POLYMER
·
2023
·
IF 4.6
Peng Wei,Dong Huang,Chen Luo,Yang Sui,Xi Li,Qingkun Liu,Bensheng Zhu,Chuanbo Cong,Qiong Zhou,Xiaoyu Meng
Due to its uncomplicated manufacturing procedure for large-scale industrialization and adaptable conductivity, the competitive proton exchange membrane (PEM) matrix employed is sulfonated poly (ether ether ketone). However, the conflict between the strong proton conductivity and high stability of SPEEK-based PEM constantly upsets the equilibrium; the primary chain of SPEEK will conduct more protons if additional sulfonic acid is introduced, but it also causes a high swelling ratio and lowers stability. To tackle this challenging issue, we coupled the high intrinsic proton conductivity of phosphotungstic acid (HPW) and the excellent stability of polyimide (PI) nanofibers in a single PEM. In particular, sandwich-structure hybrid membranes (PI/SPEEK + HPW) were created to reduce HPW loss under operational conditions, further improving stability. Consequently, the swelling ratio and conductivity of the premium sandwich-structure PI/SPEEK + HPW-20 were 29% and 223.4 mS cm −1 under 60 °C and 100% RH, their respective values were 8% larger than those of SPEEK. Its proton conductivity reached 170.9 mS cm −1 during 13 days of exposure under 60 °C and 100% RH, which would be 30% better than that of SPEEK over the same treatment. Protons in these membranes were transported through Grotthus and vehicle mechanism, and the establishment of an acid-rich layer at the surface among PI nanofiber with HPW/SPEEK, which was confirmed by FTIR, XPS , and TEM , is responsible for these superior performances. From our point of view, our findings might encourage more studies into the creation of high-performance PEM.
研究领域:
材料科学
·
高分子化学
·
能源材料
·
电化学
·
膜科学与技术
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2024
·Vol. 50
·期 3
·e202400232
·
IF 1.7
Bo Hao,Caixian Xu,Geng Chen,Yuangen Lu,Li Zhang
In response to issues such as poor accuracy and unstable delay times encountered in the practical use of tungsten-based delay compositions, an analysis of the combustion performance of tungsten-based delay compositions with the addition of copper oxide was conducted. This study selected five tungsten-based composite delay compositions prepared by blending tungsten-based delay compositions with copper oxide at different content, aiming to investigate the influence of varying copper oxide proportions on the combustion characteristics of tungsten-based delay compositions. Microscopic morphologies and thermal decomposition behaviors of the tungsten/copper oxide delay compositions were analyzed using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), while combustion products were examined by X-ray diffraction (XRD). The results indicate that copper oxide exerts a strong catalytic decomposition effect on tungsten-based delay compositions. Specifically, a low concentration of copper oxide enhances the combustion rate of tungsten-based delay compositions, while an increase in copper oxide content subsequently slows down the combustion rate. Notably, tungsten-based delay compositions with 9% copper oxide content demonstrate high precision, good stability, and a relatively slow combustion rate, offering a wider range of adjustability for controlling the combustion speed of delay compositions and providing a feasible method for managing the delay time range in practical applications.
研究领域:
材料科学
·
火工品技术
·
燃烧学
·
无机化学
·
功能材料
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Haonan Qu,Bingyi Liu,Guohua Gao,Yiming Ma,Yanmei Zhou,Hua Zhou,Li Li,Yonghong Li,Shengjian Liu
Levulinic acid (LA) is a versatile key building block in the conversion of carbohydrates and it is an important basic chemical with various potential uses. MIL-100(Fe) loading with insoluble lysine functionalized phosphotungstic acid (Lys-PM 2 ) as heterogeneous catalysts have been synthesized for the conversion of glucose to LA in water. The optimized yield of LA is obtained by using Lys-PM 2 to catalyze glucose conversion is comparable to the majority of effective catalysts. The highest yield of LA (57.9%) is obtained at 150 °C for 9 h with 100 mg glucose and 25 mg Lys-PM 2 , since the Brønsted acidity and Lewis acidity of Lys-PM 2 . And the catalyst is able to recycle at least four times. It demonstrates the potential of Lys-PM 2 for the conversion of biomass.
