Materials
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2018
·Vol. 11
·期 11
·2112
·
IF 2.467
Meng Wu,Bingxin Wang,Qianku Hu,Libo Wang,Aiguo Zhou
The effect of etching solution on the synthesis process of two-dimensional vanadium carbide (V2C MXene) was researched. Three etching solutions were used to etch ternary carbide V2AlC at 90 °C. The three solutions were: lithium fluoride + hydrochloric acid (LiF + HCl), sodium fluoride + hydrochloric acid (LiF + HCl), and potassium fluoride + hydrochloric acid (KF + HCl). It was found that only NaF + HCl solution was effective for synthesizing highly pure V2C MXene. The existence of sodium (Na+) and chloridion (Cl−) in etching solution was essential for the synthesis. The thermal stability of the as-prepared V2C MXene in argon or air was studied. From thermogravimetry and differential thermal analysis, V2C MXene was found to be stable in argon atmosphere at a temperature of up to 375 °C. As the temperature increased, V2C MXene was gradually oxidized to form nanoparticles composed of vanadium trioxide (V2O3) and a part of V2C MXene was broken and transformed to vanadium carbide (V8C7) at 1000 °C. In air atmosphere, V2C MXene was stable at 150 °C. At 1000 °C, V2C MXene was oxidized to form vanadium pentoxide (V2O5).Keywords:MXene;V2C;synthesis;thermal stability
研究领域:
材料科学
·
化学
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ruizheng Xu,Guiyu Wei,Zhemin Xie,Sijie Diao,Jianfeng Wen,Tao Tang,Li Jiang,Ming Li,Guanghui Hu
Increasing the efficiency of charge transfer and separation efficiency of photogenerated carriers are still the main challenges in the field of semiconductor-based photocatalysts. Herein, we synthesized g-C 3 N 4 @V 2 C MXene photocatalyst by modifying g-C 3 N 4 using V 2 C MXene. The prepared photocatalyst exhibited outstanding photocatalytic performance under visible light. The degradation efficiency of methyl orange by g-C 3 N 4 @V 2 C MXene photocatalyst was as high as 94.5%, which is 1.56 times higher than that by g-C 3 N 4 . This was attributed to the V 2 C MXene inhibiting the rapid recombination of photogenerated carriers and facilitating rapid transfer of photogenerated electrons (e − ) from g-C 3 N 4 to MXene. Moreover, g-C 3 N 4 @V 2 C MXene photocatalyst showed good cycling stability. The photocatalytic performance was higher than 85% after three cycles. Experiments to capture free radicals revealed that superoxide radicals (·O 2 − ) are the main contributors to the photocatalytic activity. Thus, the proposed g-C 3 N 4 @V 2 C MXene photocatalyst is a promising visible-light catalyst.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Yafeng Chen,Heliang Yao,Fantao Kong,Han Tian,Ge Meng,Shuize Wang,Xinping Mao,Xiangzhi Cui,Xinmei Hou,Jianlin Shi
Oxygen evolution reaction (OER) is a pivotal electrochemical reaction process for many renewable energy technologies. Due to the sluggish OER kinetics, searching for efficient low-cost non-precious metal catalysts is one of the crucial but very challenging steps. Herein, V 2 C MXene synergistically coupled with hypophosphite-intercalated FeNi (oxy)hydroxide (H 2 PO 2 − /FeNi-LDH-V 2 C) electrocatalyst is synthesized. The H 2 PO 2 − /FeNi-LDH-V 2 C exhibits excellent OER performance with an overpotential of 250 mV (η 10 ) and small Tafel slope of 46.5 mV dec −1 in 1.0 M KOH electrolyte, and excellent rechargeable Zn-air battery performance with superior open circuit potential (1.42 eV), power density (137 mW cm −2 ) and well durability. The strong interaction and electronic coupling with prominent charge-transfer between FeNi-LDHs and V 2 C MXene endow the composite significant OER performance and structural stability, and the adsorption/desorption balance for the OER reaction pathway, eventually promoting the intrinsic activity. This work demonstrates the great promise of MXene-based nanohybrids as advanced electrocatalysts for renewable energy applications.
