首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
    
The rapid development of wearable electronics requires energy storage devices capable of withstanding both static and dynamic deformations. The versatility of textile supercapacitors renders them promising candidates, but their low electrochemical performance especially under mechanical deformation, poses many limitations for practical use. In this study, MXene-based textile supercapacitors are designed and fabricated using hierarchical spacer fabrics as the skeleton to provide robust mechanical support and stable performance. Ti3C2Tx MXene is adopted as the current collector and active material for the spacer fabric supercapacitor, resulting in an impressive areal capacitance of 415 mF cm−2 with a MXene loading of 4.2 mg cm−2. Remarkable stability and durability are achieved in the form of three-dimensional (3D) textile supercapacitors, even under both static and dynamic deformations. The compressive behaviors of these supercapacitors can be easily adjusted (e.g., from 10 to 168 KPa at 50% compression) by altering the spacer fabric structure, demonstrating their energy-absorption (damping of kinetic energy) capability and their potential to meet the requirements of various wearable applications.  相似文献   

2.
    
Assembling 2D-material (2DM) nanosheets into micro- and macro-architectures with augmented functionalities requires effective strategies to overcome nanosheet restacking. Conventional assembly approaches involve external binders and/or functionalization, which inevitably sacrifice 2DM's nanoscale properties. Noble metal ions (NMI) are promising ionic crosslinkers, which can simultaneously assemble 2DM nanosheets and induce synergistic properties. Herein, a collection of NMI–2DM complexes are screened and categorized into two sub-groups. Based on the zeta potentials, two assembly approaches are developed to obtain 1) NMI-crosslinked 2DM hydrogels/aerogels for heterostructured catalysts and 2) NMI–2DM inks for templated synthesis. First, tetraammineplatinum(II) nitrate (TPtN) serves as an efficient ionic crosslinker to agglomerate various 2DM dispersions. By utilizing micro-textured assembly platforms, various TPtN–2DM hydrogels are fabricated in a scalable fashion. Afterward, these hydrogels are lyophilized and thermally reduced to synthesize Pt-decorated 2DM aerogels (Pt@2DM). The Pt@2DM heterostructures demonstrate high, substrate-dependent catalytic activities and promote different reaction pathways in the hydrogenation of 3-nitrostyrene. Second, PtCl4 can be incorporated into 2DM dispersions at high NMI molarities to prepare a series of PtCl4–2DM inks with high colloidal stability. By adopting the PtCl4–graphene oxide ink, various Pt micro-structures with replicated topographies are synthesized with accurate control of grain sizes and porosities.  相似文献   

3.
    
Striving for the sixth-generation communication technology discovery, semiconductors beyond Si with wider bandgaps as well as non-conventional metals are actively being sought to achieve high speeds whilst maintaining devices miniaturization. 2D materials may provide the potential for downsizing, but their functional advantage over existing counterparts still longs to be discovered. Along that path, surface-adsorbed or bulk-intercalated water molecules remaining after wet-chemical synthesis of 2D materials are generally seen as obstacles to high-performance achievement. Herein, the control of such water within the interlayers of solution-processed metallic 2D titanium carbide (MXene) by vacuum annealing duration is demonstrated. Moreover, the impact of water removal on work function (WF) and functional terminations is unveiled for the first time. Furthermore, the usefulness of such water for controlling a novel Schottky diode in contact with an n-type oxide semiconductor, niobium-doped strontium titanate (Nb:SrTiO3) is observed. The advantage of MXene compared to conventional gold as facile processing, WF tunability, and lower turn-on voltage in the Schottky anode application is highlighted. This fundamental study shows the way for a novel Schottky diode preparation in atmospheric conditions and provides implications for further research directions aiming at commercialization.  相似文献   

4.
    