研究领域:
催化化学
·
绿色化学
·
生物质能源
·
有机转化
·
材料化学
·
可持续化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Chuangang Yao,Jixing Yang,Sigeng Chen,Jian Meng,Kedi Cai,Qingguo Zhang
Cu doped SrFe 0.9- x Cu x W 0.1 O 3- δ ( x = 0, 0.1, 0.2 and 0.3) perovskites were investigated as SOFC cathode materials . The effects of Cu doping on properties of SFCW samples were studied systematically. The oxygen content (3- δ ) decreased by Cu doping, which leading to the decrement of electrical conductivity and the increment of TECs of SFCW samples. The ASR first decreases with x from 0 to 0.2 and then it increases when x up to 0.3. The ASR values are 0.161, 0.134, 0.102 and 0.117 Ω cm 2 at 800 °C for SFCW samples with x = 0, 0.1, 0.2 and 0.3, respectively. The corresponding activation energy are 0.90, 0.88, 0.78 and 0.86 eV. The lowest ASR and activation energy for ORR of SFCW2 is a result from the joint effects of electrical conductivity , oxygen vacancy concentration and thermal expansion caused by Cu doping. The research results obtained in this study suggesting SFCW2 is a good cathode candidate for SOFC.
研究领域:
材料科学
·
电化学
·
能源材料
·
无机非金属材料
·
固态离子学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-13
·
IF 14.7
Gong Yaru,Dou Wei,Lu Bochen,Zhang Xuemei,Zhu He,Ying Pan,Zhang Qingtang,Liu Yuqi,Li Yanan,Huang Xinqi,Iqbal Muhammad Faisal,Zhang Shihua,Li Di,Zhang Yongsheng,Wu Haijun,Tang Guodong
N -type polycrystalline SnSe is considered as a highly promising candidates for thermoelectric applications due to facile processing, machinability, and scalability. However, existing efforts do not enable a peak ZT value exceeding 2.0 in n -type polycrystalline SnSe. Here, we realized a significant ZT enhancement by leveraging the synergistic effects of divacancy defect and introducing resonance level into the conduction band. The resonance level and increased density of states resulting from tungsten boost the Seebeck coefficient. The combination of the enhanced electrical conductivity (achieved by increasing carrier concentration through WCl 6 doping and Se vacancies) and large Seebeck coefficient lead to a high power factor. Microstructural analyses reveal that the co-existence of divacancy defects (Se vacancies and Sn vacancies) and endotaxial W- and Cl-rich nanoprecipitates scatter phonons effectively, resulting in ultralow lattice conductivity. Ultimately, a record-high peak ZT of 2.2 at 773 K is achieved in n -type SnSe 0.92 + 0.03WCl 6 .
研究领域:
材料科学
·
热电学
·
固体物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 27
·期 4
·3549-3556
·
IF 1.569
Wang Lu,Yang Zhouyong,Ni Xiuyuan
We prepare the mesoporous polythiophene–WO 3 film through in situ polymerization which is initiated by WO 3 , and fabricate the electrochromic device with the composite film. The influences of the electrolyte ions, film morphologies and counter electrode on the electrochromism of the devices are explored by UV–Vis transmittance spectra and cyclic voltammetry tests. With the aim to enhance the contrast optical transmittance, we develop the binary composite electrolytes of LiClO 4 and N(C 4 H 9 ) 4 ClO 4 solution which can promote intercalation/deintercalation process. Besides that, we use polyethylene oxide as pore-forming agent on the polythiophene–WO 3 films, so that it will be easier for electrolyte ions to diffuse in the porous film. A NiO layer also has a complementary effect on the cathodic coloration films and increases the contrast optical transmittance remarkably. Equipped with the binary electrolyte and the NiO layer as the counter electrode, the film device exhibits high performance with the contrast optical transmittance (ΔT) of 62 % and the coloration efficiency of 212.6 cm 2 /C.
研究领域:
材料科学
·
电化学
·
功能材料
·
纳米材料
·
能源材料
·
表面科学
✓ 已验证
DOI
高影响因子
Materials Today Physics
·
2022
·
IF 11.021
Zilin Ruan,Jianchen Lu,Baijin Li,Qizan Chen,Zhenliang Hao,Lei Gao,Jinming Cai
Structural defects in two-dimensional materials offer an effective way to engineer their functionalities. In-situ local measurements to build the structure-function relationship are crucial for future device technology. Here, we present a comprehensive study of intrinsic defects in single-layer WS 2 grown by chemical vapor deposition using a combination of scanning tunneling microscopy/spectroscopy, non-contact atomic force microscopy and density functional theory calculations. We probed the rarely observed positively charged defects and the intersection of adjacent charging rings at sufficiently high bias caused by subsurface defects. We also directly identified and visualized the widely observed negatively charged defects as chalcogen vacancies-related defects. The results reported here will guide future efforts of targeted defect engineering and doping of the single-layer transition metal dichalcogenides .