研究领域:
材料科学
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电化学
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可再生能源
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
·
IF 4.539
Qihuang Deng,Yuehao Huang,Binghe Chen,Maolin Bo,Yefeng Feng
Strontium titanate (STO) is a ferroelectric ceramic that shows paraelectric behaviour at room temperature , leading to a low dielectric constant in polymer composites with STO particles for energy storage applications. In this study, to improve the dielectric constant of polymer/STO composites, STO filler was modified via its hybridisation with conductive V 2 C MXene to form high-polarity interphase. The high-polarity mechanism of the V 2 C/STO interphase was analysed using density functional theory (DFT) calculations. An interesting connection between V 2 C and STO through an interfacial single oxygen atom was observed. Polymer composites containing hybrid filler exhibited balanced electrical properties, including a high dielectric constant, low tanδ, and high breakdown strength . The novelty of this study lies in the strategy of improving the dielectric response of a paraelectric ceramic filler through heterojunction modification. Consequently, the composite with 9 wt% hybrid filler exhibited a high dielectric constant of ~87 and low tanδ of ~0.038 at 100 Hz along with a reasonably high breakdown strength of ~233 MV/m. It is expected that this study will contribute to the effective design of high-polarity hybrid ceramic fillers for advanced composite dielectric applications.
研究领域:
材料科学
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电介质物理学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
·
IF 8.1
Zhongxuan Lin,Zhenluo Yuan,Huanhuan Zhang,Shuyan Guan,Xiaojiao Wang,Shiqian Zhao,Guangxin Fan,Yanping Fan,Baozhong Liu
Lowering the dehydrogenation temperature and maintaining high dehydrogenation capacity are greatly hindering the practical application of α-AlH 3 for the hydrogen fuel cell industry. Herein, the layered accordion-like V 2 C MXene is synthesized and doped into α-AlH 3 by mild ball milling . The 1 wt.% V 2 C-catalyzed α-AlH 3 possesses excellent dehydrogenation performance with a low initial decomposition temperature of 70.5 °C and a high hydrogen release capacity of 8.1 wt.%. Furthermore, 7.8 wt.% of hydrogen could be quickly released from α-AlH 3 -1 wt.% V 2 C composite within 15 min at 120 °C, with a lower activation energy of 69.5 kJ/mol than that of as-received sample. The excellent dehydrogenation performance is attributed to the high activity of the zero valence V catalyst which is transformed from the multivalent V during ball milling and to promote dissociation and reorganization of hydrogen. This effective approach significantly enhances the dehydrogenation of α-AlH 3 , providing a hopeful approach for modifying metal hydrides .
研究领域:
材料科学
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无机化学
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能源化学
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纳米材料
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储氢材料
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2021
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IF 4.527
Qihuang Deng,Wei Xiong,Bingshuang Mao,Maolin Bo,Yefeng Feng
Increasing the dielectric constant of polymer/sulfide ceramic composites by using wide-bandgap semiconducting sulfide ceramic fillers like ZnS is difficult because of their low interface polarization. To increase the dielectric constant, in this study, ternary polymer-based composite films were designed and fabricated using a hybrid filler consisting of shell-like ZnS particles and core-like V 2 C MXene particles. First, V 2 C MXene with a multi-layered structure was synthesized from the simplest raw materials followed by the in-situ hydrothermal growth of ZnS particles around the V 2 C particles. Then, binary polymer/ZnS and ternary polymer/V 2 C–ZnS composites were fabricated, and their dielectric, conductive, and electrical breakdown properties were investigated. Finally, the effect of interfacial bonding between the V 2 C and ZnS phases was investigated by density functional theory calculations, and the contribution of V 2 C/ZnS interfacial bonding to the higher dielectric constant of the ternary composites than that of the binary composites was explained. The ternary composites exhibited balanced electrical properties suitable for energy storage applications. The ternary composite with 10 wt% hybrid filler loading exhibited a high dielectric constant of ~52, a low dielectric loss of ~0.11 at 100 Hz, and a high electrical breakdown strength of ~202 MV m −1 . This study paves the way for the facile fabrication of high-performance composite dielectrics for application in advanced capacitors.