As a new 2D material, MXene (Ti3C2Tx) shows great potential as a smart multifunctional humidity-responsive actuator due to its high hydrophilicity and conductivity but suffers from ambient oxidation and mechanical brittleness. Inspired by the mussels, the authors overcome these weaknesses by designing and fabricating a nacre-like and lamellar-structured composite film that consists of polydopamine-modified MXene and bacterial cellulose nanofibers, which shows improved properties as a moisture-driven actuator. The actuator has high conductivity (2848 S cm–1), excellent tensile strength (406 MPa), and toughness (15.3 MJ m–3). Moreover, the actuator is highly sensitive to moisture with the advantages of fast response (1.6 s), large deformation (176°), and high actuation force output (6.5 N m–2). It is additionally demonstrated that the actuator works as the electrical switch, robotic arm, and motor in a moisture-driven manner. Overall, it is believed that this work improves the drawbacks of current MXene-based actuators, laying the groundwork for their wider applications as moisture-driven devices.  相似文献   

5.
    
2D Ti3C2Tx MXene, possessing facile preparation, high electrical conductivity, flexibility, and solution processability, shows good application potential for enhancing device performance of perovskite solar cells (PVSCs). In this study, tetrabutylammonium bromide functionalized Ti3C2Tx (TBAB-Ti3C2Tx) is developed as cathode buffer layer (CBL) to regulate the PCBM/Ag cathode interfacial property for the first time. By virtue of the charge transfer from TBAB to Ti3C2Tx demonstrated by electron paramagnetic resonance and density functional theory, the TBAB-Ti3C2Tx CBL with high electrical conductivity exhibits significantly reduced work function of 3.9 eV, which enables optimization of energy level alignment and enhancement of charge extraction. Moreover, the TBAB-Ti3C2Tx CBL can effectively inhibit the migration of iodine ions from perovskite layer to Ag cathode, which synergistically suppresses defect states and reduce charge recombination. Consequently, utilizing MAPbI3 perovskite without post-treatment, the TBAB-Ti3C2Tx based device exhibits a dramatically improved power conversion efficiency of 21.65% with significantly improved operational stability, which is one of the best efficiencies reported for the devices based on MAPbI3/PCBM with different CBLs. These results indicate that TBAB-Ti3C2Tx shall be a promising CBL for high-performance inverted PVSCs and inspire the further applications of quaternary ammonium functionalized MXenes in PVSCs.  相似文献   

6.
    
Heterostructures offer an exceptional possibility of combining individual 2D materials into a new material having altered properties compared to the parent materials. Germanane (GeH) is a 2D material with many favorable properties for energy storage and catalysis, however, its performance is hindered by its low electrical conductivity. To address the low electrochemical performance of GeH, a heterostructure of GeH and Ti3C2Tx is fabricated. The Ti3C2TX is a layered material belonging to the family of MXenes. The resulting heterostructure (GeMXene) at a defined mass ratio of GeH and Ti3C2Tx shows superior capacitive performance that surpasses that of both pristine materials. The effect of the size of cations and anions for intercalation into GeMXene in different aqueous salt solutions is studied. GeMXene allows only cation intercalation, which is evidenced by the gravimetric electrochemical quartz crystal microbalance (EQCM) technique. The capacitive performance of the GeMXene is compared in neutral, acidic, and alkaline electrolytes to determine the best electrochemical performance. This unleashes the potential use of GeMXene heterostructure in different electrolytes for supercapacitors and batteries. This work will pave the way to explore the heterostructures of other 2D materials such as novel MXenes and functionalized germanane for highly energy-storage efficient systems, and beyond.  相似文献   

7.
    
