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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.
Due to the expansion of human production activities, toxic ammonia (NH3) is excessively released into the atmosphere, being a huge threat to human health and the natural environment. Therefore, it is of great significance to design an easy-synthesized gas-sensing material with both good room temperature sensitivity and selectivity for trace-level NH3 detection. Herein, we fabricate a chemiresistive NH3 gas sensor with enhanced performance based on Ni(OH)2/Ti3C2Tx hybrid materials. The Ni(OH)2/Ti3C2Tx hybrid materials are synthesized by an in-situ electrostatic self-assembly method. Attributed to the formation of interfacial heterojunctions and the modulation of carrier density, the Ni(OH)2/Ti3C2Tx hybrid sensor exhibits high response, outstanding repeatability, good selectivity and stability in low concentrations of NH3. Moreover, the Ni(OH)2/Ti3C2Tx hybrid sensor has a higher response to 10 ppm NH3 at the relative humidity of 40% and 60%, which makes it promising for applications in real complex environments with high humidity. Benefitting from the low power consumption and easy fabrication process, the Ni(OH)2/Ti3C2Tx hybrid sensor possesses a broad application prospect in the internet of things (IoT) environmental monitoring.  相似文献   

3.
《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   

4.
A series of high-response and fast-response/recovery n-butanol gas sensors was fabricated by adding ZnO to In2O3 in varying molar ratios to form ZnO-In2O3 nanocomposites via a facile co-precipitation hydrothermal method. Morphological characterizations revealed that the shape of pure In2O3 was changed from irregular cubes into irregular nanoparticles, 30–50?nm in size, with the addition of ZnO. Compared with the pure In2O3 gas sensor, the ZnO-In2O3 gas sensor exhibits superior n-butanol sensing performance. With the introduction of ZnO, the response of the sensor to n-butanol was improved from 17 to 99.5 at 180?°C for a [Zn]:[In] molar ratio of 1:1. In addition, the ZnO-In2O3 gas sensors show a reduced optimal working temperature, excellent selectivity to n-butanol, and good repeatability. The response of the ZnO-enhanced In2O3-based sensors showed a strong linear relationship with the n-butanol gas concentration, allowing for the quantitative detection of n-butanol gas.  相似文献   

5.
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   

6.
《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   

7.
The nanostructured two-dimensional (2D) materials for humidity sensing applications have become increasingly attractive. However, 2D materials have negative aspects of easily stacking and agglomerating multilayers. Here, a novel resistive-type humidity sensor utilizing multi-layer titanium carbide (Ti3C2Tx) films as sensitive material is demonstrated. The humidity sensor exhibits an ultrasensitive and reversible sensing performance in a wide relative humidity range. Furthermore, the ultrafast response and recovery properties are achieved at room temperature. The Fourier transform infrared spectroscopy is used to investigate the adsorption of water vapor on Ti3C2Tx surfaces. A rapid capillary condensation of water vapor on the unique accordion-like microstructures and the hierarchical nanostructures of hydroxyl-riched Ti3C2Tx surface are supposed to be responsible for the super adsorption capability for water vapor. The electrostatic field induced by adsorbed water molecules is proposed to explain the resistance change of the titanium carbide humidity sensor. This work highlights the unique advantages of humidity sensor with layered 2D materials of Ti3C2Tx MXenes, including ultrasensitive, good reversibility and fast recovery at room temperature.  相似文献   

8.
《Ceramics International》2021,47(18):25531-25540
Ti3C2Tx exhibits excellent electromagnetic (EM) shielding and electrochemical properties. However, the inherent re-stacking tendency and easy oxidation of Ti3C2Tx limit its further application. In this study, a multi-walled carbon nanotube/polyaniline composite (CNT/PANI, denoted as C–P) was introduced into Ti3C2Tx nanosheets to obtain a Ti3C2Tx–CNT/PANI composite (T@CP). Owing to the integrated effects of Ti3C2Tx and C–P, the contribution of absorption was significantly improved, which finally enhanced the EM shielding performance of T@CP. The highest total EM shielding effectiveness (SET) was close to 50 dB (49.8 dB), which was substantially higher than that of pure Ti3C2Tx (45.3 dB). Moreover, T@CP demonstrated outstanding supercapacitive performance. The specific capacitance of T@CP (2134.5 mF/cm2 at 2 mV/s) was considerably higher than that of pure Ti3C2Tx (414.3 mF/cm2 at 2 mV/s). These findings provide a new route for the development of high-efficiency Ti3C2Tx-based bifunctional EM shielding and electrochemical materials.  相似文献   

