Materials Research Express
·
2019
·Vol. 6
·期 11
·115507
·
IF 1.449
Qiong Wu,Tiankuo Yao,Minqi Sheng,Jialun Shi,Fan Lv
The high-performance catalytic electrodes are always required in industrial water electrolysis for enhancing the efficiency of energy conversion. In this paper, we utilized a simple electroless deposition method to deposit Co-W-P on carbon cloth (CC), to construct a bifunctional Co-W-P/CC self-supported electrode for electrochemical water splitting in 1.0 M KOH. The Co-W-P on CC is amorphous and displays nodular structure. The molar ratio of Co2+/WO42− in the synthesis process makes remarkable influence on the catalytic activity of Co-W-P/CC. For optimized Co-W-P/CC-3 (Co2+/WO42− molar ratio about 6:1), an overpotential of 150 mV at −10 mA·cm−2 is required with a Tafel slope of 137.3 mV·dec−1 toward hydrogen evolution reaction (HER), and an overpotential of 350 mV at 10 mA·cm−2 is required with a Tafel slope of 113.2 mV·dec−1 toward oxygen evolution reaction (OER). Furthermore, when functioned as a bifunctional electrode for overall water splitting, the electrolyzer of Co-W-P/CC (−)//Co-W-P/CC (+) shows the cell voltage of 1.74 V at 10 mA·cm−2, as well as superior stability with negligible increase of cell voltage (0.05 V) over 20 h. The work provides an efficient and inexpensive electrode material, which can be used to replace the noble metal-based catalysts for electrochemical water splitting.
研究领域:
材料科学
·
能源化学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Ruoning Zhang,JingjingYu,Nan Liu,Yanxiang Gao,Like Mao
This study reported a novel approach to stabilize W/O emulsions with nanoparticles and oleogel from ethylcellulose (EC), and the emulsions were applied for multiple delivery. Microstructural observations revealed that EC nanoparticles were distributed within the water droplets and at the interface, and EC oleogel was in the continuous phase. Storage modulus and viscosity were higher, and thixotropic structural recovery rates were lower, in the emulsions with more EC nanoparticles. Both EC nanoparticles and oleogels worked to stabilized the emulsions upon freeze-thawing, as only minor water or oil was released. Upon heating, some EC nanoparticles transited from the interface to the oil phase, and water droplets were aggregated. The interface was recreated when the samples were re-emulsified. When curcumin and anthocyanin were incorporated, both bioactives had improved light stability. During in vitro study , curcumin was mostly released at the early stage of intestinal digestion, while anthocyanin was released at later stage.
研究领域:
食品科学
·
材料科学
·
生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Metals
·
2023
·Vol. 13
·期 5
·937
·
IF 2.9
Chuanbin Wang,Yongxin Cheng,Sumeng Hu,Kejia Kang,Yuzhe Han,Xudan Zhang,Ronghan Wei,Guoqiang Luo
W-Si-C composites with high relative densities and good mechanical and wear properties were successfully prepared by spark plasma sintering. The influence of SiC content on the relative density, microstructure, mechanical properties and wear characteristics was investigated. The results indicated that the reaction between SiC and W at their interface produced W2C and W5Si3. SiC also reacted with oxygen impurities at the W grain boundary to form SiO2. The purification of the grain boundaries of W was carried out by SiO2synthesis. Reactive sintering reduces the free energy of the system and facilitates the densification process of W-Si-C composites. This results in a significant increase in the relative density of W-Si-C composites, which reaches a maximum of 98.12%, higher than the 94.32% of pure tungsten. The hardness significantly increases from 4.33 GPa to 8.40 GPa when the SiC content is 2 wt% compared to pure tungsten due to the generation of the hard ceramic phase and the increase in relative density. The wear resistance of the W-Si-C composites was significantly improved with little SiC addition. The wear rate significantly decreased from 313.27 × 10−3mm3/N·m of pure tungsten to 5.71 × 10−3mm3/N·m of W-0.5 wt% SiC. SEM analyses revealed that the dominant wear mechanism of pure tungsten was attributed to fatigue wear, while that of W-Si-C composites was due to abrasive wear.Keywords:W-Si-C composites;spark plasma sintering;interface reaction;mechanical properties;wear characteristics