The excellent electronic and electrochemical properties make 2D MXenes suitable candidates for sensors, batteries, and supercapacitors. However, the metallic-like behavior of MXenes hinders their potential for optoelectronic devices such as photodetectors. In this study, the band gap of metalloid Ti3C2Tx MXene is successfully opened to 1.53 eV with phenylsulfonic acid groups and realized a transistor and high-performance near-infrared photodetector array for a flexible vision sensory-neuromorphic system. The phenylsulfonic acid groups modified Ti3C2Tx MXene (S-Ti3C2Tx)-based flexible photodetector has a maximum responsivity of 8.50×102 A W−1 and a detectivity of 3.69×1011 Jones under 1064 nm laser irradiation. Moreover, the fabricated flexible vision sensory-neuromorphic system for image recognition realizes a high recognition rate >0.99, leading to great potential in the field of biological visual simulation and biomimetic eye. Besides conventional devices with Au as the conductive electrodes, all Ti3C2Tx MXene-based devices are also fabricated with S-Ti3C2Tx as the photosensitive material and unmodified Ti3C2Tx as the conductive electrodes, exhibiting comparable optoelectronic performances.  相似文献   

8.
    
2D transition metal carbide Ti3C2Tx (T stands for surface termination), the most widely studied MXene, has shown outstanding electrochemical properties and promise for a number of bulk applications. However, electronic properties of individual MXene flakes, which are important for understanding the potential of these materials, remain largely unexplored. Herein, a modified synthetic method is reported for producing high‐quality monolayer Ti3C2Tx flakes. Field‐effect transistors (FETs) based on monolayer Ti3C2Tx flakes are fabricated and their electronic properties are measured. Individual Ti3C2Tx flakes exhibit a high conductivity of 4600 ± 1100 S cm−1 and field‐effect electron mobility of 2.6 ± 0.7 cm2 V−1 s−1. The resistivity of multilayer Ti3C2Tx films is only one order of magnitude higher than the resistivity of individual flakes, which indicates a surprisingly good electron transport through the surface terminations of different flakes, unlike in many other 2D materials. Finally, the fabricated FETs are used to investigate the environmental stability and kinetics of oxidation of Ti3C2Tx flakes in humid air. The high‐quality Ti3C2Tx flakes are reasonably stable and remain highly conductive even after their exposure to air for more than 24 h. It is demonstrated that after the initial exponential decay the conductivity of Ti3C2Tx flakes linearly decreases with time, which is consistent with their edge oxidation.  相似文献   

9.
    
  相似文献   

10.
    
Harnessing solar energy for the conversion of CO2 into value-added chemicals and fuels represents a promising strategy for sustainable development. Photo-to-thermal (PTT) conversion, an often-underestimated factor, offers a remarkable approach to enhance the photocatalytic transformation of CO2, by reducing the activation energy of catalytic reactions and accelerating reaction kinetics. In order to achieve a higher energy return on investment (EROI), in this study, a sulfur-vulcanized, multi-layer Ti3C2 MXene is unveiled, capable of efficient sunlight-driven CO2 photoreduction, by capitalizing on PTT conversion across the full visible-to-near-infrared (NIR) spectrum. The vulcanization strategy is pivotal here, as it not only introduces an abundance of reactive sites but also extends the NIR response (peaking at 1095 nm) of MXene. The resulting rapid PTT and synergistic photo-thermal-catalytic CO2 reduction constitute a significant advance in this area, where CH4 (12.03 mmol g−1 h−1) and C2H4 (3.55 mmol g−1 h−1) yields are achieved with a C2+ selectivity of 29.76% under concentrated natural sunlight. This work sets a new benchmark for EROI with an average solar-to-carbon-fuel (STF) conversion efficiency greater than 0.045%.  相似文献   

11.
    
MXenes are a large and rapidly expanding family of 2D materials that, owing to their unique optoelectronic properties and tunable surface termination, find a wide range of applications including energy storage and energy conversion. In this work, Ti3C2Tx MXene nanosheets are applied as a novel type of electron transport layer (ETL) in low‐temperature processed planar‐structured perovskite solar cells (PSCs). Interestingly, simple UV‐ozone treatment of the metallic Ti3C2Tx that increases the surface Ti? O bonds without any change in its bulk properties such as high electron mobility improves its suitability as an ETL. Improved electron transfer and suppressed recombination at the ETL/perovskite interface results in augmentation of the power conversion efficiency (PCE) from 5.00% in the case of Ti3C2Tx without UV‐ozone treatment to the champion PCE of 17.17%, achieved using the Ti3C2Tx film after 30 min of UV‐ozone treatment. As the first report on the use of pure MXene layer as an ETL in PSCs, this work shows the great potential of MXenes to be used in PSCs and displays their promise for applications in photovoltaic technology in general.  相似文献   

12.
    
