Science China-Materials
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2022
·Vol. 66
·期 3
·1062-1070
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IF 8.64
Wang Yang,Chen Sai,Sun Jiachen,Xie Yufei,Zhao Zhi-Jian,Pei Chunlei,Gong Jinlong
Supported vanadium oxides (VO x ) are alternative candidates for non-oxidative propane dehydrogenation (PDH) owing to their competitive performance. This paper describes the roles of V−O sites on PDH over monomeric VO x species supported on ZrO 2 , Al 2 O 3 and SiO 2 . With the control of pre-reduction, stable structures of V−O sites are obtained for PDH, including V−O-support (V−O−S), V−OH and V=O sites. By tuning the V densities over individual support, the propylene formation rate shows a linear correlation with the number of the V−O−S site, which indicates the V−O−S site plays a decisive role in PDH rather than V−OH and V=O sites. Moreover, the specific activity per V−O−S site over ZrO 2 (8.2 × 10 −3 s −1 ) is higher than those over Al 2 O 3 (6.7 × 10 −3 s −1 ) and SiO 2 (2.8 × 10 −3 s −1 ), due to the discrepant Lewis acidity of various V−O−S sites. This research provides a fundamental insight into the intrinsic nature of V−O sites for non-oxidative propane dehydrogenation.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2019
·Vol. 91
·期 2
·302-309
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IF 1.986
Zou Jian,Xiao Lei,Zhu Li,Chen Xuanyan
In this study, monoclinic vanadium dioxide (VO 2 ) nanoparticles were synthesized by one-step rapid hydrothermal treatment of a sol precursor, and the obtained products were examined using various analytical methods. Results indicated that monoclinic VO 2 nanoparticles could be obtained using ammonium metavanadate as the precursor at a high concentration of 2.37 M and the shortest duration was only 1 h. X-ray diffraction (XRD) revealed that VO 2 presented high crystallinity with a pure monoclinic phase. Phase transition latent heat of VO 2 was estimated to be 45.5 J/g. Furthermore, VO 2 powders were mostly composed of granules with a size distribution ranging from 20 nm to 100 nm. Monoclinic VO 2 nanoparticles were derived from the decomposition of the intermediate (NH 4 ) 2 V 4 O 9 .
Monoclinic vanadium dioxide (VO 2 ) nanoparticles can be synthesized by one-step rapid hydrothermal treatment of sol precursor with high concentration.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2016
·Vol. 6
·期 5
·74
·
IF 2.964
Yongli Dong,Xiaoyu Niu,Weina Song,Dong Wang,Liqiang Chen,Fulong Yuan,Yujun Zhu
The vanadium oxide/reduced graphene oxide (VOx/RGO) composites have been prepared by a simple solvothermal method with the assistance of cationic surfactant cetyltrimethylammonium bromide (CTAB). The microstructure and morphology of the resultant VOx/RGO composites have been well characterized. The VOxnanoparticles are highly dispersed on the RGO sheets with a particle size of about 25 nm. When used as hydroxylation catalysts, the VOx/RGO composites are more efficient than individual RGO and vanadium oxide catalysts. The enhanced catalytic performance may be related to not only the well dispersed VOxactive species, but also the hydrophobic surface and huge π-electron system of RGO for the adsorption and activation of benzene. In addition, the effects of calcination conditions on the microstructure and catalytic properties of VOx/RGO composites have also been investigated. The uniform VOxnanoparticles on the separated RGO sheets show highly efficient catalytic performance, while the formation of aggregated HxV2O5and bulk V2O5species along with the destruction of RGO sheets are poor for the hydroxylation of benzene. Up to 17.4% yield of phenol is achieved under the optimized catalytic reaction conditions.Keywords:vanadium oxide;reduced graphene oxide;benzene;hydroxylation;phenol
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Journal of Materials Chemistry C
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2022
·Vol. 10
·期 40
·15000-15007
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IF 8.067
Han Zhang,Wenqing Zhu,Lu Huang,Chen Yi,Ruilin Chen,Yipeng Chen,Jun Li
