APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Jishu Han,Fangxu Dai,Ying Liu,Ruiyang Zhao,Lei Wang,Shouhua Feng
The photocatalytic hydrogen production has become one of the most promising strategies to solve the energy crisis and environmental pollution. Novel CdSe/SrTiO 3 nanocomposites (average diameter ≈ 114.6 nm) with high photocatalytic activity are synthesized and used for visible light photocatalytic water splitting for hydrogen production . Through optimizing the concentration of CdSe QDs, CdSe/SrTiO 3 nanocomposites exhibit increased visible light absorption and enhanced photocatalytic hydrogen evolution efficiency compared to SrTiO 3 nanoparticles. The maximum H 2 evolution amount reaches to 3350.53 μmol in 8 h by using CdSe/SrTiO 3 -3 as catalyst. Owing to the formation of heterojunction at the interface between CdSe and SrTiO 3 , the electrochemical impedance spectrum of CdSe/SrTiO 3 -3 exhibits the smallest arc radius and the photocurrent density of CdSe/SrTiO 3 -3 reaches to 0.26 μA cm −2 . The photogenerated electrons are effectively separated and transferred and the recombination of electron-hole pairs is avoided, thus significantly improving the photocatalytic hydrogen production performance of CdSe/SrTiO 3 nanocomposites.
研究领域:
材料科学
·
物理化学
·
纳米催化
·
能源材料
·
光催化
✓ 已验证
DOI
高影响因子
IONICS
·
2019
·Vol. 25
·期 10
·4567-4576
·
IF 2.289
Xu Chun-Sheng,Yu Hai-Tao,Guo Chen-Feng,Xie Ying,Ren Ning,Yi Ting-Feng,Zhang Guo-Xu
To improve the stability and performance of the cathode materials, an ionic conductor layer was coated successfully on the surface of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 (LMNC) microspheres. The structural analysis confirmed that LiV 3 O 8 coating did not change the basic structure of LMNC, and all obtained materials are solid solutions with a good-layered structure and a good crystallinity. The microscopy measurement showed that the thickness of the coating layer for the LV-3 sample is about 2.5 nm. This appropriate layer is helpful for improving the surface stability of LMNC and the diffusion of lithium, leading to an obvious enhancement of the electrochemical performance. Our result confirmed that the average discharge specific capacities for LV-3 sample at 0.1 C, 0.2 C, 0.5 C, 1 C, and 3 C are respectively 265.9, 219.1, 188.0, 156.3, and 121.5 mAh g −1 , which are much larger than the values of other samples. After 50 cycles at a 1 C rate, the capacity retentions for different samples are 60.7%, 74.0%, 87.6%, and 70.4%, indicating that LV-3 sample exhibits the best performance. Furthermore, EIS measurements showed that the diffusion coefficient for LV-3 sample is calculated to be 1.26 × 10 −15 cm 2 s −1 , which is also the largest value among all considered samples. Our experiments identified that coating an ionic conductive layer on the cathode material surface will significantly improve their rate capacity and cycling stability.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态离子学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 45
·51348
·
IF 3.125
Junming Chen,Jinxuan He,Longquan Liu,Yongzhu He,Xiaobin Huang
Polymeric ablative materials (PAMs) are widely used in spacecraft currently for thermal insulation. However, it is challenging to find a single filler that can improve both ablative and mechanical properties of PAMs. In this study, a new type of hybrid cross-linked polyphosphazene microspheres (PHC) is added to ethylene propylene diene monomer (EPDM) composites as a filler for the first time and its influence on the ablation, mechanical, and thermal properties of EPDM is investigated. The results show that the addition of 3 phr PHC increases the ablation performance by about 10% and enhances the mechanical properties by 20% approximately. In addition, the ablation mechanism is studied in accordance with SEM, FTIR, and Raman spectroscopy. On the one hand, PHC has the effect of catalyzing carbonization, thus increasing the rate of residual carbon; on the other hand, PHC changes the morphology of the char layer, forming a cross-linked structure containing P─O─Si bonds on the surface. The findings regarding catalyzing carbonization and the special char layer structure could guide the design of ablative materials.
研究领域:
高分子材料
·
航天热防护
·
复合材料科学
·
材料化学
·
热力学
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2015
·Vol. 2015
·期 1
·371404
·
IF 1.644
Wei-Wen Li,Wei-Ming Ji,Yi Liu,Feng Xing,Yu-Kai Liu
This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT). In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt%) were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA) method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM), respectively. The experimental results showed that CNT/cement composite presented higher flexural strength index than that of a pure cement paste. Additional CNT could improve the vibration-reduction capacity of cement paste. Furthermore, the experiments proved that CNT could bridge adjacent hydration products and support load transfer within cement matrix, which contributed to the energy dissipation during the loading process.
