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1.
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, In2O3 nanocubes/Ti3C2Tx MXene nanocomposites were synthesized using In2O3 nanocubes and layered Ti3C2Tx MXene via a facile hydrothermal self-assembly method. Characterization results indicated that the In2O3 nanocubes with sizes approximately 20–130 nm in width were well dispersed on the surface of layered Ti3C2Tx MXene to form numerous heterostructure interfaces. Based on the synergistic effects of electronic properties and gas-adsorption capabilities, In2O3 nanocubes/Ti3C2Tx 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   

2.
《Ceramics International》2020,46(12):20306-20312
Although the antibacterial properties of MXene nanosheets containing Ti3C2Tx are known, their antifungal properties have not been well studied. Herein, we present for the first time a report on the antifungal properties of Ti3C2Tx MXene. The Ti3C2Tx MXene was obtained by first exfoliating MAX phase of Ti3AlC2 with concentrated hydrofluoric acid, then the Ti3C2Tx was intercalated and deliminated by ethanol treatment and ultrasonication process. The delaminated Ti3C2Tx MXene nanosheets (d-Ti3C2Tx) 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 Ti3C2Tx MXene was characterized by lamellar structure alternating with layers of Ti, Al and C. The EDX results revealed that the delaminated Ti3C2Tx 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 Ti3C2Tx MXene nanosheets. The antifungal activity of the delaminated Ti3C2Tx 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-Ti3C2Tx 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-Ti3C2Tx MXene nanosheets. These new findings suggest that d-Ti3C2Tx MXene nanosheets developed in this work could be a promising anti-fungi material.  相似文献   

3.
Ti3C2Tx MXene, an emerging two-dimensional (2D) ceramic material, has rich interfaces and strong conductive networks. Herein, we have successfully built a heterostructure between Ti3C2Tx MXene and WS2 to improve electromagnetic absorption performance. X-ray diffraction and X-ray photoelectron spectroscopy were used to determine the successful synthesis of Ti3C2Tx/WS2 composite. Field emission scanning electron microscopy and transmission electron microscopy images show that WS2 nanosheets are evenly dispersed on the accordion-like Ti3C2Tx MXene. Importantly, Ti3C2Tx MXene/WS2 composite has sufficiently high dielectric loss and impedance matching due to self-adjusting conductivity and 2D heterostructure interfaces. As a result, the Ti3C2Tx/WS2 composite has a minimum reflection loss (RLmin) 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 Ti3C2Tx ceramics and 2D materials.  相似文献   

4.
《Ceramics International》2021,47(21):29930-29940
MXene (Ti3C2Tx) is a novel, two-dimensional (2D) layered material that is atomically thin, exhibits good mechanical strength, and is ideal for fabricating efficient membranes for molecular separation. However, the applications of MXene membranes are limited by their low water permeability owing to narrow channels and high tortuosity. A novel strategy for introducing artificial pores on the surface of MXene nanosheets via gentle in situ chemical etching with hydrogen peroxide (H2O2) to prepare porous MXene nanosheets (PMS) is reported herein. This greatly increases the water permeability of MXene membranes while retaining the high rejection of small-molecule dyes. Permeable pores generated on MXene nanosheets transform the transport model of water molecules in the membrane from typical horizontal transport pathways dominated by interlayer channels to longitudinal–lateral three-dimensional transport pathways, affording increased water molecule transport channels and reduced transport distance. Based on different etching conditions, the obtained membranes exhibit high pure-water permeability ranging from 9.37 to 42.48 L m−2 h−1 bar−1. Moreover, mild etching maintains the 2D structure of the membrane and retains a nearly complete rejection of congo red dye. This study provides a novel and effective strategy for preparing high-performance porous laminar MXene membranes for dye-separation applications.  相似文献   

5.
《Ceramics International》2022,48(11):15721-15728
Developing a new strategy to effectively prevent the restacking of MXene nanosheets will have significant impacts on designing flexible supercapacitor electrodes. Herein, a novel Ti3C2Tx/polyvinyl alcohol (PVA) porous sponge with 3D interconnected structures is prepared by sol-gel and freeze-dried methods. This Ti3C2Tx/PVA porous sponge is used as the template of in-situ polyaniline (PANI) polymerization, and the fabricated PANI@Ti3C2Tx/PVA hydrogel composite is applied as flexible supercapacitors electrodes. 1D conductive polymer chains PVA could increase the interlayer spacing of Ti3C2Tx nanosheets, which is beneficial to expose more electrochemical active sites. The supercapacitor based on PANI@Ti3C2Tx/PVA hydrogel composite exhibits the coexistence of double-layer capacitance and pseudocapacitance behavior. This supercapacitor shows a maximum areal specific capacitance of 103.8 mF cm?2 at 2 A m?2, and it also exhibits a maximum energy density of 9.2 μWh·cm?2 and an optimum power density of 800 μW cm?2. The capacitance of this supercapacitor is almost not change under different bending angles. Moreover, 99% capacitance retention is achieved after 10 000 charge/discharge cycles of the supercapacitor. The synergistic effect between PANI and Ti3C2Tx/PVA composite may improve the number of reactive sites and provide efficient channels for ion diffusion/electron transport.  相似文献   

