Co-reporter:Tengfei Li, Tianmo Liu, Liqiong Zhang, Tao Fu, Hongmei Wei
Computational Materials Science 2017 Volume 126() pp:103-107
Publication Date(Web):January 2017
DOI:10.1016/j.commatsci.2016.09.028
The slip systems and comparative twinnability of TiC have been investigated in term of generalized stacking fault energy curves and the relevant energy properties by the density functional theory based first principles calculations. The possible slip systems of three low index planes were taken into consideration in TiC. When a pre-existing twin fault was considered, it was found that the slip in the twin plane had the much lower unstable stacking fault energy which might induce the alteration of the deformation mechanism and result in the enhancement of toughness.
Co-reporter:Dongfeng Shi, Tianmo Liu, Tianyu Wang, Dewen Hou, Shuoqing Zhao, Shahid Hussain
Journal of Alloys and Compounds 2017 Volume 690(Volume 690) pp:
Publication Date(Web):5 January 2017
DOI:10.1016/j.jallcom.2016.08.076
•{10–12} Twins across twin boundaries traced by in situ electron backscatter diffraction (EBSD) technique.•A twin impacting a grain boundary and stimulate the nucleation of new twin in neighbouring grain.•Multiple variants twins inside one grain caused by pair twins.In AZ31 magnesium alloy, {10–12} twin pair generated at grain boundary is easy to be observed. In current study, we trace the process of twins impacting grain boundaries and stimulating the nucleation of new twins in neighbouring grains by in situ electron backscatter diffraction (EBSD) technique. Multiple twin variants (caused by twin pair) inside one grain is found in EBSD map, which is considered as the cause of strain hardening for it significantly retard the rate of propagation and growth of twinning during subsequent deformation.
Co-reporter:Huicong Chen, Tianmo Liu, Shihua Xiang, Yanxiang Liang
Journal of Alloys and Compounds 2017 Volume 690(Volume 690) pp:
Publication Date(Web):5 January 2017
DOI:10.1016/j.jallcom.2016.08.154
•Abnormal migration of twin boundaries was revealed.•Intersecting twins have a significant effect on further twinning behavior.•Further imposed strain can be accommodated by double twins.Twin boundary (TB) migration under the condition of the interaction between different {10–12} twin variants with a high misorientation of 60.4° was investigated by using in-situ electron backscattered diffraction technique combined with Schmid factor analysis. It was found that TBs would continue to migrate when the sides of intersecting twin bands enclose an acute angle, but cease to migrate on the sides making an obtuse angle. Besides, due to the twin-twin interaction, half locked and entirely locked twin boundaries occurred as deformation progressed. Moreover, strain accommodated by double twin and new active twin was found at further imposed strain in current study.
Co-reporter:Liqiong Zhang, Tianmo Liu, Tengfei Li, Shahid Hussain
Physica E: Low-dimensional Systems and Nanostructures 2017 Volume 94(Volume 94) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.physe.2017.06.028
•Monolayer MoS2 doped with single, double, triple and tetra-atoms of P, Cl, O, Se at the surface S site.•The doping mechanism of monolayer MoS2 is studied by electronic properties.•The influence of Cl atoms is more remarkable than P.Through the first principle calculation, electronic properties of monolayer MoS2 doped with single, double, triple and tetra-atoms of P, Cl, O, Se at the surface S site are discussed. Among the substitutional dopant, our calculation results show that when P atoms are doped on a monolayer MoS2, a shift in the Fermi energy into the valence band is observed, making the system p-type. Meanwhile, band gap gradually decreases as increasing the number of P atoms. On the contrary, Cl is identified as a suitable n-type dopant. It is observed that Cl for initial three dopant behaved as magnetic and afterwards returned to non-magnetic behavior. The band gap of the Cl doped system is also dwindling gradually. Finally, O and Se doped systems have little effect on electronic properties near band gap. Such doping method at the S site, and the TDOS and PDOSs of each doping system provide a detailed of understanding toward working mechanism of the doped and the intrinsic semiconductors. This doping model opens up an avenue for further clarification in the doping systems as well as other dopant using this method.
