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14篇 您的检索式:作者名="MENG XiangKang"
    题名 作者 年代 出处 被引量
1High-performance asymmetric supercapacitors based on reduced graphene oxide/polyaniline composite electrodes with sandwich-like structure显示文摘The sandwich-like structure of reduced graphene oxide/polyaniline(RGO/PANI) hybrid electrode was prepared by electrochemical deposition. Both the voltage windows and electrolytes for electrochemical deposition of PANI and RGO were optimized. In the composites, PANI nanofibers were anchored on the surface of the RGO sheets, which avoids the re-stacking of neighboring sheets. The RGO/PANI composite electrode shows a high specific capacitance of 466 F/g at 2 m A/cm^2 than that of previously reported RGO/PANI composites. Asymmetric flexible supercapacitors applying RGO/PANI as positive electrode and carbon fiber cloth as negative electrode can be cycled reversibly in the high-voltage region of 0–1.6 V and displays intriguing performance with a maximum specific capacitance of 35.5 m F cm^(-2). Also, it delivers a high energy density of 45.5 m W h cm^(-2) at power density of 1250 m W cm^(-2). Furthermore, the asymmetric device exhibits an excellent long cycle life with 97.6% initial capacitance retention after 5000 cycles.Such composite electrode has a great potential for applications in flexible electronics, roll-up display,and wearable devices.Jun Ma Shaochun Tang Junaid Ali Syed Dongyun Su Xiangkang Meng 2018Journal of Materials Science & Technology2018,34,7:3
2Controllable synthesis of metal particles by a direct current electrochemical approach显示文摘Shapes of copper and silver particles were successfully controlled by using a very simple,effective direct-current electrochemical approach without introducing any additives or templates. A diverse range of shapes and also different inner structures were thus accessible. The products prepared at relatively high potentials have flowerlike morphologies and exhibit flakes as building blocks. The uniformly thick flakes intersect mutually,have smooth surfaces and outwardly wavy edges. The particle diameter and the flake density can be easily controlled by changing potential and/or deposition time. With a decrease of potential,the particles' shapes changed from flower to bud,to sphere and to octahedron. Surface plasmon resonance (SPR) properties of the supported metal particles were investigated by UV-Vis diffuse reflectance spectra (UV-Vis DRS) and surface enhanced Raman scattering (SERS). It was found that the copper octahedra exhibited three characteristic bands,and SERS effect increases with the number of flakes within individual particles. Based on the experimental results,the mechanism for direct-current electrochemical growth of metal nanostructures was discussed.ShaoChun Tang XiangKang Meng 2009Science China(Technological Sciences)2009,52,9:2
3Preparation of Pt–GO composites with high-number-density Pt nanoparticles dispersed uniformly on GO nanosheets显示文摘Pt–GO composites with high-number-density Pt nanoparticles dispersed uniformly on GO nanosheets were prepared using ethylene glycol as reducer at 180 °C. The nanoparticles had an average size of 12 nm with corners and edges on their surfaces. The composites had electrochemically active surface area of 31.7 m^2g^(-1) with a ratio(I_f/I_r =0.96) of the forward anodic peak current(I_f) to the reverse anodic peak current(I_r) in cyclic voltammetry curves, which is much higher than those of the reported Pt nanodendrites/reduced graphene oxide composites.Nanting Li Shaochun Tang Xiangkang Meng 2016Progress in Natural Science:Materials International2016,26,2:1
4Synthesis of nanorods and nanowires using biomolecules under conventional- and microwave-hydrothermal conditions显示文摘Feng Gao Qingyi Lu Xiangkang Meng Sridhar Komarneni 2008Journal of Materials Science2008,,7:1
