ACS Nano
·
2019
·
IF 13.903
Xifan Chen,Yuanzhi Zhu,Miao Zhang,Jinyi Sui,Wenchao Peng,Yang Li,GuoLiang Zhang,Fengbao Zhang,Xiaobin Fan
MXenes, a family of two-dimensional (2D) transition-metal carbide and nitride materials, are supposed to be promising pseudocapacitive materials because of their high electronic conductivity and hydrophilic surfaces. MXenes, prepared by removing the “A” elements of their corresponding MAX phases by hydrofluoric acid (HF) or LiF–HCl etching, possess abundant terminal groups like −F, −OH, and −O groups. It has been proven that the MXenes with fewer −F terminal groups and more −O groups showed a higher pseudocapacitor performance. In organic reactions, −OH and −X (X = halogen) groups could turn to ether groups in strong nucleophilic reagent. Inspired by that, herein, we report an n-butyllithium-treated method to turn the −F and −OH terminal groups to −O groups on the Ti3C2Tx MXenes. Two types of Ti3C2Tx MXenes prepared by either HF or LiF–HCl etching were systematically investigated, and a comparison with the traditional KOH/NaOH/LiOH-treated method was also carried out. It is found that most of the −F terminal groups on the Ti3C2Tx MXenes can be successfully removed by n-butyllithium, and abundant −O terminal groups were formed. The n-butyllithium-treated Ti3C2Tx MXenes show promising applications in high-performance pseudocapacitors. A record high capacitance of 523 F g–1 at 2 mV s–1 was obtained for the n-butyllithium-treated Ti3C2Tx MXenes, and 96% capacity can remain even after 10 000 cycles.
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PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2017
·
IF 2.084
Zheng Wei,Zhang Peigen,Tian Wubian,Qin Xia,Zhang Yamei,Sun ZhengMing
To modify the adsorption performance of Ti 3 C 2 T x MXene , we report a facile approach to expand the interlayer spacing of Ti 3 C 2 T x and to tune its surface functional groups by hot alkaline solution treatment. In the treatment, the interlayer spacing of Ti 3 C 2 T x MXene is increased by up to 29% by LiOH, and the surface functional groups are tuned by converting -F to -OH. Among the MXenes, LiOH-Ti 3 C 2 T x and NaOH-Ti 3 C 2 T x can faster adsorb methylene blue (MB) than other MXene adsorbents; NaOH-Ti 3 C 2 T x possesses the highest adsorption capacity (189 mg/g) for MB, which can be ascribed to the cooperation of surface adsorption and intercalation adsorption. The experimental data suggest that the enhanced adsorption toward cationic dyes can be best described by a Langmuir isotherm.
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高影响因子
Metals
·
2022
·Vol. 12
·期 12
·2022
·
IF 2.695
Buxiang Wang,Qing Shu,Haodong Chen,Xuyao Xing,Qiong Wu,Li Zhang
It remains a formidable challenge to prepare an economical and stable electrocatalyst for hydrogen evolution reaction using non-precious metals. In this study, MXene (Ti3C2Tx) nanosheets were prepared by high-energy ultrasound treatment, and Cu nanoparticles were prepared by NaBH4as a reducing agent. Then, the electrocatalyst Cu/Ti3C2Tx, suitable for hydrogen evolution reaction (HER), was prepared by supporting Cu with Ti3C2Tx. The structure, morphology, crystal phase and valence state of the obtained catalyst were determined by a variety of characterization analysis methods, and the influence of these properties on the catalytic performance is discussed here. The results of Brunner–Emmet–Teller (BET) showed that Ti3C2Txcan effectively inhibit Cu agglomeration. Results of Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) showed that Cu has metallic and oxidized states. X-ray Photoelectron Spectroscopy (XPS) further revealed the existence of multivalent states in Cu, which would contribute to the formation of electron transfer channels and the enhancement of electrocatalytic activity. In addition, the Cu/Ti3C2Txcatalyst has strong hydrophilicity, as