Journal of Materials Chemistry C
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2017
·Vol. 5
·期 30
·7621-7628
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IF 5.256
Xinliang Li,Xiaowei Yin,Meikang Han,Changqing Song,Xinnan Sun,Hailong Xu,Laifei Cheng,Litong Zhang
Herein, Ti2CTx MXene and its derivatives with various heterogeneous structures were constructed via etching and a facile oxidation treatment. The effect of different oxidation conditions on their structural evolution and phase composition was studied in detail. Compared with that of pristine Ti2CTx MXene, the improvement in the electromagnetic wave absorption capability of the as-prepared Ti2CTx/TiO2 and C/TiO2 nanocomposites was attributed to their enhanced polarization loss and stronger conductivity loss. The enhanced polarization loss is caused by the generated heterogeneous interfaces and higher specific surface area, and the stronger conductivity loss is due to the completely exfoliated carbon layers. Additionally, the remaining multilayered structure after exfoliation of the carbon layers favors energy dissipation. The C/TiO2 nanocomposites attain a minimum reflection coefficient of −50.3 dB at 7.1 and 14.2 GHz, and an effective absorption bandwidth of 4.7 GHz (covering the whole X-band) with a matching thickness of 2.1 mm; this indicates their excellent electromagnetic wave absorption properties. We believe that these nanocomposites with a heterogeneous structure also hold great promise for application in the fields of photocatalysis, lithium batteries, water purification, etc.
研究领域:
材料科学
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电磁学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Guozhen Liu,Song Liu,Kang Ma,Haoyu Wang,Xiaoyue Wang,Gongping Liu,Wanqin Jin
Recently, owing to their excellent structural and transport properties, two-dimensional membranes have attracted tremendous interest for their potential application in molecular separation. In this work, a new type of functionalized Ti2CTx MXene membrane was proposed by introducing different kinds of polyelectrolytes to regulate the membrane physicochemical structure for pervaporation dehydration of isopropanol dehydration. The morphology, physical, and chemical properties of powders and MXene-based membranes were studied by SEM, AFM, FTIR, XPS, and contact angle test. Meanwhile, the effect of polyelectrolyte functionalization on the MXene membrane performance for isopropanol dehydration was also studied. The results showed that the poly(diallyldimethylammonium chloride) (PDDA) functionalized MXene membrane possesses the highest separation performance owing to the optimized electrostatic effect and hydrophilicity. Besides, other influencing factors including PDDA concentration, MXene loading, and operating conditions on the MXene membrane performance were also systematically investigated. The developed PDDA functionalized MXene membrane showed excellent separation performance for dehydration of 90 wt % isopropanol/water at 50 °C with a total flux of 1237 g/m2·h and separation factor of 1932, showing great potential in application of solvent dehydration.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 19
·12095-12104
·
IF 10.733
Guozhen Liu,Jie Shen,Yufan Ji,Quan Liu,Gongping Liu,Jian Yang,Wanqin Jin
Two-dimensional (2D) material membranes have shown great potential for molecular separation. However, it remains challenging to controllably tune 2D material membrane structures with ordered nanochannels without non-selective defects. Herein, for the first time, 2D Ti2CTx MXene membranes were designed and fabricated for efficient solvent dehydration via a new strategy. Specifically, positively charged hyperbranched polyethylenimine was intercalated between negatively charged MXene nanosheets to assemble regular stacking structures via electrostatic interactions, followed by interfacial polymerization with trimesoyl chloride to seal possible non-selective defects. This strategy realized integrated Ti2CTx membranes as thin as ∼100 nm with highly ordered 2D nanochannels, thereby exhibiting outstanding separation performance: the water content was enriched to >99 wt% in permeate from 10 wt% water/isopropanol mixtures. Compared with commonly studied Ti3C2Tx MXene membranes prepared by the same approach, the Ti2CTx membranes showed higher selectivity with similarly high flux. The membrane fabrication approach developed herein offers a powerful platform for the rational design of 2D material thin films for precise molecular separation and other applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Bin Sun,Xusheng Dong,Huapeng Li,Yupeng Shang,Yuxin Zhang,Falu Hu,Shaonan Gu,Yue Wu,Tingting Gao,Guowei Zhou
