CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yajie Chen,Wei Ren,Zilong Zheng,Ganggang Wu,Bin Hu,Junhong Chen,Jiaxin Wang,Chunpei Yu,Kefeng Ma,Xinli Zhou,Wenchao Zhang
The development of nanothermites with adjustable reactivity has always been the research hotspot in the field of energetic materials, and its key issue is to control the interfacial contact extent and diffusion length between fuel and oxidizer. Here, the 3DOM CuO/Al, 3DOM CuO/Al-NPs and CuO-NPs/Al-NPs nanothermites, which show a gradual decrease in contact extents between reactants, were firstly prepared simultaneously using magnetron sputtering, P4VP self-assembly and ultrasonic mixing, respectively. The DSC thermograms show that the heat release of the 3DOM CuO/Al (sputtering 200 nm Al) can reach 2541.4 J/g, much larger than either value of the prepared 3DOM CuO/Al-NPs and CuO-NPs/Al-NPs. The activation energies of these CuO/Al systems also exhibit the similar results as the heat releases. However, the 3DOM CuO/Al-NPs can lead to the highest combustion pressure (24.6 MPa), the shortest pressure rise time (0.067 ms), and the fastest pressurization rate (647.98 GPa/s), followed orderly in corresponding values by the CuO-NPs/Al-NPs and 3DOM CuO/Al. All data indicate that the contact extent between CuO and Al plays a great effect on the overall reactivity, and their differences in structure and volume are responsible for the diverse combustion pressure performance. Furthermore, the presence of reaction voids between components can promote the O diffusion to enhance the continuous mass and heat transfer for an efficacious reaction. Hence, it is believed that similar methods can be used to improve the contact extent and diffusion length between fuels and oxidants so as to achieve an adjustment in reactivity for various nanothermites.
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高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2020
·
IF 2.213
Yali He,Hongliang Sun,Weijiang Liu,Wenjie Yang,Aijun Lin
Fe/Al bimetallic particles were synthesized by chemical deposition. The materials were characterized by XRD and SEM. The structures of material with lower iron loading are solid ball like with a small amount of zero-valent iron. The structures of material with higher iron loading are porous ball like whose outer surface is almost entirely coated with zero-valent iron and provides more active sites. Different parameters affecting Cr(VI) removal rates were listed as research targets. The results showed that the removal rates can reach more than 90% under optimum conditions. In addition, Cr(VI) removal experiment was in accordance with the pseudo-first-order kinetics. SEM, FT-IR and XPS analysis were characterized after the reaction and the results proved that galvanic cell effect, the properties of reducibility of zero-valent metals, Fe(III)-Cr(III) mix phase hydroxides were the main surface reaction mechanisms for the reaction of Fe/Al bimetal with Cr(VI).
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PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Yong Liu,Ni Tan,Jinrui Guo,Jianlong Wang
In this study, a novel Al°-CNTs-Cu 2 O composite, capable of activating O 2 to generate H 2 O 2 and further to reactive oxygen species (ROSs) at a wide pH range, was synthetized, characterized and applied for the degradation of sulfamerazine. In the activation of O 2 by Al°-CNTs-Cu 2 O composite, H 2 O 2 was generated from the reaction of O 2 with Al°-CNTs, which could be catalytically decomposed into O 2 − and OH by Cu 2 O, the formed Cu(II) could be rapidly reduced to Cu 2 O by Al°-CNTs in composite, which made Al°-CNTs-Cu 2 O composite reusable and decreased the leaching of copper ions into solution. The removal efficiency of SMR and TOC was 73.91 % and 56.80 %, respectively at initial pH = 5.8, T = 20 °C, O 2 flow rate = 100 mL/min, Al°-CNTs-Cu 2 O dosage = 2 g/L, SMR = 50 mg/L, and reaction time = 60 min. The removal efficiency of SMR kept almost unchanged and the concentration of copper ions in solution was below 0.5 mg/L. The Al°-CNTs-Cu 2 O/O 2 process could be used as a novel catalyst for the degradation of refractory organic contaminants in water and wastewater by Fenton-like process at a wide pH range through the in situ generation of H 2 O 2 .