measured by contact angle, which is conducive to HER. Ti3C2Txhas acceptable electrocatalytic hydrogen evolution performance: under alkaline conditions, when the current density is 10 mA cm−2, HER overpotential is as low as 128 mV and the Tafel slope is as low as 126 mV dec−1. Meanwhile, Ti3C2Txshowed adequate stability for HER (94.0% of the initial mass activity after 1000 CV cycles). This work offers insights into the development of high-performance non-precious metal-based catalysts to achieve the high performance of HER in alkaline electrolytes.Keywords:hydrogen evolution reaction;electrocatalyst;Cu;MXene (Ti3C2Tx) nanosheets
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Kai Yang,Min Luo,Daotong Zhang,Chaozheng Liu,Zhao Li,Liangcai Wang,Weimin Chen,Xiaoyan Zhou
Porous carbon (PC) can effectively alleviate the typical self-stacking phenomenon of 2D MXene-based films as a spacer, and can easily customize their porous structure. Nevertheless, the contact between 3D PC and 2D MXene flakes is generally presented at a point-to-point form owing to the irregular shape of PC, leading to a low efficiency on electron delivery and stress concentration with a fragile characteristic in the resulting films. Herein, 1D carbon nanotube (CNT) was introduced to construct a highly conductive net structure, tightly anchoring PC on MXene flakes, thus ensuring fast electron delivery by increasing the contact area between MXene and PC. Additionally, the interwoven CNTs bridge the horizontal MXene flakes, making internal structure more integral, thereby enhancing the flexibility. Consequently, the Ti 3 C 2 T x (a typical MXene)/CNT/PC (TCP) film has an ability to bear a large scan rate of 1 V s −1 and shows a high areal specific capacitance of 364.8 mF cm −2 at 0.5 mA cm −2 which remains above 80% even at a high current density of 50 mA cm −2 . Furthermore, the fabricated flexible quasi-solid-state supercapacitor (SC) demonstrates a large areal energy density of 10.5 μ Wh cm −2 at 29.8 μ W cm −2 . This study provides a promising approach to overcome the poor flexibility of MXene/PC film without sacrificing the conductivity, meanwhile paving a way for the development of flexible SCs with large charge storage capacity and high rate capability.
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高影响因子
DESALINATION
·
2021
·
IF 9.501
Jie Zhang,Fengli Li,Haoqin Zhang,Rui Ding,Jingtao Wang,Wenpeng Li
Monovalent selective ion-exchange membranes with characteristics of interception of multivalent ions and passage of monovalent ions , have aroused widespread research interest. However, most of monovalent selective ion-exchange membranes are dense polymer membranes, which suffer from low ion flux. Herein, a highly aligned two-dimensional (2D) thin anion lamellar composite membrane was developed successfully to address this weakness by assembling sulfonated Ti 3 C 2 T x ( STi 3 C 2 T x ) nanosheets on quaternized-chitosan (QCS) modified commercial Nylon-66 microfiltration membrane (N66). The QCS modified N66 that provides continuous sites and the STi 3 C 2 T x lamellar ion channel that endows electrostatic repulsion and ion steric effect synergistically enhance the flux and selectivity of the composite membrane. Concretely, the resultant 2D thin anion lamellar composite membrane (N66-QCS/STi 3 C 2 T x ) achieves a high Cl − /SO 4 2− selectivity and Cl − flux of 14.67 and 20.35 × 10 −8 mol s −1 cm −2 , which are 1.94 and 3.08 times higher than the commercial Neosepta ACS (7.56 and 6.60 × 10 −8 mol cm −2 s −1 ). Furthermore, the negatively charged N66-QCS/STi 3 C 2 T x shows favorable hydrophilicity and sufficient antifouling potential. The strategy of fabricating sulfonated Ti 3 C 2 T x anion-exchange membrane provides fundamental information for the rational design of separation membranes that target to acquire high comprehensive performance.
