共查询到20条相似文献,搜索用时 15 毫秒
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Armin VahidMohammadi Mehrnaz Mojtabavi Nuala Mai Caffrey Meni Wanunu Majid Beidaghi 《Advanced materials (Deerfield Beach, Fla.)》2019,31(8)
Electrochemical capacitors (ECs) that store charge based on the pseudocapacitive mechanism combine high energy densities with high power densities and rate capabilities. 2D transition metal carbides (MXenes) have been recently introduced as high‐rate pseudocapacitive materials with ultrahigh areal and volumetric capacitances. So far, 20 different MXene compositions have been synthesized and many more are theoretically predicted. However, since most MXenes are chemically unstable in their 2D forms, to date only one MXene composition, Ti3C2Tx, has shown stable pseudocapacitive charge storage. Here, a cation‐driven assembly process is demonstrated to fabricate highly stable and flexible multilayered films of V2CTx and Ti2CTx MXenes from their chemically unstable delaminated single‐layer flakes. The electrochemical performance of electrodes fabricated using assembled V2CTx flakes surpasses Ti3C2Tx in various aqueous electrolytes. These electrodes show specific capacitances as high as 1315 F cm?3 and retain ≈77% of their initial capacitance after one million charge/discharge cycles, an unprecedented performance for pseudocapacitive materials. This work opens a new venue for future development of high‐performance supercapacitor electrodes using a variety of 2D materials as building blocks. 相似文献
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Yongchang Dong Sergii Chertopalov Kathleen Maleski Babak Anasori Longyu Hu Sriparna Bhattacharya Apparao M. Rao Yury Gogotsi Vadym N. Mochalin Ramakrishna Podila 《Advanced materials (Deerfield Beach, Fla.)》2018,30(10)
MXenes comprise a new class of 2D transition metal carbides, nitrides, and carbonitrides that exhibit unique light–matter interactions. Recently, 2D Ti3CNTx (Tx represents functional groups such as ? OH and ? F) was found to exhibit nonlinear saturable absorption (SA) or increased transmittance at higher light fluences, which is useful for mode locking in fiber‐based femtosecond lasers. However, the fundamental origin and thickness dependence of SA behavior in MXenes remain to be understood. 2D Ti3C2Tx thin films of different thicknesses are fabricated using an interfacial film formation technique to systematically study their nonlinear optical properties. Using the open aperture Z‐scan method, it is found that the SA behavior in Ti3C2Tx MXene arises from plasmon‐induced increase in the ground state absorption at photon energies above the threshold for free carrier oscillations. The saturation fluence and modulation depth of Ti3C2Tx MXene is observed to be dependent on the film thickness. Unlike other 2D materials, Ti3C2Tx is found to show higher threshold for light‐induced damage with up to 50% increase in nonlinear transmittance. Lastly, building on the SA behavior of Ti3C2Tx MXenes, a Ti3C2Tx MXene‐based photonic diode that breaks time‐reversal symmetry to achieve nonreciprocal transmission of nanosecond laser pulses is demonstrated. 相似文献
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Transparent,Flexible, and Conductive 2D Titanium Carbide (MXene) Films with High Volumetric Capacitance
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Chuanfang Zhang Babak Anasori Andrés Seral‐Ascaso Sang‐Hoon Park Niall McEvoy Aleksey Shmeliov Georg S. Duesberg Jonathan N. Coleman Yury Gogotsi Valeria Nicolosi 《Advanced materials (Deerfield Beach, Fla.)》2017,29(36)
2D transition‐metal carbides and nitrides, known as MXenes, have displayed promising properties in numerous applications, such as energy storage, electromagnetic interference shielding, and catalysis. Titanium carbide MXene (Ti3C2Tx ), in particular, has shown significant energy‐storage capability. However, previously, only micrometer‐thick, nontransparent films were studied. Here, highly transparent and conductive Ti3C2Tx films and their application as transparent, solid‐state supercapacitors are reported. Transparent films are fabricated via spin‐casting of Ti3C2Tx nanosheet colloidal solutions, followed by vacuum annealing at 200 °C. Films with transmittance of 93% (≈4 nm) and 29% (≈88 nm) demonstrate DC conductivity of ≈5736 and ≈9880 S