9.
《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   

10.
《Ceramics International》2021,47(21):29995-30004
Novel and highly effective electromagnetic interference (EMI) shielding materials are desirable to attenuate unwanted electromagnetic radiation or interference produced by electrical communication devices. Here, functional Ti3C2Tx@Ni particles with a core@shell and sandwich like structure were fabricated using the facile electroless plating technique. The core@shell structured Ti3C2Tx@Ni consists of a Ti3C2Tx core and a Ni shell. In the core, thin Ni layers are sandwiched in between Ti3C2Tx flakes. EMI shielding effectiveness (SE) values of Ti3C2Tx@Ni/wax composites increased with increasing Ti3C2Tx@Ni content. The average EMI SE value of 60 wt% Ti3C2Tx@Ni/wax composite was 43.12 dB, increased by 73% as compared with 24.93 dB for the same content of pristine Ti3C2Tx in wax in the frequency range 2–18 GHz. An average EMI SE of 74.14 dB was achieved in the 80 wt% Ti3C2Tx@Ni/wax. The enhanced EMI shielding performance should be ascribed to the synergic effect of the absorption loss of the Ti3C2Tx core and the magnetic loss of the Ni shell and the inner Ni layers.  相似文献   

11.
《Ceramics International》2022,48(17):24656-24665
This study aims to provide insights into the absorption and shielding performances of Fe3O4 modified oligo-layered Ti3C2Tx towards microwave electromagnetic interference. Oligo-layered Ti3C2Tx was modified by Fe3O4 nanoparticles (60 nm) via a facile electrostatic assembly approach at different loading rates. This composite was shown to have high dielectric constant and high permeability compared with oligo-layered Ti3C2Tx. The microwave electromagnetic absorbing and shielding performances were monitored through a vector network instrument with focuses on the EMI performance. The sample Ti3C2Tx/Fe3O4 with a 5:1 mass ratio of Ti3C2Tx to Fe3O4 displayed the optimized EMI shielding performance. The average SE value was 62.19 dB, and the maximum value was 68.72 dB at 18 GHz with a 2.6 mm thickness. The EMI shielding mechanism was understood based on the conductive loss, magnetic loss, dipole polarization, and multiple scattering. Results suggests that Ti3C2Tx/Fe3O4 composites are expected to be superior EMI shielding material.  相似文献   

12.
《Ceramics International》2021,47(24):34437-34442
The development of semiconductor-based room-temperature methane (CH4) gas sensors is appealing but challenging. Herein, we report a CH4 gas sensor operating at room temperature based on Ti2CTx MXene, a novel p-type sensing material, achieving high-performance CH4 detection with visible light assistance. The Ti2CTx MXene based device showed more than seven-fold improvement for CH4 detection under visible-light irradiation, and the response/recovery times were also sharply decreased. The excellent CH4 sensing performance at room temperature could be attributed to the visible-light photocatalytic CH4 oxidation activity of the Ti2CTx sensing material. CH4 oxidation was revealed by photocatalytic measurement, O2-TPD and in-situ IR spectroscopies. The present work demonstrates the novel application of Ti2CTx MXene as a promising p-type sensing material for methane detection at room temperature. Moreover, the concept of “photocatalysis-enhanced gas sensing” can be employed in room-temperature gas sensors based on other novel semiconductors.  相似文献   

13.
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   

14.
《Ceramics International》2015,41(8):9823-9827
In2O3 nanorods decorated with Cr2O3 nanoparticles were synthesized by thermal evaporation of In2S3 powder in an oxidizing atmosphere followed by solvothermal deposition of Cr2O3 and their ethanol gas sensing properties were examined. The pristine and Cr2O3-decorated In2O3 nanorods exhibited responses of ~524% and ~1053%, respectively, to 500-ppm ethanol at 200 °C. The Cr2O3-decorated In2O3 nanorod sensor showed stronger electrical response to ethanol gas at 200 °C than the pristine In2O3 nanorod counterpart. The former also showed faster response and recovery than the latter. The pristine and Cr2O3-decorated In2O3 nanorod sensors showed the strongest response to ethanol gas at 250 and 200 °C, respectively. The Cr2O3-decorated In2O3 nanorod sensor showed selectivity for ethanol gas over other reducing gases. The underlying mechanism for the enhanced response, sensing speed and selectivity of the Cr2O3-decorated In2O3 nanorod sensor for ethanol gas is discussed.  相似文献   