Exploiting Zn metal-free anode materials would be an effective strategy to resolve the problems of Zn metal dendrites that severely hinder the development of Zn ion batteries (ZIBs). However, the study of Zn metal-free anode materials is still in their infancy, and more importantly, the low energy density severely limits their practical implementations. Herein, a novel (NH4)2V10O25 · 8H2O@Ti3C2Tx (NHVO@Ti3C2Tx) film anode is proposed and investigated for constructing “rocking-chair” ZIBs. The NHVO@Ti3C2Tx electrode shows a capacity of 514.7 mAh g−1 and presents low potential which is 0.59 V (vs Zn2+/Zn) at 0.1 A g−1. The introduction of Ti3C2Tx not only affords an interconnected conductive network, but also stabilizes the NHVO nanobelts structure for a long cycle life (84.2% retention at 5.0 A g−1 over 6000 cycles). As a proof-of-concept, a zinc metal-free full battery is successfully demonstrated, which delivers the highest capacity of 131.7 mAh g−1 (mass containing anodic and cathodic) and energy density of 97.1 Wh kg−1 compared to all reported aqueous “rocking-chair” ZIBs. Furthermore, a long cycling span of 6000 cycles is obtained with capacity retention reaching up to 92.1%, which is impressive. This work is expected to provide new moment toward V-based materials for “rocking-chair” ZIBs.  相似文献   

13.
    
2D MXenes have been widely applied in the field of electrochemical energy storage owning to their high electrical conductivity and large redox‐active surface area. However, electrodes made from multilayered MXene with small interlayer spacing exhibit sluggish kinetics with low capacity for sodium‐ion storage. Herein, Ti3C2 MXene with expanded and engineered interlayer spacing for excellent storage capability is demonstrated. After cetyltrimethylammonium bromide pretreatment, S atoms are successfully intercalated into the interlayer of Ti3C2 to form a desirable interlayer‐expanded structure via Ti? S bonding, while pristine Ti3C2 is hardly to be intercalated. When the annealing temperature is 450 °C, the S atoms intercalated Ti3C2 (CT‐S@Ti3C2‐450) electrode delivers the improved Na‐ion capacity of 550 mAh g?1 at 0.1 A g?1 (≈120 mAh g?1 at 15 A g?1, the best MXene‐based Na+‐storage rate performance reported so far), and excellent cycling stability over 5000 cycles at 10 A g?1 by enhanced pseudocapacitance. The enhanced sodium‐ion storage capability has also been verified by theoretical calculations and kinetic analysis. Coupling the CT‐S@Ti3C2‐450 anode with commercial AC cathode, the assembled Na+ capacitor delivers high energy density (263.2 Wh kg?1) under high power density (8240 W kg?1), and outstanding cycling performance.  相似文献   

14.
    
Metal thiophosphite has demonstrated promising application potential as an anode material for sodium-ion batteries. Nevertheless, the intrinsic low electrical conductivity and drastic volume expansion impede its commercialization. Herein, a series of metal thiophosphite/Ti3C2Tx (metal = Fe, Ni, Co, and Cd) composites are constructed via Lewis acidic molten salt etching followed by synchronous phospho-sulfurization. The Ti3C2Tx substrate endows the thiophosphite/Ti3C2Tx hybrids with high electrical conductivity. Importantly, thiophosphite grown on the MXene layers exhibits a 3D cross-linked structure, which not only facilitates electron/ion transport, but also maintains robust structural stability owing to the space confinement effect. As a proof of concept, FePS3/Ti3C2Tx demonstrates remarkable rate performance (827.4 and 598.1 mAh g−1 at 0.1 and 10 A g−1, respectively) along with long-term cycling stability (capacity retention of 93.7% after 2000 cycles at 5 A g−1). Impressively, the FePS3/Ti3C2Tx//NVPO full cell exhibits a high reversible capacity of 396.8 mAh g−1 over 1350 cycles at 2 A g−1. The sodium storage mechanism of FePS3/Ti3C2Tx anode is further unveiled through in situ XRD/ex situ HRTEM characterizations and theoretical calculations. This work provides a fresh perspective on enhancing the electrochemical performance of thiophosphite through the in situ construction of thiophosphite/Ti3C2Tx hybrids.  相似文献   