cm?1, respectively. Such highly transparent, conductive Ti3C2Tx films display impressive volumetric capacitance (676 F cm?3) combined with fast response. Transparent solid‐state, asymmetric supercapacitors (72% transmittance) based on Ti3C2Tx and single‐walled carbon nanotube (SWCNT) films are also fabricated. These electrodes exhibit high capacitance (1.6 mF cm?2) and energy density (0.05 µW h cm?2), and long lifetime (no capacitance decay over 20 000 cycles), exceeding that of graphene or SWCNT‐based transparent supercapacitor devices. Collectively, the Ti3C2Tx films are among the state‐of‐the‐art for future transparent, conductive, capacitive electrodes, and translate into technologically viable devices for next‐generation wearable, portable electronics. 相似文献
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Jing Guo Benjamin Legum Babak Anasori Ke Wang Pavel Lelyukh Yury Gogotsi Clive A. Randall 《Advanced materials (Deerfield Beach, Fla.)》2018,30(32)
Nanocomposites containing 2D materials have attracted much attention due to their potential for enhancing electrical, magnetic, optical, mechanical, and thermal properties. However, it has been a challenge to integrate 2D materials into ceramic matrices due to interdiffusion and chemical reactions at high temperatures. A recently reported sintering technique, the cold sintering process (CSP), which densifies ceramics with the assistance of transient aqueous solutions, provides a means to circumvent the aforementioned problems. The efficacious co‐sintering of Ti3C2Tx (MXene), a 2D transition carbide, with ZnO, an oxide matrix, is reported. Using CSP, the ZnO–Ti3C2Tx nanocomposites can be sintered to 92–98% of the theoretical density at 300 °C, while avoiding oxidation or interdiffusion and showing homogeneous distribution of the 2D materials along the ZnO grain boundaries. The electrical conductivity is improved by 1–2 orders of magnitude due to the addition of up to 5 wt% MXene. The hardness and elastic modulus show an increase of 40–50% with 0.5 wt% MXene, and over 150% with 5 wt% of MXene. The successful densification of ZnO–MXene nanocomposite demonstrates that the cold sintering of ceramics with 2D materials is a promising processing route for designing new nanocomposites with a diverse range of applications. 相似文献
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Hüseyin Enis Karahan Kunli Goh Chuanfang Zhang Euntae Yang Cansu Yıldırım Chong Yang Chuah M. Göktuğ Ahunbay Jaewoo Lee Ş. Birgül Tantekin-Ersolmaz Yuan Chen Tae-Hyun Bae 《Advanced materials (Deerfield Beach, Fla.)》2020,32(29):1906697
MXenes are emerging rapidly as a new family of multifunctional nanomaterials with prospective applications rivaling that of graphenes. Herein, a timely account of the design and performance evaluation of MXene-based membranes is provided. First, the preparation and physicochemical characteristics of MXenes are outlined, with a focus on exfoliation, dispersion stability, and processability, which are crucial factors for membrane fabrication. Then, different formats of MXene-based membranes in the literature are introduced, comprising pristine or intercalated nanolaminates and polymer-based nanocomposites. Next, the major membrane processes so far pursued by MXenes are evaluated, covering gas separation, wastewater treatment, desalination, and organic solvent purification. The potential utility of MXenes in phase inversion and interfacial polymerization, as well as layer-by-layer assembly for the preparation of nanocomposite membranes, is also critically discussed. Looking forward, exploiting the high electrical conductivity and catalytic activity of certain MXenes is put into perspective for niche applications that are not easily achievable by other nanomaterials. Furthermore, the benefits of simulation/modeling approaches for designing MXene-based membranes are exemplified. Overall, critical insights are provided for materials science and membrane communities to navigate better while exploring the potential of MXenes for developing advanced separation membranes. 相似文献
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Soyeong Ahn Tae-Hee Han Kathleen Maleski Jinouk Song Young-Hoon Kim Min-Ho Park Huanyu Zhou Seunghyup Yoo Yury Gogotsi Tae-Woo Lee 《Advanced materials (Deerfield Beach, Fla.)》2020,32(23):2000919
