| 1. |
- Feng, Peizhong, et al.
(författare)
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Combustion synthesis of (Mo1-xCrx)Si-2 (x=0.00-0.30) alloys in SHS mode
- 2012
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Ingår i: Advanced Powder Technology. - : Elsevier BV. - 0921-8831 .- 1568-5527. ; 23:2, s. 133-138
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Tidskriftsartikel (refereegranskat)abstract
- Combustion synthesis was adopted to successfully synthesize molybdenum-silicon-chromium (Mo-Si-Cr) alloys by the mode of self-propagating high-temperature synthesis (SHS). The experimental study of combustion synthesis of Mo-Si-Cr alloys was conducted on elemental powder compacts. Powder compacts with nominal compositions including MoSi2, (Mo0.95Cr0.05)Si-2, (Mo0.90Cr0.10)Si-2, (Mo0.85Cr0.15)Si-2, (Mo0.80Cr0.20)Si-2, (Mo0.75Cr0.25)Si-2 and (Mo0.20Cr0.30)Si-2 were employed in combustion synthesis experiments. The combustion mode, combustion temperature, flame-front propagation velocity and product structure were investigated. The results showed that Mo-Si-Cr alloys were synthesized by an unsteady state combustion mode with a spiral-trajectory reaction front. The peak combustion temperature reduced with the addition of Cr to Mo-Si system. The flame-front propagation velocity decreased with an increase in Cr content of the powder compact. The X-ray diffraction (XRD) results showed that the crystal structure of the combustion product changed from CIIb-type structure (Mo0.90Cr0.10)Si-2 to C40-type structure (Mo0.80Cr0.15)Si-2 with increase in Cr content of Mo-Cr-Si alloys. The intensities of diffraction peaks of the C40-type phase gradually increased with increase in Cr content.
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| 2. |
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| 3. |
- Gu, Xiuquan, et al.
(författare)
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ZnO based heterojunctions and their application in environmental photocatalysis
- 2016
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 27:40
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Forskningsöversikt (refereegranskat)abstract
- As an alternative to TiO2 photocatalysts, ZnO exhibits a large potential for photocatalytic (PC) applications in environmental treatments, such as degradation of wastewater, sterilization of drinking water, and air cleaning. However, the efficiency achieved with ZnO to date is far from that expected for commercialization, due to rapid charge recombination, photo-corrosion as well as poor utilization of solar energy. Fortunately, in recent years, a great number of breakthroughs have been achieved in PC performance (including activity and stability) of micro-/ nano-structured ZnO by forming heterojunctions (HJs) with metal nanoparticles (NPs), carbon nanostructures and other semiconductors. In most cases, the improvement of PC performance was ascribed to the better charge separation at the interfaces between ZnO and the other components. Sometimes, the formation of hybrids is also in favor of visible light harvesting. This review summarizes recent advances in the fields of environmental photocatalysis by ZnO based HJs, and especially emphasizes their abilities in degradation of organic pollutants or harmful substances in water. We aim to reveal the mechanism underlying the enhanced PC performance by constructing HJs, and extend the potential of ZnO HJ photocatalysts for future trends, and practical, large-scale applications in environment-related fields.
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| 4. |
- Wang, Xiaohong, et al.
(författare)
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Effects of tungsten and aluminum additions on the formation of molybdenum disilicide by mechanically-induced self-propagating reaction
- 2010
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 490:1, s. 388-392
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Tidskriftsartikel (refereegranskat)abstract
- The effects of tungsten and aluminum additions to Mo–Si system on the formation of MoSi2 by mechanically-induced self-propagating reaction in a high-energy ball mill were investigated by X-ray diffraction. The incubation time for mechanically-induced self-propagating reaction to form MoSi2 was 90 min in Mo–Si system. With the addition of tungsten to Mo–Si system, the incubation time of mechanically-induced self-propagating reaction of (Wx,Mo1−x)Si2 system was prolonged. It was due to the decrease of adiabatic temperature with increase in x, and the mechanically-induced self-propagating reaction was not observed until 150 min of high-energy milling in (Wx,Mo1−x)Si2 powder sample with x equals to 0.4. Conversely, the minor aluminum (y < 0.2 in Mo(Si1−y,Aly)2 system) substituting for silicon had shorten the incubation period and accelerated the reaction. When tungsten and aluminium were added simultaneously to Mo–Si system, the mechanically-induced self-propagating reaction was observed in (W0.1,Mo0.9)(Si0.9,Al0.1)2 sample, but it was not observed in (W0.2,Mo0.8)(Si0.8,Al0.2)2 and (W0.3,Mo0.7)(Si0.7,Al0.3)2 samples.
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