In this work, CuO-TiO2 nanoparticles with different CuO mass contents of 2%, 8%, 12%, and 20% are synthesized by flame spray pyrolysis (FSP) method and applied to catalytic combustion of lean CO. The nano-catalyst is characterized by N-2-physisorption isotherms, X-ray diffraction (XRD), transmission electron microscopy (TEM), H-2-TPR (temperature-programmed reduction) and X-ray photoelectron spectroscopy (XPS). All the catalysts possess a high specific surface area, of which the CuO-TiO2 nanoparticles with 2 wt.% Cu (2CT) is as high as 98 m(2)/g, and exhibits a spherical structure with a diameter of 15-20 nm. Compared with other methods, the FSP method can significantly improve the loading of CuO without producing large crystalline CuO particles on the catalyst surface. Interestingly, the addition of CuO will essentially change the lattice structure of TiO2 for all catalysts, including its crystal spacing and XRD diffraction angle. Copper cations are embedded in TiO2 lattice to promote the transformation from anatase to rutile by producing oxygen defect at high flame temperature. The interaction between CuO and TiO2 has significant influence on its physicochemical properties. A lower onset reduction temperature on the sample with higher CuO loading is obtained due to the hydrogen spillover effect in H-2 -TPR test. Moreover, the loaded CuO increases the content of more stable rutile phase in the materials, so that it reduces the strong metal-support interaction (SMSI) effect of CuO and anatase phase to improve the properties of CO catalytic combustion. The synthesized CuO-TiO2 nanoparticles can achieve complete combustion conversion of lean CO at lower temperature of 120 degrees C. (C) 2018 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Lithium sulfide (Li2S) provides a promising route for lithium storage due to high theoretical specific capacity (1166 mAh g(-1)). The electrochemical performance of Li2S can be significantly enhanced by forming Li2S-carbon composites with the introduction of carbon. However, the complex synthesis method of Li2S carbon composites restrains the large-scale productivity. Herein, we propose a facile route to prepare carbon coated Li2S-carbon nanotube composites (Li2S@C-CNT) via spray drying and heat treatment, which is a low-cost and large-scale method for facile synthesis of Li2S-carbon composites. For the Li2S@C-CNT composites, Li2S nanoparticles are contacted with surrounding particles due to the 3D CNTs framework. The novel construction not only suppresses the diffusion of polysulfides during cycling, but also remarkably accelerates the transport of electron and ion, resulting in a high specific capacity (1100 mAh g(-1)) and good cycling performance. The rational designed architecture and good electrochemical performance of Li2S@C-CNT will pave the avenue for realizing high energy density of Li2S-based batteries. (C) 2018 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Current laser-plasma interaction theory supports that the plasma energy e.g. electron temperature would increase by the effect of inverse bremsstrahlung (IB) absorption, when a laser beam passed through the plasma. However, in this paper, we found an interesting laser cooling arc plasma effect (LCAPE) during kilo-Watt fiber laser-TIG hybrid welding. Based on theoretical modelling and experiments, we observed that a temperature decrease of more than 5000 K at the tail of the argon plasma occurred under different process parameters during hybrid welding of 316L stainless steel. We proposed the LCAPE is caused by the laser-induced metal vapor. The mechanism mainly includes the convection cooling and enhanced radiation of the arc plasma by the metal vapor. Our findings could broaden the theory of laser-plasma interaction and provide a theoretical reference to the modulation and control of plasma in industries. (C) 2018 Elsevier Ltd. All rights reserved.

In order to identify the effect of ultra-fine transition metal catalyst on the in-situ combustion of heavy oil, thermal analysis and isoconversional method were used to evaluate the burning oxidation kinetics of three ultra-fine transition metal particles—NiO, α·Fe2O3 and Co3O4. And then, one-dimensional in-situ combustion experiment was carried out by the optimized catalyst. The experimental results showed that, in the presence of Co3O4, the activation energy of heavy oil decreased the most, up to 41.7 %. Meanwhile, Co3O4 had higher catalytic activity, that made it suitable for in-situ combustion experiment. Compared to conventional in-situ combustion, high temperature oxidation reaction of crude oil was enhanced under the catalytic condition of Co3O4. The oxygen utilization ratio increased by 6.79 %, the combustion time shortened by 11.8 %, the average temperature of the leading edge of combustion increased by 20 ℃, the maximum temperature difference of the leading edge of combustion reduced by 4 ℃, the combustion was more stable, the advance speed of the leading edge increased by 0.042 cm/min, the final oil displacement efficiency increased by 5.7 %, and the viscosity reduction rate of the produced oil increased by 7.2 %. The research results have important guiding significance for expanding the application of heavy oil recovery by in-situ combustion.