15.
         下载免费PDF全文
Two-dimension (2D) van der Waals heterojunction holds essential promise in achieving high-performance flexible near-infrared (NIR) photodetector. Here, we report the successful fabrication of ZnSb/Ti3C2Tx MXene based flexible NIR photodetector array via a facile photolithography technology. The single ZnSb/Ti3C2Tx photodetector exhibited a high light-to-dark current ratio of 4.98, fast response/recovery time (2.5/1.3 s) and excellent stability due to the tight connection between 2D ZnSb nanoplates and 2D Ti3C2Tx MXene nanoflakes, and the formed 2D van der Waals heterojunction. Thin polyethylene terephthalate (PET) substrate enables the ZnSb/Ti3C2Tx photodetector withstand bending such that stable photoelectrical properties with non-obvious change were maintained over 5000 bending cycles. Moreover, the ZnSb/Ti3C2Tx photodetectors were integrated into a 26 × 5 device array, realizing a NIR image sensing application.  相似文献   

16.
    
In the emerging Internet of Things, stretchable antennas can facilitate wireless communication between wearable and mobile electronic devices around the body. The proliferation of wireless devices transmitting near the human body also raises interference and safety concerns that demand stretchable materials capable of shielding electromagnetic interference (EMI). Here, an ultrastretchable conductor is fabricated by depositing a crumple‐textured coating composed of 2D Ti3C2Tx nanosheets (MXene) and single‐walled carbon nanotubes (SWNTs) onto latex, which can be fashioned into high‐performance wearable antennas and EMI shields. The resulting MXene‐SWNT (S‐MXene)/latex devices are able to sustain up to an 800% areal strain and exhibit strain‐insensitive resistance profiles during a 500‐cycle fatigue test. A single layer of stretchable S‐MXene conductors demonstrate a strain‐invariant EMI shielding performance of ≈30 dB up to 800% areal strain, and the shielding performance is further improved to ≈47 and ≈52 dB by stacking 5 and 10 layers of S‐MXene conductors, respectively. Additionally, a stretchable S‐MXene dipole antenna is fabricated, which can be uniaxially stretched to 150% with unaffected reflected power <0.1%. By integrating S‐MXene EMI shields with stretchable S‐MXene antennas, a wearable wireless system is finally demonstrated that provides mechanically stable wireless transmission while attenuating EM absorption by the human body.  相似文献   

17.
    
Transition metal carbides (TMCs) grown by chemical vapor deposition (CVD) offer promise for numerous novel phenomena and applications in the 2D limit. Despite considerable efforts thus far, the flexible customization of TMCs and their heterostructures still remains challenging. Herein, a substrate engineering is developed to achieve customized manufacturing of ultrathin WC single crystals and WC/graphene (WC-G) heterostructures by varying the concentration of Zn in Cu-Zn alloy substrate. It is worth noting that Zn atoms can remarkably reduce the nucleation density of graphene and promote the nucleation of WC. Thus, an increasing Zn content is applied to synergistically modulate the growth of graphene and WC, enabling the controllable fabrication of WC and WC-G heterostructures. The synthesized WC crystals exhibit an ultrathin nature down to 3 nm, as well as high crystalline, ultra-clean surface, and superb chemical stability. Based on that, the typical metallic properties with a temperature-dependent resistance (nearly 1.30 Ω at 300 K and nearly 0.08 Ω at 1.7 K) and low resistance as well as excellent nonlinear optical performance of WC are demonstrated. This work provides fresh insights into regulating the growth behavior of multiblock-structured carbides and promotes the study of their optic and electronic properties.  相似文献   

18.
    
