COMPOSITES PART B-ENGINEERING
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2025
·
IF 14.2
Yang Hu,Dewei Ni,Bowen Chen,Feiyan Cai,Xiaoyu Wang,Yanmei Kan,Yusheng Ding,Shaoming Dong
Structure and stealth integrated materials that simultaneously deliver mechanical loading and broadband electromagnetic wave (EMW) absorption performance are critical for next generation stealth aircraft. Although conventional carbon fiber reinforced ceramic matrix composites (C f /CMCs) exhibit outstanding load-bearing capacity, their inherent EMW reflection characteristics often fail to meet stealth requirements. This work proposes a multiscale design strategy synergizing microscopic defect engineering with macroscopic gradient permittivity modulation. Accordingly, (SiO 2 –C) f /(CrZrHfNbTa)C–Si 3 N 4 –SiBCN composite featuring self-adaptive impedance matching and multi-mechanism EMW absorption were successfully constructed. The material demonstrates acceptable load-bearing capacity (101 ± 5 MPa) while achieving a remarkably high effective absorption bandwidth (EAB) per unit thickness (2.68 GHz mm −1 ). More importantly, radar cross section (RCS) simulations reveal that the sample achieves a remarkable RCS reduction of 35.52 dB m 2 . This surpasses most reported materials system, demonstrating high practical application potential. Density functional theory calculations reveals that defect engineering (lattice distortion and point defects) in the sample constructs new polarization centers at the microscopic level, which significantly enhances polarization relaxation loss for improved EMW absorption. On the other hand, macroscopic structural design (SiO 2f -C f -SiO 2f ) significantly optimizes the impedance matching, which effectively broadens EAB. The multiscale design strategy overcomes the inherent conflict between strong EMW reflection and attenuation in carbon fibers, which provides a novel material solution for stealth aircraft.
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DOI
高影响因子
Journal of Physical Chemistry C
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2025
·
IF 3.2
Xiang Chen,Shaohua Chen,Pengxin Liu,Chaodan Pu
We report the efficient C–C coupling between benzyl alcohol and benzaldehyde to hydrobenzoin using CdSe/CdS quantum dots as visible-light photocatalysts and sodium oxide as a cocatalyst. The optimized conditions resulted in a reaction with a selectivity of hydrobenzoin >95%, an apparent quantum yield of 23.6% under the excitation by 520 nm LED, and a turnover frequency of 56.8 mmol g–1 h–1. Reactant concentration-dependent experiments demonstrated that benzaldehyde can process fast proton-coupled electron transfer, improving the utilization of photogenerated electrons. Photoluminescence quenching experiments and reactions with deuterated benzaldehyde confirmed that due to the in situ produced hydrogen ions, the hydroxymethyl radicals would process efficient reverse conversion from hydroxymethyl radicals to benzyl alcohol, resulting in noneffective charge transfer. Formation of sodium benzyloxide can eliminate the in situ produced hydrogen ions around the hydroxymethyl radical, suppressing this reverse conversion and improving the utilization efficiency of transferred holes and electrons.
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Tianxiang Guo,Zijun Men,Xiaoqing Wang,Gujie Yao,Baijiang Liu,Xilai Wang,Yarong Du,Da Jin
Electrochemical carbon dioxide reduction reactions (ECO 2 RR) for ethanol synthesis represents a highly valuable yet challenging objective, mainly due to the low selectivity and elusive formation mechanism. This study aims to address this challenge by designing a pulsed-electrodeposited bimetallic CuAg catalyst. The surface morphology and elemental valence state distribution of the CuAg catalyst were comprehensively characterized using BET/SEM/EDS/XRD/XPS techniques. Subsequently, the electrocatalytic performance was systematically investigated based on CV/LSV/EIS/GC/ 1 H NMR methods. The results indicated that the CuAg catalyst attained a Faradaic efficiency of 11.39 % for ethanol production at a current density of 84 mA·cm −2 , along with an ethanol/ethylene selectivity of 8.26. In combination with the analysis of DFT calculations, the incorporation of Ag into the Cu catalyst enhanced the catalytic performance primarily through three mechanisms: increasing the specific surface area and porosity to generate more Cu active sites and high ESCA , modifying the electronic structure of Cu atoms to facilitate the C–C coupling pathway, and reducing the interfacial resistance to promote reaction kinetic rates. These findings provide atomic-level insights into the ECO 2 RR mechanism and establish a novel paradigm for the design of bimetallic catalysts to achieve the efficient synthesis of multi-carbon fuels such as ethanol.
