio-effects is far from being understood. Here we present insight into the mechanism of toxicity in vitro of the 2D Ti3C2 MXene. The most important results of this work are that using simple, inexpensive, post-delamination treatments, such as ultrasonication or mild thermal oxidation it is possible to ‘tune’ the cytotoxicity of the Ti3C2Tz flakes. Sonication of Ti3C2Tz flakes, or sonication followed by mild oxidation in the water at 60 °C, renders them selectively toxic to cancer cells as compared to non-malignant ones. It relates to the appearance of superficial titanium (III) oxide (Ti2O3) layer corresponding to the type of post-treatment. The presence of surface-Ti2O3 results in a noticeably higher generation of oxidative stress compared to pristine 2D Ti3C2. Our findings give evidence that the sonication and thermal treatments were successful in changing the nature of the surface terminations on the Ti3C2Tz surfaces. This study makes a significant contribution to the future rationalized surface-management of 2D Ti3C2 MXene as well as encourages new rationalized applications in biotechnology and nanomedicine.Bullet points:1. First study on 2D Ti3C2 MXene superficially oxidized to titanium (III) oxide i.e. Ti2O3.2. By sonication Ti3C2Tz MXene flakes followed by mild thermal oxidation in the water at 60 °C for 24 h, it is possible to ‘tune’ the toxicity of the flakes to cancerous cell lines.3. Decreases in cell viabilities were dose-dependent.4. Highest cytotoxic effect was observed for thermally oxidized samples.5. The thermally oxidized samples were also selectively toxic towards all cancerous cell lines up to 375 mg l−1.6. Reactive oxygen species generation was identified as a mechanism of toxicity.

High areal capacitance of vanadium oxides intercalated Ti3C2 MXene for flexible supercapacitors with high mass loading

Flexible all-solid-state supercapacitors (ASSSs) have caught the scientific attention to meet the explosive demand for portable and wearable electronic devices. However, it is difficult for flexible electrode materials to obtain a high areal capacitance at a high mass loading, which limits their commercial applications. In this study, vanadium oxide (V2O5) nanoparticles are introduced into Ti3C2 flakes with the aid of cetyltrimethylammonium bromide (CTAB). The intercalation of V2O5 particles in the interlayer of Ti3C2 establishes a hierarchical structure and facilitates the electrolyte penetration. As a result, the prepared CT-Ti3C2@V2O5 composite electrode achieves a high areal capacitance of 2065 mF cm−2 at 3 mA cm−2 and superior active mass loading (15 mg cm−2). Meanwhile, over 93% capacitance is maintained after 6000 cycles at 18 mA cm−2. The ASSS based on CT-Ti3C2@V2O5 delivers a high areal capacitance of 477 mF cm−2 at 1 mV s−1 and exhibits stable performance at different bending states, which reaches to the advanced level for the ASSSs based on MXenes.

Surface interactions between 2D Ti3C2/Ti2C MXenes and lysozyme

This work presents a comprehensive study on the surface-property changes of 2D flakes of MXenes (Ti3C2 and Ti2C) upon interacting with the model cationic protein – lysozyme, using time-resolved dynamic light scattering and zeta potential. The study was also aimed at investigating how MXenes stoichiometry, structure, surface chemistry and exposure concentration effects its interactions with lysozyme. We found that the adsorption of lysozyme on 2D Ti2C and Ti3C2 flakes occurred effectively, leading to changes in MXenes zeta potential in a concentration-dependent manner. The lysozyme adsorption efficiency varied, depending on the surface chemistry and stoichiometry of the investigated MXenes. The results showed that the Ti3C2 MXene exhibited a higher adsorption of lysozyme in comparison to Ti2C MXene. The zeta potential assays revealed that the adsorption mechanism for MXenes was mainly electrostatic. We also demonstrated the lysozyme release from the MXene surface during pH changes to basic environment. Our findings highlight the importance of evaluating MXenes interactions with biomacromolecules and the mechanism for potential protein adsorption prior to designing e.g. drug delivery systems. We have shown that protein adsorption dramatically changes the surface-physicochemical properties of the MXenes, which may have a significant impact on the effectiveness and safety of future delivery, separation and purification systems dedicated to particular proteins.