研究领域:
材料科学
·
建筑材料
·
复合材料
·
土木工程材料
·
功能材料
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Lvlv Ji,Lei Zhu,Jianying Wang,Zuofeng Chen
A self-supported copper sulfide (CuS) nanowire array (NWA) of hierarchical and porous structure has been developed on Cu foil via two consecutive liquid-solid reactions at room temperature. The composition, structure and morphology of the as-prepared CuS NWA samples have been systematically investigated by a series of techniques. When applied as cathode for the hydrogen evolution reaction (HER) in neutral solution, the optimized CuS NWA electrode exhibits excellent HER performance with high long-term stability. To achieve current densities of 10 and 100 mA cm −2 , it requires overpotentials of only ∼97 and ∼226 mV, respectively. The excellent catalytic performance of CuS NWA toward HER is attributable to the binder-free electrode construction strategy, the unique porous nanowire array structure, and the small solubility product ( K sp ) value of CuS that guarantees the high catalyst stability.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2018
·
IF 2.687
Xue Chen,Ning Li,Yuan Li,Ping Che
In this work the CH 3 NH 3 PbI x Cl 3−x perovskite is obtained by applying vacuum-rotary evaporation procedure with a precursor solution of PbCl 2 and CH 3 NH 3 I in dimethylformamide. Thermal gravimetric and differential thermal analysis (TG-DTA) and the variable temperature powder X-ray diffraction ( in situ XRD) are employed to research the effect of thermal treatment on the decomposition and the crystal structure of perovskite . It is found that tetragonal to cubic phase transition in the typical perovskite disappears in mixed perovskite crystals because the stabilizing action of Cl. The excess Cl in the precursor leads to the intermediate structure CH 3 NH 3 PbCl 3 , and then transforms into CH 3 NH 3 PbI 3 with temperature increasing.
研究领域:
材料科学
·
无机化学
·
固体物理
·
能源材料
·
晶体学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·Vol. 43
·期 10
·2100-2107
·
IF 5.2
Jing Yan,Junyu Hong,Xiaohui Li,Bojana Milićević,Lei Zhou,Chunyan Jiang,Mingmei Wu
Nowadays, high-quality phosphor-converted white light-emitting diodes (pc-WLEDs) ought to include cyan-emitting phosphors allowing for full-spectrum light similar to sunlight. Herein, we report a garnet-structured Ce 3+ -doped SrLu 2 Ga 1.5 Al 2.5 SiO 12 (SLGASO) phosphor that significantly compensates for the absence of cyan light, known as the “cyan cavity”. The SLGASO host crystallizes into a cubic structure with the I a 3 ¯ d space group. The cell parameters were determined using Rietveld refinement. Under 430 nm blue excitation, SLGASO:Ce 3+ emits intense cyan-green light in the 450–700 nm wavelength range. The representative SLGASO:0.07Ce 3+ phosphor has an internal quantum efficiency (IQE) of 95.4% and excellent thermal stability, remaining 92.7% of its initial emission intensity at 152 °C. After 155 d of immersion in water, the luminous intensity of SLGASO:0.07Ce 3+ remains constant, confirming its waterproofness. Furthermore, a pc-WLED device with luminous efficiency (LE) of 101.58 lm/W, color rendering index ( Ra ) of 91, correlated color temperature (CCT) of 4536 K, and Commission Internationale de L'Eclairage (CIE) chromaticity coordinates of (0.3555, 0.3390) was fabricated by combining as-prepared cyan-green-emitting SLGASO:0.07Ce 3+ , yellow-emitting Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ), and red-emitting (Ca,Sr)AlSiN 3 :Eu 2+ phosphors, as well as a 450 nm blue chip. These findings indicate that SLGASO:0.07Ce 3+ phosphor can bridge the cyan gap and improve the performance of as-fabricated full-visible-spectrum WLEDs.
研究领域:
材料科学
·
光学材料
·
固态照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2015
·Vol. 41
·期 3
·1550-1558
·
IF 3.313
Meilin Lv,Shuang Ni,Zhuo Wang,Tongcheng Cao,Xiaoxiang Xu
Doping has generally been served as one of the most efficient strategies for the improvement of wide band gap semiconductor photocatalysts . However, atomic arrangements of doped elements in the host crystal structure have often been overlooked, particularly during the investigation and evaluation of dopant functionality. It is known that electronic structures of a semiconductor are profoundly controlled by atomic occupancies in different crystallographic positions. Knowledge about dopant accommodations in the crystal structure and their influence towards photocatalytic performance is highly desired. Here, we investigated four compositional and structural relevant compounds CrNbO 4 , CrTaO 4 , Sr 2 CrNbO 6 and Sr 2 CrTaO 6 with the aim to study the effects of cation ordering/disordering upon their photocatalytic activity . Our results showed that ordered cations, namely Cr and Nb/Ta, are detrimental to the photocatalytic performance. Theoretical calculations indicate that cation ordering would enlarge the band gap and inhibit charge transfer between Cr and Nb/Ta. Our findings imply that ordered dopants in photocatalytic materials would severely offset the benefits of doping and might be a reason for the decreased activity at high doping levels often encountered.