研究领域:
材料科学
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电气工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Yafeng Chen,Ge Meng,Tao Yang,Chang Chen,Ziwei Chang,Fantao Kong,Han Tian,Xiangzhi Cui,Xinmei Hou,Jianlin Shi
Earth-abundant MoS 2 has attracted great attentions as a promising hydrogen evolution reaction (HER) electrocatalyst , but it is limited by sluggish water dissociation and strong adsorption of the oxygen-containing intermediates in alkaline media. Herein, an interfacial engineering strategy to fabricate Co-doped 1T-MoS 2 coupling with V 2 C MXene was reported to improve the HER kinetics of MoS 2 . DFT calculations predict that the construction of heterogeneous interfaces between V 2 C MXene and Co-doped 1T-MoS 2 can effectively reduce the energy barrier of water dissociation and optimize the free energy of hydrogen adsorption. As a result, the synthesized Co-MoS 2 /V 2 C@CC nanohybrid exhibits excellent HER performance with small overpotentials of 70.1, 263.2 and 296 mV to achieve current densities of 10, 500 and 1000 mA cm −2 , respectively, and outstanding stability for 50 h HER test without degradation. Additionally, the overall hydrazine-assisted water splitting (OHzS) system catalyzed by Co-MoS 2 /V 2 C@CC in both anode and cathode requires only 0.33 V to achieve a current density of 10 mA cm −2 with significant long-term durability.
研究领域:
材料科学
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电催化
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理论计算
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 44
·27406-27412
·
IF 3.945
Xuan Yin,Haohao Chen,Lai Jiang,Chang Liang,Haosheng Pang,Dameng Liu,Bing Zhang
Two modified V2C-MXene nanocoatings are prepared through different molecular weights of polyacrylic acid (polyacrylic acid with ∼4 50 000 is marked as LPAA, and polyacrylic acid with ∼4 000 000 is marked as HPAA) and two-dimensional V2C-MXene. Their properties are characterized using a ball-on-disc tribometer, three-dimensional white-light interferometry topography images, optical microscope, Raman spectrometer, focused ion beam/scanning electron microscope and high-resolution transmission electron microscope/energy dispersive X-ray spectrometer (HRTEM/EDS). As a result, an ultralow friction (μ ≈ 0.073 ± 0.024) and an ultralow wear (3.41 × 10−7 mm3 N−1 m−1 for ball scar, and 7.49 × 10−8 mm3 N−1 m−1 for disc track) are achieved for the LPAA@V2C vs. steel ball system tested under 4 N in the air through tribo-physicochemical interactions. During the rubbing process, the LPAA@V2C nanocoating is transferred onto counter-bodies to form mixed-phase lubricative tribofilms. Monitoring via a HRTEM/EDS, the mixed-phase lubricative tribofilms are found to be mainly composed of amorphous carbon phases containing O and V and layered nano-debris along the sliding surface. The tribofilm's stable structure is the key to realizing ultralow friction and ultralow wear through the LPAA modification. These findings disclose that MXene-based nanomaterials can be applied for material engineering and mechanical engineering under common working conditions.
研究领域:
材料科学
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机械工程
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DOI
PubMed
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
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2021
·Vol. 50
·期 4
·2182-2189
·
IF 1.938
Feng Yefeng,Zhao Xiaomiao,Chen Peiyao,Bo Maolin,Deng Qihuang,Zhao Anning,Fu Junjie
High-dielectric-constant (high- k ) polymer–ceramic composites with low-level dielectric loss are expected to enable excellent energy storage. However, high conductivity and high dielectric loss often occur simultaneously with high dielectric constant. To obtain a high dielectric constant but with low conductivity and low dielectric loss, in this work, we studied the ternary polyvinylidene fluoride (PVDF)/La 2 TiO 5 /V 2 C dielectric composite system, which takes advantage of the synergistic effect between the high content (0 wt.% to 40 wt.%) of pseudo-perovskite filler La 2 TiO 5 and the low content (2 wt.%) of highly conductive two-dimensional filler V 2 C. Comparisons with the binary PVDF/La 2 TiO 5 composite system revealed that the ternary PVDF/La 2 TiO 5 /V 2 C composite dielectric system enabled balance and optimization of the comprehensive electrical properties of the composite material. Significantly elevated permittivity as well as depressed low-level dielectric loss were obtained in the ternary composites. The optimized ternary composite with 40 wt.% La 2 TiO 5 and 2 wt.% V 2 C exhibited high dielectric constant of 47 and low dielectric loss of 0.17 at 1 kHz. This work might enable facile fabrication of promising composite dielectric materials based on this excellent synergetic filler strategy.