Exploring versatile materials that efficiently adsorb pollutants from wastewater is of critical importance for environmental remediation. As an emerging 2D material, MXene features a hydrophilic surface with abundant oxygen-containing groups that render a negatively charged surface, implying its great potential for removing cationic pollutants from wastewater. Given its remarkable properties, a novel Ti 2 CT x MXene as an adsorbent is synthesized through selective etching of Al layer from Ti 2 AlC and then ultrasonic exfoliation. The adsorption studies indicate that Ti 2 CT x exhibits highly efficient methylene blue (MB, cationic dye) removal performance, the maximum adsorption capacity can reach as high as 2460.9 mg g −1 , which is considerably higher than the values of graphene (83.2 mg g −1 ) and anionic dye removal (methyl orange, 122.6 mg g −1 ). Furthermore, the adsorption behavior fits well with the pseudo-second-order kinetic and Langmuir isotherm models, and thermodynamic analysis indicates that the adsorption is spontaneous and endothermic. Based on scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra analysis, the principal adsorption mechanism is related to the electrostatic interaction between Ti 2 CT x and MB molecules. Meanwhile, the result is also confirmed by adsorption experiments at different pH values and background ions. This work shows that the MXene family materials can be applied as high efficiency adsorbent for removing cationic dyes from wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Bao Shi,Lu Chen,Tien-Chien Jen,Xinying Liu,La Li,Aibing Chen,Guozhen Shen
Freestanding and flexible MXene electrodes have exhibited great potential in wearable energy device design through over 10 years of rapid development but are yet limited by the restacking of nanosheets and the complex and lengthy ion transport paths that reduce their performance at high charge–discharge rates. Herein, we provide a molten salt method assisted by a selective etching process for the directional vertical growth of Ti2CTx MXene nanosheets on carbon fiber (CF) substrates, showing several advantages: (1) bifunctional CF, which acts as both a self-supported freestanding flexible substrate and carbon source during the synthesis of the Ti2AlC MAX phase, (2) eliminating the need for collecting the powder Ti2CTx MXene from the acid mixture after the selective etching process and filtration steps to obtain freestanding and flexible MXene films, and (3) the directional vertical arrangement of Ti2CTx shortens the ion diffusion path and the integrated structure of nanosheets and carbon fibers speeds up ion transport. As a result, the fabricated Ti2CTx MXene@CF//Zn@Cu@CF hybrid Zn-ion supercapacitor delivers a high areal capacitance of 380 mF/cm2, an energy density of 52.77 μWh/cm2 at 5 mV/s, excellent stability with 90.06% capacity retention after 10 000 cycles, and 89.76% capacity retention after storing in air for 30 days. The directional vertical Ti2CTx MXene nanosheets can be extended to other application areas, such as sensors, catalysts, detectors, electromagnetic shielding, etc.
研究领域:
材料科学
·
电化学
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能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2024
·Vol. 35
·期 34
·345402
·
IF 2.9
Ruixue Liu,Sainan Wei,Bao Shi,Yizhi Ma,Luning Sun,Wei Wang
The continuous advancements in wearable electronics have drawn significant attention toward 2D MXenes materials for energy storage owing to their abundant availability, adaptability, and distinctive physicochemical properties. Two unresolved concerns currently revolve around environmental pollution by F-containing etching and finite kinetics caused because of re-stacking of nanosheets. In this study, Al was electrochemically etched from porous Ti2AlC electrodes without the use of fluorine, through a selective electrochemical etching process in dilute hydrochloric acid. Subsequently, Ti2CTx MXene was vertically grown on carbon fiber (CF) substrates. The resulting Ti2CTx@CF electrodes are lightweight, thin, and flexible, exhibiting a surface capacitance of 330 mF cm−2 at a constant current density of 1 mA cm−2 after 2000 cycles. They display a surface capacitance retention of 96.16% and a high energy density of 45.3 μWh cm−2 at a power density of 0.497 mW cm−2. These metrics underscore the Ti2CTx@CF electrode's commendable multifunctionality, electrochemical performance, ion transport efficiency, and charge storage capacity. Moreover, a flexible energy storage electrode material with a high area capacity was developed by combining Ti2CTx MXene nanosheets, possessing a large specific surface area, with a flexible carbon fabric substrate.