The hole-injection layer (HIL) plays a critical role in the efficiency and stability of organic light-emitting diodes (OLEDs). However, inorganic HIL materials, such as transition metal oxides (TMOs), usually suffer the problems of low conductivity and mismatched work function at ITO/hole-transport layer (HTL) interfaces, which limits the hole-injection in OLEDs. In this paper, a gold (Au) and lithium (Li) co-doping strategy has been employed to fabricate a vanadium oxide (VOx) HIL through solution processing at low temperature for improving device performance. Compared to non-doped VOx and Au-doped VOx films, co-doping with an optimal molar ratio of Au and Li endows the VOx films with both higher electrical conductivity and proper work function matching with the ITO anode and HTL, which leads to efficient hole-injection and improved carrier balance in the device with the Au and Li co-doped VOx (Au,Li:VOx) HIL. As a result, the device with the Au,Li:VOx HIL shows a peak power efficiency of 50.2 lm W−1 and a maximum external quantum efficiency (EQE) of 19.9%, which are superior to those of the counterpart with the VOx HIL (34.4 lm W−1 and 18.1%). Meanwhile, the device shows distinguished stability. This work indicates that Au and Li co-doping is an effective method to obtain an efficient VOx HIL with excellent hole-injection ability, which provides a promising avenue to enhance OLED performance.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
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2024
·Vol. 26
·期 14
·2302224
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IF 3.4
Mtawa Alsaadi,Kittitat Lerttraikul,Sojiphong Chatraphorn,Salinporn Kittiwatanakul
Due to the growing need for smart windows for buildings to reduce energy usage, vanadium dioxide (VO 2 ) has been investigated as a potential material for thermochromic smart windows due to its ease of implementation and simplicity in industrial production. VO 2 undergoes a reversible phase shift from a monoclinic (M, P21/c) semiconductor to a rutile (R, P42/mnm) metal at a critical temperature of 68 °C. This transition is accompanied by acute variations in IR reflectance, transmittance, and electrical resistance. Despite substantial developments in thermochromic materials, their optical and transition properties are still unsatisfactory. In the past several decades, many methods for enhancing optical properties have been reported, including composite films, multilayer structures, and element doping. Recent developments in thermochromic smart windows to improve both optical properties and durability have been surveyed in this review. Additionally, future growth trends have been provided by the possibility of commercially manufacturing VO 2 smart windows.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2025
·
IF 4.7
Quanhua Wang,Yuhao Zong,Yanchao Liu,Haixia Hu,Yanwei Yue,Xingxing Xie,Lixing Guo,Qingyuan Hu,Hu Wang,Jinke Li,Jiajun Shi,Lichen Zhang,Jiajun Zheng,Shuwei Chen
The design and development of a highly efficient and stable catalyst for styrene (ST) obtained from ethylbenzene (EB) dehydrogenation reaction is urgently required because a commercial Fe–K-based catalyst often undergoes severe deactivation resulted from the active phase decomposition into inactive ferrite compound at high temperatures (>600 °C). Herein, ultra-fine Al 2 O 3 nanofibers which are further self-assembled to form uniform rod-like morphology (R–Al 2 O 3 ) were fabricated via a facile sol-gel strategy and further utilized as support to dispersing vanadium species (V/R–Al 2 O 3 ). The physicochemical properties of the samples were systematically characterized by XRD, Raman, SEM, TEM, H 2 -TPR, CO 2 -TPD, XPS, and 27 Al MAS NMR techniques. It is found that except that R–Al 2 O 3 support has the merits of a high specific surface area, lager pore volume, and uniform mesopore structure, the presence of the unsaturated pentacoordinate Al 3+ ions plays a pivotal role in better dispersing V active species, with the existence of the isolate and/or polymeric forms. As compared to V/C–Al 2 O 3 (commercial Al 2 O 3 as support), the V/R–Al 2 O 3 catalyst endows outperformed catalytic performances for oxidative dehydrogenation of ethylbenzene in the presence of CO 2 (OEBDH-CO 2 ). In which, the V/R–Al 2 O 3 catalyst gives a high EB catalytic activity and good stability without significant deactivation phenomenon being detected even after the third regeneration test. Such a result can be principally ascribed to that R–Al 2 O 3 support with excellent textural properties can better disperse V species so as to expose more active sites, which is beneficial for improving the conversion efficiency of EB. More importantly, keeping/regaining high valence state of V species in the V/R–Al 2 O 3 catalyst under CO 2 as a soft oxidant effectively promotes Mars-Van Krevelen redox cycle, further suppressing the catalyst deactivation. This work provides a rational design strategy for a high efficiency and stable dehydrogenation catalyst by optimizing the textural properties of Al 2 O 3 support and introducing the unsaturated pentacoordinate Al 3+ ions.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Zhongshao Li,Shuwen Zhao,Zewei Shao,Hanxiang Jia,Aibin Huang,Ping Jin,Xun Cao