研究领域:
材料科学
·
凝聚态物理
·
纳米科技
·
表面科学
·
二维材料
·
半导体物理
✓ 已验证
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 49
·36622-36632
·
IF 3.9
Lijun Xu,Qian Tong,Bing Hu
Through a simple room-temperature process, different amounts of Keggin-type quaternary ammonium silicotungstate were successfully encapsulated into the metal–organic framework (MOF) material ZIF-67. The catalysts were characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and BET analysis. An extraction and catalytic oxidation desulfurization system was studied using H2O2 as an oxidant and a deep eutectic solvent (DES) as an extractant. Using the 43.06%-SiW12@ZIF-67 composite under optimal reaction conditions, DBT present in a model oil could be deeply and effectively removed. The catalyst was reused 6 times, and the desulfurization rate still exceeded 90%. Finally, a possible desulfurization mechanism is proposed.
研究领域:
催化
·
环境化学
·
材料科学
✓ 已验证
DOI
高影响因子
Nano Research
·
2023
·Vol. 17
·期 4
·3035-3042
·
IF 9.9
Bian Chenchen,Wang Jinhui,Liu Huanhuan,Yan Yin,Zhang Ping,Yang Weilong,Jia Sensen,Guo Xiaodan,Cai Guofa
Electrochromic devices (ECDs) have been extensively investigated as promising candidates in broad cutting-edge applications, such as smart windows, electronic labels, adaptive camouflage, etc. However, they have suffered from either inadequate color variations or poor cycling stability for a long time. Herein, we developed a general strategy to boost the cyclic stability and enrich the color variations of ECDs by scrupulous design of the composition and nanostructure of electrodes, in which porous tin oxide (SnO 2 ) nanosheets serve as the scaffold and typical metal oxides or conducting polymers as the active electrochromic materials. Various electrochromic composite materials, including polyaniline (PANI)@SnO 2 , V 2 O 5 @SnO 2 , and WO 3 @SnO 2 heterostructured nanoarrays were prepared by the facile wet-chemical method. These composite electrodes exhibit remarkable electrochromic performances, e.g., superior cycling stability (more than 2000 cycles), rich color variations (more than 5 colors for PANI@SnO 2 ), and enlarged optical modulation. These excellent performances account for the heterogenous porous nanoarrays, which not only facilitate the intercalation/extraction of ions but also relieve the stress generated during the electrochemical process. In addition, diverse prototypes of complementary multicolor ECD with excellent cycling stability (over thousands of cycles) and rich color variations (8 colors) were realized for the first time. We believe that our work put forward a general strategy for developing high-quality multicolor complementary electrochromic devices.
研究领域:
材料科学
·
纳米技术
·
电化学
·
光电子学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2016
·Vol. 8
·期 7
·1399-1409
·
IF 4.724
Juan Yang,Xiaoxiao Shen,Yingjie Li,Linyan Bian,Jun Dai,Dongsheng Yuan
The selective conversion of alcohol into aldehyde in water was achieved over Bi 2 WO 6 -reduced graphene oxide (RGO) photocatalysts. The Bi 2 WO 6 -RGO-H catalysts were synthesized by an electrostatic self-assembly method followed by hydrothermal reduction. It was found the valence band and conduction band edges of Bi 2 WO 6 -RGO-H underwent a continuous increase in energy with the increasing weight ratio of graphene oxide, which resulted in a high selectivity to aldehydes. Furthermore, Bi 2 WO 6 -RGO samples with different degrees of reduction of RGO were prepared, and the conversion of alcohol was influenced greatly by the RGO reduction degree. Based on the results of photo-electrochemistry and photoluminescence spectroscopy, the clear enhancement in alcohol conversion can be ascribed to the efficient separation of photogenerated charge carriers, which results from the fast migration of photoelectrons between excited Bi 2 WO 6 and highly reduced RGO. Additionally, based on the results of radical-trapping and ESR spectroscopy, the primary reactive species and a plausible pathway for alcohol oxidation over Bi 2 WO 6 -RGO were proposed. Graphical Green synthesis : Highly selective and efficient conversions of alcohols into aldehydes can be achieved in aqueous suspensions of Bi 2 WO 6 -reduced graphene oxide (RGO) under artificial solar light irradiation. The selectivity to the product aldehydes can be tuned with the weight ratios of graphene oxide, and the conversion of reactant alcohols can be controlled by the reduction degree of RGO.