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PubMed
高影响因子
Colloid and Interface Science Communications
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2020
·
IF 2.831
Jiaxing Song,Tao Guo,Miao Yao,Jialin Chen,Wen Ding,Xiaonan Zhang,Fengli Bei,Junyi Huang
Graphene oxide (GO) with outstanding mechanical properties and high temperature stability is attractive to many researchers. As a flame retardant, GO also has been widely used in fire resistance applications of polymers. Herein, to explore ignition resistance effect of GO on nanothermite, GO/Al/MnO 2 nanocomposites were prepared. Due to the large specific surface area, GO can completely cover the surface of nanothermite components. Thermal results showed that exothermic thermite reaction occurred in the range of 500 °C to 600 °C while with GO addition, thermite reaction did not happen at all. Originally, combustion phenomenon of Al/MnO 2 nanothermite was intense with bright flame, but GO/Al/MnO 2 nanocomposites cannot be ignited even if the current on heating wires was higher. The physical barrier of GO hinders the direct contact between fuel and oxidizer which prevents the occurrence of self-propagating thermite reaction. This work provides guiding significance to the design of nanothermite flame retardant.
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高影响因子
APPLIED SURFACE SCIENCE
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2020
·
IF 6.182
Wei Luo,Yi Liu,Fan Li,Jinghao Huo,Dan Zhao,Jianfeng Zhu,Shouwu Guo
The novel V 2 CT x MXenes have gained increasing attention as anode materials in lithium-ion batteries, but to boost their practical to the theoretical values is still challenging. Herein, the partially etched V 2 CT x was oxidized in the presence of H 2 O 2 through a hydrothermal reaction and the electrochemical properties of as-obtained oxidized V 2 CT x were assessed. It is illustrated that the oxidized V 2 CT x possesses a large surface interlayer spacing, and enriched with VO 2 (A) and O-terminate groups. Once used as anode materials for Li-ion batteries, the oxidized V 2 CT x shows enhanced specific lithium ion storage capacities of 318 mAh·g −1 at 100 mA·g −1 after 100 cycles, and 125 mAh·g −1 at 1000 mA·g −1 after 1000 cycles, and better cycling stability and excellent rate performance over the V 2 CT x .
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2020
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IF 3.408
Si Li,Dakui Zhao,Huili Wang,Yu Zhang,Wenjiang Huang,Ying Zhou
The valence electron structure (VES) of MoSi 2 -based solid solution alloys was studied herein by the bond length difference (BLD) method based on the empirical electron theory (EET) of solids and molecules and the average atomic model. Compared to those for a MoSi 2 alloyed with Al or Mg separately, alloying with Mg + Al together significantly decreased the bond energy of the main bond branch and the ratio of the number of covalent valence electrons to the total number of valence electrons in the Mo(Si 0.92 Al x Mg 0.08- x ) 2 solid solutions and increased the lattice electrons. Thus, alloying MoSi 2 with Mg + Al together reduced the hardness and strength of MoSi 2 and increased its fracture toughness above what occurred when Mg or Al were added separately. The combined impact of the impurities was especially noticeable when MoSi 2 was alloyed with 4 at% Mg+4 at% Al. Based on those results, Mo(Si 0.92 Al x Mg 0.08- x ) 2 solid solution alloys were made, their mechanical properties were tested, and the experimental results were consistent with those of the theory.