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Jianxu Wang,Jiang Guo,Qiuyi Lv,Zhijiang Ma,Xuyao Feng,Yuhiu Lu,Jing Gao,Wensheng Chen,Bin Deng,Ruijin Yu
A series of novel orange-red emitting tungstate phosphors, Ca 3 La 2 W 2 O 12 (CLWO): x Sm 3+ (0.005 ≤ x ≤ 0.30) were successfully prepared through the solid-state method at high temperature. The space group is hexagonal R 3 ‾ m . Under 600 nm monitoring, a large charge transfer band from 250 to 340 nm composed of the electron transition of O 2- –Sm 3+ and O 2- –W 6+ and represented the strongest excitation at 300 nm. CLWO:Sm 3+ emitted orange-red light at 600 nm ( 4 G 5/2 – 6 H 7/2 ) under the strongest excitation of 300 nm. The intensity ratio of the electric-dipole and magnetic-dipole of all the samples were bigger than 1. With the Sm 3+ -doped concentration increasing, the upward tendency of ratio values originated from the increased degree of lattice distortion . The calculated R c (21.32 Å) and Q (3.78) represented the dipole–dipole interaction to account for the concentration quenching. With the temperature changing from 300 to 400 K, the chromaticity coordinates of samples just have a tiny difference (Δ x = 1.02 × 10 −4 , Δ y = 1.01 × 10 −4 ). The thermal activation energy was calculated to be 0.42 eV and T 0.5 > 480 K. The color purity of all the phosphors reached 98.9%. Ultimately, a white light-emitting diode (w-LED) was fabricated by coating trichromatic (red, blue, and green) phosphors on a near-ultraviolet chip. The fabricated w-LED revealed a high color rendering index (R a = 91, R 9 = 41) and a good chromaticity coordinate (0.320, 0.363) in the white area. Thus, these orange-red phosphors CLWO:Sm 3+ with high thermal stability and high color purity can be potentially used in w-LED applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xiaohui Ma,Wenjun Li,Chaojun Ren,Hongda Li,Xintong Liu,Xinyang Li,Tianyu Wang,Mei Dong,Shujing Liu,Shaowei Chen
Herein, noble-metal-free In 2 S 3 -WC and In 2 S 3 -based photocatalysts with dual cocatalysts of flower-like MoS 2 and bulk WC were synthesized through a facile solvothermal reaction. Electrochemical results indicated WC increased the interface conductance of photocatalyst and boosted the transference of photogenerated carriers. The optimal In 2 S 3 -WC show a hydrogen production rate of 128.11 μmol·h −1 ·g −1 , which is around 6 times higher than In 2 S 3 -1%Pt (20.73 μmol·h −1 ·g −1 ). The above results demonstrate commercial WC has a crucial impact of replacing precious metal and separating carriers. Morphology characterization exhibited hydrangea In 2 S 3 and flower-like MoS 2 were attached to bulk WC. Gratifyingly, photocurrent, impedance and photoluminescence results demonstrated MoS 2 further effectively separated the photogenerated carriers. Remarkably, the higher hydrogen generation rate of 390.52 μmol·h −1 ·g −1 obtained by the optimal ternary In 2 S 3 -WC-MoS 2 composite was around 3 and 18 times higher than the optimal In 2 S 3 -WC and In 2 S 3 -1% Pt. The photocatalytic results demonstrated that "W-Mo auxiliary pairs" was a great efficient synergistic cocatalyst for In 2 S 3 to increase active sites and improve e - -h + pairs separation for H 2 generation. Furthermore, a probable reaction mechanism of the enhanced photocatalytic H 2 generation was also proposed. This presented research provides an effective concept to design novel and efficient noble-metal-free photocatalyst with "W-Mo auxiliary pairs" for prominent H 2 generation activity.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2019
·
IF 6.355
Wei Liu,Jiao Di,Wuxing Zhang,Lihong Xue,Youwei Yan
The oxidation behavior of W-Si bulk composite was investigated to evaluate its performance on the simulating accidental environment in the future fusion reactor. Tungsten trisilicide is the main functional phase, which can form amorphous SiO y and polycrystalline WO 3 with nano-porous network during oxidation. This special structure can not only retard W volatilization, but also offer well self-adaption adjustment to different phases. In addition, cracks at the oxide scale/composite interface can be self-healed with the help of this structure. Protrusions are found on the surface of the oxidized W-32Si related with Fe impurity. The vapour-liquid-solid mechanism for the protrusions is proposed.
