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1.
Highly active two-dimensional (2D) nanocomposites have been widely concerned in the field of gas sensors because of their unique advantages and synergistic effects. 2D/2D SnO 2 nanosheets/Ti 3C 2T x MXene nanocomposites were synthesized by using layered Ti 3C 2T x MXene and uniform SnO 2 nanosheets by hydrothermal method. Characterization results show that the SnO 2 nanosheets are well dispersed and vertically anchored on the layered Ti 3C 2T x MXene surface, forming heterogeneous interfaces. Based on the gas-adsorption capabilities and synergistic effects of electronic properties, SnO 2 nanosheets/Ti 3C 2T x MXene nanocomposites show high triethylamine (TEA) gas-sensing performance at low temperature (140 °C). The sensor responses of the nanocomposites and pure SnO 2 nanosheets to 50 ppm of TEA are 33.9 and 3.4, respectively. An enhancement mechanism for SnO 2 nanosheets/Ti 3C 2T x MXene nanocomposites is proposed for highly sensitive and selective detection of TEA at low temperature. The combination strategy of two-dimensional metal oxide semiconductor and multilayer MXene provides a new way for the development of cryogenic gas sensors in the future. 相似文献
2.
Ti 3C 2T x MXene, an emerging two-dimensional (2D) ceramic material, has rich interfaces and strong conductive networks. Herein, we have successfully built a heterostructure between Ti 3C 2T x MXene and WS 2 to improve electromagnetic absorption performance. X-ray diffraction and X-ray photoelectron spectroscopy were used to determine the successful synthesis of Ti 3C 2T x/WS 2 composite. Field emission scanning electron microscopy and transmission electron microscopy images show that WS 2 nanosheets are evenly dispersed on the accordion-like Ti 3C 2T x MXene. Importantly, Ti 3C 2T x MXene/WS 2 composite has sufficiently high dielectric loss and impedance matching due to self-adjusting conductivity and 2D heterostructure interfaces. As a result, the Ti 3C 2T x/WS 2 composite has a minimum reflection loss (RL min) of −61.06 dB at 13.28 GHz. Besides, it has a broad effective absorption bandwidth (EAB) of 6.5 GHz, with EAB >5.0 GHz covering a wide range of thickness. Such impressive results may provide experience for the application of Ti 3C 2T x ceramics and 2D materials. 相似文献
3.
Ti 3C 2T x MXene has attracted extensive attention in the field of electromagnetic (EM) protection over recent years. Multilayer Ti 3C 2T x (M-Ti 3C 2T x), as an intermediate product of MXene ultra-thin structure, has potential advantages in the field of EM protection. Herein, the M-Ti 3C 2T x was obtained by HCl/LiF etching Ti 3AlC 2. The microwave absorption (MA) and electromagnetic interference (EMI) shielding performance of Ti 3AlC 2 and M-Ti 3C 2T x were compared. The mechanism research of MA and EMI shielding indicates that the construction of local conductive network plays a leading role in the EM wave attenuation. The sample with 30% M-Ti 3C 2T x display RL min of ?50.26 dB, and corresponding bandwidth of 4.64 GHz at the thickness of 1.7 mm. Especially, the metastructure based on the EM parameters of M-Ti 3C 2T x/wax exhibits ultra-wide bandwidth (15.54 GHz). Our research will provide a basis for the design of MXene-based EM protection performance. 相似文献
4.
