INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
·
IF 4.229
Xin Zhang,Zhengyang Shen,Ni Jian,Jianjiang Hu,Fang Du,Jianhua Yao,Mingxia Gao,Yongfeng Liu,Hongge Pan
Herein, we demonstrate the successful preparation of a novel complex transition metal oxide (TiVO 3.5 ) by oxidizing a solid-solution MXene (Ti 0.5 V 0.5 ) 3 C 2 at 300 °C and its high activity as a catalyst precursor in the hydrogen storage reaction of MgH 2 . The prepared TiVO 3.5 inherits the layered morphology of its MXene precursor, but the layer surface becomes very coarse because of the presence of numerous nanoparticles . Adding a minor amount of TiVO 3.5 remarkably reduces the dehydrogenation and hydrogenation temperatures of MgH 2 and enhances the reaction kinetics. The 10 wt% TiVO 3.5 -containing sample exhibits optimal hydrogen storage properties, as it desorbs approximately 5.0 wt% H 2 in 10 min at 250 °C and re-absorbs 3.9 wt% H 2 in 5 s at 100 °C and under 50 bar of hydrogen pressure. The apparent activation energy is calculated to be approximately 62.4 kJ/mol for the MgH 2 -10 wt% TiVO 3.5 sample, representing a 59% reduction in comparison with pristine MgH 2 (153.8 kJ/mol), which reasonably explains the remarkably reduced dehydrogenation operating temperature. Metallic Ti and V are detected after ball milling with MgH 2 ; they are uniformly dispersed on the MgH 2 matrix and act as actual catalytic species for the improvement of the hydrogen storage properties of MgH 2 .
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MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
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2018
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IF 3.414
Bowen Pu,Junwei Sha,Enzuo Liu,Chunnian He,Naiqin Zhao
Traditional laminated metal matrix composites are confined to two-component system of pure metal matrix and its reinforcement. To achieve further improvement of the applied mechanical properties , in this work, the soft phase of laminated composites was enhanced by alloying with Cu. The synergistic effect of Cu on phases of both soft and hard including in-situ catalyzing and precipitation hardening was firstly explored. The laminated graphene nanosheets (GNSs) /AlCu composites of 2 vol% GNSs, were fabricated by ball milling and hot-rolling processes with much higher mechanical properties. The multi-pass hot rolling provided the solution-precipitation process of Cu transforming into Al 2 Cu and significantly increased the dislocation density of the original soft Al matrix. In addition, the fracture mechanism and fracture model of the laminated GNSs/AlCu composites were also investigated.
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CHEMISTRY-A EUROPEAN JOURNAL
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2018
·Vol. 24
·期 69
·18556-18563
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IF 5.16
Shuaikai Xu,Yohan Dall'Agnese,Junzhi Li,Yury Gogotsi,Wei Han
Graphical Flexible freestanding hybrid rGO/MXene films with enhanced Li-ion storage capacity are fabricated by vacuum-assisted filtration method followed by a simple thermal treatment. In the hybrid films, reduced graphene oxide nanosheets act as a binder, which bridges electrochemically active conducting MXene particles. The effect of the surface functional group (-OH) on Li-storage performance of MXenes is evaluated. Two-dimensional transition-metal carbides called MXenes are emerging electrode materials for energy storage due to their metallic electrical conductivity and low ion diffusion barrier. In this work, we combined Ti 2 CT x MXene with graphene oxide (GO) followed by a thermal treatment to fabricate flexible rGO/Ti 2 CT r film, in which electrochemically active rGO and Ti 2 CT r nanosheets impede the stacking of layers and synergistically interact producing ionically and electronically conducting electrodes. The effect of the thermal treatment on the electrochemical performance of Ti 2 CT x is evaluated. As anode for Li-ion storage, the thermally treated Ti 2 CT r possesses a higher capacity in comparison to as-prepared Ti 2 CT x . The freestanding hybrid rGO/Ti 2 CT r films exhibit excellent reversible capacity (700 mAh g −1 at 0.1 Ag −1 ), cycling stability and rate performance. Additionally, flexible rGO/Ti 3 C 2 T r films are made using the same method and also present improved capacity. Therefore, this study provides a simple, yet effective, approach to combine rGO with different MXenes, which can enhance their electrochemical properties for Li-ion batteries.