研究领域:
材料科学
·
核工程
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 38
·13396-13404
·
IF 7.059
Liangmiao Zhang,Fang Xia,Jianing Yao,Tianli Zhu,Hui Xia,Guang Yang,Bin Liu,Yanfeng Gao
Monoclinic VO2(M) has been considered as one of the most promising materials for fabricating energy-saving smart windows, but its scalable synthesis is still a great challenge. In this work, pure and tungsten (W)-doped VO2(M) nanoparticles (20–50 nm) were prepared by a simple hydrothermal recrystallization method using an amorphous precursor obtained from coprecipitation in a mixed VOSO4 and NaOH solution (pH = 9). The phase transition temperature of the obtained W-doped VO2(M) nanoparticles decreases with increasing W-doping, by −28.4 °C per at% of W in the range of 0–1.1 at%. The mechanism of hydrothermal recrystallization was studied by using ex situ powder X-ray diffraction (PXRD) and in situ synchrotron radiation-based PXRD. It was found that the hydrothermal synthesis underwent two steps: (1) recrystallization of amorphous precursor to VO2(B) crystals, and (2) allotropic phase transformation from the metastable intermediate VO2(B) to VO2(M). In addition, the fabricated films using VO2(M) with 0.7 at% W-doping showed excellent thermochromic performance, with a suitable phase transition temperature of 42.7 °C, high average luminance transmittance of up to 61.7%, and good solar energy modulation ability of 11.7%, making them a suitable material for efficient and low-cost energy saving smart windows.
研究领域:
材料科学
·
纳米技术
·
能源效率
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2018
·Vol. 11
·期 14
·2332-2339
·
IF 7.411
Zhong-Yu Xie,Jin Deng,Yao Fu
Graphical Fatty acids slim down : A new method for γ-lactone preparation based on ring contraction has been developed. Starting from macrolides, W(OTf) 6 was used to catalyze ring-opening polymerization then depolymerization to produce the stable five-membered γ-lactones in the ionic liquid [EMIM]OTf. γ-Lactones were also produced when the substrate was extended to terminal hydroxyfatty acids. γ-Lactones are an important class of fine chemical products and are widely used in perfumes, medicines, pesticides, dyes, and other fields. Herein, a new method for γ-lactones preparation based on ring contraction was developed. Starting from macrolides, W(OTf) 6 was used to catalyze the ring-opening polymerization then depolymerization. The depolymerization step was not a common ring-closing process, and the carbon number of the ring was reduced one by one by rearrangement to form the most thermodynamically stable five-membered ring compounds. γ-Caprolactone (180 °C for 10 h) was obtained in a yield of 94 % when [EMIM]OTf was used as the solvent, and the yield of isolated product was up to 85 %. The interaction of various components and the reaction mechanism were studied by FTIR spectroscopy and 1 H NMR spectroscopy, respectively. Furthermore, γ-lactones could be produced when the substrate was extended to terminal hydroxyfatty acids. Unexpectedly, the catalyst was poisoned by 1 equivalent of H 2 O added during the process and thus the yield decreased greatly. The reaction is green and simple, and proceeds in one pot with high atom economy (100 % for macrolides and with water as the only byproduct for terminal hydroxyfatty acid), which provides a promising approach to synthesizing γ-lactones.
研究领域:
有机化学
·
绿色化学
✓ 已验证
DOI
PubMed
高影响因子
Materials Research Express
·
2024
·Vol. 11
·期 7
·076520
·
IF 1.8
Yuanhang Fang,Tingbian Zhan,Xiaojun Li,Changyou Xie,Xinggao Zhang,Weizhan Wang,Xiansong Jiang
A W-Zr alloy doped with ceramic powder W54.5Zr35-xNi6.7Fe3.3Mo0.5 (ZrO2) x was prepared by powder metallurgy. The effects of the ceramic content on the dynamic and static compressive mechanical behavior and energy release properties of the alloy were studied. The results showed that the addition of ceramics enhanced the energy release characteristics of the W-Zr alloy, and made the alloy break more thoroughly and the fragment cloud distribute evenly. The reaction delay time was shorter and the energy release reaction was more complete. However, the maximum temperature of the alloy reaction decreased. In addition, the addition of ceramics improves the mechanical properties of the material, and its compressive strength is much higher than that of traditional W-Zr alloys.(ZrO2)1 exhibited good mechanical behavior and energy release characteristics. The aftereffect damage performance was further verified using a ballistic gun experiment. Ballistic gun test results showed that (ZrO2) 1 can penetrate A92124 aluminum targets with a thickness of 2 mm at a speed of 809.3 m s−1 and ignite post-target absorbent cotton, with both penetration and post-target damage capabilities.