Different kinds of two-dimensional hybrid electrodes have high theoretical capacitance and energy density. However, the origin of the electrochemical storage mechanism still remains elusive in alkaline, acid and neutral electrolytes. Herein, the interstratification-assembled Ti 3C 2T x MXene/NiCo-LDHs electrodes were successfully prepared and studied in different electrolytes by in-situ Raman spectroscopy. The results show that H 2O molecules in neutral electrolyte combine with –OH at the end of Ti 3C 2T x MXene during charging, and debonding occurs during discharge. Similarly, this reaction also occurs in the discharge process with NiCo-LDHs and provides smaller pseudocapacitance characteristics. Although this pseudocapacitance reaction also occurs in acidic and alkaline electrolytes, however, the difference is that the hydrogen ions will promote the electrochemical performance of Ti 3C 2T x MXene and has a certain corrosion consumption effect on NiCo-LDHs, but generally improve the electrochemical performance of Ti 3C 2T x MXene/NiCo-LDHs. Interestingly, the OH ? in alkaline electrolyte can promote the electrochemical performance of NiCo-LDHs, and produce a new electrochemical reaction with –F between the layers of Ti 3C 2T x MXene, which greatly improves the overall electrochemical performance of this hybrid electrodes. As a result, Ti 3C 2T x MXene/NiCo-LDHs electrodes have the best electrochemical performance in alkaline electrolyte with capacitance of 283 F g ?1, energy density of 14.2 Wh kg ?1 and power density of 3007.1 W kg ?1. This work lays a foundation for the preparation of high-performance two-dimensional hybrid electrochemical energy storage devices. 相似文献
5.
Two-dimensional layered Ti 3C 2T x MXene was prepared through hydrothermal etching method with LiF and hydrochloric (HCl) acid. Ti 3C 2T x was further treated with oxygen plasma activated by microwave energy to obtain the activated Ti 3C 2T x at different temperatures ranging from 350 °C to 550 °C. The gas-sensing properties of raw Ti 3C 2T x and Ti 3C 2T x activated with oxygen microwave plasma were tested toward different volatile organic compounds gases. The results indicated that Ti 3C 2T x activated at 500 °C exhibited excellent gas-sensing properties at room temperature (25 °C) to 100 ppm ethanol with a value of 22.47, which is attributed to the enhancement of the amount of oxygen functional groups and defects on the MXene Ti 3C 2T x film, and in turn to lead to more oxygen molecules adsorption and desorption reaction in the active defect sites. The enhancement of ethanol-sensing performance demonstrated that the activated Ti 3C 2T x possess great potential in gas sensing. 相似文献
6.
Highly active two-dimensional (2D) nanocomposites, integrating the unique merits of individual components and synergistic effects of composites, have been recently receiving attention for gas sensing. In this work, In 2O 3 nanocubes/Ti 3C 2T x MXene nanocomposites were synthesized using In 2O 3 nanocubes and layered Ti 3C 2T x MXene via a facile hydrothermal self-assembly method. Characterization results indicated that the In 2O 3 nanocubes with sizes approximately 20–130 nm in width were well dispersed on the surface of layered Ti 3C 2T x MXene to form numerous heterostructure interfaces. Based on the synergistic effects of electronic properties and gas-adsorption capabilities, In 2O 3 nanocubes/Ti 3C 2Tx MXene nanocomposites exhibited high response (29.6%–5 ppm) and prominent selectivity to methanol at room temperature. Meanwhile, the low detection concentration could be reduced to ppm-level, the response/recovery times are shortened to 6.5/3.5 s, excellent linearity and outstanding repeatability. The strategy of compositing layered MXene with metal oxide semiconductor provides a novel pathway for the future development of room temperature gas sensors. 相似文献
7.
