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1.
《Ceramics International》2022,48(7):9059-9066
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 SnO2 nanosheets/Ti3C2Tx MXene nanocomposites were synthesized by using layered Ti3C2Tx MXene and uniform SnO2 nanosheets by hydrothermal method. Characterization results show that the SnO2 nanosheets are well dispersed and vertically anchored on the layered Ti3C2Tx MXene surface, forming heterogeneous interfaces. Based on the gas-adsorption capabilities and synergistic effects of electronic properties, SnO2 nanosheets/Ti3C2Tx MXene nanocomposites show high triethylamine (TEA) gas-sensing performance at low temperature (140 °C). The sensor responses of the nanocomposites and pure SnO2 nanosheets to 50 ppm of TEA are 33.9 and 3.4, respectively. An enhancement mechanism for SnO2 nanosheets/Ti3C2Tx 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.
《Ceramics International》2022,48(14):20146-20157
Ti-based oxide hierarchical nanocomposites assembled into a two-dimensional structure were synthesized via a facile, flash oxidation of MXene (Ti3C2Tx) at 200–900 °C for 1 or 3 min. The oxidation temperature primarily controlled the phase composition. Particularly, TiOF2 nanoparticles decorated MXene sheets formed at low oxidation temperatures (200 and 400 °C) and exhibited preferable activity in methylene blue (MB) photodegradation, reaching a ~90 % and ~56 % removal under ultraviolet and visible light illumination for 3 h, respectively. Due to the excellent electronic conductivity of MXene, the decreasing bandgap energy extended absorption in the visible range of the solar spectrum, suggesting a promising candidate for wide-range responsive photocatalytic applications. In contrast, TiO2 nanoparticles assembled into 2D morphology formed at high temperatures (500–900 °C), possessing good microwave transparent performance because of low imaginary permittivity and dielectric loss tangent.  相似文献   

3.
《Ceramics International》2022,48(22):33412-33417
Ti3C2Tx MXene has attracted extensive attention in the field of electromagnetic (EM) protection over recent years. Multilayer Ti3C2Tx (M-Ti3C2Tx), as an intermediate product of MXene ultra-thin structure, has potential advantages in the field of EM protection. Herein, the M-Ti3C2Tx was obtained by HCl/LiF etching Ti3AlC2. The microwave absorption (MA) and electromagnetic interference (EMI) shielding performance of Ti3AlC2 and M-Ti3C2Tx 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-Ti3C2Tx display RLmin 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-Ti3C2Tx/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.
《Ceramics International》2022,48(16):22845-22853
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 Ti3C2Tx/DFPS composites with exceptional EMI shielding performance were fabricated by immersing porous DF-based ceramics into Ti3C2Tx 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   

5.
《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   

6.
Most of the ancient buildings are made of inflammable wooden structures, which have serious potential safety hazards. Applying fire-retardant coating is one of the simplest and most effective means of fire prevention in ancient wooden buildings. In this work, we have demonstrated that the Ti3C2Tx transition metal carbide/carbonitride (MXene) was applied as the synergetic agent, waterborne epoxy resin as the film-forming agent, ammonium polyphosphate, dipentaerythritol, and melamine (P-C-N system) as the intumescent fire-retardant system to prepare Ti3C2Tx/epoxy intumescent fire-retardant coating (TEIFC). The results showed that MXene has significantly improved the fire-retardant performance of the coating. By incorporating 3 wt% Ti3C2Tx (TEIFC-3, with 62 wt% P-C-N system), the coating displayed UL-94 V-0 rating with the limiting oxygen index value of 38%. In addition, the combination of Ti3C2Tx and P-C-N system enhanced the Shore hardness of the coating to 95 SHD (TEIFC-3). Furthermore, TEIFC-3 presented high thermal stability with the THRI of 177.0°C and Tdmax of 380.5°C. This work provides a novel strategy for the design and preparation of intumescent fire-retardant coating, which will greatly broaden the industrial applications of MXene-based polymer composites in the field of fire prevention of ancient buildings.  相似文献   

7.
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   

8.
《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   

9.
《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   

10.
《Ceramics International》2022,48(5):6116-6123
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 Ti3C2Tx MXene conducting nanosheets and CaCu3Ti4O12 (CCTO) dielectric particles embedded in silicone rubber were studied. It was found that a ternary composite with 1.2 wt% (0.40 vol%) Ti3C2Tx 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   

11.
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   

12.
A novel free radical scavenger, multi-layered Ti3C2Tx MXene (ML-Ti3C2Tx), has been studied by evaluating its scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH?). It exhibits high scavenging efficiency (95% in 10 min) at low dosage (0.06 mg/mL). Based on the analysis of structure and surface states of ML-Ti3C2Tx before and after reaction with DPPH? and a series of comparative experiments, including few-layered Ti3C2Tx MXene (FL-Ti3C2Tx), original Ti3AlC2, and soluble Ti species derived from ML-Ti3C2Tx, the observed high scavenging activity is attributed to the intrinsic reducing property of ML-Ti3C2Tx rather than the hydrogen donation ability from surface functional groups. A model is proposed to explain the scavenging mechanism.  相似文献   