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高影响因子
JOURNAL OF CATALYSIS
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2020
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IF 7.888
Pengju Yang,Qi Zhang,Zonglin Yi,Jian Wang,Hengquan Yang
The selective reduction of carbon dioxide (CO 2 ) into fuels and chemicals is expected to play a key role in achieving a carbon–neutral sustainable energy economy. Activation of CO 2 is the most important step in this process. As the electron transfer to CO 2 is the rate-limiting step for CO 2 activation, it is significant to modulate the electronic structure of CO 2 reduction catalysts to enhance their activities. However, the intrinsic relationships between electronic properties of catalysts and their catalytic activities remains somewhat unclear, which limits the rational design of highly-efficient CO 2 reduction catalysts. Herein, a catalyst-insulator–metal system consisting of Al as an electron-donor material was designed to modulate the electronic structure of cobalt oxide (Co 3 O 4 ) catalyst. The electrons in Al can be efficiently tunneled to Co 3 O 4 across an ultrathin self-formed Al 2 O 3 insulating layer. Experimental and theoretical results undoubtedly confirm that high electron density on Co 3 O 4 favours the adsorption and activation of CO 2 , while lowers the energy barrier for the formation of COOH* and especially lowers the desorption energy barrier of CO* intermediates, thereby significantly accelerating the reaction kinetics of CO 2 -to-CO photoreduction. The turnover frequency per Co atom of Co 3 O 4 /Al 2 O 3 -Al is much higher than that of Co 3 O 4 . The apparent quantum yield (AQY) of Co 3 O 4 /Al 2 O 3 -Al catalyst highly reaches 3.8% at 420 nm, which is superior to those of most reported catalysts. Besides, the increase in electron density on Co 3 O 4 can effectively inhibit the competing hydrogen evolution reaction. The selectivity of CO increases from 57.9% for Co 3 O 4 to 82.4% for Co 3 O 4 /Al 2 O 3 -Al. Significantly, the catalytic efficiency can be rationally tuned through controlling the content and particle size of Al. This work stablishes the links between the electronic structure of catalysts and their catalytic activities toward CO 2 reduction reaction. Moreover, this Al 2 O 3 -Al structure reported here, may be used as an unprecedented platform for the electronic effect study of other heterogeneous catalysts.
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VACUUM
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2020
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IF 2.906
Jiaxing Song,Tao Guo,Miao Yao,Jialin Chen,Wen Ding,Fengli Bei,Yiming Mao,Zhongshen Yu,Junyi Huang,Xiaonan Zhang,Qin Yin,Shuo Wang
The performance of energetic materials is mainly reflected in two aspects, thermal performance and combustion performance. To figure out the differences in reaction performance, in this paper, thermal and combustion properties of Al/CuO, Al/Fe 2 O 3 and Al/MnO 2 nanothermites were studied respectively by thermal analysis and fast heating wire experiments. According to the thermal analysis, the exothermic peak temperature points of Al/MnO 2 , Al/CuO, Al/Fe 2 O 3 nanothermites were 552.1 °C, 563.1 °C and 565.3 °C, respectively, while the sequence of activation energy calculated from low to high was Al/Fe 2 O 3 , Al/CuO, Al/MnO 2 nanothermites. By the way, the values of Al/CuO and Al/Fe 2 O 3 nanothermites showed little difference in temperature and activation energy. The ignition energy characterized by direct current had little difference among them, and the sequence from low to high was Al/MnO 2 , Al/Fe 2 O 3 , Al/CuO nanothermites, corresponding to 1.169 A, 1.214 A and 1.221 A, respectively. As for burning rate, Al/CuO burnt the fastest clearly while the Al/Fe 2 O 3 burnt the longest. In terms of combustion performance, Al/CuO and Al/MnO 2 were basically the same, with little splash of sparks, and the concentrations of combustion energy were better. The combustion phenomenon of Al/Fe 2 O 3 nanothermite was quite unique with a large number of scattered sparks and poor energy concentration. Finally, the intrinsic reasons for above different phenomena of these three nanothermites were analyzed and discussed.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yapeng Tian,Chenhui Yang,Yi Tang,Yangyang Luo,Xiaojie Lou,Wenxiu Que
Supercapacitors with an advanced high volumetric energy density require a match of both electrodes materials and suitable electrolyte. Here, aqueous asymmetric supercapacitors are designed by employing layered Ti 3 C 2 T x as negative electrodes and highly compact activated carbon (AC) as positive electrodes. Ti 3 C 2 T x //AC asymmetric supercapacitors (Ti 3 C 2 T x //AC ASCs) with 1.7 V voltage window are designed by regulating the mass ratio of both electrodes, which results from the shift of the open circuit potential with different applied voltages. Then, dual-ion hybrid supercapacitors (Ti 3 C 2 T x //AC-KBr HSCs) are also constructed by introducing redox active (KBr) into traditional electrolyte (H 2 SO 4 ) for Ti 3 C 2 T x //AC ASCs to achieve a high volumetric energy density, in which fast hydronium ion intercalated pseudocapacitance happens at the Ti 3 C 2 T x negative electrode, while redox reaction of Br − /Br 3 − within the highly compact AC happens at the positive electrode. As a result, the Ti 3 C 2 T x //AC-KBr HSC achieves a high volumetric capacitance of 250 F cm −3 at 2 mV s −1 , a volumetric energy density of as high as 102.8 Wh L −1 at 424 W L −1 and an outstanding cycling stability with 122% capacitance retention after 6000 cycles. Furthermore, the self-discharge performance for the Ti 3 C 2 T x //AC-KBr HSC is obviously improved, which is mainly ascribed to the adsorption of oxidized species at the AC surface.