Flexible wearable strain sensors have received extensive attention in human–computer interaction, soft robotics, and human health monitoring. Despite significant efforts in developing stretchable electronic materials and structures, developing flexible strain sensors with stable interfaces and low hysteresis remains a challenge. Herein, Ti3C2Tx MXene/AgNWs/liquid metal strain sensors (MAL strain sensor) with self-healing function are developed by exploiting the strong interactions between Ti3C2Tx MXene/AgNWs/LM and the disulfide and hydrogen bonds inside the self-healing poly(dimethylsiloxane) elastomers. AgNWs lap the Ti3C2Tx MXene sheets, and the LM acts as a bridge to increase the lap between Ti3C2Tx MXene and AgNWs, thereby improving the interface interaction between them and reducing hysteresis. The MAL strain sensor can simultaneously achieve high sensitivity (gauge factor for up to 3.22), high linearity (R2 = 0.98157), a wide range of detection (e.g., 1%–300%), a fast response time (145 ms), excellent repeatability, and stability.In addition, the MAL strain sensor before and after self-healing is combined with a small fish and an electrothermally driven soft robot, respectively, allowing real-time monitoring of the swinging tail of the small fish and the crawling of the soft robot by resistance changes.  相似文献   

19.
Intercalation-type reaction that occurs in polyanion materials is considered to be a facile way to counter the mismatched relationship between the large K+ and compact host structure for potassium ion batteries (PIBs). However, the large “dead” weight and poor conductivity introduced by the polyanion framework severely limit the electrochemical performance of polyanion anodes. Herein, a new rigid K+ host of 1D π-Ti2O(PO4)2 with carbon-coated (TOP@C) is simply synthesized through a simple Ti3C2Tx-derived method. The density functional theory (DFT) calculations and experimental results show that the potassium storage properties are unquestionably improved by the small cell volume change during cycling, the intercalation pseudo-capacitance energy storage mechanism, and the large K-storage tunnels with lower migration energy (0.23 eV) of TOP@C anode (134.5 mAh g-1 after 2000 cycles at 1.0 A g-1). The TOP@C//PTCDA full batteries, which clearly illustrate their promising application in advanced PIBs, successfully achieved a high energy density of 119.4 Wh kg-1 and a power density up to 632.8 W kg-1 with regard to the total mass of TOP@C and PTCDA.  相似文献   

20.
    
Since discovered in 2011, transition metal carbides or nitrides (MXenes) have attracted enormous attention due to their unique properties. Morphology regulation strategies assembling 2D MXene sheets into 3D architecture have endowed the as-formed porous MXene with a better performance in various fields. However, the direct patterning strategy for the porous MXene into integration with multifunctional and multichannel electronic devices still needs to be investigated. The metal-assisted electro-gelation method the authors propose can directly generate porous-structured MXene hydrogel with a tunable feature. By electrolyzing the sacrificial metal, the released metal cations initiate the electro-gelation process during which electrostatic interactions occur between cations and the MXene sheets. A high spatial resolution down to micro-meter level is achieved utilizing the method, enabling high-performance hydrogels with more complex architectures. Electronics prepared through this metal-assisted electro-gelation process have shown promising applications of the porous MXene in energy and biochemical sensing fields. Energy storage devices with a capacitance at 33.3 mF cm−2 and biochemical sensors show prominent current responses towards metabolites (sensitivity of H2O2: 165.6  µ A mm −1 cm−2; sensitivity of DA: 212 nA  µ m −1 cm−2), suggesting that the metal-assisted electro-gelation method will become a prospective technique for advanced fabrication of MXene-based devices.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号