Although several transparent conducting materials such as carbon nanotubes, graphene, and conducting polymers have been intensively explored as flexible electrodes in optoelectronic devices, their insufficient electrical conductivity, low work function, and complicated electrode fabrication processes have limited their practical use. Herein, a 2D titanium carbide (Ti3C2) MXene film with transparent conducting electrode (TCE) properties, including high electrical conductivity (≈11 670 S cm−1) and high work function (≈5.1 eV), which are achieved by combining a simple solution processing with modulation of surface composition, is described. A chemical neutralization strategy of a conducting-polymer hole-injection layer is used to prevent detrimental surface oxidation and resulting degradation of the electrode film. Use of the MXene electrode in an organic light-emitting diode leads to a current efficiency of ≈102.0 cd A−1 and an external quantum efficiency of ≈28.5% ph/el, which agree well with the theoretical maximum values from optical simulations. The results demonstrate the strong potential of MXene as a solution-processable electrode in optoelectronic devices and provide a guideline for use of MXenes as TCEs in low-cost flexible optoelectronic devices. 相似文献
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Three‐Dimensional Printing of Multifunctional Nanocomposites: Manufacturing Techniques and Applications
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Rouhollah D. Farahani Martine Dubé Daniel Therriault 《Advanced materials (Deerfield Beach, Fla.)》2016,28(28):5794-5821
The integration of nanotechnology into three‐dimensional printing (3DP) offers huge potential and opportunities for the manufacturing of 3D engineered materials exhibiting optimized properties and multifunctionality. The literature relating to different 3DP techniques used to fabricate 3D structures at the macro‐ and microscale made of nanocomposite materials is reviewed here. The current state‐of‐the‐art fabrication methods, their main characteristics (e.g., resolutions, advantages, limitations), the process parameters, and materials requirements are discussed. A comprehensive review is carried out on the use of metal‐ and carbon‐based nanomaterials incorporated into polymers or hydrogels for the manufacturing of 3D structures, mostly at the microscale, using different 3D‐printing techniques. Several methods, including but not limited to micro‐stereolithography, extrusion‐based direct‐write technologies, inkjet‐printing techniques, and popular powder‐bed technology, are discussed. Various examples of 3D nanocomposite macro‐ and microstructures manufactured using different 3D‐printing technologies for a wide range of domains such as microelectromechanical systems (MEMS), lab‐on‐a‐chip, microfluidics, engineered materials and composites, microelectronics, tissue engineering, and biosystems are reviewed. Parallel advances on materials and techniques are still required in order to employ the full potential of 3D printing of multifunctional nanocomposites. 相似文献
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A 2D Conductive Organic–Inorganic Hybrid with Extraordinary Volumetric Capacitance at Minimal Swelling
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Kefeng Xiao Donglin Jiang Rose Amal Da‐Wei Wang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(26)
Rational design and synthesis of 2D organic–inorganic hybrid materials is important for transformative technological advances for energy storage. Here, a 2D conductive hybrid lamella and its intercalation properties for thin‐film supercapacitors are reported. The 2D organic–inorganic hybrid lamella comprises periodically stacked 2D nanosheets with 11.81 Å basal spacing, and is electronically conductive (605 S m?1). In contrast to the pre‐existing organic‐based 2D materials, this material has extremely low gas‐permeable porosity (16.5 m2 g?1) in contrast to the high ionic accessibility. All these structural features collectively contribute to the high capacitances up to 732 F cm?3, combined with small structural swelling at as low as 4.8% and good stability. At a discharge time of 6 s, the thin‐film intercalation electrode delivers an energy density of 24 mWh cm?3, which universally outperforms the surface‐dominant capacitive processes in porous carbons. 相似文献