5Reduced Graphene Oxide Supported Bimetallic CobaltPalladium Nanoparticles with High Catalytic Activity towards Formic Acid Electro-oxidation显示文摘In this work,we report the growth of uniformly dispersed bimetallic cobalt-palladium nanoparticles(NPs) on reduced graphene oxide(RGO) nanosheets to prepare CoPd-RGO composites via a two-step procedure,where firstly formed Co NPs are used as seeds for the subsequent growth of Pd.The generation of Co NPs on RGO is performed by an in-situ reduction reaction with the reducer ethylene glycol under oil bath at180 ℃.According to composition,size and microstructure analyses,NPs in the resulting CoPd-RGO have an average particle size of 5 nm,and Pd is added to one side of Co NPs,thus forming Co-Pd bimetallic interfaces.The involved formation mechanism is suggested.The composite is used as an electro-catalyst for the formic acid oxidation in alkaline electrolyte,and the catalytic performance is investigated by cyclic voltammetry and chronopotentiometry etc.The results show that the composite has the highest electrocatalytic activity,the best electrochemical stability and the highest resistance to CO poisoning than those of the monometallic composite and commercial Pd black at the same loading.This is due not only to the small size of NPs with Co-Pd bimetallic interfaces providing more active atoms accessible for reactants,but also to the electric synergistic effect between metals and graphene.Nanting Li Shaochun Tang Xiangkang Meng 2015Journal of Materials Science & Technology2015,31,1:1
6Effects of hydrothermal temperature on formation and decoloration characteristics of anatase TiO_2 nanoparticles显示文摘This paper describes the effects of temperature on the complex intermediate processes from the precursor to the fully-crystallized anatase TiO2 nanoparticles in hydrothermal synthesis. The anatase TiO2 nanoparticles were synthesized in a wide temperature range below 230°C. The composition, morphology, and methylene blue (MB) decoloration characteristics of the obtained products were investigated by X-ray diffraction, Fourier transform infrared spectroscope, X-ray photoelectron spectroscope, and scanning and transmission electron microscope. The dehydrating polycondensation of Ti(IV)-hydrates and the decomposition of (NH4)2Ti3O7 intermediates with the temperature increase lead to the direct formation of anatase TiO2 nanoparticles under the hydrothermal environments. The strong MB decoloration of the hydrothermal products obtained at the low (≤130°C) and high (≥180°C) temperatures are attributed to the adsorption of Ti(IV)-hydrates and the photocatalysis of anatase TiO2 nanoparticles, respectively.LU HongBin ZHOU YouZhen VONGEHR Sascha TANG ShaoChun MENG XiangKang 2012Science China(Technological Sciences)2012,55,4:1
7Concentration-dependent Morphology Control of Pt-coated-Ag Nanowires and Effects of Bimetallic Interfaces on Catalytic Activity显示文摘Silver nanowires(NWs) coated with platinum(Pt) nanoparticles were synthesized via a galvanic partial replacement of Ag NWs in an aqueous K_2PtCl_6 solution at room temperature. The products were characterized using a combination of electron microscopies,selected area electron diffraction,energydispersive X-ray mapping and X-ray diffraction. The surface morphology and Pt/Ag composition ratios are controlled by adjusting the K_2PtCl_6 concentration. Different concentrations result in various surface morphologies including rough nanoparticle coating,porous and relatively smooth surfaces. The formation mechanism was discussed based on the lattice constants' difference,concentration driven nucleation,consumption of Ag NWs,and stoichiometry of the replacement reaction. The effects of the bimetallic interface on the catalytic activity toward the reduction of 4-nitrophenol by sodium borohydride were studied. The activity of Ag–Pt NWs is highly enhanced over monometallic nanostructures,and optimized by a low Pt loading of 1.34 at.%,which indicates a catalytic role of the inter-metallic interface for the electron transfer.Yongguang Wang Xiangyu Wang Bo Sun Shaochun Tang Xiangkang Meng 2016Journal of Materials Science & Technology2016,32,1:1
8Thermodynamics of Bainitic Formation in Carbon-depleted Region in Fe-C Alloys显示文摘Thermodynamic analysis for the formation of bainitic ferrite in carbon -depleted region has been conducted. The results show that the driving force of bainitic formation increases with depleting of carbon in parent austenite and with decreasing the transformation temperature. The critical driving force (absolute value) at the Bs temperature is 600-1 200 J / mol, which increases as the mean carbon content of Fe-C alloys increases. The freshly-formed bainitic ferrite has partial supersaturation of carbon, which increases smoothly with decreasing the transformation temperature Therefore, the displacive formation of bainitic ferrite in carbon-depleted region is thermodynamically feasible in the whole temperature range of bainitic reaction.Xiaolei WU Xiangkang MENG Xiyan ZHANG Yanqing YANG and Mokuang KANG(Dept. of Materials Science and Technology, 401, Northwestern Polytech. University, Xi’an, 710072, China) 1994Journal of Materials Science & Technology1994,10,6:0
