查找使用阿拉丁产品的科研文献

MXene functionalized whispering gallery mode microbubble resonator for Pb2+ sensing

Lu Cai,Yu-xiao Liu,Hao Jing,Li-ke Li,Kai Gao,Jin-ze Zhang,Yu-jie Wang,Si-rui Huang

This study proposes a novel optical fiber sensor that integrates two-dimensional MXene materials with a microbubble whispering gallery mode (WGM) resonator for the detection of lead ions (Pb 2+ ). Utilizing the inherent negative surface charge of MXene nanosheets, a uniform functionalized film was formed on the inner surface of the microbubble cavity, enabling specific binding to Pb 2+ . Experimental results demonstrated a nonlinear response ( R 2  > 0.99) over a Pb 2+ concentration range of 0–1000 mg/L, with a detection limit of 5 mg/L, meeting the standard requirements for monitoring lead ions in industrial wastewater. The sensor also exhibits high selectivity toward Pb 2+ in the presence of interfering ions such as Zn 2+ , Ni 2+ , and Cd 2+ . Furthermore, owing to the inherent microfluidic channel of the microbubble cavity, this structure is suitable for real-time monitoring in complex aqueous environments, highlighting the great potential of the MXene-microbubble resonator platform for environmental heavy metal detection.

MXene Nanofibers as Highly Active Catalysts for Hydrogen Evolution Reaction

Wenyu Yuan,Laifei Cheng,Yurong An,Heng Wu,Na Yao,Xiaoli Fan,Xiaohui Guo

Nonprecious metal catalysts for hydrogen evolution reaction (HER) have recently received growing attention. Herein, we designed a highly active MXene nanofiber catalyst with a high specific surface area (SSA) via the hydrolyzation of bulk MAX ceramics, and a subsequent HF etching process. Compared with traditional MXene flakes, the MXene nanofibers delivered a much higher SSA and exposed more active sites in the cross section. As a result, the MXene nanofiber delivered an enhanced HER activity with a low overpotential of 169 mV at a current density of 10 mA cm–2, a depressed Tafel slope of 97 mV dec–1, and low electrochemical resistance. The improved SSA and exposed active sites are responsible for the enhanced activity. This work provides a novel synthesis method for MXene nanofibers, and MXene nanofibers are also promising for applications in batteries, supercapacitors, and catalytic fields.

High-Temperature Oxidized Mo2CTx MXene for a High-Performance Supercapacitor

Huajun Xu,Honglei Dong,Xintong Liu,He Qiao,Gang Chen,Fei Du,Yohan Dall’Agnese,Yu Gao

Molybdenum carbide (Mo2CTx MXene) did not possess suitable properties for supercapacitors. Herein, a short oxidation method of Mo2CTx in air at moderately high temperatures is proposed for fabricating a Mo2C/MoO3 heterostructure. The stability of Mo2CTx in air up to 700 °C and the phase transition at higher temperatures are confirmed. Such a heterostructure is beneficial in reducing the diffusion energy barrier of H+. In the aqueous system, the Mo2C/MoO3 electrode delivers a capacitance of up to 811 F g–1. A fully assembled symmetric solid-state supercapacitor delivers 224 F g–1 with an excellent retention rate of 91.05% after 7500 cycles. Besides, the supercapacitor can work at the low temperature of −60°, showing good low-temperature properties. The approach presented in this work opens a promising way to turn a neglected MXene, assumed to be unsuitable for supercapacitors, into one of the top-performing supercapacitor electrodes.

Ti3C2Tx MXene Quantum Dots with Enhanced Stability for Ultrafast Photonics

Fumei Yang,Yanqi Ge,Teng Yin,Jia Guo,Feng Zhang,Xian Tang,Meng Qiu,Weiyuan Liang,Ning Xu,Cong Wang,Yufeng Song,Shixiang Xu,Sanshui Xiao

MXenes, as an emerging group of two-dimensional materials, have attracted significant interest for diverse photoelectric applications by virtue of their tunable terminated surface, excellent electrical conductivity, and strong nonlinear optical response. They are usually synthesized via strategies involving hydrofluoric acid, which may result in oxygenic and hydrophilic termination groups on the MXene surface and thus decrease their stability in air. Herein, a mild synthesis method based on electrochemical exfoliation is proposed to prepare Ti3C2Tx MXene quantum dots (QDs), which are highly fluorinated to enhance stability. The open-aperture Z-scan system was employed to measure the nonlinear transmittance of the MXene QDs and proves their broadband saturable absorption from 540 to 1550 nm. By integrating the MXene QD saturable absorber into an ytterbium-doped fiber laser, a set of highly stable 357 ps mode-locked pulses centered at 1069.17 nm was achieved under a low threshold power of 54 mW. In addition, tunable mode-locked optical spectra could be observed in the cavity when switching the polarization state. This work provides an environmentally friendly approach to synthesize stable MXene QDs and opens an avenue for the realization of low-threshold and tunable photonics applications based on MXene QDs.