Vanadium dioxide (VO 2 ) has already been widely concerned as a thermochromic smart window material. However, the Achilles heel of VO 2 is susceptible to degradation by water and oxygen in the air, which has limited its commercialization. Until now, it has remained unclear what effect water has on the deterioration of VO 2 , hindering the solution to this dilemma. In this work, the degradation mechanism of VO 2 during natural aging was proposed based on density functional theory (DFT) calculation and experimental analysis, and the role of water in the degradation process was discussed in detail. The results showed that water affects the deterioration reaction by influencing the adsorption behavior of oxygen on the VO 2 surface, destroying the dense structure, and participating in the reaction in the form of combined water. This work fills the degradation mechanism gap of VO 2 , helps to design high-performance structures of VO 2 -based smart coatings, and provides theoretical guidance to solve the problem of VO 2 weatherability.
研究领域:
材料科学
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物理化学
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2022
·
IF 4.654
Hao Niu,Suting Xie,Xinyu Zhao,Huawei Yang,Lixia Yang,Liangjiu Bai,Donglei Wei,Wenxiang Wang,Hou Chen
Aerobic oxidative desulfurization (AODS) promises an emerging method for deep sulfur removal of fuel oil, which requires high-performance catalysts to cost-effectively convert thiophenes into sulfones. In this paper, we report the fabrication of a highly efficient and durable AODS catalyst by loading N-doped amorphous vanadium oxide on reduced graphene oxide via high-temperature ammonia (NH3) treatment. The morphology, phase state, element electronic state, and catalytic performance of the catalysts at different calcination temperatures were systematically studied. The phase transition principle of vanadium species at different ammoniation temperatures as well as its effect on the catalytic performance was revealed. The optimal catalyst ammoniated at 400 °C achieved rapid and full conversion of various thiophenes under the reaction condition of 90–120 °C and normal pressure using air as the oxygen source, showing excellent activity. Moreover, the catalyst maintained its activity after six repeated uses and is expected to act as a cost-efficient and robust catalyst for AODS.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Dinghan Wang,Tao Zhang,Xun Zhang,Yixiang Chen,Dan Yu,Wei Wang
With the development of infrared detection technology, to protect the exposure targets are more difficult than before. And traditional camouflage protection technologies have mainly focused on infrared stealth materials in fixed conditions by the adjustment of surface infrared emissivity or thermal insulation. However, with the increasing temperature of from engine, the risk of exposure possibility will greatly rise due to the change of emissivity and thermal insulation effect in reality. Hence, the development of intelligent infrared stealth materials that can respond to the temperature is an important tool for solving these problems. Here, we designed an infrared stealth fabric with macroscopic temperature-indicating adjustable emissivity, in which polyester fabric (PET) was used as the substrate, which was firstly modified with dopamine，3-thiolpropyltrimethoxysilane (KH-590) and N-isopropylacrylamide (NIPAAM)，by clicking on chemistry to obtain the temperature-responsive effect of the fabric material, and coated with vanadium dioxide (VO 2 ) powders in waterborne polyurethane (WPU). Importantly, the emissivity of the VO 2 coating layer will decrease with the increase of temperature from 0.95 to 0.68. Meantime, the fabric will shrink with the rising temperature, successfully forming a heat-insulating air layer between the composites and the target, thus further enhancing the IR stealth performance with the air layer thermal insulation. As we expected, when heated to 50 ℃, the surface temperature of the resulting fabric remains about 30 ℃. Therefore, this research on temperature response intelligent fabric based on the combined action of low infrared emissivity and heat isolation offers novel insights for high infrared stealth materials’ fabrication.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2021