研究领域:
材料科学
·
半导体物理
·
光催化
·
固体化学
·
能源材料
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2016
·
IF 2.421
Changqing Fang,Xin Yu,Ruien Yu,Pei Liu,Xiaoting Qiao
Isocyanate modified asphalt samples were got by adding quantitative isocyanate into the base asphalt. Isocyanate and nano particles composite modified asphalt samples were produced by adding quantitative isocyanate and three different kinds of inorganic nanoparticles (Silicon dioxide, Titanium dioxide, Zinc oxide) into the base asphalt respectively. Isocyanate modified asphalt, isocyanate and nanoparticles composite modified asphalt were characterized by taking physical tests, SEM, fluorescence microscopy, TG and FTIR tests, which demonstrated that the high and low temperature performance of isocyanate and nano particles composite modified asphalt had been improved effectively. From the microscopic view, the modification of the base asphalt was very significant. Results also indicated that the temperature sensitivity of composite modified asphalt had been decreased. Meanwhile, the thermal stability had been improved when compared with the base asphalt and isocyanate modified asphalt.
研究领域:
材料科学
·
道路工程
·
高分子化学
·
纳米技术
·
应用化学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ruiyong Wang,Xiaohui Kang,Ruiqiang Wang,Rui Wang,Huanjing Dou,Jing Wu,Chuanjun Song,Junbiao Chang
The interactions between trypsin and caffeine/theophylline were investigated by fluorescence spectroscopy , UV–visible absorption spectroscopy , resonance light scattering and synchronous fluorescence spectroscopy under mimic physiological conditions . The results revealed that the fluorescence quenching of trypsin by caffeine and theophylline was the result of the formed complex of caffeine–trypsin and theophylline–trypsin. The binding constants and thermodynamic parameters at three different temperatures were obtained. The hydrophobic interaction was the predominant intermolecular forces to stabilize the complex. Results showed that caffeine was the stronger quencher and bound to trypsin with higher affinity than theophylline .
研究领域:
生物化学
·
分子药理学
·
药物代谢
·
蛋白质-配体相互作用
·
光谱学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Yan Liu,Hanpeng Gao,Shuyi Li,Zhiwu Han,Luquan Ren
Inspired by rose petals, a novel and facile method to prepare smart surface with controllable wettability for transfer and patterned storage of droplets was presented. The smart surface was obtained by alternately depositing PDDA and PSS on a copper substrate with mastoid structure prepared by laser processing. It was found that the wettability of the as-prepared copper surface can switch reversibly between superhydrophobic and superhydrophilic state. In addition, the as-prepared surface had excellent physical and chemical stability. In theory, our droplet storage platform can be processed into any size and shape to achieve different requirements for droplet storage. This study provides a simple route to fabricate bioinspired rewritable platform with reversibly switchable wettability for lossless transfer and patterned storage of droplets. It may be helpful for the development of the devices for droplet transfer and functionalized droplet storage. This method can also be applied to biodetection, microfluidic switching, and chemical microreaction.
研究领域:
表面科学
·
微流控
·
生物医学工程
·
功能材料
·
仿生学
·
分析化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 98
·55256-55262
·
IF 3.708
Zhijian Wu,Ya Xiong,Guoqiang Guan,Lingjun Kong,Shuanghong Tian
A new pyrolytic process was successfully used to prepare hollow-like spherical sludge chars (HSC). In the process, pre-formed cotton spheres with a low density were firstly coated by a layer of sludge paste containing ZnCl2 to form cotton fiber@sludge spheres and then pyrolyzed at 500 °C for 2 h. The resulting HSC possessed a diameter of about 3 mm, a low density of 0.1008 g cm−3 and a high surface area of 1008 m2 g−1. The column adsorption behavior showed that the adsorption capacity and rate constant of HSC for methylene blue reached 186.4 mg g−1 and 0.232 mL min−1 mg−1. The adsorption capacity is about 8.4 and 12 fold of the adsorption capacities of GAC (22.28 mg g−1) and SC (15.26 mg g−1), respectively, and the adsorption rate constant is about 1.3 fold of that of GAC and SC. The great adsorption capacity and rate constant can be considerably dependent on the special hollow-like spherical structure of HSC.
研究领域:
环境科学
·
材料科学
·
化学工程
·
污染控制
·
吸附技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）