Bioinspired MXene-integrated colloidal crystal arrays for multichannel bioinformation coding

Feika Bian,Lingyu Sun,Lijun Cai,Yu Wang,Yuanjin Zhao

Information coding strategies are becoming increasingly crucial due to the storage demand brought by the information explosion. In particular, bioinformation coding has attracted great attention for its advantages of excellent storage capacity and long lifetime. Herein, we present an innovative bioinspired MXene-integrated photonic crystal (PhC) array for multichannel bioinformation coding. PhC arrays with similar structure to Stenocara beetle’s back are utilized as the substrate, exhibiting properties of high throughput and stability. MXene nanosheets are further integrated on the PhC array’s substrate with the assistance of the adhesion capacity of mussel-inspired dopamine (DA). Benefitting from their fluorescence resonance energy transfer effect, MXene nanosheets can quench the fluorescence signals of quantum dot (QD) modified DNA probes unless the corresponding targets exist. Additionally, these black MXene nanosheets can enhance the contrast of structural color. In this case, the encrypted information can be easily read out by simply observing the fluorescence signal of DNA probes. It is demonstrated that this strategy based on bioinspired MXene-integrated PhC arrays can realize high-throughput information encoding and encryption, which opens a chapter of bioinformation coding.

Bioinspired light-driven photonic crystal actuator with MXene-hydrogel muscle

Mingzhu Li,Lei Yuan,Yifan Liu,Florian Vogelbacher,Xiaoyu Hou,Yanlin Song,Qunfeng Cheng

The butterfly Apatura ilia ’s wings change colors during flapping, which plays a major role in conveying information and avoiding predators. Inspired by the muscle-driven flapping mechanism, here, we fabricate a highly efficient photothermally responsive MXene-hydrogel muscle and achieve a dynamic structural color imaging system based on the MXene-hydrogel muscle manipulated photonic crystal actuator arrays. Our optimized MXene-hydrogel-muscle artificial muscle has a stable and quick photothermal response owing to the high photothermal transformation efficiency of MXene (∼100%). Consequently, our photonic crystal (PhC) actuator exhibits robust structural stability and fatigue resistance (more than 500 cycles), and its response time is ∼5 s. The PhC actuator can give real-time visual feedback in response to heating and near-infrared irradiation. They offer exciting possibilities for applications in sensors, displays, camouflage coatings, cryptography, and many other fields. Our experiments and theoretical analysis reveal the quantitative structure-activity relationship of the responsive PhC actuator.

Synthesis and thermal stability of two-dimensional carbide MXene Ti3C2

Zhengyang Li,Libo Wang,Dandan Sun,Yude Zhang,Baozhong Liu,Qianku Hu,Aiguo Zhou

We investigated the synthesis of quasi-two-dimensional carbide (Ti 3 C 2 ), with the name of MXene, by immersing Ti 3 AlC 2 in 40% or 49% hydrofluoric acid (HF) at 0   °C, 15   °C or 60   °C. The influences of time, temperature, and source of Ti 3 AlC 2 on the synthesis were researched. It was found that Ti 3 C 2 synthesized from pressureless synthesized Ti 3 AlC 2 was highly oriented compared to that from hot-pressed Ti 3 AlC 2 . As-synthesized Ti 3 C 2 could be further exfoliated by intercalation with urea, dimethylsulfoxide or ammonia. From the results of thermogravimetry and differential scanning calorimetry, Ti 3 C 2 MXene with F/OH termination was found to be stable in argon atmosphere at temperature up to 800   °C. In oxygen atmosphere, at 200   °C, parts of MXene layers were oxidized to obtain an interesting structure: anatase nano-crystals were evenly distributed on 2D Ti 3 C 2 layers. At 1000   °C, MXene layers were completely oxidized and anatase phase fully transformed to rutile in oxygen atmosphere.