9Facile Synthesis of Bimetallic Au@Pd Nanoparticles with Core-shell Structures on Graphene Nanosheets显示文摘In this paper, we report a simple one-step thermal reducing method for synthesis of bimetallic Au@Pd nanoparticles with core-shell structures on the graphene surface. This new type of Au@Pd e G composites is characterized by transmission electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. It is found that Au@Pd nanoparticles with an average diameter of 11 nm are well dispersed on the graphene surface, and the Au core quantity as well as the Pd shell thickness can be quantitatively controlled by loading different amounts of metallic precursors, and the involved core-shell structure formation mechanism is also discussed. The ternary Pt/Au@Pd e G composites can also be synthetized by the subsequent Pt doping. The catalytic performance of Au@Pd e G composites toward methanol electro-oxidation in acidic media is investigated. The results show that Au@Pd e G composites exhibit higher catalytic activity, better stability and stronger tolerance to CO poisoning than Pd-G and Au-G counterparts.Nanting Li Shaochun Tang Xiangkang Meng 2014Journal of Materials Science & Technology2014,30,11:0
10Adapting Nanotech Research as Nano-Micro Hybrids Approach Biological Complexity,A Review显示文摘Today’s emergence of nano-micro hybrid structures with almost biological complexity is of fundamental interest.Our ability to adapt intelligently to the challenges has rami?cations all the way from fundamentally changing research itself,over applications critical to future survival,to posing globally existential dangers.Touching on speci?c issues such as how complexity relates to the catalytic prowess of multi-metal compounds,we discuss the increasingly urgent issues in nanotechnology also very generally and guided by the motto‘Bio Is Nature’s Nanotech’.Technology belongs to macro-evolution;for example integration with arti?cial intelligence(AI)is inevitable.Darwinian adaptation manifests as integration of complexity,and awareness of this helps in developing adaptable research methods that can?nd use across a wide range of research.The second half of this work reviews a diverse range of projects which all bene?ted from‘playful’programming aimed at dealing with complexity.The main purpose of reviewing them is to show how such projects bene?t from and?t in with the general,philosophical approach,proving the relevance of the‘big picture’where it is usually disregarded.Sascha Vongehr Shaochun Tang Xiangkang Meng 2016Journal of Materials Science & Technology2016,32,5:0
11In-situ polymerized nanosilica/acrylic/epoxy hybrid coating:Preparation,microstructure and properties显示文摘An in-situ polymerization method was employed to synthesize the nanosilica/acrylic/epoxy (SAE) hybrid coating on AISI 430 stainless steel (430SS), as compared with a traditional blending method. Mi- crostructures of the blending SAE hybrid coating (BC) and in-situ SAE hybrid coating (ISC) were characterized by transmission electron microscopy (TEM). Corrosion resistance of BC and ISC on 430SS was evaluated by the neutral salt spray test and potentiodynamic polarization technique. Failure mechanism of the BC on 430SS was suggested by the microstructures and corrosion behaviors. Serious aggregation of nanosilica particles in the BC impairs its structural uniformity and induces the flaws formation. These flaws in the BC initiates the failures of pitting, filiform corrosion and peeling which are accelerated by the O2 concentration cell and H+ self-catalysis in chlorine-containing moist environments. The ISC-coated 430SS shows a more advantageous corrosion resistance than that of the BC-coated. The ISC-coated 430SS can suffer the salt spray over 1000 h. Besides, it exhibits a high corrosion potential beyond 0.925 V and good passivation characteristics during the potentiodynamic polarization.LU HongBin GU MinHao HUANG JianFeng HU Yong MENG XiangKang 2009Science China(Technological Sciences)2009,52,8:0
