Microplastics (MPs) are distributed in a wide range of aquatic and terrestrial ecosystems throughout the planet. They are known to adsorb hazardous substances and can transfer them across the trophic web. To eliminate...
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Microplastics (MPs) are distributed in a wide range of aquatic and terrestrial ecosystems throughout the planet. They are known to adsorb hazardous substances and can transfer them across the trophic web. To eliminate MPs pollution in an environmentally friendly process, we propose using a photocatalytic process that can easily be implemented in wastewater treatment plants (WWTPs). As photocatalysis involves the formation of reactive species such as holes (h(+)), electrons (e(-)), hydroxyl (OH?), and superoxide ion (O-2(?-)) radicals, it is imperative to determine the role of those species in the degradation process to design an effective photocatalytic system. However, for MPs, this information is limited in the literature. Therefore, we present such reactive species' role in the degradation of high-density polyethylene (HDPE) MPs using c,N-TiO2. Tert-butanol, isopropyl alcohol (IPA), Tiron, and cu(NO3)(2) were confirmed as adequate OH?, h(+), O-2(?-) and e(-) scavengers. These results revealed for the first time that the formation of free OH? through the pathways involving the photogenerated e(-) plays an essential role in the MPs' degradation. Furthermore, the degradation behaviors observed when h(+) and O-2(?-) were removed from the reaction system suggest that these species can also perform the initiating step of degradation.
The surface microstructural evolution, mechanical properties and ablation behaviors of nitrogen-doped c/c-ZrcSiccomposites by hot isostatic pressing(HIP) have been studied via multiple-characterizations. Results show...
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The surface microstructural evolution, mechanical properties and ablation behaviors of nitrogen-doped c/c-ZrcSiccomposites by hot isostatic pressing(HIP) have been studied via multiple-characterizations. Results show that the post-treatment of nitridation has significant effects on mechanical strength with grain refinement by virtue of in-situ SEM observations. After nitridation, the dense nano-grained ZrO/Zr2O and Si3N4 ceramics are generated on the top layer. Besides, the evident carbon nanowires exist at boundary of Sic-Si3N4 phases. The ZrN/Si3N4 eutectic structures are also detected with the transformation of ZrSi phase. What's more, the ablation-resistant performances are strikingly improved after nitridation-treatment with the highly compact multi-oxide scales obtained.
To obtain unbroken sulfides with delicate morphology from metal-organic frameworks (MOFs), a method for in situ growth of SiO2 protective layers on the surface of MOFs is proposed. This strategy can be successfully ex...
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To obtain unbroken sulfides with delicate morphology from metal-organic frameworks (MOFs), a method for in situ growth of SiO2 protective layers on the surface of MOFs is proposed. This strategy can be successfully expanded to a variety of MOFs (ZIF-67, cu-MOF, ZIF-8, and PBA). Importantly, room-temperature Na-SeS2 batteries with co9S8@SiO2/c prepared from ZIF-67 as cathode host are assembled. Due to the hollow structure that can relieve the volume expansion and the co-adsorption of sodium polysulfides/sodium polyselenides by co9S8@SiO2/c, the SeS2/co9S8@SiO2/ccathode shows excellent rate performance and coulombic efficiency. In addition, ex situ X-ray diffraction and in situ Raman results show that S-8 and Se-8 are generated after the discharge of SeS2, and Se-8 is preferentially oxidized during charging.
The influence of cr and Al content on the oxidation behaviour of Fecr(Al) model alloys after breakaway oxidation at 600 degrees c and the underlying mechanisms were investigated in detail with thermogravimetrical anal...
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The influence of cr and Al content on the oxidation behaviour of Fecr(Al) model alloys after breakaway oxidation at 600 degrees c and the underlying mechanisms were investigated in detail with thermogravimetrical analysis (TGA), thermodynamiccalculations and advanced electron microscopy. The results showed that a crcontent of >18 wt% drastically reduced the growth rate of the Fe-rich oxide scale, formed after breakaway oxidation, for FecrAl alloys but not for Fecr alloys. This was attributed to the ability of the Fe(18-25)crAl alloys to prevent internal oxidation, which enables the formation of a healing layer.
We demonstrated the efficient coupling of BiFeO3 (BFO) ferroelectric material within the carbon-sulfur (c-S) composite cathode, where polysulfides are trapped in BFO mesh, reducing the polysulfide shuttle impact, and ...
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We demonstrated the efficient coupling of BiFeO3 (BFO) ferroelectric material within the carbon-sulfur (c-S) composite cathode, where polysulfides are trapped in BFO mesh, reducing the polysulfide shuttle impact, and thus resulting in an improved cyclic performance and an increase in capacity in Li-S batteries. Here, the built-in internal field due to BFO enhances polysulfide trapping. The observation of a difference in the diffusion behavior of polysulfides in BFO-coupled composites suggests more efficient trapping in BFO-modified c-S electrodes compared to pristine c-S composite cathodes. The X-ray diffraction results of BFO-c-S composite cathodes show an orthorhombic structure, while Raman spectra substantiate efficient coupling of BFO in c-S composites, in agreement with SEM images, showing the interconnected network of submicron-size sulfur composites. Two plateaus were observed at 1.75 V and 2.1 V in the charge/discharge characteristics of BFO-c-S composite cathodes. The observed capacity of ~1600 mAh g(-1) in a 1.5-2.5 V operating window for BFO30-c-10-S-60 composite cathodes, and the high cyclic stability substantiate the superior performance of the designed cathode materials due to the efficient reduction in the polysulfide shuttle effect in these composite cathodes.