6.
《Ceramics International》2022,48(14):20324-20331
As one of the typical MXenes materials, 2D Ti3C2Tx has attracted extensive attention in the field of energy storage. However, due to the restacking problem of Ti3C2Tx nanosheets, the electrochemical performance of Ti3C2Tx is unsatisfactory. In this paper, a scheme is proposed to obtain 3D aerogel with 1D channels by directional freeze drying of Ti3C2Tx. With the help of the unidirectional channels, the 3D Ti3C2Tx/Sodium alginate (SA) aerogel can effectively solve the stacking problem of Ti3C2Tx nanosheets, and it also accelerates the diffusion of ions. The Ti3C2Tx/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 H2SO4 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   

7.
Ti3C2Tx 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 Ti3C2Tx MXene flakes exhibit tunable PL under ambient conditions. The as-prepared Ti3C2Tx 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 TiO2 defects that exist on the surface of Ti3C2Tx. Our study expounds on the optical properties of Ti3C2Tx MXene and is helpful for comprehensively understanding this novel material.  相似文献   

8.
As one of the novel two-dimensional metal carbides, Ti3C2Tx has received intense attention for lithium-ion batteries. However, Ti3C2Tx has low intrinsic capacity due to the fact that the surface functionalization of F and OH blocks Li ion transport. Herein a novel “plane-line-plane” three-dimensional (3D) nanostructure is designed and created by introducing the carbon nanotubes (CNTs) and SnO2 nanoparticles to Ti3C2Tx via a simple hydrothermal method. Due to the capacitance contribution of SnO2 as well as the buffer role of CNTs, the as-fabricated sandwich-like CNTs@SnO2/Ti3C2Tx nanocomposite shows high lithium ion storage capabilities, excellent rate capability and superior cyclic stability. The galvanostatic electrochemical measurements indicate that the nanocomposite exhibits a superior capacity of 604.1 mAh g?1 at 0.05?A?g?1, which is higher than that of raw Ti3C2Tx (404.9 mAh g?1). Even at 3?A?g?1, it retains a stable capacity (91.7 mAh g?1). This capacity is almost 5.6 times higher than that of Ti3C2Tx (16.6 mAh g?1) and 58 times higher than that of SnO2/Ti3C2Tx (1.6 mAh g?1). Additionally, the capacity of CNTs@SnO2/Ti3C2Tx for the 50th cycle is 180.1 mAh g?1 at 0.5?A?g?1, also higher than that of Ti3C2Tx (117.2 mAh g?1) and SnO2/Ti3C2Tx (65.8 mAh g?1), respectively.  相似文献   

9.
《Ceramics International》2022,48(5):6338-6346
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 Ti3C2Tx 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 Ti3C2Tx MXene and fabricate high-performance MXene-based EMW absorbers.  相似文献   

10.
《Ceramics International》2023,49(2):2081-2090
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, Ti3C2Tx/Ag/MWCNTs/Ag composites with good capacitive properties were successfully prepared by Ti3C2Tx 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 Ti3C2Tx 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 Ti3C2Tx and improve its surface utilization. However, the preparation process unavoidably leads to partial oxidation of Ti3C2Tx, which deteriorates its electrochemical properties. Owing to the synergy between Ti3C2Tx, Ag NPs and MWCNTs, the Ti3C2Tx/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   

11.
《Ceramics International》2022,48(3):3884-3894
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 Ti3C2Tx MXene/NiCo-LDHs electrodes were successfully prepared and studied in different electrolytes by in-situ Raman spectroscopy. The results show that H2O molecules in neutral electrolyte combine with –OH at the end of Ti3C2Tx 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 Ti3C2Tx MXene and has a certain corrosion consumption effect on NiCo-LDHs, but generally improve the electrochemical performance of Ti3C2Tx 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 Ti3C2Tx MXene, which greatly improves the overall electrochemical performance of this hybrid electrodes. As a result, Ti3C2Tx 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   