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高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Zhenzhen Liu,Li Wang,Yingxi Xu,Jianyu Guo,Siyong Zhang,Yan Lu
In this study, Ti 3 C 2 T X @PEDOT composite is synthesized using multilayer Ti 3 C 2 T X and conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) by a simple in-situ polymerization method. The PEDOT component effectively solves the problem of Ti 3 C 2 T X layers stacking and further improves the specific surface area of Ti 3 C 2 T X . Besides, additional pseudocapacitance is also provided by the added PEDOT component. In 1 M H 2 SO 4 , the Ti 3 C 2 T X @PEDOT (1:10) composite exhibits a higher capacitance (564 F g −1 ) at the current density of 1 A g −1 compared to the original Ti 3 C 2 T X material, and excellent cycling performance with a capacitance retention of 96.5% after 10,000 charge/discharge cycles at a current density of 10 A g −1 . The Ti 3 C 2 Tx@PEDOT(1:10)-based symmetric supercapacitor shows a specific capacitance of 100 F g −1 at the current density of 1 A g −1 , and an energy density of 6.34 Wh kg −1 at the power density of 4077 W kg −1 . The enhanced electrochemical performance and stability are due to the surface redox process and synergistic effects of the Ti 3 C 2 T X @PEDOT.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Xiaobao Zhang,Baiyi Shao,Zemin Sun,Zhe Gao,Yong Qin,Ce Zhang,Fangming Cui,Xiaojing Yang
Nobel metal Pt composites show high catalytic activity for hydrogen evolution reaction (HER) but limited in application by high Pt contents and therefore the cost. Herein, a series of Pt nanoparticle (NP)-deposited 2D Ti3C2Tx MXenes were prepared by an atomic layer deposition (ALD) method with relatively low Pt contents (0.98–3.10 wt %) and showed excellent HER catalytic activity and stability. The electrochemical results indicated that the prepared catalysts showed the optimal HER activity as the ALD deposition cycle reached 40, with an overpotential of 67.8 mV approaching that of the commercial Pt/C catalyst (64.2 mV). The excellent behavior was attributed to the homogeneous dispersion of the Pt NPs and the good conductivity of the 2D Ti3C2Tx MXene supports.
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高影响因子
Metals
·
2024
·Vol. 14
·期 8
·922
·
IF 2.6
Wei Guo,Buxiang Wang,Qing Shu
Hydrogen (H2) is considered to be the best carbon-free energy carrier that can replace fossil fuels because of its high energy density and the advantages of not producing greenhouse gases and air pollutants. As a green and sustainable method for hydrogen production, the electrochemical hydrogen evolution reaction (HER) has received widespread attention. Currently, it is a great challenge to prepare economically stable electrocatalysts for the HER using non-precious metals. In this study, a Co/Co3O4/Ti3C2Txcatalyst was synthesized by supporting Co/Co3O4with Ti3C2Tx. The results show that Co/Co3O4/Ti3C2Txhas excellent HER activity and durability in 1 mol L−1KOH, and the overpotential and Tafel slope at 10 mA·cm−2were 87 mV and 61.90 mV dec−1, respectively. The excellent HER activity and stability of Co/Co3O4/Ti3C2Txcan be explained as follows: Ti3C2Txprovides a stable skeleton and a large number of attachment sites for Co/Co3O4, thus exposing more active sites; the unique two-dimensional structure of Ti3C2Txprovides an efficient conductive network for rapid electron transfer between the electrolyte and the catalyst during electrocatalysis; Co3O4makes the Co/Co3O4/Ti3C2Txcatalyst more hydrophilic, which can accelerate the release rate of bubbles; Co/Co3O4can accelerate the adsorption and deionization of H2O to synthesize H2. This study provides a new approach for the design and preparation of low-cost and high-performance HER catalysts.