研究领域:
电催化
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能源化学
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材料化学
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表面科学
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环境化学
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物理化学
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DOI
高影响因子
RARE METALS
·
2024
·Vol. 43
·期 4
·1513-1523
·
IF 9.6
Zhang Ze-Yu,Wang Hai-Bin,Zhang Fei-Fei,Li Jing-Wei,Hu Xin-Zhuo,Yan Si-Wei,Bai Yi-Ming,Zhang Xun,Shen Gu-Rong,Yin Peng-Fei,Yang Jing,Dong Cun-Ku,Mao Jing,Liu Hui,Du Xi-Wen
Electrocatalysis of CO 2 reduction reaction is an effective way to convert CO 2 into high value-added products, but the selectivity of Cu-based catalysts for C 2+ products needs to be improved due to the high energy barrier of C–C coupling. Therefore, a viable catalyst design strategy to decrease energy barrier of C–C coupling should be put forward. Here, a nanocavity-enriched CuPd single atom alloy (CuPd SAA) catalyst is designed to promote C–C coupling process. The faradaic efficiency of CuPd SAA for ethylene and C 2+ reaches 75.6% and 85.7% at − 0.7 V versus reversible hydrogen electrode (RHE), respectively. Based on the results given by in situ characterization, the porous hollow structure dramatically increases the ratio of the linear-bond *CO, thus enhancing the faradaic efficiency for ethylene. Density functional theory (DFT) calculation reveals that the Pd doping can regulate the electronic structure of neighboring Cu atoms to decrease the energy barrier of C–C coupling, further improving the faradaic efficiency. This work provides a new idea for designing catalyst with high selectivity for ethylene. Graphical abstract
研究领域:
材料科学
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化学
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电化学
·
催化
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DOI
高影响因子
Frontiers in Chemistry
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2020
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IF 3.693
Zhang Xin,Zhang Xuelian,Ren Zhuanghe,Hu Jianjiang,Gao Mingxia,Pan Hongge,Liu Yongfeng
In this paper, we report amorphous-carbon-supported TiB2 nanoparticles having sizes of 2–4 nm (nano-TiB2@C) as highly active catalysts for hydrogen storage in NaAlH4. Nano-TiB2@C was synthesized by a simple calcination at 550°C with Cp2TiCl2 and MgB2 (molar ratio of 1:1) as precursors. The addition of 7 wt% nano-TiB2@C reduced the onset dehydrogenation temperature of NaAlH4 by 100 to 75°C. A practically available hydrogen capacity of 5.04 wt% could be desorbed at 140°C within 60 min, and completely hydrogenated at 100°C within 25 min under a hydrogen pressure of 100 bar. Notably, the hydrogen capacity was almost unchanged after 20 cycles, which shows the stable cyclability, considerably higher than those of structures catalyzed by Ti halides or TiO2. The stable catalytic function was closely related to the in-situ-formed Ti–Al alloy, which considerably facilitated the dissociation and recombination of H–H and Al–H bondings.