Co-reporter:Shuoqing Zhao, Tianmo Liu, Muhammad Sufyan Javed, Wen Zeng, Shahid Hussain, Yu Zhang, Xianghe Peng
Electrochimica Acta 2016 Volume 191() pp:716-723
Publication Date(Web):10 February 2016
DOI:10.1016/j.electacta.2016.01.106
•Cu-doped δ-MnO2 microspheres are successfully synthesized via a hydrothermal method without using any template and surfactant.•Cu-doped MnO2 porous microspheres exhibited a high capacitance of 300 F g−1 at scan rate of 5 mV s−1.•Excellent cycling stability: 89.7% capacitance retention after 5000 cycles.•The fabricated solid state flexible supercapacitor shows a excellent stability in different voltage windows.•Three charged supercapacitors connected in series can light a blue light emitting diode (LED).Cu-doped δ-MnO2 microspheres are rationally synthesized via a simple and facile hydrothermal process without using any template and surfactant. The samples are characterized by XRD, EDS, SEM, TEM and BET for their structure, morphology, elemental composition and specific surface area. The prepared Cu-doped δ-MnO2 samples are further investigated as electrodes for solid state flexible supercapacitor, which is expected to deliver a high specific capacitance (300 F g−1 at scan rate of 5 mV s−1), a maximum energy density of 47.4 Wh kg−1 at a power density of 259 W kg−1 and long-term cycling stability (89.7% capacitance retention after 5000 times repetition at current density of 5 A g−1). Electrochemical impedance spectroscopy (EIS) demonstrates the low resistance nature of the prepared sample. All of the results suggest that the solid state MnO2 device with excellent electrochemical performance and low cost has a vast potential for significant and clean power source in the future.
Co-reporter:Xinliang Kuang, Tianmo Liu, Dongfeng Shi, Wenxia Wang, Mingping Yang, Shahid Hussain, Xianghe Peng, Fusheng Pan
Applied Surface Science 2016 Volume 364() pp:371-377
Publication Date(Web):28 February 2016
DOI:10.1016/j.apsusc.2015.12.172
Highlights
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Hierarchical SnO2 nanostructures made of superfine nanorods were controlled hydrothermal synthesized.
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The diameter and density of the nanorods can be tailored by adding NaOH.
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The as-prepared SnO2 nanostructures were found showing enhanced gas sensing activity to ethanol.
Co-reporter:Liyang Lin, Tianmo Liu, Jianlin Liu, Rong Sun, Jinghua Hao, Kemeng Ji, Zhongchang Wang
Applied Surface Science 2016 Volume 360(Part A) pp:234-239
Publication Date(Web):1 January 2016
DOI:10.1016/j.apsusc.2015.11.018
Highlights
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The groove-like NiMoO4 hollow nanorods are reported.
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The novel architecture exhibits a high capacitance of 1102.2 F g−1.
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90% capacitance retention is obtained after 1000 cycles.
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The fabrication process is one-pot, large-scale, stable and controllable.
Co-reporter:Dongfeng Shi, Tianmo Liu, Dewen Hou, Huicong Chen, Fusheng Pan, Hongbing Chen
Journal of Alloys and Compounds 2016 Volume 685() pp:428-435
Publication Date(Web):15 November 2016
DOI:10.1016/j.jallcom.2016.05.338
•Study the effect of twin–twin interactions through in situ EBSD.•Parallel geometry between identical twins would facilitate the twin growth.•Non-parallel geometry and intersecting twins restrict twin growth.Electron backscattered diffraction serial image analyses on AZ31 magnesium alloy compressed along RD at different strain levels revealed that twin–twin interactions are found to correlate with mechanical hardening. Four typical twin–twin structures are investigated: (1) Parallel twins with single variant; (2) Interacting twins with single variant; (3) Parallel twins with double variants; (4) Interacting twins with double variants. We studied twin–twin interactions by combining experimental observations and Schmid factor analysis. Due to twins intersecting with each other, the limited growth rate of twins was observed in EBSD maps. The intersection between different twin variant pairs was found to retard the twin growth and promote the nucleation of new twins near intersection region. Besides, “Apparent crossing” twin structure is a limiting case, in which the twin is crossed by a couple of twins, and the interaction region grow slowly. Twin–twin boundary migration is also observed during deformation in this paper, which is considered as an important cause to prohibit twins for further propagate and growth. All these features can be related to twinning-induced hardening.