12.
《Ceramics International》2022,48(16):22681-22690
Benefiting from its large specific surface area, abundant defects and functional groups, two-dimensional (2D) laminated Ti3C2Tx MXene is a kind of electromagnetic wave (EMW) absorber with great potential. However, the impedance mismatch caused by the excessive conductivity, inappropriate permittivity and lack of magnetic loss seriously hinders the application of MXene to EMW absorption. Herein, multidimensional hierarchical Ni/TiO2/C nanocomposites composed of three-dimensional (3D) hydrangea-like Ni/C microspheres and well-arranged 2D carbon sheets embedded with TiO2 nanoparticles were successfully fabricated from a Ni-based trimellitic acid framework (Ni-BTC) and Ti3C2Tx MXene via facile in-situ solvothermal assembly and annealing processes. As expected, excellent EMW absorption properties were obtained only by changing the annealing temperature. The minimum reflection loss (RLmin) value of -45.6 dB and the effective absorption bandwidth (EAB) of 3.40 GHz (14.6–18.0 GHz) with a layer thickness of only 1.5 mm is obtained by annealing the sample at 700 °C. The outstanding ternary multilayer structure and the optimization of magnetoelectric synergy in impedance matching jointly create its remarkable EMW absorption performance. This work is expected to provide a simple and effective method to design MXene-based EMW absorbing materials possessing high absorption intensity, light weight, wide EAB and thin thickness.  相似文献   

13.
Ti3C2Tx (MXene), a new kind of 2D ceramic nanosheets, is receiving more and more attention in the fields of medicine, biology, energy, electronics, etc. However, the preparation and application of MXene in hydrogel is still in its infancy period. Here, we review the latest progress (after 2018) related to MXene hydrogels in time. Aiming at the key issue of the dispersion stability of MXene in hydrogel systems, the preparation strategy, mechanism, advantages and disadvantages of MXene hydrogels are sorted out in detail, and the potential application prospects of MXene composite hydrogel are introduced. Finally, future viewpoints are put forward for the dispersion stability challenges that need solving in the design of MXene hydrogel.  相似文献   

14.
《Ceramics International》2023,49(18):29962-29970
The few-layered Ti3C2Tx/WO3 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 WO3 nanorods were successfully anchored on the surface and between layers of few-layered Ti3C2Tx 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 Ti3C2Tx MXene and WO3 nanorods. Compared with the original WO3 nanorods, the few-layered Ti3C2Tx/WO3 nanorods foam composite material displays excellent gas sensing properties for NO2 detection at low temperature, in particular the optimal value of gas sensing response (Rg/Ra) reaches to 89.46 toward 20 ppm NO2 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 Ti3C2Tx MXene provided faster transport channels of free carriers, and the heterojunctions formed by few-layered Ti3C2Tx MXene and WO3 nanorods enhanced the carriers separation efficiency. Meanwhile, the low-density layered structure of few-layered Ti3C2Tx/WO3 nanorods foam composite material provides convenient diffusion paths for gas molecules to the surface of WO3 nanorods.  相似文献   

15.
Two-dimensional layered Ti3C2Tx MXene was prepared through hydrothermal etching method with LiF and hydrochloric (HCl) acid. Ti3C2Tx was further treated with oxygen plasma activated by microwave energy to obtain the activated Ti3C2Tx at different temperatures ranging from 350 °C to 550 °C. The gas-sensing properties of raw Ti3C2Tx and Ti3C2Tx activated with oxygen microwave plasma were tested toward different volatile organic compounds gases. The results indicated that Ti3C2Tx 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 Ti3C2Tx 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 Ti3C2Tx possess great potential in gas sensing.  相似文献   

16.
《Ceramics International》2021,47(20):28304-28311
Semiconductor-metal heterostructure, especially represented by various inorganic semiconductors-platinum (Pt) hybrids, is widely applied in converting solar power to chemical energy. Given the scarcity of Pt and the availability of coupling, the development of a non-Pt regimen and facile assembly strategy is critical. In this study, CdxZn1-xS/Ti3C2 ultrathin MXene composites were availably prepared with a facile electrostatic assembly strategy. The unique 0D/2D assembly demonstrated remarkably enhanced performance toward photocatalytic hydrogen production compared with bare CdxZn1-xS. Spectroscopic characterization analysis and band theory discussion substantiated the effects of electronic interaction and the Schottky barrier arising from intimate contact of CdxZn1-xS and Ti3C2 MXene on the swift separation of photoinduced electron-hole pairs. Successful application of electrostatic self-assembled CdxZn1-xS with ultrathin MXene opens a new area of utilizing electrical difference and band theory to prepare rational semiconductor/MXene Schottky structure towards various photocatalytic reactions.  相似文献   