Although the antibacterial properties of MXene nanosheets containing Ti 3C 2T x are known, their antifungal properties have not been well studied. Herein, we present for the first time a report on the antifungal properties of Ti 3C 2T x MXene. The Ti 3C 2T x MXene was obtained by first exfoliating MAX phase of Ti 3AlC 2 with concentrated hydrofluoric acid, then the Ti 3C 2T x was intercalated and deliminated by ethanol treatment and ultrasonication process. The delaminated Ti 3C 2T x MXene nanosheets (d-Ti 3C 2Tx) were characterized using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), and Raman spectroscopy. It was found that Ti 3C 2T x MXene was characterized by lamellar structure alternating with layers of Ti, Al and C. The EDX results revealed that the delaminated Ti 3C 2T x MXene nanosheets were composed of Ti, C, Si, O, F, and a trace amount of Al. The XRD and Raman spectra further indicated the elimination of Al and the formation of two-dimensional Ti 3C 2T x MXene nanosheets. The antifungal activity of the delaminated Ti 3C 2T x MXene was determined against Trichoderma reesei using the modified agar disc method. Observation using inverted phase contrastmicroscopy revealed inhibited fungus growth with the absence of hyphae around the discs treated wtih MXene. The surrounding of the control groups without an inclusion of MXene was found with large number of hyphae and spores. In addition, the spores of the fungi treated with the samples containing d-Ti 3C 2T x MXene nanosheets did not germinate even after 11 days of culture. The results demonstrated disruption to the hemispheric structural formation of fungi colony, inhibition of hyphae growth and cell damage for fungi grown on the d-Ti 3C 2T x MXene nanosheets. These new findings suggest that d-Ti 3C 2T x MXene nanosheets developed in this work could be a promising anti-fungi material. 相似文献
8.
Ti 3C 2T x MXene has been reported to be a metallic two-dimensional (2D) material with high conductivity, whereas its photoluminescence (PL) mechanism is still under debate. Herein, we demonstrate that large Ti 3C 2T x MXene flakes exhibit tunable PL under ambient conditions. The as-prepared Ti 3C 2T x MXene flakes emit blue, yellow-green and red light under different excitation wavelengths. Their PL emission wavelengths redshift as the excitation wavelength changes from violet to red light. Surface modification of the MXenes can further tune the PL peak wavelength into the near infrared region. Using density function theory (DFT) calculations, this excitation wavelength-dependent PL can be correlated to TiO 2 defects that exist on the surface of Ti 3C 2T x. Our study expounds on the optical properties of Ti 3C 2T x MXene and is helpful for comprehensively understanding this novel material. 相似文献
9.
By combining the advantages of doping to change the electronic structure of molybdenum disulfide (MoS 2), transition metal phosphides, and MXene, we proposed the idea of designing and preparing a new type of composite material, P-doped MoS 2/Ni 2P/Ti 3C 2T x heterostructures (denoted as P@MNTC), to serve as the hydrogen evolution reaction (HER) catalyst of electrochemical water splitting. The as-prepared P@MNTC heterostructures show a significant HER activity with an overpotential of 120 mV at 10 mA cm –2 in alkaline electrolyte, with decreasing 105 and 125 mV compared with those of MoS 2 and MXene, respectively. The density functional theory indicates that the P doping and synergy effect of Ti 3C 2T x can enhance the activation of MoS 2 and thus promote dissociation and absorption of H 2O during HER process. This strategy provides a promising way to develop high-efficiency MoS 2- and Ti 3C 2T x-based composite catalysts for alkaline HER. 相似文献
10.
The few-layered Ti 3C 2T x/WO 3 nanorods foam composite material was synthesized by electrostatic self-assembly and bidirectional freeze-drying technologies. The phase structure and microstructure of synthesized samples was characterized by XRD, FESEM, TEM and their gas sensing properties estimated via a self-designed equipment with four test channels. The results demonstrate WO 3 nanorods were successfully anchored on the surface and between layers of few-layered Ti 3C 2T x MXene by electrostatic self-assembly strategy and the composite material simultaneously has a low-density foam morphology by means of bidirectional freeze-drying processes. There exists a typical heterostructure at the interfaces owing to the inseparable contact between the few-layered Ti 3C 2T x MXene and WO 3 nanorods. Compared with the original WO 3 nanorods, the few-layered Ti 3C 2T x/WO 3 nanorods foam composite material displays excellent gas sensing properties for NO 2 detection at low temperature, in particular the optimal value of gas sensing response ( Rg/Ra) reaches to 89.46 toward 20 ppm NO 2 at 200 °C. The gas sensing mechanism was also discussed. The increase of gas sensitivity is attributed to a fact that during the reaction process of gas sensing, the excellent conductivity of the few-layered Ti 3C 2T x MXene provided faster transport channels of free carriers, and the heterojunctions formed by few-layered Ti 3C 2T x MXene and WO 3 nanorods enhanced the carriers separation efficiency. Meanwhile, the low-density layered structure of few-layered Ti 3C 2T x/WO 3 nanorods foam composite material provides convenient diffusion paths for gas molecules to the surface of WO 3 nanorods. 相似文献
11.