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PubMed
高影响因子
Journal of Materials Chemistry A
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2018
·Vol. 6
·期 36
·17713-17723
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IF 9.931
Xiang Ke,Shuangfeng Guo,Gensheng Zhang,Xiang Zhou,Lei Xiao,Gazi Hao,Ning Wang,Wei Jiang
In this study, to improve the safety in the preparation process of energetic materials, vacuum freeze-drying technology is applied to develop nanoenergetic thin films in which Al nanoparticles (Al NPs) are used as the fuel and polyvinylidene fluoride (PVDF) powders act as the oxidant. The whole process effectively avoids high temperature and thus ensures operational safety. The morphology and composition characterizations confirm that Al NPs are dispersed uniformly in the hydrophobic energetic binder, endowing the films with increased water-proof, anti-aging and anti-corrosion characteristics. The results of thermal analysis show that a pre-ignition reaction (PIR) destroys the Al2O3 shell and a sharp exothermic peak from the reaction between the exposed Al core and PVDF is found before the melting point of Al. Combustion tests reveal that the film with the highest content of Al NPs possesses the fastest flame propagation speed. The preliminary reaction mechanism obtained by probing the reaction products and intermediates suggests that a two-step reaction exists when the film is slowly heated in N2, while a competitive reaction between oxidation and fluorination of Al NPs is observed when the film burns in air. These results indicate the promising potential of vacuum freeze-drying technology in manufacturing nanoenergetic materials.
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ACS Nano
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2018
·
IF 13.709
Yanan Ma,Yang Yue,Hang Zhang,Feng Cheng,Wanqiu Zhao,Jiangyu Rao,Shijun Luo,Jie Wang,Xueliang Jiang,Zhitian Liu,Nishuang Liu,Yihua Gao
A piezoresistive sensor based on ultralight and superelastic aerogel is reported to fabricate MXene/reduced graphene oxide (MX/rGO) hybrid 3D structures and utilize their pressure-sensitive characteristics. The MX/rGO aerogel not only combines the rGO’s large specific surface area and the MXene’s (Ti3C2Tx) high conductivity but also exhibits rich porous structure, which leads to performance better than that of single-component rGO or MXene in terms of the pressure sensor. The large nanosheets of rGO can prevent the poor oxidization of MXene by wrapping MXene inside the aerogel. More importantly, the piezoresistive sensor based on the MX/rGO aerogel shows extremely high sensitivity (22.56 kPa–1), fast response time (<200 ms), and good stability over 10 000 cycles. The piezoresistive sensor based on the MX/rGO hybrid 3D aerogel can easily capture the signal below 10 Pa, thus clearly testing the pulse of an adult at random. Based on its superior performance, it also demonstrates potential applications in measuring pressure distribution, distinguishing subtle strain, and monitoring healthy activity.
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PubMed
高影响因子
BIOLOGICAL TRACE ELEMENT RESEARCH
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2018
·Vol. 186
·期 2
·467-473
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IF 2.361
Cao Changyu,Luo Junchong,Li Xiaowen,Zhang Mengdan,Zhang Haoji,Zhang Jipei,Wang Kai
The aim of this study was to evaluate the protective effects of SeY (selenium-rich yeast) against Al (aluminum)-induced inflammation and ionic imbalances. Male Kunming mice were treated with Al (10 mg/kg) and/or SeY (0.1 mg/kg) by oral gavage for 28 days. The degree of inflammation was assessed by mRNA expression of inflammatory biomarkers. Ionic disorders were assessed by determining the Na + , K + , and Ca 2+ content, as well as the alteration in ATP-modifying enzymes (ATPases), including Na + K + -ATPase, Ca 2+ -ATPase, Mg 2+ -ATPase, Ca 2+ Mg 2+ -ATPase, and the mRNA levels of ATPase’s subunits in kidney. It was observed here that SeY exhibited a significant protective effect on the kidney against the Al-induced upregulation of pro-inflammatory and downregulation of anti-inflammatory cytokines. Furthermore, a significant effect of Al on the Na + , K + , Ca 2+ , and Mg 2+ levels in kidney was observed, and Al was observed to decrease the activities of Na + K + -ATPase, Mg 2+ -ATPase, and Ca 2+ Mg 2+ -ATPase. The mRNA expression of the Na + K + -ATPase subunits and Ca 2+ -ATPase subunits was regulated significantly by Al. Notably, SeY modulated the Al-induced alterations of ion concentrations, ATPase activity, and mRNA expression of their subunits. These results suggest that SeY prevents renal toxicity caused by Al via regulation of inflammatory responses, ATPase activities, and transcription of their subunits.
