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51.
《Ceramics International》2022,48(15):21988-21995
Bi4O5Br2/MnxZn1-xFe2O4 nanocomposites with impressive photocatalytic and recyclability properties were synthesised using a microemulsion method. In addition to the photocatalytic effect, the crystal structure and morphology, photoelectrochemical characteristics, magnetic effect and photocatalytic mechanism of Bi4O5Br2/MnxZn1-xFe2O4 were also investigated. As the best sample, the removal rate of the Bi4O5Br2/MnxZn1-xFe2O4 photocatalyst with 7.5 wt% MnxZn1-xFe2O4 to rhodamine B (RhB) reached up to 99.4% within 60 min. The enhanced photocatalyst activity was mainly attributed to the type-II heterojunction formed between Bi4O5Br2 and MnxZn1-xFe2O4, which not only optimised the energy band structure, but also led to the building of an interior electromagnetic field within the Bi4O5Br2/MnxZn1-xFe2O4 heterojunction. Meanwhile, the constantly producing and migrating h+ and ·O2? were the main active components. In particular, the results of the saturation magnetization tests and magnetic recovery experiments revealed that the magnetic composite photocatalyst can be recovered effectively. The results of the removal rate of RhB remaining at 85.2% after five uses reflected the advantages of the stability of the Bi4O5Br2/MnxZn1-xFe2O4 photocatalyst. In brief, this paper presented an original idea to develop a novel composite magnetic photocatalyst and research the enhancement mechanism of photocatalysis. 相似文献
52.
The capture of particles by charged droplets was simulated by considering the electrostatic interactions of droplet-droplet and droplet-particle. The results indicate that the electrostatic repulsion between droplets leads to a dynamic accumulation mode of particles. However, the droplet spacing has an insignificant effect on the capture efficiency when the electrostatic deposition predominates. The increase of droplet charge remarkably improves the capture efficiency, in which the capture of fine particles accounts for the largest proportion. Compared to the droplet charge, the droplet size shows a limited improvement in the capture efficiency. Reducing the droplet velocity prolongs the capture time instead of enhancing the capture capacity per unit time, thereby improving capture efficiency. 相似文献
53.
为解决大直径且齿宽较宽的分段式齿圈的铣齿问题,提出采用偏心放置的主程序调用子程序循环加工的铣齿方法。根据主程序数学模型和子程序数学模型构建偏心放置铣齿方法的数学模型,基于VERICUT的仿真模型和仿真主、子程序,实现齿槽的开粗和精铣仿真加工;通过VERICUT对比分析功能模块,以齿面残留模型为依据,验证了偏心放置铣齿方法的可行性。 相似文献
54.
《Ceramics International》2022,48(12):16997-17008
Effective design and fabrication of novel visible light-oriented photocatalysts is an existing challenging task that requires further dedicated efforts, and it has been always a main concern among the scientific community. This study deals with the design and fabrication of an extremely active and ultrafast ternary photocatalyst based on Ag nanoparticles, polypyrrole doped carbon black (PPy-C) and mesoporous TiO2 (m-TiO2). Sol-gel methodology along with sonication and photodeposition routes have been employed for the successful creation of the ternary framework. Ternary photocatalyst composed of uniform spherical titania nanoparticles (10–15 nm in size) perfectly intermingled with the polymeric linkage of PPy-C. Fruitful creation of unique trio photocatalyst between AgNPs, PPy-C and m-TiO2 was confirmed by XPS and XRD. FTIR analysis further supports the development of nanocomposite photocatalyst. TEM analysis showed uniform spherical m-TiO2 nanoparticles (10–15 nm in size) covered by PPy-C with compact nodes like appearance interlocked very well among each other. The newly developed Ag@PPy-C/m-TiO2 ternary photocatalyst exhibited band gap energy in desired visible range of spectra. The photocatalytic efficiency for all created photocatalysts has been evaluated taking Imidacloprid (insecticide derivative) and methylene blue (MB) dye as target pollutants. The novel Ag@PPy-C/m-TiO2 photocatalyst produced astonishing results with ultrafast removal of both Imidacloprid as well MB dye under visible light irradiation. The newly created ultrafast Ag@PPy-C/m-TiO2 photocatalyst has removed 96.0% of the insecticide Imidacloprid in only 25 min with almost ? 2.65 times more efficient than bare m-TiO2 towards the removal of insecticide derivative. The present report offers a highly encouraging and vastly talented Ag@PPy-C/m-TiO2 ternary photocatalyst, enabling the ideal management of extremely lethal and notorious chemicals. 相似文献
55.