研究领域:
材料科学
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能源化学
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DOI
PubMed
高影响因子
OPTICAL MATERIALS
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2022
·
IF 3.754
Xinning Xu,Zongliang Xiao,Yuhang Wang,Yinuo Yan,Junwei Shen,Yawen Nie,Weixiong You,Di Wu,Lei Han,Fengqin Lai
Ultraviolet-C (UVC) light shows important application prospects in disinfection, disease phototherapy, cancer photodynamic therapy, etc. Here, a novel UVC upconversion phosphor δ -Y 2 Si 2 O 7 :Pr 3+ with excellent optical properties was successfully prepared by the high-temperature solid-state reaction method and the sol-gel method. The XRD results clarified the law of phase transition from the β -/ γ -Y 2 Si 2 O 7 to the δ -Y 2 Si 2 O 7 phase. The diffuse reflection spectra of phosphors prepared by two different methods exhibited two obvious absorption bands related to the 3 H 4 → 3 P 2 and 3 H 4 → 1 D 2 transitions of Pr 3+ ions. And the values of the band gap were estimated by diffuse reflection spectra, which are in good agreement with the value calculated by DFT . Under the excitation of 460 nm laser, two emission peaks corresponding to the 4 f 5 d → 3 H 4 and 4 f 5 d → 3 H 5 transitions of Pr 3+ ions were discovered at ∼247 nm and ∼258 nm in the range of 230–280 nm. Additionally, the phosphor prepared by the sol-gel method has a higher emission intensity than the phosphor prepared by the high-temperature solid-state reaction method. With the help of temperature-dependent emission spectra , the phosphor prepared by two methods demonstrated outstanding thermal stability up to 150 °C, and the luminescent intensity at 150 °C remained 86.8% and 87.9% of that at ambient temperature, respectively. The results mentioned above suggest that the Y 2 Si 2 O 7 :Pr 3+ phosphor may have potential applications in the field of disinfection.
研究领域:
材料科学
·
光学
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
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IF 6.844
Min Wang,Jianmin Lu,Lihua Li,Hongji Li,Huifang Liu,Feng Wang
Selective oxidative cleavage of C C bond is pivotal for producing functionalized molecules, useful for organic synthesis and biomass utilization. We herein report the oxidative C(OH) C bond cleavage of secondary alcohols to acids over a copper/1, 10-phenanthroline complex with molecular oxygen as the oxidant. A wide range of secondary alcohols are converted into acids with up to 98% yields. More interestingly, it is effective for breaking up lignin model systems into acids, which is rarely achieved in previous studies. Density functional theory (DFT) calculations indicate a copper-oxo-bridged oxygen dimer is the active species for the C H bond cleavage which is the rate-determining step for C C bond.
研究领域:
有机化学
·
催化化学
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DOI
高影响因子
CORROSION SCIENCE
·
2026
·
IF 10.3
Kangran Wei,Mengen Hu,Chengwan Yang,Xian Dang,Ming Li,Yuhan Zhu,Yanhui Chu,Xiaoye Hu,Liwen Yan,Zhulin Huang
Although Ta 4 HfC 5 ceramic has a highest melting point reported, it ablates rapidly in oxidative environment because Ta 2 O 5 has a low melting point of 1872 °C. In this work, ultrafine Ta-Hf-C solid-solution powders (49∼70 nm) with tunable Ta/Hf ratio were synthesized via a solvothermal route combined with carbothermal reduction using a liquid-phase precursor. Ta-Hf-C solid-solution bulks with relative densities of 98–99% were subsequently obtained by an ultra-fast pressure sintering technique. The effects of Ta/Hf ratio on densification behavior, mechanical properties, and oxidation–ablation resistance were systematically evaluated. Among all compositions, the 1TaC-4HfC ceramic exhibited the lowest mass and linear ablation rates of 0.422 mg/s and 14.237 μm/s after 120 s exposure to laser irradiation at a heat flux of 30 MW/m 2 , with a surface temperature up to 3800 °C. During ablation, a dense protective oxide layer formed through the reaction between HfO 2 and Ta 2 O 5 , generating Hf 6 Ta 2 O 17 coatings on the HfO 2 framework, while molten Ta 2 O 5 acted as a liquid bonding phase to wet and integrate the oxide phases with the residual carbide skeleton. This synergistic HfO 2 /Hf 6 Ta 2 O 17 /Ta 2 O 5 composite structure effectively suppressed oxygen permeation and enhanced high-temperature stability above 3000 °C.