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Changwei Shi Kwadwo Asare Owusu Xiaoming Xu Ting Zhu Guobin Zhang Wei Yang Liqiang Mai 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(48)
Electrochemical energy storage (EES) devices have attracted immense research interests as an effective technology for utilizing renewable energy. 1D carbon‐based nanostructures are recognized as highly promising materials for EES application, combining the advantages of functional 1D nanostructures and carbon nanomaterials. Here, the recent advances of 1D carbon‐based nanomaterials for electrochemical storage devices are considered. First, the different categories of 1D carbon‐based nanocomposites, namely, 1D carbon‐embedded, carbon‐coated, carbon‐encapsulated, and carbon‐supported nanostructures, and the different synthesis methods are described. Next, the practical applications and optimization effects in electrochemical energy storage devices including Li‐ion batteries, Na‐ion batteries, Li–S batteries, and supercapacitors are presented. After that, the advanced in situ detection techniques that can be used to investigate the fundamental mechanisms and predict optimization of 1D carbon‐based nanocomposites are discussed. Finally, an outlook for the development trend of 1D carbon‐based nanocomposites for EES is provided. 相似文献
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Olfactory sensing and perception play an important role in people's daily lives and greatly affects senses, emotions, and behavior. In particular, the development of the controlled release of aroma enhances human's well‐being and strengthens interactions with surroundings through olfactory display, especial when combined with visual and audial cues. Here, Ti3C2 MXene plays a dual‐function role as the adsorption site of aroma molecules and the heating source for the controlled release of aroma molecules. Due to abundant termination groups on the surface and the metallic nature, Ti3C2 MXene provides abundant active sites for the interaction with aroma molecules; simultaneously, MXene can be electrically heated to thermally desorb the aroma molecules from the interaction sites. This approach eliminates the interface incompatibility issues between the heating source and the molecular encapsulation layer in conventional olfactory display system. This work presents the controlled release of the aroma molecule phenethyl alcohol (PA) using Ti3C2 MXene paper. Ti3C2 MXene paper serves as the adsorption material and a heating source that achieves 100 °C within 1 s. The relative amount of PA released reaches nearly 100% after 1 min of heating. 相似文献
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Ahrom Ryu Haena Yim Soyeon Yoo Jiseul Park Dong-Gyu Lee Jun Young Lee Hyun-Cheol Song Seung Hyub Baek Sahn Nahm Ji-Won Choi 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(28):2300526
Polymer-based nanocomposites are desirable materials for next-generation dielectric capacitors. 2D dielectric nanosheets have received significant attention as a filler. However, randomly spreading the 2D filler causes residual stresses and agglomerated defect sites in the polymer matrix, which leads to the growth of an electric tree, resulting in a more premature breakdown than expected. Therefore, realizing a well-aligned 2D nanosheet layer with a small amount is a key challenge; it can inhibit the growth of conduction paths without degrading the performance of the material. Here, an ultrathin Sr1.8Bi0.2Nb3O10 (SBNO) nanosheet filler is added as a layer into poly(vinylidene fluoride) (PVDF) films via the Langmuir–Blodgett method. The structural properties, breakdown strength, and energy storage capacity of a PVDF and multilayer PVDF/SBNO/PVDF composites as a function of the thickness-controlled SBNO layer are examined. The seven-layered (only 14 nm) SBNO nanosheets thin film can sufficiently prevent the electrical path in the PVDF/SBNO/PVDF composite and shows a high energy density of 12.8 J cm−3 at 508 MV m−1, which is significantly higher than that of the bare PVDF film (9.2 J cm−3 at 439 MV m−1). At present, this composite has the highest energy density among the polymer-based nanocomposites under the filler of thin thickness. 相似文献
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