17.
《Ceramics International》2022,48(5):6600-6607
Ti3C2Tx, as a novel two-dimensional material, displays promising prospects in NH3 detection at room temperature. However, the NH3 detection limit of pristine Ti3C2Tx is still a major research concern. Therefore, it is important to explore new Ti3C2Tx-based nanocomposites for better NH3-sensing performance. In the present experiment, Ti3C2Tx/In2O3 nanocomposites were successfully synthesized by ultrasonication and characterized by XRD, FESEM, TEM, XPS, and BET. The optimal Ti3C2Tx/In2O3-based sensor had a high response of 63.8% (30.4 times higher than that of pristine Ti3C2Tx) to 30 ppm NH3 at room temperature. In addition, the optimal Ti3C2Tx/In2O3-based sensor had stable repeatability, excellent selectivity, and long-term stability, while exhibiting excellent potential for NH3 detection at room temperature.  相似文献   

18.
《Ceramics International》2021,47(20):28642-28649
Ti3C2Tx MXene has attracted remarkable attention due to its promising applications in energy storage and sensors. However, traditional MXene preparation methods used HF as etchant, which was highly toxic and harmful to human and environment. Moreover, the aqueous etchants will also result in the combination of OH, O and F groups on the surfaces, making it difficult to control the varieties and contents of the surface terminations. In this paper, a green and mild electrochemical exfoliation method was proposed to synthesize Ti3C2Fx and synchronously control its fluorination degree on the surface. A non-aqueous ionic liquid, [BMIM][PF6]-based solution was used as electrolyte. The as-prepared Ti3C2Fx was fluorinated with the CF and TiF3 groups, which were electrochemically active and contributed to the excellent cycling stability of the MXene anode-based Li-ion batteries. These findings provided a facile strategy to prepare MXene materials and dope MXene with tailored property for MXene-based energy devices applications.  相似文献   

19.
Plasma processing technology, as a promising method to enhance photocatalytic activity of catalyst, is gradually attracting extensive interest from researchers. However, the main mechanism of plasma-treated photocatalyst on hydrogen production is not clear. In this work, 2D Ti3C2Tx MXene is selected as a co-catalyst of graphitic carbon nitride (g-C3N4), which carries out a plasma treatment (500°C) under N2/H2 atmosphere. Due to plasma treatment, there is a higher proportion Ti–O functional groups on surface of layered Ti3C2Tx MXene, especially for Ti4+. The obtained g-C3N4/p-Ti3C2Tx photocatalyst with sandwich-like structure shows an enhanced photocatalytic activity. The rate of hydrogen generation of CN/pTC3.0 sample without Pt co-catalyst is 25.4 and 2.4 times that of pure g-C3N4 and CN/TC3.0 samples, respectively. The improved photocatalytic activity is attributed to presence of Ti4+ due to plasma treatment, which can capture photo-induced electron from g-C3N4 and improve the separation of electrons and holes after visible light irradiation. The cyclic hydrogen production of the photocatalyst demonstrates good photocatalytic stability. In addition, this method of plasma treatment under N2/H2 atmosphere is feasible to develop a high-performance co-catalyst, which can be extended to other photocatalysts with two-dimensional structure for photocatalytic water-splitting applications.  相似文献   

20.
《Ceramics International》2021,47(18):25755-25762
The introduction of high-efficiency electrocatalysts can improve the efficiency of oxygen evolution reaction (OER). However, the synergistic effect of elcetrocatalyst and cocatalyst is rarely studied. In this paper, by combining FeNi layered double hydroxide (LDH) electrocatalyst with a two-dimensional (2D) Ti3C2 co-catalyst on TiO2 photocatalyst, the OER performance of TiO2/Ti3C2/FeNi LDH is greatly improved due to the synergistic coupling effect. The microstructure, electrochemical performance and oxygen generation mechanism of TiO2/Ti3C2/FeNi LDH are investigated in this paper. The results showed that the vertical array of FeNi LDH nanosheets created many nanoscale channels for reaction intermediates, enabling them to enter the most active sites on the surface. More importantly, the addition of Ti3C2 with high conductivity greatly effectively improved the charge separation and transfer between TiO2 and FeNi LDH. Therefore, the required over-potential for current density 100 mA/cm2 was only 633 mV for TiO2/2 Ti3C2/FeNi LDH. Meanwhile, Tafel slope was as low as 30 mV/dec with good stability. This work provides a reference for using Ti3C2 as a new type of co-catalyst material to obtain an efficient, stable and economical OER reaction catalyst.  相似文献   

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