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DOI
高影响因子
Materials Today Energy
·
2026
·
IF 8.1
Yipeng Nie,Longquan Deng,Zipei Cui,Zhao Jiang,Wenchao Sheng
Coupling hydrogen evolution reaction (HER) with glycerol oxidation reaction (GOR) in a hybrid electrolyzer represents a highly promising approach for green hydrogen production and glycerol upgrading. However, the limited activity and stability of existing GOR catalysts restrict the energy efficiency of the coupled system. In this study, Pd/C and Pd 4 Ag x /C catalysts were synthesized to investigate the impact of Ag on the activity and stability of Pd-based catalysts for GOR. The optimized Pd 4 Ag 8 /C demonstrated a specific activity of 17.4 ± 0.1 mA cm −2 Pd and a mass activity of 13.2 ± 0.3 A mg −1 Pd , both being more than 10 times higher than those of Pd/C. Combined results of ultra-performance liquid chromatography and density functional theory calculations revealed that the introduction of Ag promotes C−C cleavage in glyceric acid on Pd sites, facilitating electron transfer in GOR and thereby enhancing the GOR activity. The GOR coupled HER hybrid electrolyzer using Pd 4 Ag 8 /C as the GOR catalyst achieved a significant reduction of ∼1.07 V in cell voltage compared to conventional water electrolysis system at a current density of 10 mA cm −2 with a favorable operational stability, and realized the production of high-value-added chemicals, demonstrating the promising potential in both hydrogen production and upgrade of glycerol.
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DOI
高影响因子
Journal of Energy Storage
·
2026
·
IF 10.7
Binbin Liu,Xiaorui Yang,Jian Ren,Meng Yang,Xiaodong Shen,Yong Kong
Silicon oxycarbide (SiOC)-based materials hold significant potential as anodes of lithium-ion batteries (LIBs) due to their high theoretical capacity, low volume expansion, and excellent electrochemical stability. However, they exhibit low initial Coulombic efficiency (ICE) and poor cycling stability. In this study, carbon/silicon oxycarbide (C/SiOC) composites were synthesized using a facile sol-gel method followed by ambient pressure drying and thermal treatment. The phase composition of SiOC was tuned by the oxygen content of precursors to achieve a high content of reversible phase for Li storage. Among four organosilanes including trimethylethoxysilane (TMES), 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), methyltriethoxysilane (MTES), and tetraethoxysilane (TEOS), TMCTS leads to the highest content of SiO 3 C and SiO 2 C 2 phases owing to moderate oxygen content, which are responsible for Li storage. Hence, the C/SiOC composite with TMCTS as precursor exhibits significantly higher initial Coulombic efficiency (70.53%) than those with TMES, MTES, and TEOS as precursors (68.86%, 43.85%, and 33.11%), which this value exceeds the typical ICE range of 50–60% reported for other SiOC-based materials. It was demonstrated that a higher oxygen content of the precursor promotes the generation of Li 2 O during the lithiation process, which acts as a robust structural buffer to enhanced structural stability. TMCTS-derived C/SiOC composite exhibited excellent cyclic stability over long-term cycling, retaining 601.87 mAh·g −1 after 100 cycles at 0.1 A·g −1 . The results verify the critical role of phase composition of SiOC as anodes of LIBs, providing a new strategy to design SiOC-based materials with high electrochemical performance by tuning phase composition of SiOC from its precursor.