13.
《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   

14.
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   

15.
Demand for high-performance electromagnetic (EM) wave absorbing materials with high-temperature resistance is always urgent for application in a harsh environment. In this contribution, two-dimensional material, Ti3C2Tx MXene, was introduced into a hyperbranched polyborosilazane. After pyrolyzation, the as-prepared TiC/SiBCN ceramics present excellent EM wave absorption in X-band. The TiC nanograins appearing after annealing provide multilevel reflection and interface polarization. Dipole polarization formed at interface defects, in company with interfacial polarization, also makes a great contribution to enhanced EM wave absorption. The TiC/SiBCN nanocomplex prepared with 5 wt% Ti3C2Tx MXene possesses a minimum reflection coefficient of −45.44 dB at 10.93 GHz and abroad bandwidth 8.4 and 12.4 GHz, almost covering the entire X-band. Tuning the thickness in the range of 2.35-2.54 mm, the effective absorption band can achieve the entire X-band. And the EM wave absorbing performance has been maintained to a large extent at 600°C with the minimum reflection coefficient of −26.12 dB at 12.13 GHz and the effective absorption bandwidth of 2 GHz. Last but not the least, TiC/SiBCN ceramics offer a good thermal stability in argon as well as in air atmosphere, making it possible to serve in high-temperature detrimental environments. This study is expected to provide a new perspective for the design of high-performance absorbing materials that are able to be used in harsh environments, especially in high temperatures.  相似文献   

16.
The proliferation of electronic devices and wireless communication is leading to serious electromagnetic (EM) interference. In this work, Ti3C2/cement composites were developed as high efficiency EM functional materials by introducing exfoliated Ti3C2Tx MXene with cement for green buildings with EM shielding function. In the composites, few-layered Ti3C2 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   

17.
《Ceramics International》2022,48(17):25111-25119
Electromagnetic wave (EMW) absorbing materials have been widely applied in the fields of military and engineering areas. It is of great significance to develop high-performance EMW absorbing materials. This work assembled the sandwich-like Ti3C2Tx based nanocomposites by the microwave-assisted annealing of CoFe-MOF@Ti3C2Tx (CFMF@Ti3C2Tx) precursors at different temperatures. Results show that, as the heat treatment temperature is 450 °C, the sandwich-like Ti3C2Tx@CoFe@TiO2 nanocomposites present better EMW absorption properties. The minimum reflection loss (RL) value was ?62.9 dB at 17.95 GHz with a thin thickness of 1.2 mm. Moreover, the effective absorption bandwidth (EAB) value was 5.02 GHz (12.74–17.76 GHz) with a thickness of 1.4 mm. The application of microwave-assisted annealing contributed to the formation of CoFe nanoparticles and TiO2 nanoparticles because of the ultra-fast heating rate. The introduction of the nanoparticles enhanced the multiple polarization, optimized the impedance matching and introduced magnetic loss, leading to the improvement of EMW absorption. When the annealing temperature further increased to 550 °C, the EMW absorbing performance was weakened, which was mainly correlated with the decrement of the interface area due to the increase of the TiO2 nanoparticle size and CoFe nanoparticle size. Thus, the loss effect of the multiple interface polarization weakens in the EMW absorption. In addition, the high permittivity of Ti3C2Tx disappears, which deteriorated the impedance matching and attenuation ability of EMW. Ultimately, sandwich-like Ti3C2Tx@CoFe@TiO2 nanocomposite with satisfactory EMW absorbing properties is established, promising for various EMW absorbing applications.  相似文献   

18.
By combining the advantages of doping to change the electronic structure of molybdenum disulfide (MoS2), transition metal phosphides, and MXene, we proposed the idea of designing and preparing a new type of composite material, P-doped MoS2/Ni2P/Ti3C2Tx 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 MoS2 and MXene, respectively. The density functional theory indicates that the P doping and synergy effect of Ti3C2Tx can enhance the activation of MoS2 and thus promote dissociation and absorption of H2O during HER process. This strategy provides a promising way to develop high-efficiency MoS2- and Ti3C2Tx-based composite catalysts for alkaline HER.  相似文献   

19.
《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   

20.
《Ceramics International》2020,46(13):21482-21488
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 Ti3C2Tx (N–Ti3C2Tx) film electrode with a hydrothermal method using hydrazine hydrate (N2H4∙H2O) as a nitrogen source. At a scan rate of 2 mV s−1, the N–Ti3C2Tx film electrode exhibits a high specific capacitance of 340 F g−1 and no capacitance degradation after 10,000 cycles in 1 M H2SO4 electrolyte. These results show that the N–Ti3C2Tx 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   

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