As one of the typical MXenes materials, 2D Ti 3C 2T x has attracted extensive attention in the field of energy storage. However, due to the restacking problem of Ti 3C 2T x nanosheets, the electrochemical performance of Ti 3C 2T x is unsatisfactory. In this paper, a scheme is proposed to obtain 3D aerogel with 1D channels by directional freeze drying of Ti 3C 2T x. With the help of the unidirectional channels, the 3D Ti 3C 2T x/Sodium alginate (SA) aerogel can effectively solve the stacking problem of Ti 3C 2T x nanosheets, and it also accelerates the diffusion of ions. The Ti 3C 2T x/SA-5 electrode can still reach the mass capacitance of 284.5 F g ?1 and the areal capacitance of 4030.4 mF cm ?2 at 2 mV s ?1 when the loading is 14.2 mg cm ?2 in 1 M H 2SO 4 electrolyte. In addition, the electrode showed good cycling performance without capacitor degradation after 20,000 cycles at 50 mV s ?1. These results suggest that by using the strategy of building special 3D structure of 2D MXene with 1D unidirectional channels, high performance supercapacitor electrodes with high mass loading can be realized. 相似文献
12.
The potential of two-dimensional layered MXenes in electromagnetic wave (EMW) absorption needs further development. Herein, we carried out the in situ growth of carbon nanotubes (CNTs) on the surface of Ti 3C 2T x MXene at ultra-low temperature via chemical vapor deposition. The obtained CNTs exhibited a bamboo-like structure and were accompanied by helical carbon nanofibers. The ultra-low temperature solved the problem that the high temperature required in the traditional CNT growth process would destroy the structural integrity of MXene. The lush CNT forest cross-linked the MXene layers, transforming the two-dimensional layered structure into a three-dimensional conductive network, providing abundant conductive channels for carriers, optimizing the impedance matching of the CNT/MXene hybrid, and resulting in a significant dielectric loss. The as-prepared CNT/MXene hybrid exhibited a minimal reflection loss of ?52.56 dB (99.9994% EMW absorption) in the X-band. This work proposes a new idea to enhance the EMW absorption properties of Ti 3C 2T x MXene and fabricate high-performance MXene-based EMW absorbers. 相似文献
13.
The proliferation of electronic devices and wireless communication is leading to serious electromagnetic (EM) interference. In this work, Ti 3C 2/cement composites were developed as high efficiency EM functional materials by introducing exfoliated Ti 3C 2T x MXene with cement for green buildings with EM shielding function. In the composites, few-layered Ti 3C 2 MXene were dispersed homogeneously throughout the cement matrix. The EM properties of the composites were studied as a function of the MXene content. With increasing MXene content, real and imaginary part of permittivity was significantly improved owing to the polarization and electrical conduction caused by the MXene phase. Composites with 15 wt.% MXene showed good EM absorbing properties with a maximum effective absorbing bandwidth of 2.67 GHz. Strong EM shielding can be achieved when MXene content increased to 25 wt.%. The EM shielding effectiveness of such composites was higher than 22.0 dB, and the dominating shielding mechanism was EM absorption. This work finds new materials for the development of advanced green buildings with EM shielding function. 相似文献
14.