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PubMed
高影响因子
IONICS
·
2018
·Vol. 24
·期 11
·3367-3373
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IF 2.347
Zhang Rui-Tao,Han Jia-Jun,Liu Pan,Bao Chang-Yuan,Cheng Jin-Ning
Graphene oxide (GO) was synthesized by an improved Hummers method and then reduced with NaBH 4 ; GO became rGO with regular layered structure. Polyaniline (PANI)/rGO composite was prepared by a adsorption double oxidant method with rGO as a template. Some physical characterization methods (Fourier transform infrared spectroscopy analysis, X-ray diffraction, scanning electron microscope, and transmission electron microscope) were used to analyze the morphology and crystallinity of the composite. The electrochemical properties were characterized by cyclic voltammetry, impedance spectroscopy, galvanostatic charge/discharge, and rate capability. The first discharge specific capacity of the rPANI/rGO and PANI/rGO was 181.2 and 147.8 mAh/g. After 100 cycles, the capacity retention rate was still 90.2 and 88.9% separately, and the coulombic efficiency of batteries is close to 100%. These results demonstrate the composite has exciting potentials for the cathode material of lithium-ion battery.
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CHEMICAL ENGINEERING JOURNAL
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2012
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IF 3.461
Bo Yang,Shubo Deng,Gang Yu,Yonghong Lu,Hong Zhang,Jianzhong Xiao,Gang Chen,Xiaobing Cheng,Lili Shi
Nanoscale Al particles with average diameter of about 100 nm were employed to prepare Pd/Al nanoparticles (NPs) by chemical displacement deposition. It was proved that Pd 2+ acidic deposition solution was superior to its alkaline deposition solution in terms of Pd loading rate on Al NPs. The Pd/Al NPs were characterized by ICP–OES, SEM, TEM, XRD, BET and then used to explore hydrodechlorination (HDC) performance of 3-chlorophenol (3-CP) in aqueous solution. Major factors affecting HDC efficiency were investigated including Al substrate sizes, pH, Pd loadings in Pd/Al NPs, dosage of Pd/Al NPs, and temperature. The optimal results indicated that nanoscale Pd/Al bimetallic particles were highly effective for 3-CP HDC. HDC efficiency was only about 30% in 50 min reaction with micron sizes of Pd/Al particles (100–400 mesh), whereas it increased to 99.7% within 30 min using Pd/Al NPs at 25 °C. Aqueous pH presented remarkable effect on HDC and pH 3–4 was the optimum range for HDC as pH varied from 2 to 11. Pd loadings and Pd/Al dosages were optimized for highly effective HDC as 1.16 wt.% and 2 g/L, respectively. In addition, higher HDC performance was obtained while reaction temperature arrived at 45 °C and 0.389 mM of 3-CP could be completely dechlorinated into phenol only within 10 min reaction.