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Kexuan Jing,Weizong Wang,Shijie Wang,He Ma,Ran Song,Kang Liang,Shujun Cai,Yurong Ren,Jianbin Li,Zhengping Ding
With high lithium storage performance and low intercalation/deintercalation potentials, silicon-based anode is one of the most promising anode materials for the development of high-energy density lithium-ion batteries (LIBs). Despite the considerable advances made by Si/C negative electrodes in the commercial field, there remains scope for enhancement in terms of their low-temperature performance. In this work, we put forward a novel additive, which is tetrakis(trimethylsilyl)silane (TTS). Theoretical calculations and differential capacity curves demonstrated that the additive is able to preferentially carbonate solvents for decomposition and that the chemical bonds formed by the breakage facilitated the formation of surface films. The incorporation of O-Si-C-rich structures into solid electrolyte interface (SEI) film allows for the attainment of better mechanical properties and high ionic conductivity. The particular SEI is capable of tolerating significant alterations in the volume of Si/C anode particles, thereby preventing the irreversible depletion of lithium ions and electrolytes. Thus, the Si/C half-cell with TTS additive exhibits higher reversible capacity (582.1 mAh g -1 at room temperature, 212.3 mAh g -1 at -20°C), high-rate performance (440.3 mAh g -1 at 2 C), and excellent capacity retention (76.2% after 150 cycles at room temperature, 77.9% after 200 cycles at -20°C). Furthermore, our research explores the impact of TTS on the formation of amorphous silicon. On the one hand, the formed SEI containing O-Si-C structure has better mechanical properties and ionic conductivity, which inhibit the fragmentation of Si/C particles and reduce the irreversible consumption of Li + . On the other hand, an increase in Li + concentration can increase the amorphous silicon content in the lithiation process. Specifically, the introduction of TTS promotes the formation of the amorphous silicon (a-Si) phase, and the content of the a-Si phase is closely related to the reversible capacity and cycling stability of the silicon anode. The unique phase-regulation mechanism is the key to the ability of TTS modification to enhance the low-temperature electrochemical performance of Si/C anode. This work provides an effective method for the development of materials suitable for operation at low-temperature.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Xueni Zhao,Pengfei Wang,Jiamei Zheng,Jiao Liu,Zhi Yang,Lijun Yang
Multilayered C–Si–Al coatings with various morphologies were deposited on carbon fibers (CFs) using magnetron sputtering . The thickness of the coatings was increased from 0.5 to 1.5 μm by magnetron sputtering between 90 and 120 min. C–Si–Al coatings of suitable thickness were heat-treated at 600 °C and transformed into C–Si–Al 2 O 3 coatings by one-step anodic oxidation (AO). The oxidation time for the one/two-step anodic oxidation and the ratio of oxidation time for the two-step anodic oxidation significantly influenced the morphologies of the C–Si–Al 2 O 3 (AO) coatings. Al 2 O 3 coatings with satisfactory morphologies and structures were prepared by two-step anodic oxidation with a total time of 30 min and a ratio of 1:1 between the initial and secondary oxidation times. The multilayered C–Si–Al 2 O 3 (AO) coatings were modified to C–Si–Al 2 O 3 coatings by secondary heat treatment at 1050 °C. Subsequently, hot-press sintering was used to prepare CFs with multilayered C–Si–Al 2 O 3 coating-reinforced hydroxyapatite (CF/C–Si–Al 2 O 3 /HA) composites. The multilayered C–Si–Al 2 O 3 -coated CFs demonstrated good resistance to oxidation and thermal shock . This could effectively protect CFs from oxidative damage and maintain its strengthening effect during sintering. The multilayered C, Si, and Al 2 O 3 coatings effectively reduced the difference between the coefficient of thermal expansion of the CFs and HA matrixes. The interfacial gaps between the multilayered coatings and HA were reduced. This could enhance the mechanical performance of the composites. The CF/C–Si–Al 2 O 3 /HA composites exhibited improved mechanical properties with a bending strength of 83.94 ± 12.29 MPa, and fracture toughness of 2.45 ± 0.08 MPa m 1/2 . This study can broaden the application of CF/C–Si–Al 2 O 3 /HA biocomposites as bone-repair materials and help obtain CF-reinforced composites with excellent mechanical properties that are fabricated or serviced at high temperatures.
研究领域:
材料科学
·
生物医学工程
·
陶瓷复合材料
·
表面工程
·
生物材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）