研究领域:
材料科学
·
能源化学
·
电化学
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高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2024
·Vol. 39
·期 14
·2082-2094
·
IF 2.7
Gao Chenyu,Deng Jikun,He Jiaxing,Wang Zechuan,Sheng Yuanyuan,Liu Junwu,Zhong Honghai,Tong Guoqing,Jiang Yang
A novel Cu/Ti 3 C 2 T X laminated composite foil was prepared using a combination of electroplating and electrophoretic deposition. The results indicate that the average thermal expansion coefficient of the Cu/ Ti 3 C 2 T X composite foil decreased by 11.26% compared to that of pure copper. Due to the high electron mobility of Ti 3 C 2 T X and the favorable Cu/ Ti 3 C 2 T X interface, the electrical conductivity of the Cu/ Ti 3 C 2 T X composite foil exceeded that of pure copper by 8.7%, reaching 6.2147 × 10 7 S·m −1 , and its thermal conductivity increased from 381.5 W/m·K to 423.5 W/m·K. The study revealed that a thinner, looser Ti 3 C 2 T X layer with fewer layers is more favorable for copper penetration and filling, enabling a continuous network-like structure and resulting in significantly improved thermal and electrical properties of the composite copper foil. These findings position the Cu/Ti 3 C 2 T X foil as a promising candidate for electronic encapsulation and super-conductivity. Graphical Abstract
研究领域:
材料科学
·
电化学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Xuefeng Zhang,Yong Liu,Shangli Dong,Jianqun Yang,Xudong Liu
MXenes is one of the most promising flexible electrode materials for supercapacitor . However, the nanosheets in the MXenes electrode by vacuum filtration are prone to restack during preparation, which largely hinders the full utilization of their surfaces and active sites. In this contribution, the self-restacking of MXene nanosheets (prepared by etching with HCl + LiF) could be prevented effectively by introducing MXene nanoparticles (prepared by etching with HF) as interlayer spacers. The Ti 3 C 2 T x -10 flexible (the electrode with 10% mass fraction nanoparticles) exhibits an excellent specific capacitance of 372 F g −1 at 1 A g −1 which is much higher than that of Ti 3 C 2 T x film, and an impressive cycling stability up to 95% capacitance retention after 5000 cycles. The significant improvement in electrochemical performance is mainly due to that the open sandwich-like structure of the flexible electrode based on multi-scaled Ti 3 C 2 T x provides huge surface area and more active sites.
研究领域:
材料科学
·
能源存储
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高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 11
·2956
·
IF 5.076
Tao Lin,Wenlong Liu,Bin Yan,Jing Li,Yi Lin,Yinghui Zhao,Zheng Shi,Sheng Chen
Electrochromic materials and devices are attracting intense attention because of their low energy consumption and open-circuit memory effect. Considering the difficult processing characteristics of electrochromic conductive polymers, we developed a facile and scalable strategy to prepare solution processable polyaniline (PANI)-based nanocomposites by introducing two-dimensional titanium carbon nanosheets (MXene) through a self-assembly approach. The PANI/MXene nanocomposite can be fabricated into porous films via spray-coating process, which show an obvious synergetic effect of both materials, leading to superior electrochromic properties. The optical contrast of the optimized PANI/MXene film reached as high as 55% at =700 nm, and its response times were 1.3 s for coloration and 2.0 s for bleaching, respectively. In addition, the composite film also showed excellent cycle stability (after 500 cycles, the ΔT retention was above 87%). The improved electrochromic properties are owed to the high conductivity of MXene and the formation of the porous composite film structure, which promote the electronic/ionic transfer and migration efficiency. This research suggests that the self-assembly method and the conductive polymer/MXene nanocomposites have a potential application in the fields of electronic functional films and devices.Keywords:self-assembly;MXene;polyaniline;nanostructures;electrochromic electrode
研究领域:
材料科学
·
化学工程
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PubMed
高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
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.
研究领域:
材料科学
·
纳米技术
·
光子学
·
光电学
·
激光物理
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