MXene-Coated Planar Microwave Resonator Sensor for Ultrasensitive Humidity Monitoring

Luqman Ali,Gaofeng Wang,Fanyi Meng,Xumin Ding,Kishor Kumar Adhikari,Cong Wang

MXene/NiO Composites for Chemiresistive-Type Room Temperature Formaldehyde Sensor

Baoyu Huang,Xinwei Tong,Xiangpeng Zhang,Qiuxia Feng,Marina N. Rumyantseva,Jai Prakash,Xiaogan Li

In this work, MXene/NiO-composite-based formaldehyde (HCHO) sensing materials were successfully synthesized by an in situ precipitation method. The heterostructures between the MXene and NiO nanoparticles were verified by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The HCHO sensing performance of the MXene/NiO-based chemiresistive-type sensors was investigated. Compared to pure MXene and NiO materials, the sensing performance of the MXene/NiO-P2-based sensor to HCHO gas at room temperature was significantly enhanced by the formation of MXene/NiO heterojunctions. The response of the MXene/NiO-P2 sensor to 50 ppm HCHO gas was 8.8, which was much higher than that of the pure MXene and NiO. At room temperature, the detectable HCHO concentration of the MXene/NiO-P2-based sensor was 1 ppm, and the response and recovery time to 2 ppm HCHO was 279 s and 346 s, respectively. The MXene/NiO-P2 sensor also exhibited a good selectivity and a long-term stability to HCHO gas for 56 days. The in situ Fourier transform infrared (FTIR) spectra of the MXene/NiO-P2 sensor, when exposed to HCHO gas at different times, were investigated to verify the adsorption reaction products of HCHO molecules.Keywords:chemiresistive-type formaldehyde sensor;MXene/NiO;heterojunctions;room temperature

Hydrogen Release and Uptake of MgH2 Modified by Ti3CN MXene

Xiantun Huang,Chenglin Lu,Yun Li,Haimei Tang,Xingqing Duan,Kuikui Wang,Haizhen Liu

MgH2has a high hydrogen content of 7.6 wt% and possesses good reversibility under normal conditions. However, pristine MgH2requires a high temperature above 300 °C to release hydrogen, with very slow kinetics. In this work, we utilized Ti3CN MXene to reduce the operating temperature and enhance the kinetics of MgH2. The initial temperature of MgH2decomposition can be lowered from 322 °C for pristine MgH2to 214 °C through the employment of Ti3CN. The desorbed MgH2+ 7.5 wt% Ti3CN can start absorption at room temperature, while the desorbed pristine MgH2can only start absorption at 120 °C. The employment of Ti3CN can significantly improve the hydrogen release kinetics of MgH2, with the desorption activation energy decreasing from 121 to 80 kJ mol−1. Regarding thermodynamics, the desorption enthalpy changes of MgH2and MgH2+ 7.5 wt% Ti3CN were 79.3 and 78.8 kJ mol−1, respectively. This indicates that the employment of Ti3CN does not alter the thermal stability of MgH2. Phase evolution studies through the use of X-ray diffraction and electron diffraction both confirm that Ti3CN remains stable during the hydrogen release and uptake process of the composite. This work will help understand the impact of a transition metal carbonitride on the hydrogen storage of MgH2.

Tubular MXene/SS membranes for highly efficient H2/CO2 separation

Mide Luo,Zong Lu,Yali Zhao,Yufei Wang,Yanying Wei,Haihui Wang

Accurately constructing membranes based on two-dimensional (2D) materials on commercial porous substrates remains a significant challenge for H 2 purification. In this work, a series of tubular 2D MXene membranes are prepared on commercial porous stainless steel substrates via fast electrophoretic deposition. Compared with other methods, such as filtration or drop coating, and so on. such preparation route shows the advantages of simple operation, high efficiency for membrane assembly (within 5 min) with attractive reproducibility, and ease for scale-up. The tubular MXene membranes present excellent gas separation performance with hydrogen permeance of 1290 GPU and H 2 /CO 2 selectivity of 55. Furthermore, the membrane displays extremely stable performance during the long-term test for more than 1250 h, and about 93% of the membranes from one batch have exceeded the DOE target for CO 2 capture. Most importantly, this work provides valuable referential significance for other 2D materials-based membranes for future application development.

Formation of MXene-Derived/NiCoFe-LDH Heterostructures for Supercapacitor Applications

Yihan Guo,Tongxiang Chen,Yongjin Zou

In this study, MXene-derived/NiCoFe-LDH heterostructures with three-dimensional interconnected porous network microstructures were prepared, leveraging the excellent electrical conductivity and growth platform provided by the MXene material. The remarkable specific capacitance of metal oxides was fully exploited. The composite exhibited high specific capacitance and excellent stability, with a specific capacitance of 1305 F g−1at 1 A g−1and a capacitance of 85.7% of the initial performance after 6000 charge/discharge tests at 10 A g−1. A two-electrode assembly was constructed using activated carbon as the negative electrode material corresponding to 49.5 Wh kg−1at 800 W kg−1, indicating that the electrodes could achieve rapid charge/discharge. The findings of this study indicate that the composite material comprising LDH/MXene has significant potential for supercapacitor applications.Keywords:supercapacitor;MXene;layered double hydroxide;three-dimensional