研究领域:
材料科学
·
电气工程
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Yefeng Feng,Hongrong Qiu,Bingshuang Mao,Maolin Bo,Qihuang Deng
High dielectric constant and breakdown strength of composite dielectrics are key for high energy density in capacitors. However, high dielectric constant is frequently accompanied by rather low breakdown strength. To obtain high dielectric constant and breakdown strength, in this work, polymer-based ternary composites bearing V 2 C MXene-Cu 2 O hybrid filler have been prepared. First, V 2 C and V 2 C-Cu 2 O fillers were synthesized. Then, binary polymer/V 2 C and ternary polymer/V 2 C-Cu 2 O composite films were fabricated. Via measurements, significantly optimized electric traits were realized in ternary composites compared with binary ones. In ternary system , higher dielectric constant was attributed to high-polarity V 2 C/Cu 2 O interface-phase, notably reduced dielectric loss low polymer/V 2 C interface leakage conductance, and greatly improved breakdown strength low total leakage current . Finally, V 2 C/Cu 2 O interfacial effect was disclosed using density functional theory (DFT) calculations. Electronic migration and stable bonding at interface were rationalized. Ternary composite with 7 wt% filler showed a high dielectric constant of ~55 and low dielectric loss of ~0.085 at 100 Hz as well as high breakdown strength of ~332 MV m −1 . In novelty, V 2 C/Cu 2 O interface-phase containing quantum-sized high-polarity micro-regions has been proposed to contribute to high dielectric constant of ternary system. This research might enable preparation of advanced composite dielectric materials.
研究领域:
材料科学
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电气工程
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2020
·Vol. 31
·期 8
·2008033
·
IF 16.836
Ying Liu,Yue Jiang,Zhe Hu,Jian Peng,Weihong Lai,Dianlun Wu,Shouwei Zuo,Jing Zhang,Bin Chen,Ziwen Dai,Yingguo Yang,Yang Huang,Wei Zhang,Wei Zhao,Wang Zhang,Lei Wang,Shulei Chou
Vanadium-based materials are fascinating potential cathodes for high energy density Zn-ion batteries (ZIBs), due to their high capacity arising from multi-electron redox chemistry. Most vanadium-based materials suffer from poor rate capability, however, owing to their low conductivity and large dimension. Here, we propose the application of V 2 C MXene (V 2 CT x ), a conductive 2D nanomaterial, for achieving high energy density ZIBs with superior rate capability. Through an initial charging activation, the valence of surface vanadium in V 2 CT x cathode is raised significantly from V 2+ /V 3+ to V 4+ /V 5+ , forming a nanoscale vanadium oxide (VO x ) coating that effectively undergoes multi-electron reactions, whereas the inner V-C-V 2D multi-layers of V 2 CT x are intentionally preserved, providing abundant nanochannels with intrinsic high conductivity. Owing to the synergistic effects between the outer high-valence VO x and inner conductive V-C-V, the activated V 2 CT x presents an ultrahigh rate performance, reaching 358 mAh g −1 at 30 A g −1 , together with remarkable energy and power density (318 Wh kg −1 /22.5 kW kg −1 ). The structural advantages of activated V 2 CT x are maintained after 2000 cycles, offering excellent stability with nearly 100% Coulombic efficiency. This work provides key insights into the design of high-performance cathode materials for advanced ZIBs.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Qihuang Deng,Furong Zhou,Maolin Bo,Yefeng Feng,Yuehao Huang,Cheng Peng
High dielectric response and electric insulation are desired in high-energy-density polymer/ceramic composites. Low dielectric response is found in polymer composites with semiconductors. To balance a high dielectric constant and breakdown strength, in this work, the polymer-based composites with de novo synthesized V 2 C MXene-CuO hybrid-particles were fabricated. High dielectric response of composites was attributed to strong electron polarization at ceramic/ceramic heterojunction. High insulation was ascribed to fluorine-induced electron-trap effect. The first principle calculations verified the electron-transfer mechanism at V 2 C/CuO van der Waals heterojunctions. Compared with polymer/CuO binary composites, polymer/V 2 C-CuO ternary composites exhibited the improved comprehensive electric properties (remarkably improved dielectric response and slightly damaged insulation). Ternary composite with 10 wt% V 2 C-CuO showed a high dielectric constant of 89, low dielectric loss of 0.23, low conductivity of 6.8 × 10 −7 S m −1 at 100 Hz and high breakdown strength of 204 MV m −1 . This study might enable a facile preparation of cutting-edge nanocomposite dielectrics.
研究领域:
材料科学
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电气工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）