研究领域:
材料科学
·
力学
·
能源材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xiaohui Wu,Jingkang Xu,Yulan Jing,Yuanxun Li,Hua Su
The increasing demand for miniaturized electronic devices requires the development of advanced medium-high K materials. In this work, novel (Ti 1/2 W 1/2 ) 5+ -substituted LiNb 0.6- x (Ti 1/2 W 1/2 ) x Ti 0.5 O 3 (LNT- x TW, 0 ≤ x ≤ 0.12) ceramics were successfully prepared by the solid-state method. The increase in TW content led to the formation of LNT-0.08 TW ceramic with medium-high K and high Q × f after sintering at 1050 °C. This ceramic also recorded improved characteristics with ε r ∼53.84, Q × f ∼7482 GHz and τ f ∼43.43 ppm/°C related to ionic polarizability, large grains, high densification, and [Ti 2 O 3 ] 2+ / N layers. In addition, Li 2 O–B 2 O 3 –SiO 2 –CaO–Al 2 O 3 (LBSCA) used as an effective sintering aid, improved densification and promoted sintering by not only decreasing the temperature to 900 °C, but also enhancing the microwave dielectric properties with ε r ∼49.46, Q × f ∼8149 GHz, and τ f ∼12.04 ppm/°C. The Q × f value was estimated to 1.15 ∼ 2-fold higher than other LNT-based ceramics within stable τ f . More encouragingly, the LNT-0.08 TW ceramic also showed good chemical match with Ag, suggesting usefulness for miniaturized LTCC devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ruiying Zhai,Yijie Yang,Peilin Lei,Jiahao Lu,Sisi Chen,Xiaoqi Sun
In this article, a green pigment Bi 1.95-x Pr x W 0.05 MoO 6+δ (x = 0.1–0.5) co-doped with Pr and W was developed using high temperature solid-phase synthesis method. The microstructure, color performance, and optical characteristics of the novel pigment was analyzed using x-ray diffraction instrument (XRD), field-emission scanning electron microscopy (FESEM), L∗ a∗ b∗ color date, and ultraviolet–visible–near infrared light spectrophotometer. The results indicate that all the samples possess a monoclinic structure, characterized by the space group P21/c(14). Compared to Bi 2-x Pr x MoO 6+δ doped solely with Pr 6 O 11 , the Pr/W co-doped Bi 2 MoO 6 pigment demonstrates superior green coloration. The solar reflectance in the near-infrared region of all pigment samples exceeds 80 %, highest value reaches 92.82 %. In thermal insulation tests, the temperature difference between the Bi 1.95-x Pr x W 0.05 MoO 6+δ pigment coating and a blank galvanized sheet reaches up to 10.3 °C after 60 min under infrared lamp irradiation. The color difference Δ E∗ of the pigment powder after immersion in acid and alkali solution and high-temperature calcination are less than 5, indicating good chemical stabilities in acidic, alkaline and high-temperature environments. To our knowledge, Bi 1.95-x Pr x W 0.05 MoO 6+δ has the highest reflectivity among green pigments without toxic metals.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Transactions of the Indian Ceramic Society
·
2025
·
IF 1.5
Yuting Li,Mingyong Jia,Yueqi Wu,Chi Zhang,Yaojun Lin,Fei Chen
Integrating boron carbide ceramics (B4C) with tungsten (W) presents great potential for the development of advanced shielding materials. This study focuses on achieving exceptional bonding between B4C and W by fine-tuning the graded interfaces guided by the comprehensive thermodynamic reaction information. The results show that as the W content increases in the graded interlayers, the unstable entropy between B4C and W system drives the reaction progress along the following stages, W2B5 → W2B5 + WB → WB + WC → W2B + W2C. The multi-scale cracks within B4C/W composites and B4C/W graded materials are mainly due to mismatched properties and inherent brittleness of the induced interphases, which can be effectively mitigated by reducing phases such as WB and WC.
研究领域:
材料科学
·
工程学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）