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Micro & Nano Letters
·
2014
·Vol. 9
·期 2
·132-135
·
IF 0.799
Chunmei Jiang,Yongjun Ma,Fengqi Zhao,Lun Wei,Heng Zhang,Chonghua Pei
A simple and effective way for preparing AlB 2 nanopowders was developed using solid state reaction with a mixture of nanometre-sized powders of aluminium and amorphous boron. The optimum synthesis conditions and the structural characteristics of the products were carefully investigated by means of X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and an energy dispersive spectrometer. The best result was obtained at a synthesis temperature of 900°C for 2 h with a molar ratio of 1:1.8. The obtained AlB 2 nanopowders consisted of numerous anomalous spherical particles with the grain size ranging from 100 to 200 nm. Furthermore, differential scanning calorimetry analysis showed that the combustion characteristics of the as-prepared AlB 2 nanopowders were better than that of the commercial AlB 2 powder under the same condition.
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SURFACE & COATINGS TECHNOLOGY
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2015
·
IF 1.998
Xiaogang Guo,Xueming Li,Hongru Li,Daixiong Zhang,Chuan Lai,Wulin Li
In this study, the nano-Al/Ni energetic composite coatings (ANECCs) have been successfully fabricated by the electrophoretic deposition (EPD) method at the room temperature and normal pressure. Isopropyl alcohol is demonstrated to act as the suitable dispersion agent for the EPD. The SEM and EDS results show that the obtained ANECCs are relatively smooth and evenly distributed. Both the phase constitution and exothermic behavior of the ANECCs are characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis at the same while. In addition, the kinetics of the nanoparticles during the EPD process are investigated in detail. The exothermic performance of products studies show that the ANECCs prepared by EPD exhibit the great combustion performance and thermodynamic properties. Furthermore, the combustion processes of samples are recorded and analyzed by the high-speed photography. This work demonstrates that EPD method is a facile and effective approach in the preparation of Al/Ni energetic coatings with the widespread application.
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Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 34
·9752-9759
·
IF 0
Xiulin Fan,Xuezhang Xiao,Lixin Chen,Liuting Zhang,Jie Shao,Shouquan Li,Hongwei Ge,Qidong Wang
NaAlH4, a prototypical high energy density complex hydride, possesses a favorable thermodynamics and high hydrogen storage capacity. However, the poor kinetics and degradation of cycling stability retard its practical application. To ease these problems, CeB6, CeF3 and CeO2 nanoparticles with a size of about 10 nm are synthesized by the wet-chemistry method and introduced into NaAlH4 systems as additives in this work. The results show that all of the nanoparticles are effective in improving the hydriding–dehydriding kinetics of NaAlH4, and nano-CeB6 possesses the highest catalytic activity. The rehydrogenation of dehydrogenated NaAlH4 doped with nano-CeB6 can be accomplished in less than 20 min with a high capacity of 4.9 wt%, which shows a 20% increase in capacity compared to that of chloride-doped NaAlH4. Due to the structural stability and good dispersion of nano-CeB6 and nano-CeF3, a favorable cycling stability with high capacity retention is achieved for their doped samples. Moreover, hydrogen can be released from the hydrogenated sample doped with nano-CeB6 at a temperature as low as 75 °C, fulfilling the operation temperature of a PEM fuel cell. In the nano-CeO2 doped NaAlH4 system, CeO2 is first reduced to CeH2.51. In the subsequent cycles, the formed CeH2.51 gradually transforms into Ce–Al, and simultaneously the kinetics of the doped system is further enhanced. It is believed that the utilization of Ce-based nanoparticles as catalysts would substantially improve the practical applications of NaAlH4 for hydrogen storage.
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MATERIALS LETTERS
·
2015
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IF 2.489
Haibo Duan,Jingjing Diao,Naru Zhao,Yijuan Ma
Hollow mesoporous bioactive glass microspheres (HMBGMs) were fabricated via a hydrothermal-assisted self-transformation method employing cetyltrimethyl ammonium bromide (CTAB) as a mesoporous template. The morphology, structure, particle size and specific surface area of HMBGMs were characterized by various methods. The results demonstrated that the solid BG spheres prepared in a Sto¨ber solution could spontaneously transform to hollow structure by incubating in hydrothermal condition. Meanwhile, the shell thickness of HMBGMs could be controlled by the hydrothermal time. In vitro drug release studies demonstrated that the HMBGMs exhibited a sustained release property. The obtained HMBGMs may have potential applications in drug delivery and bone tissue regeneration.
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