《Ceramics International》2022,48(9):12112-12117
Gallium oxide (Ga2O3) is a promising candidate for next-generation solar-blind photodetectors (PDs) because of its large bandgap of 4.9 eV. Its single-crystal nanorod structure improves its photoelectric performance, which promotes carrier transformation and separation. However, Ga2O3 nanorods fabricated by the hydrothermal method have many oxygen vacancies, which largely enhance the dark current and reduce the on/off ratio of PDs, restricting application of such devices. Therefore, in this paper, dual strategies are applied to reduce the dark current of a metal–semiconductor–metal-structured Ga2O3 nanorod PD fabricated by the hydrothermal method. Through these dual strategies, which include annealing treatment and the application of a polymethyl methacrylate (PMMA) coating, the dark current of the PD is reduced from 1.34 × 10?7 to 2.04 × 10?9 A at 1 V, resulting in the on/off ratio of the PD reaching as high as 3.24 × 104. Besides, the responsivity and detectivity of the device reach 1.73 A/W and 2.53 × 1012 Jones respectively, which represents better performance than those of other reported Ga2O3 nanorod array PDs. Results have shown that the new strategy adopted can greatly improve the performance of Ga2O3-based ultraviolet photodetectors. 相似文献
56.
Chengcong Zhang 《Science & Technology of Welding & Joining》2018,23(5):394-399
The longitudinal residual stresses in the friction stir-welded plates of 5A06 aluminium and pure copper were determined using the contour method. The results revealed the presence of high tensile and compressive residual stresses on the aluminium and copper sides, respectively. The residual stresses were detected on the weld zone as well as the thermo-mechanically affected zone (TMAZ) of the aluminium plate. In contrast, the compressive residual stresses in the copper plate had a much narrower width along the weld line. Peak tensile stresses up to 240?MPa were found in the TMAZ of the aluminium plate. 相似文献
57.
The process of cemented carbides manufacturing requires rapid and field elemental analytical techniques to control and evaluate the properties of products. Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is such a potential elemental analytical technique. In this work, a portable LIBS instrument combined with a CF method was developed for the analysis of cemented carbides. Three batches of cemented compact carbides without reference samples were analyzed. Qualitative and quantitative analysis of the samples were achieved by using the portable LIBS instrument combined with CF method. To validate the analysis results, X-ray fluorescence spectrometry (XRF) was used to analyze the samples as well. The results of CF-LIBS agreed well with the results of XRF, with relative errors between ?29.53 and 24.70%. The results demonstrated that the portable LIBS instrument combined with CF method was capable for direct and rapid analysis without any need of standard measurements. Notably, with the portable LIBS instrument combined with CF method, acceptable accuracy could be obtained, which is promising for practical field applications. 相似文献
58.
《Calphad》2020
In this study, the Ga–Te binary system was reassessed by means of the CALPHAD method using a modified lattice stability parameter for Te as well as experimental data for this binary system. The two-sublattice ionic solution model was applied for the liquid phase, and the intermediate phases were described by the sublattice model. A set of self-consistent thermodynamic parameters was optimized for all the phases in the Ga–Te binary system, which reproduced the phase diagram and the thermodynamic properties well. Using the reevaluated Ga–Te system, previously assessed Ga–Se system, and modified Se–Te system, a critical evaluation of the Ga–Se–Te ternary system was performed. The calculated vertical sections, isothermal sections, and liquidus projection agreed reasonably well with the experimental data. Immiscibility in the liquid phase was observed, and the origin of this behavior is discussed from a thermodynamic perspective. 相似文献
59.
60.
Devendrasinh Darbar M.R. Anilkumar Vijayaraghavan Rajagopalan Indranil Bhattacharya Hendry Izaac Elim T. Ramakrishnappa F.I. Ezema Rajan Jose M.V. Reddy 《Ceramics International》2018,44(5):4630-4639
Optimization of electrodes for charge storage with appropriate processing conditions places significant challenges in the developments for high performance charge storage devices. In this article, metal cobaltite spinels of formula MCo2O4 (where M = Mn, Zn, Fe, Ni and Co) are synthesized by oxalate decomposition method followed by calcination at three typical temperatures, viz. 350, 550, and 750 °C and examined their performance variation when used as anodes in lithium ion batteries. Phase and structure of the materials are studied by powder x-ray diffraction (XRD) technique. Single phase MnCo2O4,ZnCo2O4 and Co3O4 are obtained for all different temperatures 350 °C, 550 °C and 750 °C; whereas FeCo2O4 and NiCo2O4 contained their constituent binary phases even after repeated calcination. Morphologies of the materials are studied via scanning electron microscopy (SEM): needle-shaped particles of MnCo2O4 and ZnCo2O4, submicron sized particles of FeCo2O4 and agglomerated submicron particle of NiCo2O4 are observed. Galvanostatic cycling has been conducted in the voltage range 0.005–3.0 V vs. Li at a current density of 60 mA g?1 up to 50 cycles to study their Li storage capabilities. Highest observed charge capacities are: MnCo2O4 – 365 mA h g?1 (750 °C); ZnCo2O4 – 516 mA h g?1 (550 °C); FeCo2O4 – 480 mA h g?1 (550 °C); NiCo2O4 – 384 mA h g?1 (750 °C); and Co3O4 – 675 mA h g?1 (350 °C). The Co3O4 showed the highest reversible capacity of 675 mA h g?1; the NiO present in NiCo2O4 acts as a buffer layer that results in improved cycling stability; the ZnCo2O4 with long needle-like shows good cycling stability. 相似文献