Effective electromagnetic interference (EMI) shielding materials have garnered substantial interest for their efficacy in attenuating electromagnetic wave energy, ensuring data confidentiality, ensuring the operational stability of fragile electronic systems. To begin, artificially cultured diatom frustules (DF)-derived porous silica (DFPS) skeletons were constructed as templates in this study. Porous ceramics hot-pressed at 800 °C displayed a high compressive strength with a high specific surface area due to their three-dimensional (3D) multilayered and porous structures. Then, mechanically robust Ti 3C 2T x/DFPS composites with exceptional EMI shielding performance were fabricated by immersing porous DF-based ceramics into Ti 3C 2T x solutions and annealing in an argon environment to increase the materials’ shielding efficiency (SE). The EMI SE of composites hot-pressed at 800 °C achieved the maximum EMI SE of 43.2 dB in the X-band and a compressive strength of 67.5 MPa, establishing a hitherto unreported balance of mechanical characteristics and shielding performance. Prolonged transmission paths, multiple dissipation, scattering and reflection of electromagnetic energy were achieved using a well-maintained hierarchical porous silica framework decorated with MXene, with adsorption caused by surface MXene serving as the primary shielding mechanism for the composites. Due to their superior overall performance, MXene/DFPS EMI shielding composites have a bright future in the aircraft sector as delicate electronic device components. 相似文献
15.
In order to obtain a high photoelectrochemical performance, co-catalysts loading is the most commonly used way, which can facilitate reactions and suppress the charge recombination. In this paper, a novel composite of ZnO/Ti3C2TX photoanode was fabricated by a facile spin coating of precipitating Ti3C2TX (MXene) flakes onto the surface of ZnO, as co-catalyst for enhanced photoelectrochemical (PEC) water splitting. Under simulated sunlight, the optimum composite of ZnO/Ti3C2TX photoanode showed the photocurrent density as 1.2 mA cm?2 at 1.23 VRHE, which is 1.4 times higher than that of pristine ZnO without Ti3C2TX co-catalyst (0.83 mA cm?2 at 1.23 VRHE). The ZnO/Ti3C2TX photoanode showed a photoconversion efficiency of 0.32% and maintained a stable photocurrent over 2000s. The Ti3C2TX (MXene) flakes as co-catalyst to promote the charge transfer and accelerates the reaction kinetics in ZnO/Ti3C2TX photoanode. This work delivers a two-dimensional (2D) material Ti3C2TX (MXene) as co-catalyst for enhanced ZnO photoanode PEC water splitting. 相似文献
16.
In this work, TiO 2/MXene composites were successfully synthesized through an in-situ solvothermal method, where the morphology of TiO 2 nanoparticles (NPs) was modified by different concentrations of agents. Ti 3C 2T x with electronic storage characteristics was employed as a co-catalyst to enhance the photocatalytic degradation activity by capturing photogenerated electrons. The experimental results reveal that, with the help of C 3H 8O agents, TiO 2 NPs are uniformly distributed on the surface of Ti 3C 2T x. The TiO 2/Ti 3C 2T x-C 3H 8O composite showed the highest photocatalytic activity of 90.5% after 75 min under mercury light irradiation, which is 57.9% higher than that of the pure TiO 2 photocatalyst. The photocatalytic activity is promoted due to the high photoelectron transmission performance of the TiO 2/Ti 3C 2T x composites. 相似文献
17.