12An estimation method on failure stress of micro thickness Cu film-substrate structure显示文摘The failure of thin film-substrate structure occurs mainly at the thin film or the interface. However, the characterizing and estimating methods of failure stress in thin film are neither uniform nor effective because there are some complex effects of such as size, interface and stress state on the failure behavior of thin film-substrate structure. Based on the scanning electron microscope (SEM) in-situ in- vestigation on the failure models of the Cu thin film-substrate structure and the nano scratched testing results, the failure stresses in different thicknesses of the Cu film-substrate were characterized, which were compared and confirmed by other methods, such as Stoney formula and other empiric equations. These results indicate that the novel estimating method of failure stress in thin film based on the critical wavelength of surface unstable analysis is better than other methods. The main reason is that the novel estimating method of failure stress in meso thickness film fully considered the effect factors of free surface unstable behavior and elastic anisotropy of thin film. Therefore, the novel estimating method of failure stress assists people to understand the critical interfacial strength and to set up the failure criterion of thin film-substrate structure.WANG XiShu LI Ying MENG XiangKang 2009Science China(Technological Sciences)2009,52,8:0
13MOFs derived ZnSe/N-doped carbon nanosheets as multifunctional interlayers for ultralong-Life lithium-sulfur batteries显示文摘The shuttle effect and slow conversion rate of lithium polysulfides(LiPSs)have become the main obstructs to the development of lithium-sulfur(Li-S)batteries.Herein,the low cost metal-organic frameworks derived nitrogen-doped carbon nanosheets embedded with zinc selenide nanoparticles(ZnSe/NC nanosheets)were designed and synthesized for Li-S batteries.As the LiPSs trapping-layer,these nanocomposites provide some key benefits:(1)The nitrogen doping changes local electron distribution in the carbon nanosheets,thus the electrical conductivity is greatly improved for facilitating the transport of electrons/ions.(2)Nitrogen atoms and ZnSe nanoparticles play an important role in anchoring the LiPSs via chemical interactions.(3)The remarkable catalytic activity of ZnSe nanoparticles can accelerate the redox kinetics of LiPSs.As a result,the Li-S battery with the ZnSe/NC nanosheets modified separator exhibits ultralong lifespan over 1500 cycles with a small capacity loss of only 0.046%per cycle at 1 C,which is superior over those reported values.Furthermore,the Li-S battery with a high sulfur loading of 4.71 mg cm^(-2) can still maintain a high areal capacity of 4.28 mAh cm^(-2) after 50 cycles.This work provides a new route to the design of multifunctional low cost and high-performance separators for remarkably stable Li-S batteries.Biao Wang Dongyue Sun Yilun Ren Xiaoya Zhou Yujie Ma Shaochun Tang Xiangkang Meng 2022Journal of Materials Science & Technology2022,,30:0
14Formation of hierarchically 3D cactus-like architecture as efficient Mott-Schottky electrocatalyst for long-life Li-S batteries显示文摘Searching for new promising electrocatalysts with favorable architectures allowing abundant active sites and remarkable structure stability is an urgent task for the practical application of lithium-sulfur(Li-S)batteries.Herein,inspired by the structure of natural cactus,a new efficient and robust electrocatalyst with three-dimensional(3D)hierarchical cactus-like architecture constructed by functional zero-dimensional(0D),one-dimensional(1D),and two-dimensional(2D)components is developed.The cactus-inspired catalyst(denoted as Co@NCNT/NCNS)consists of N-doped carbon nanosheets(NCNS)and standing Ndoped carbon nanotubes(NCNT)forest with embedded Co nanoparticles on the top of NCNT,which was achieved by an in situ catalytic growth technique.The unique structure design integrates the advantages of 0D Co accelerating catalytic redox reactions,1D NCNT providing a fast electron pathway,and 2D NCNS assuring strong structure stability.Especially,the rich Mott-Schottky heterointerfaces between metallic Co and semiconductive NCNT can further facilitate the electron transfer,thus improving the electrocatalyst activity.Consequently,a Li-S battery with the Co@NCNT/NCNS modified separator achieves ultralong cycle life over 4000 cycles at 2 C with ultralow capacity decay of 0.016%per cycle,much superior over that of recently reported batteries.This work provides a new strategy for developing ultra-stable catalysts towards long-life Li-S batteries.Biao Wang Yilun Ren Shaowei Chen Qingxi Zhai Yuxuan Shi Yujie Ma Shaochun Tang Xiangkang Meng 2023Nano Research2023,16,7:0
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