Herein, pulsed Dc sputtering of the AlN film on top of the Si (111) substrate is reported on. First, major articles on the reactive sputtering of AlN film on top of Si (111) substrate that were published in the past 3...
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Herein, pulsed Dc sputtering of the AlN film on top of the Si (111) substrate is reported on. First, major articles on the reactive sputtering of AlN film on top of Si (111) substrate that were published in the past 30 years are tabulated. Then, a sputtering recipe to produce a consistent and high-crystal-quality (as measured by the full width at half maximum [FWHM] of rocking curve) AlN film across varying substrate temperatures (250-450 degrees c) and sputtering powers (1200-2400 W) is proposed. In addition, the influence of both parameters to in-plane stress is demonstrated, in agreement with similar trends that have been reported in the literature for AlN films on other substrates. The best sample is produced at a substrate temperature of 350 degrees c and sputtering power of 1800 W, resulting in FWHM of rocking curve of 1.84 degrees, surface roughness of 1 nm, and in-plane stress of +300 MPa. The recipe herein is beneficial for integration of AlN thin film in complementary metal-oxide-semiconductor and micro-electromechanical system processes.
作者：
Razaq, IramSimons, Keith E.Onwudili, Jude A.Aston Univ
Energy & Bioprod Res Inst Coll Engn & Phys Sci Birmingham B4 7ET W Midlands England SHV Energy
Sustainable Fuels NL-2132 JL Hoofddorp Netherlands Aston Univ
Dept Chem Engn & Appl Chem Coll Engn & Phys Sci Birmingham B4 7ET W Midlands England
Sustainable fuel-range hydrocarbons can be produced via the catalytic decarboxylation of biomass-derived carboxylic acids without the need for hydrogen addition. In this present study, 5 wt% platinum on carbon (Pt/c) ...
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Sustainable fuel-range hydrocarbons can be produced via the catalytic decarboxylation of biomass-derived carboxylic acids without the need for hydrogen addition. In this present study, 5 wt% platinum on carbon (Pt/c) has been found to be an effective catalyst for hydrothermally decarboxylating butyric acid in order to produce mainly propane and carbon dioxide. However, optimisation of the reaction conditions is required to minimise secondary reactions and increase hydrocarbon selectivity towards propane. To do this, reactions using the catalyst with varying parameters such as reaction temperatures, residence times, feedstock loading and bulk catalyst loading were carried out in a batch reactor. The highest yield of propane obtained was 47 wt% (close to the theoretical decarboxylation yield of 50 wt% on butyric acid basis), corresponding to a 96% hydrocarbon selectivity towards propane. The results showed that the optimum parameters to produce the highest yield of propane, from the range investigated, were 0.5 g butyric acid (0.57 M aqueous solution), 1.0 g Pt/c (50 mg Pt content) at 300 degrees c for 1 h. The reusability of the catalyst was also investigated, which showed little or no loss of catalytic activity after four cycles. This work has shown that Pt/c is a suitable and potentially hydrothermally stable heterogeneous catalyst for making biopropane, a major component of bioLPG, from aqueous butyric acid solutions, which can be sourced from bio-derived feedstocks via acetone-butanol-ethanol (ABE) fermentation.
Microstructural evolution of silicon-modified aluminide coating during 10,000 h aging at 650 degrees c was systematically investigated. Upon aging, the coating was gradually transformed from a multilayered structure t...
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Microstructural evolution of silicon-modified aluminide coating during 10,000 h aging at 650 degrees c was systematically investigated. Upon aging, the coating was gradually transformed from a multilayered structure to a double-layer structure, with the matrixes of Al-Fe-Si compounds and beta-(Fe, Ni)Al in the two layers, respectively. An internal oxide layer formed below the coating, while the thickness of interdiffusion zone (IDZ) increased as the inward diffusion of Al. Precipitate evolutions in both the coating and the IDZ were discussed, which clarifies the microstructural origin of long-term stability of the coating. The phase evolution of Al-Si coating in prolonged aging was further discussed.
In chemical liquid vapor deposition (cLVD) technique, carbon preform density is a crucial factor to control the microstructure of c/c-Zrc-Siccomposites, which also determines the ablation resistance. The effects of p...
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In chemical liquid vapor deposition (cLVD) technique, carbon preform density is a crucial factor to control the microstructure of c/c-Zrc-Siccomposites, which also determines the ablation resistance. The effects of preform density on the microstructure and ablation behavior of cLVD-c/c-Zrc-Siccomposites were studied. Results demonstrated the composites prepared from the preform with a density of 0.91 g/cm(3) showed a dense microstructure and proper ceramiccontent. Under an oxyacetylene flame, the composites displayed an excellent ablation resistance. The good ablation resistance was ascribed to the proper preform density, which promoted the formation of uniform and continuous protective layer of ZrO2-SiO2.
Needle optimization is widely used in visible and infrared region, but it is rarely utilized in X-ray and extreme ultraviolet waveband. We use Needle optimization to design Pt/c X-ray supermirrors, and the grazing inc...
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Needle optimization is widely used in visible and infrared region, but it is rarely utilized in X-ray and extreme ultraviolet waveband. We use Needle optimization to design Pt/c X-ray supermirrors, and the grazing incidence angles are 1.0, 1.4, and 1.7 degree, respectively. A modified target is introduced into optilayer software. A good result is obtained by Optilayer software combined with IMD software. The difference of design results between block method and needle optimization is discussed.
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