MXene, a novel two-dimensional material composed of alternating transition metal carbon/nitrogen, has the advantages of large specific surface area, many active sites, and short ion transport paths, and has shown great potential in the field of capacitors in the beginning. However, the unique two-dimensional structure is prone to collapse and accumulation, which inhibits the electron migration rate and ion penetration, resulting in poor energy storage capacity. In this paper, Ti 3C 2T x/Ag/MWCNTs/Ag composites with good capacitive properties were successfully prepared by Ti 3C 2T x which directly reduces silver nitrate solution and further introduces nanoscale MWCNTs. Ag NPs are introduced twice to grow and distribute uniformly on the surface and between the layers of Ti 3C 2T x to play a supporting role. The introduction of MWCNTs in the intermediate process can enter the interlayer and act as spacers together with Ag NPs to prevent the collapse and stacking of Ti 3C 2T x and improve its surface utilization. However, the preparation process unavoidably leads to partial oxidation of Ti 3C 2T x, which deteriorates its electrochemical properties. Owing to the synergy between Ti 3C 2T x, Ag NPs and MWCNTs, the Ti 3C 2T x/Ag/MWCNTs/Ag composites show good electrical conductivity, low internal resistance (0.67 Ω) and extreme high capacitance contribution (97%) in electrochemical tests. 相似文献
18.
Dielectric polymer composites with conducting fillers would have great potential for diverse applications if their severe leakage loss could be addressed. In this regard, ternary composites using both ceramic and conducting materials as fillers might be an enabler for high dielectric constant and low dielectric loss. Herein, ternary composites with both Ti 3C 2T x MXene conducting nanosheets and CaCu 3Ti 4O 12 (CCTO) dielectric particles embedded in silicone rubber were studied. It was found that a ternary composite with 1.2 wt% (0.40 vol%) Ti 3C 2T x MXene and 12 wt% (2.58 vol%) CCTO could provide an overall superior performance that include a high dielectric constant of 8.8, low dielectric loss of less than 0.0015, good thermal stability up to 450 °C, and excellent mechanical properties with tensile strength of 569 kPa, elastic module of 523 kPa and elongation at break of 333%. The outstanding performance is attributed to the improved uniform dispersion and good interfacial compatibility of mixed fillers in the polymer matrix, suggesting ternary composites might be a better option over their binary counterparts in preparing high performance dielectric composites. 相似文献
19.
Two-dimensional transition metal carbide (MXene) is a promising electrode material for supercapacitors because of its excellent electrochemical properties. Here, we report a controllable and facile strategy to prepare a freestanding and flexible N-doped Ti 3C 2T x (N–Ti 3C 2T x) film electrode with a hydrothermal method using hydrazine hydrate (N 2H 4∙H 2O) as a nitrogen source. At a scan rate of 2 mV s −1, the N–Ti 3C 2T x film electrode exhibits a high specific capacitance of 340 F g −1 and no capacitance degradation after 10,000 cycles in 1 M H 2SO 4 electrolyte. These results show that the N–Ti 3C 2T x film could be used as an outstanding electrode material for high-performance supercapacitors. The operation of hydrazine treatment provides a more practical and convenient experimental method for N-doping. 相似文献
20.
Since conventional Pt/carbon catalysts usually suffer from CO poisoning as well as carbon corrosion issues during the methanol oxidation reaction, it is essential to explore high-efficiency Pt-alternative electrocatalysts supported by a robust matrix in the direct methanol fuel cells. Herein, we report a convenient low-temperature approach to the controllable fabrication of well-dispersive Rh nanocrystals in situ grown on Ti 3C 2T x MXene nanosheets. The ultrathin lamellar MXene structure reveals unique superiorities on the construction of advanced Rh-based hybrid catalysts, which can not only provide a large number of efficient anchoring sites for immobilizing small-sized Rh nanocrystals with abundant exposed catalytic crystal planes, but also enable direct electronic interaction with Rh for strong synergistic effects and facilitate the fast charge transportation during the catalytic process. As a consequence, the resulting Rh/Ti 3C 2T x hybrid exhibits prominent electrocatalytic properties towards methanol oxidation reaction, such as a large electrochemical active surface area of 71.6 m 2 g ?1, a high mass activity of 600.2 mA mg ?1, and good long-term stability, all of which are much better than those of conventional carbon-supported Rh as well as Pt/C and Pd/C catalysts. 相似文献
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