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101.
Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media. 相似文献
102.
Xiaoqing Si Jian Cao Sheng Liu Xiaoguo Song Junlei Qi Yongxian Huang Jicai Feng 《International Journal of Hydrogen Energy》2018,43(5):2977-2989
A novel low-temperature sealing method was developed to seal solid oxide fuel cells. The 3D Ni nanosheet array was pre-fabricated on faying surfaces of Crofer22APU interconnect and NiO-YSZ anode-support. Then it was covered with Au film without changing its morphology. This special nanostructure improved sintering efficiency between Ag nanoparticles and substrates. A dense joint was obtained at the low-temperature between 250 °C–300 °C. This method effectively avoided the oxidation of interconnect during sealing. When joints were sealed at 300 °C, the shear strength reached 16 MPa. The fracture was mainly located in the central Ag layer, presenting a significant plastic deformation. Due to the effective protection of Ni layer, joints also possessed excellent oxidation resistance in oxidizing atmosphere at 800 °C for 400 h. After high-temperature oxidation, the shear strength was increased to 23 MPa, revealing an increasement of 43.8% compared with the as-sealed condition (16 MPa). This sealing method has great potential in sealing solid oxide fuel cells. It also can be extended to seal other energy-conversion devices. 相似文献
103.
Xin Xie Yunhua Yang Yong-Hao Xiao Xiaomo Huang Qingshan Shi Wei-De Zhang 《International Journal of Hydrogen Energy》2018,43(14):6954-6962
Owing to its up-conversion photoluminescence, photo-induced electron transfer property, and excellent conductivity, carbon quantum dots (CQDs) have been established as effective sensitizers in combination with Fe2O3 nanowires for enhancing the catalytic activity of photoelectrochemical water oxidation. In comparison to pristine Fe2O3 nanowires, Fe2O3 nanowires decorated with CQDs demonstrate 27 orders of magnitude increase in photocurrent density at 0.23 V vs. Ag/AgCl. The mechanism of enhanced photoelectrochemical activity of CQDs/Fe2O3 composite was also investigated. Thereby, it is confirmed that the enhanced optical absorption, accelerated interfacial charge carrier transfer and effective separation of photogenerated electron-hole pairs induced by CQDs decoration account for the enhancement of CQDs/Fe2O3 nanowire arrays in photoelectrochemical application. 相似文献
104.
Fluorescence‐Activated Cell Sorters: Standing Surface Acoustic Wave (SSAW)‐Based Fluorescence‐Activated Cell Sorter (Small 40/2018) 下载免费PDF全文
105.
Xiuhui Huang Junfeng Li Jun Wang Zeqiu Li Jiayin Xu 《Frontiers of Chemical Science and Engineering》2020,14(4):534
In the last decades, many reports dealing with technology for the catalytic combustion of methane (CH4) have been published. Recently, attention has increasingly focused on the synthesis and catalytic activity of nickel oxides. In this paper, a NiO/CeO2 catalyst with high catalytic performance in methane combustion was synthesized via a facile impregnation method, and its catalytic activity, stability, and water-resistance during CH4 combustion were investigated. X-ray diffraction, low-temperature N2 adsorption, thermogravimetric analysis, Fourier transform infrared spectroscopy, hydrogen temperature programmed reduction, methane temperature programmed surface reaction, Raman spectroscopy, electron paramagnetic resonance, and transmission electron microscope characterization of the catalyst were conducted to determine the origin of its high catalytic activity and stability in detail. The incorporation of NiO was found to enhance the concentration of oxygen vacancies, as well as the activity and amount of surface oxygen. As a result, the mobility of bulk oxygen in CeO2 was increased. The presence of CeO2 prevented the aggregation of NiO, enhanced reduction by NiO, and provided more oxygen species for the combustion of CH4. The results of a kinetics study indicated that the reaction order was about 1.07 for CH4 and about 0.10 for O2 over the NiO/CeO2 catalyst. 相似文献
106.
107.
Yifei Wang Shouying Huang Xinsheng Teng Hongyu Wang Jian Wang Qiao Zhao Yue Wang Xinbin Ma 《Frontiers of Chemical Science and Engineering》2020,14(5):802
The Fischer–Tropsch synthesis (FTS) continues to be an attractive alternative for producing a broad range of fuels and chemicals through the conversion of syngas (H2 and CO), which can be derived from various sources, such as coal, natural gas, and biomass. Among iron carbides, Fe2C, as an active phase, has barely been studied due to its thermodynamic instability. Here, we fabricated a series of Fe2C embedded in hollow carbon sphere (HCS) catalysts. By varying the crystallization time, the shell thickness of the HCS was manipulated, which significantly influenced the catalytic performance in the FTS. To investigate the relationship between the geometric structure of the HCS and the physic-chemical properties of Fe species, transmission electron microscopy, X-ray diffraction, N2 physical adsorption, X-ray photoelectron spectroscopy, hydrogen temperature-programmed reduction, Raman spectroscopy, and Mössbauer spectroscopy techniques were employed to characterize the catalysts before and after the reaction. Evidently, a suitable thickness of the carbon layer was beneficial for enhancing the catalytic activity in the FTS due to its high porosity, appropriate electronic environment, and relatively high Fe2C content. 相似文献
108.
同步器齿环与碳纤维耐摩擦材料是通过胶粘剂实现粘接,而胶粘剂耐高温性能的优劣则是决定其使用寿命的决定性因素。本文研究了环氧树脂E-51体系、环氧树脂AG80体系以及基材表面处理工艺对于结构胶膜耐高温性能的影响,采用熔融共混法制备了胶粘剂并以玻璃纤维布为背衬制备了耐高温结构胶膜。采用高低温拉力机对不同体系制备的结构胶膜进行了常温、200℃高温的钢材搭接剪切强度的测试。结果表明,对于E-51体系,提高体系交联密度可显著增大常温剪切强度,但高温剪切强度明显下降;对于四官能度的AG80体系,AG80的用量是影响其高温性能的主要因素,同时基材表面喷砂水洗处理后可显著增大结构胶膜与基材粘接有效面积,进而显著改善高温性能。所制备的结构胶膜较常用胶粘剂使用更加便捷,耐高温性能优良,满足同步器齿环使用要求。 相似文献
109.
110.