15.
《Ceramics International》2022,48(9):12291-12298
Nanomaterials offer a wide range of applications in environmental nanotechnology. Hazardous pollutants in the environment are needed to be detected and controlled effectively to avoid human health risks. In this paper, we described the fine-controlled growth of In2O3 nanoparticles embedded on GO nanosheets by a facile precipitation method. The In2O3@GO nanocomposites exhibited outstanding gas sensing performance as compared with pure In2O3 nanoparticles towards NO2. At 225 °C, the sensor displayed high selectivity, best response (78) to 40 ppm NO2, quick response, and recovery times of 106s/42s. The improved sensing performances of the nanocomposite were attributed to large surface area, high gas adsorption-desorption capability, and the formation of p-n heterojunctions between In2O3 nanoparticles and GO nanosheets. The excellent gas detecting activities validate In2O3@GO nanocomposites as a promising candidate in the NO2 gas sensor industry.  相似文献   

16.
Light-weight and flexible 2D MXene-based polymer materials with low dielectric loss and high dielectric constant have drawn great attention in the power systems and modern electronic field. A series of Ti3C2Tx/EMA composites were fabricated via simple solution casting followed by a compression molding method with various mass concentrations of Ti3C2Tx (0, 1, 3, 5, 8, 10, 12, and 15 wt%). Morphological and micro structural properties of the prepared composites were studied via X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM), where the distribution of Ti3C2Tx in the Ti3C2Tx/EMA composites was confirmed. Thermal behaviors were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) investigations. The DSC analysis reveals that the % of crystallinity decreases from 11.06 with 1 wt% to 5.68 with 15 wt%, where Ti3C2Tx acts as an efficient nucleating agent. TGA data confirm the enhancement of the thermal stability of the composites upon increasing in Ti3C2Tx loading. The room temperature electrical and dielectric behavior of the studied composites were examined in the frequency range of 100 Hz–5 MHz. In this work, the 10 wt% of Ti3C2Tx loaded poly (ethylene-co-methyl acrylate) composite (EMA) showed higher dielectric permittivity (ε′ = 124.22) with lower dissipation loss (tan δ = 0.051) at 100 Hz among all weight percentages. The behavior of charge carriers in the prepared composites was studied by utilizing the impedance spectroscopy technique. The electrical parameters were calculated from the fitted Nyquist plots with a corresponding circuit model. I–V curves confirmed the conduction mechanisms of the composites. This beneficial enhancement in electrical properties recommends the composite can be utilized in flexible electronic storage devices.  相似文献   

17.
《Ceramics International》2016,42(7):8419-8424
Two-dimensional Ti3C2 nanosheets were obtained by exfoliation of synthesized Ti3AlC2 powders in 40% HF solution at room temperature. The influence of etching time on the synthesis, structural evolution during heating, and thermal stability of as-prepared Ti3C2 nanosheets were studied. The graphene-like structure of as-prepared Ti3C2 nanosheets was confirmed by XRD and SEM. TG–DTA and elemental analysis suggested that the OH and F groups attached on the surface of Ti3C2 nanosheets could be eliminated by heat treatment. It is noteworthy that Ti3C2 nanosheets are thermal stable up to 1200 °C in Ar atmosphere. In the heating process, a small quantity of TiO2 anatase emerges at 500 °C and then reacts with Ti3C2 to form a solid solution of TiCxO1−x (0<x<1) with the increase of temperature.  相似文献   

18.
To prevent restacking of the Ti3C2Tx layers, the Ti3C2Tx-foam has been successfully synthesized through thermal treatment of Ti3C2Tx-film with the hydrazine monohydrate. The interconnected porous structure of Ti3C2Tx-foam could effectively reduce the restacking of the Ti3C2Tx sheets and shorten the diffusion path of ions and accelerate the intercalation/de-intercalation of ions. The Ti3C2Tx-foam-80 used as free-standing electrode achieves a high areal capacitance of 271.2 mF/cm2 (122.7?F/g) at a scan rate of 5?mV/s in 1?M KOH electrolyte. It also exhibited a high capability rate of 65.5% from 5?mV/s to 100?mV/s and good cycle life with 88.7% retention of its initial after 10,000 cycles at a scan rate of 50?mV/s.  相似文献   

19.
Nanocrystalline In2O3-SnO2 thick films were fabricated using the screen-printing technique and their responses toward low concentrations of H2S in air (2-150 ppm) were tested at 28-150 °C. The amount of In2O3-loading was varied from 0 to 9 wt.% of SnO2 and superb sensing performance was observed for the sensor loaded with 7 wt.% In2O3, which might be attributed to the decreased crystallite size as well as porous microstructure caused by the addition of In2O3 to SnO2 without structural modification. The interfacial barriers between In2O3 and SnO2 might be another major factor. Typically, the response of 7 wt.% In2O3-loaded SnO2 sensor toward 100 ppm of H2S was 1481 at room temperature and 1921 at optimal operating temperature (40 °C) respectively, and showed fast and recoverable response with good reproducibility when operated at 70 °C, which are highly attractive for the practical application in low-temperature H2S detection.  相似文献   

20.
《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   

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