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高影响因子
Journal of Advanced Dielectrics
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2020
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IF 0
Maomao Ju,Yawei Yang,Jianqiu Zhao,Xingtian Yin,Yutao Wu,Wenxiu Que
Interfacial water evaporation through solar heating with photothermal materials is a promising strategy for seawater desalination and wastewater purification. Tightly packed 2D membranes with high reflection losses and limited vapor escape channels result in a low evaporation rate. In this work, 3D MXene architecture was fabricated by dropping the delaminated Ti 3 C 2 ( d -Ti 3 C 2 ) nanosheets onto the carbonized melamine foam (CMF) framework. Owing to the macroporous 3D architecture, more effective broadband solar absorption and vapor escaping were achieved. As a result, the 3D CMF@ d -Ti 3 C 2 -based evaporator delivers a water evaporation rate of 1.60 kg/m 2 ⋅ h with a solar-to-vapor conversion efficiency of up to 84.6%.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2020
·Vol. 31
·期 16
·13503-13510
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IF 2.22
Guo Xiaogang,Wang Jing,Liang Taotao,Yuan Binfang,Sun Qi
It is still a bottleneck to design anti-wetting homogeneous metal films or coatings with great stability via by a high-efficiency and low-cost technique with applications in fields of battery, sensors, and electronics, etc. This paper proposed an environment-friendly ultra-low-voltage electrophoretic deposition (EPD) with facile modification post-processing method to fabricate a novel extremely water-repellent functional nano-Al films with evenly loose net-like structures and high purity. The optimized stable suspension consists of water–ethanol with trace nitric acid and polyethyleneimine. Product with an ultra-high contact angle of ~ 171° and extreme low sliding angle of < 1° showed extremely anti-wetting properties, and outstanding water-repellent stability or long lifespan (> 3 years) with great potential applications. These results provide a novel approach with low-cost and less energy consumption for preparing other functional ant-wetting metal coatings with wide potential applications.
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Nano Energy
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2020
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IF 16.602
Feihong Ren,Zhendong Li,Yun Zhu,Patrice Huguet,Stefano Deabate,Deyu Wang,Zhe Peng
Uneven nucleation and fragile solid electrolyte interphase (SEI) restrict the practical application of lithium (Li) metal anode. A versatile strategy to simultaneously overcome these two drawbacks is critical for Li metal batteries (LMBs). Herein we propose an “aggressive aluminum (Al) pulverization” strategy to form abundant artificial nucleation sites and robust SEI films adjacently, leading to homogeneous Li deposition/stripping and high Li Coulombic efficiency. A core-shell structure with Al core and alumina-silica (Al 2 O 3 –SiO 2 ) shell, Al@Al 2 O 3 –SiO 2 (AAS), could be easily synthesized, by modulating the chemical diffusion of silicon (Si) element towards Si–Al alloy surface. The active SiO 2 sites not only contribute to form the robust SEI layer, but also facility the lithiation of the AAS, accelerating the conversion of reversible Li–Al alloy into inert Li 3 Al 2 phase. The as-generated AAS with Li 3 Al 2 and Li 12 Si 7 phases possess negligible Li nucleation over-potential (~0.7 mV), serving as an optimal structure for dendrite-free Li plating/stripping with a prolonged life-span of 6 times longer than that of the unprotected counterpart in carbonate electrolytes.
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高影响因子
危险品化学品经营许可证（带存储）