Sulfurized polyacrylonitrile is suggested to contain S n ( n ≤ 4) and shows good electrochemical performance in carbonate electrolytes for lithium sulfur batteries. However inferior results in ether electrolytes suggest that high solubility of Li 2 S n ( n ≤ 4) trumps the limited redox conversion, leading to dissolution and shuttling. Here, we introduce a small amount of selenium in sulfurized polyacrylonitrile to accelerate the redox conversion, delivering excellent performance in both carbonate and ether electrolytes, including high reversible capacity (1300 mA h g −1 at 0.2 A g −1 ), 84% active material utilization and high rate (capacity up to 900 mA h g −1 at 10 A g −1 ). These cathodes can undergo 800 cycles with nearly 100% Coulombic efficiency and ultralow 0.029% capacity decay per cycle. Polysulfide dissolution is successfully suppressed by enhanced reaction kinetics. This work demonstrates an ether compatible sulfur cathode involving intermediate Li 2 S n ( n ≤ 4), attractive rate and cycling performance, and a promising solution towards applicable lithium-sulfur batteries.

Solar RRLVolume 2, Issue 12 1870234 Cover PictureFree Access Simultaneous Control over Lattice Doping and Nanocluster Modification of a Hybrid CuOx/TiO2 Photocatalyst during Flame Synthesis for Enhancing Hydrogen Evolution (Solar RRL 12∕2018) Fan Yang, Fan Yang State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorMenglei Liu, Menglei Liu State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorXin Chen, Xin Chen State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorZuwei Xu, Corresponding Author Zuwei Xu xuzw@hust.edu.cn State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorHaibo Zhao, Corresponding Author Haibo Zhao hzhao@hust.edu.cn State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this author Fan Yang, Fan Yang State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorMenglei Liu, Menglei Liu State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorXin Chen, Xin Chen State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorZuwei Xu, Corresponding Author Zuwei Xu xuzw@hust.edu.cn State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this authorHaibo Zhao, Corresponding Author Haibo Zhao hzhao@hust.edu.cn State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. China China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074 P. R. ChinaSearch for more papers by this author First published: 06 December 2018 https://doi.org/10.1002/solr.201870234Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract In article no. 1800215, Zuwei Xu, Haibo Zhao, and co-workers discuss flame spray pyrolysis technology, which they believe paves a way for the large-scale production of highly efficient photocatalysts for sunlight-driven water splitting hydrogen evolution. Citing Literature Volume2, Issue12December 20181870234 RelatedInformation

Noble metal‐free hybrid photocatalysts have recently been extensively studied for their applications in the environment and energy field. However, rational design over these photocatalysts is still a challenging task because the detailed mechanism of multi‐component catalysts is not well understood yet. Here, we highlight a state‐of‐the‐art approach, one‐step flame spray pyrolysis (FSP), for preparing high‐efficiency hybrid CuO x /TiO 2 photocatalysts, where simultaneous control over lattice doping and nanocluster modification of Cu species on a TiO 2 support is achieved. Effective engineering of Cu valence is achieved, where the surface Cu + content varies from 15% to as high as 100%. Meanwhile, a high percentage (70–80 mol%) of TiO 2 photocatalytic active phase (anatase) is also maintained in the flame‐made catalysts. A dramatic enhancement in photocatalytic H 2 evolution efficiency of the hybrid catalyst is attained. The maximum photocatalytic H 2 evolution rate of the hybrid CuO x /TiO 2 catalyst under Xe lamp in a methanol aqueous solution can reach as high as 112.6 µmol h −1 , which is ≈22.1 times higher than that of commercial P25 TiO 2 . Mechanism investigation via density functional theory calculation and photoluminescence spectra validates that the bulk defect levels and surface‐deposited CuO x nanoclusters play key roles in charge separation and extending spectral response.