研究领域:
材料科学
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能源存储
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
Advanced Composites and Hybrid Materials
·
2023
·Vol. 6
·期 2
·1-15
·
IF 20.1
Miao Baoji,Cao Yange,Zhu Qingsong,Nawaz Muhammad Asif,Ordiozola Jose Antonio,Reina Tomas Ramirez,Bai Zhiming,Ren Junna,Wei Fengchun
The signal crosstalk and electromagnetic interference (EMI) problems direly need to be resolved in the rapid development of modern microwave communication technology for a better working frequency and transmission power of electronic systems. Where the new absorbing materials such as molybdenum disulfide (MoS 2 )/titania (TiO 2 )/Ti 2 CT x and MoS 2 /Ti 2 CT x composites could meet the requirement of “thin, strong, light weight, and wide band” for excellent absorbing performance. In this work, a lighter Ti 2 CT x material was selected as the matrix, and MoS 2 was in-situ grown on Ti 2 CT x matrix by traditional hydrothermal method and microwave solvothermal method. The fabricated composite exhibited synergic effect of two-dimensional heterostructural interface and double dielectric elements, where a small amount of TiO 2 and a certain proportion of MoS 2 jointly improve the impedance matching of the composite material. In here, the extreme reflection loss (RL min ) can reach − 54.70 dB (with a frequency of 7.59 GHz, 3.39 mm thickness), and the maximum effective absorption bandwidth (EAB max ) can reach 4 GHz. Polyethylene glycol 200 was used as the solvent instead of water to make Ti 2 CT x less oxidized during the composite process, where the microwave heating would attain fast speed, short time, high efficiency, and uniform product. Since, the MoS 2 /Ti 2 CT x composite without oxidizing possessed a wider effective absorption bandwidth (EAB) at a thinner thickness, thus resulting in the excellent microwave absorption performance and confirming the validity and rationality of new microwave absorption materials.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Hailong Xu,Xiaowei Yin,Xinliang Li,Minghang Li,Shuang Liang,Litong Zhang,Laifei Cheng
Lightweight absorption-dominated electromagnetic interference (EMI) shielding materials are more attractive than conventional reflection-dominated counterparts because they minimize the twice pollution of the reflected electromagnetic (EM) wave. Here, porous Ti2CTx MXene/poly(vinyl alcohol) composite foams constructed by few-layered Ti2CTx (f-Ti2CTx) MXene and poly(vinyl alcohol) (PVA) are fabricated via a facile freeze-drying method. As superior EMI shielding materials, their calculated specific shielding effectiveness reaches up to 5136 dB cm2 g–1 with an ultralow filler content of only 0.15 vol % and reflection effectiveness (SER) of less than 2 dB, representing the excellent absorption-dominated shielding performance. Contrast experiment reveals that the good impedance matching derived from the multiple porous structures, internal reflection, and polarization effect (dipole and interfacial polarization) plays a synergistic role in the improved absorption efficiency and superior EMI shielding performance. Consequently, this work provides a promising MXene-based EMI shielding candidate with lightweight and high strength features.
研究领域:
材料科学
·
电磁功能材料
·
纳米复合材料
·
聚合物基复合材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）