·
IF 9.127
Hao Liu,Pan He,Jiaxin Cao,Tao Duan,Qingquan Kong,Weitang Yao
The nature of vanadium oxides with multiple valence states and a rich species of oxides facilitates the construction of high performance batteries. Among these, vanadium dioxide (VO 2 ), despite offering several advantages, is seldom reported in anode materials due to its inferior cycling stability and rate performance caused by large volume changes. Herein, we employed a rational structural strategy to assemble VO 2 -NTs/Ti 3 C 2 anode with a multidimensional cross-linked structure using VO 2 nanotubes (VO 2 -NTs) and Ti 3 C 2 T x MXene . Specifically, the abundant multidimensional channels of VO 2 -NTs/Ti 3 C 2 reduce the diffusion impedance of the ions, and the enhanced intrinsic conductivity and highly robust structure solve the problems originally present in VO 2 , which are verified in characterization and density functional theory calculations. Consequently, the composite electrode shows ultra-high reversible capacity (1425 mAh g −1 at 1 A g −1 ), excellent cycling performance (516 mAh g −1 at 5 A g −1 after 2000 cycles) and superior rate performance (703 mAh g −1 at 10 A g −1 ), and also exhibits decent sodium storage performance, representing the best comprehensive battery performance of VO 2 -based anodes to date.
研究领域:
材料科学
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电化学
·
储能技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Mingwei Hu,Jin Huang,Qizhong Li,Rong Tu,Song Zhang,Meijun Yang,Haiwen Li,Takashi Goto,Lianmeng Zhang
Earth-abundant and low-cost hydrogen evolution reaction (HER) electrocatalysts represent a future direction for achieving sustainable hydrogen energy production. Low-cost amorphous molybdenum sulfides (MoS x ), with their highly active HER activity, have emerged as outstanding catalysts for electrochemical hydrogen production. Herein, we report the development of a synergetic amorphous MoS x hybrid catalysts on V 2 O 3 with optimized HER activity of MoS x . Our synthetic and structural characterization shows that MoS x distributes on V 2 O 3 uniformly. HER-inert V 2 O 3 provides a highly electrochemically active surface area for HER and promotes electron transport . The obtained hybrid MoS x /V 2 O 3 /CC catalyst exhibits a low overpotential of 146 mV at 10 mA cm −2 toward HER under acidic conditions, which is comparable with the current advanced catalysts, and high stability with no significant changes over 10 h of electrolysis. The density functional theory calculations also demonstrate that the interface of V 2 O 3 and MoS x helps to improve the conductivity.
研究领域:
材料科学
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能源科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 38
·32176-32182
·
IF 3.289
Fan Yang,Xingfeng Shi,Zhang Chen,Dongyun Ma,Yupeng Wu,Hongjie Luo,Yanfeng Gao
Thermochromic (TC) and electrochromic (EC) smart windows are the mostly studied categories of smart window, but they usually work in different wavebands, and each have their own advantages. This work offers a method to combine the advantages of TC and EC smart windows by synthesizing TC–EC dual-response TiO2–VO2 nanocomposite films. These films were prepared by dispersing VO2 nanoparticles (NPs) in TiO2 sols and then underwent annealing. The optimized film showed a luminous transmittance (Tlum) of 66.1% at 20 °C, 59.3% at 90 °C and a ΔTsol of 11.2%. By applying a voltage of −5 V, the film showed an EC transmittance modulation (ΔT) of 19.1% at 630 nm, a combined performance of Tlum = 44.7% and ΔTsol = 17.1% (increased by 52%). The color of the films could also be modified from a yellowish brown to a light blue, which is meaningful for practical usage. The current TiO2–VO2 nanocomposite film combines TC and EC performance, which may be an important breakthrough in energy saving smart windows.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）