Noble metal‐free hybrid photocatalysts have recently been extensively studied for their applications in the environment and energy field. However, rational design over these photocatalysts is still a challenging task because the detailed mechanism of multi‐component catalysts is not well understood yet. Here, we highlight a state‐of‐the‐art approach, one‐step flame spray pyrolysis (FSP), for preparing high‐efficiency hybrid CuOx/TiO2 photocatalysts, where simultaneous control over lattice doping and nanocluster modification of Cu species on a TiO2 support is achieved. Effective engineering of Cu valence is achieved, where the surface Cu+ content varies from 15% to as high as 100%. Meanwhile, a high percentage (70–80 mol%) of TiO2 photocatalytic active phase (anatase) is also maintained in the flame‐made catalysts. A dramatic enhancement in photocatalytic H2 evolution efficiency of the hybrid catalyst is …

It is well-known that distinct vapor plume dynamics occur during deep penetration laser welding under different keyhole penetration states. However, there is little knowledge about the physical characteristics of vapor plumes (velocity, pressure, flow patterns, etc)located inside transient keyholes of varying penetration regimes in laser welding. This lack of knowledge is primarily because mesoscale vapor plumes are highly dynamic and generally invisible. Based on a well-tested three-dimensional multiphase laser welding model, we conducted a computational study on vapor plume dynamics inside transient keyholes during the fiber laser welding of 304 austenite stainless steel as a function of keyhole penetration regimes. We observed three keyhole regimes of penetration: full penetration, partial penetration and no penetration. We then physically analyzed the vapor plumes in these regimes. We determined that the vapor plume velocities and pressures in all three regimes were uneven and oscillated following the dynamic keyhole with a characteristic timescale in sub-microseconds. Only when the keyhole approached the full penetration regime did vapor plumes begin to violently eject from the bottom of the keyhole opening, whereas in the partial penetration regime, even when the bottom part of the keyhole was open, most of the vapor plume ejected from the upper keyhole opening. This latter observation was similar to that in the no penetration mode. We studied the physical mechanism of this behavior by analyzing the keyhole temperature and vapor plume velocity distributions. We determined that the upward ejection of the vapor plume from the upper keyhole opening was the result of an uneven micro-meter scale boiling phenomenon of the transient keyhole governed by Fresnel absorptions dependent on the local inclination angle of the keyhole wall. Similarly, we determined that the ejection of the vapor plume from the bottom of the keyhole opening resulted from pressure differences between the inside and outside of the keyhole ( as long as there was a relatively stable open state at the bottom of the keyhole opening). Additionally, we conducted quantitative studies on the velocity and pressure of vapor plumes in transient keyholes for all three regimes. We observed a decrease in the average velocity of vapor plumes at the upper keyhole opening, and an increase in average velocity at the bottom opening when the penetration regime moved from no penetration to full penetration. Moreover, the pressure distributions of vapor plumes decreased and became more uniform as the penetration regime varied from no penetration to full penetration. For the investigated process parameters used for the fiber laser welding of 1 mm thick 304 stainless steel, the vapor plume pressure decreased approximately 500-1200 Pa inside the millimeter scale keyhole. The findings in this study give the first physical insights into vapor plume dynamics inside transient keyholes as a function of keyhole penetration states during deep penetration laser welding. Moreover, our findings can be used as theoretical references for welding process parameter optimization in industrial applications.

To meet the urgent demand of civil firework industry for safe oxidants, the safe and cheap oxidant barium nitrate was selected as the raw material to prepare the modified barium nitrate with higher reactivity by two modification methods. One method is expanding modification through co-crystallization by adding inorganic vesicant, the other method is activating treatment by adding thermally decomposition catalysts. The physical and chemical properties of expanded barium nitrate were characterized by SEM, SRD and DTA, as well as the safety performance and set off performance of barium nitrate fireworks. Results show that the density of modified barium nitrate decrease by 12.8%, the morphology of it is a fluffy porous structure with poor regularity and the thermal decomposition temperature decrease by 11.8 degrees C. The impact sensitivity of modified barium nitrate fireworks is 4%, the friction sensitivity is 0%, and it is safer than potassium chlorate and potassium perchlorate fireworks. The modified barium nitrate fireworks can meet the set off requirement with sudden explosive sound ratio of 97% and paper scrap ratio of 95%.