Three dimensional hierarchical network structure of S-NiFe2O4 modified few-layer titanium carbides (MXene) flakes on nickel foam as a high efficient electrocatalyst for oxygen evolution

Oxygen evolution reaction (OER) is an important kinetic process in many important renewable energy applications, while high-efficiency electrocatalysts, especially efficient non-precious metal catalysts, are very essential to overcome substantial overpotential and sluggish kinetics of OER. Here, three-dimensional (3D) Ti3C2 based conductive network structure was firstly constructed by an absorption of 2D few-layer Ti3C2 flakes (MXene) onto 3D nickel foam (NF) network, and then ultra-small sulfur-incorporated nickel ferrite nanosheets (S-NiFe2O4) were grown on the 3D Ti3C2 based conductive network structure (abbreviated as S-NiFe2O4@Ti3C2@NF) by combining a facile thiourea-assisted electrodeposition process with a low-temperature calcination process. Results indicate that the as-fabricated S-NiFe2O4@Ti3C2@NF hybrid electrode exhibits a superior OER activity, which includes only 1.50 V vs. RHE to afford a current density of 20 mA cm−2, a Tafel slope of 46.8 mV dec−1 and excellent catalytic stability in 1 M KOH. Excellent OER performances are attributed to the favorable 3D hierarchical network structure and relatively fast electron transport provided by the few-layer Ti3C2 flakes matrix, good catalytic activity and abundant catalytic active sites from the ultra-small S-NiFe2O4 nanosheets, synergistically. This work could open a feasible way for achieving a new type of 3D MXenes based hierarchical network structure for renewable energy applications.

Facile synthesis of hierarchical NaTi2(PO4)3/Ti3C2 nanocomposites with superior sodium storage performance

Herein, hierarchical layered NaTi2(PO4)3/Ti3C2 (NTP/TC) nanocomposites were massively synthesized via a simple yet scalable solvothermal strategy, and further evaluated as a promising anode for sodium ion batteries. The in situ formed NTP nanoparticles were uniformly decorated upon the Ti3C2 flakes. As a result, the NTP/TC exhibited large reversible capacities, long cycling performance and striking rate capability, thanks to its inherent structural and componential superiorities.

A hydrothermal etching route to synthesis of 2D MXene (Ti3C2, Nb2C): Enhanced exfoliation and improved adsorption performance

2D MXenes have attracted extensive attentions owing to their anisotropy, high conductivity and other extraordinary properties. The popular preparation method of MXenes usually involves HF in high concentrations, which has seriously restricted their pervasive applications. In this work, a new hydrothermal route with low-toxicity etching agents (NaBF4, HCl) was used to synthesize Ti3C2 MXene (h-Ti3C2). Compared with the Ti3C2 prepared by the traditional HF etching method (t-Ti3C2), the h-Ti3C2 has the higher c lattice parameter, larger interlayer distance and larger BET specific surface area, because of the slow release mechanism during the hydrothermal process. The hydrothermal etching method not only avoided the use of high-concentration HF, but also was more efficient to prepare Ti3C2 flakes. Moreover, the hydrothermal etching route can be extended to other MXene materials, e.g. Nb2C. We demonstrated that the h-MXenes have better adsorption performance of methylene blue and methyl orange dyes. The hydrothermal etching route proposed in this study enabled the environmental benign and high efficiency exfoliation of MXenes, displaying the promise to facilely prepare 2D MXenes and paving a way to their widespread applications.

New Ti3C2 aerogel as promising negative electrode materials for asymmetric supercapacitors

Novel 3D Ti3C2 aerogel has been first synthesized by a simple EDA-assisted self-assembly process. Its inside are channels and pores structure. The interconnected aerogel structure could efficiently restrain restacking of Ti3C2 flakes. Thus, it exhibits a large specific surface area as high as 176.3 m2 g−1. The electrochemical performances have been measured. The Ti3C2 aerogel achieves a quite high areal capacitance of 1012.5 mF cm−2 for the mass loading of 15 mg at a scan rate of 2 mV s−1 in 1 M KOH electrolyte. An asymmetric supercapacitor (ASC) has been assembled by using the Ti3C2 aerogel electrode as the negative electrode and electrospinning carbon nanofiber film as the positive electrode. The device can deliver a high energy density of 120.0 μWh cm−2 and a maximum power density of 26123 μW cm−2. A lamp panel with nineteen red light-emitting diodes has been powered by two ASCs in series.

Preparation and characterization of polymer‐Ti3C2Tx (MXene) composite nanofibers produced via electrospinning

ABSTRACTMXene, a recently‐discovered family of two‐dimensional (2D) transition metal carbides and/or nitrides, have attracted much interest because of their unique electrical, thermal, and mechanical properties. In this study, poly(acrylic acid), poly(ethylene oxide) (PEO), poly(vinyl alcohol) (PVA), and alginate/PEO were electrospun with delaminated Ti3C2 (MXene) flakes. The effect of small additions of delaminated Ti3C2 (1% w/w) on the structure and properties of the nanofibers were investigated and compared with those of the neat polymer nanofibers using scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy. Ti3C2 had an effect on the solution properties of the polymer and a greater effect on the average fiber diameter. The Ti3C2Tx/PEO solution exhibited the largest change in viscosity and conductivity with an 11% and 73.6% increase over the base polymer, respectively. X‐ray diffractograms demonstrated a high degree of crystallization for Ti3C2/PEO and a slight decrease in crystallinity for Ti3C2/PVA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45295.