研究领域:
光催化化学
·
纳米材料科学
·
环境功能材料
·
绿色合成
·
有机转化催化
·
半导体光催化剂
·
界面电荷传输
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL CHEMISTRY
·
2024
·Vol. 79
·期 2
·233-240
·
IF 1
Wai Phyu Thin,Jiang Pingping,Lu Minjia,Cui Zhixuan,Feng Shan,Zhang Pingbo
High-resolution 1 H nuclear magnetic resonance ( 1 H NMR ) was advanced to determine both epoxy value and iodine value ( IV ) of vegetable oils that occur during their epoxidation. For calibration, rather than using a series of diluted stock samples, epoxidized soybean oils with a range of IV and epoxy value synthesized using entrapped peroxophosphotungstate as the catalyst under different reaction conditions were used. During the epoxidation reaction, IV and epoxy value were tracked with respect to time using 1 H NMR and conventional volumetric methods. The integrated peak area of the olefinic hydrogens (5.3–5.5 ppm) was used to calculate the absolute number of double-bonded protons. By comparison of IV obtained by 1 H NMR and the traditional Wijs-cyclohexane methods, the correlation coefficient was R 2 = 0.9997 for the regression equation y = 1.1314 x + 1.0035, where x was the result given by 1 H NMR. The average integrated peak areas related to the hydrogens of the epoxide groups located at chemical shifts of 2.9 ppm (monoepoxide) and 3.1 ppm (diepoxide) were used to determine the epoxy value. The quantification of the number of epoxides was carried out by 1 H NMR and the values obtained were correlated with epoxide content determined by the hydrochloric acid/acetone method. As a consequence, the correlation coefficient was R 2 = 0.9991 for the regression equation y = 0.0052 x + 1.7258, where x was the average integrated peak areas related to the hydrogens of the epoxide groups by 1 H NMR. The novelty of our study lies in the simultaneous correlation between IV and epoxy value obtained from conventional titrations, the integrated peak area related to olefinic protons, and the average integrated peak area located at the hydrogen of epoxide group, calculated using 1 H NMR. This approach is used to monitor and optimize the epoxidation reaction.
研究领域:
分析化学
·
高分子科学
·
有机化学
·
光谱学
·
化学反应工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Qing Wang,Xingyue Qian,Hui Xu,Guangyu He,Haiqun Chen
Exploring effective approach to promote more comprehensive charge transfer and efficient spatial charge separation is considered to be a prospective strategy to reinforce photocatalytic degradation activity. Herein, the oxygen vacancy modified Bi 2 WO 6 /NH 2 -MIL-68(In) Z-scheme heterojunction photocatalyst was successfully fabricated via a facile solvothermal method. The chemical structure, morphology, and optical properties of the photocatalyst were characterized in detail. The optimized Bi 2 WO 6 /NH 2 -MIL-68(In) Z-scheme heterojunction displayed the maximum photocatalytic efficiency (84.3 %) for the degradation of levofloxacin (LEV), which was significantly higher than that of pure Bi 2 WO 6 (45.1 %), oxygen vacancy modified Bi 2 WO 6 (69.4 %), and NH 2 -MIL-68(In) (49.3 %). Importantly, the high-resolution mass spectrometry (HRMS), three-dimensional excitation-emission matrix (3D EEMs) fluorescence spectra, the photo-electrochemical and photo-luminescence measurement, radical trapping test, and electron spin resonance (ESR) technique were carried out to illuminate the probable degradation pathway and mechanism of the LEV. The improved photocatalytic efficiency can be ascribed to the synergetic effect between oxygen vacancy and the Z-scheme heterojunction, which can serve as trapping centers to enhance the generation of photoexcited electrons and accelerate the charge transfer. Meanwhile, the effects of pH, photocatalyst dose, LEV concentration and different kinds of harmful organic pollutants were systematically explored from the practical application. This study offers a novel perspective for the integration of defect engineering and Z-scheme heterojunction in efficient organic pollutants degradation.
研究领域:
环境科学
·
材料化学
·
光催化
·
纳米技术
·
污染物降解
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）