Co-reporter:Liyang Lin, Tianmo Liu, Yu Zhang, Xiaobin Liang, Rong Sun, Wen Zeng, Zhongchang Wang
Ceramics International 2016 Volume 42(Issue 2) pp:3138-3144
Publication Date(Web):1 February 2016
DOI:10.1016/j.ceramint.2015.10.103
Noble metals decorated two-dimensional nanostructures with a large surface-to-volume ratio raise substantial promise for many technological applications particularly for high-performance chemical sensing. Here, we design and synthesize a hierarchical heterojunction comprising ultrathin two-dimensional polycrystalline ZnO nanosheets on a large scale, which serve as reaction positions for reduced gases, and uniformly dispersed Ag nanoparticles to enhance reaction activity. We find that the Ag nanoparticles in the heterostructural system act as strong electron acceptors, inducing remarkable surface space charge layers. As a result, the heterostructural system shows significantly improved gas-sensing performance to ethanol as compared to pure ZnO. Such metal nanoparticles decorated two-dimensional polycrystalline ZnO nanosheets can be applied in not only as gas-sensing but also catalytic and photocatalytic fields.
Co-reporter:Shuoqing Zhao, Tianmo Liu, Sijia Zheng, Wen Zeng, Tengfei Li, Yu Zhang, Shahid Hussain, Dewen Hou, Xianghe Peng
Materials Letters 2016 Volume 168() pp:13-16
Publication Date(Web):1 April 2016
DOI:10.1016/j.matlet.2016.01.031
•An unusual and unique BiClO nanotube was synthesized via a hydrothermal process.•The structure and morphology were discussed systematically in this paper.•The growth mechanism of the BiClO nanostructure was proposed.•KMnO4 is quite important in the BiClO nanotube forming process.We present an unusual and unique bismuth oxychloride (BiClO) hollow nanotube fabricated by a facile and simple hydrothermal method without using any surfactant and template, such research are rarely reported to the public. Morphology analysis (SEM, TEM) revealed that the synthesized nanotube had a typical one-dimensional hollow nanostructure with a diameter of 45 nm. XRD result showed that the nanotube was pure BiClO phase without any impurity. Moreover, KMnO4 served as an effective oxidizing and etching agent in this process, which contributed to the novel and regular hollow structure. The specific growth mechanism is also proposed and discussed systematically and scrupulously.
Co-reporter:Xinliang Kuang, Tianmo Liu, Wen Zeng, Xianghe Peng, Zhongchang Wang
Materials Letters 2016 Volume 165() pp:235-238
Publication Date(Web):15 February 2016
DOI:10.1016/j.matlet.2015.10.142
•Novel Sn2O3 hierarchical nanostructures were fabricated by the hydrothermal method.•The as-prepared Sn2O3 products can transform into SnO2 by calcinations.•The possible reaction of generating Sn2O3 is discussed.We report the successful synthesis of novel Sn2O3 with hierarchical 3D nanostructures via a facile hydrothermal method for the first time. The as-prepared Sn2O3 products transform into SnO2 after calcinations (800 °C) and a simultaneous TGA and DSC analysis of the as-prepared Sn2O3 sample determines that the main increment of mass takes place in the temperature range 534–800 °C. The well-defined nanostructures are composed of thin nanosheets. The growth mechanisms are also discussed by observing the morphology revolution at various reaction times. Furthermore, the oxidation states of the Sn2O3 hierarchical nanostructures are confirmed by the shape analysis of corresponding XPS O 1s and Sn 3d peaks using the decomposition procedure.In this work, we report the successful synthesis of novel Sn2O3 with hierarchical 3D nanostructures via a facile hydrothermal method for the first time.
Co-reporter:Yanqiong Li, Tianmo Liu, He Zhang
Materials Letters 2016 Volume 176() pp:9-12
Publication Date(Web):1 August 2016
DOI:10.1016/j.matlet.2016.04.057
•Nanoneedle-assembled and nanosheet-assembled SnO2 were synthesized.•Nanoneedle-assembled SnO2 show quicker gas response and recovery.•Nanosheet-assembled SnO2 exhibit higher gas response to ethanol.SnO2 hierarchical structures assembled by nanoneedles or nanosheets were synthesized through a hydrothermal method. In order to investigate the influence of morphologies on gas sensing properties, their gas sensing performance were tested. We found that the nanoneedle-assembled hierarchical structures show quicker gas response and recovery, which may be due to the better conductivity and lower potential barrier, while the nanosheets-assembled hierarchical structures exhibit higher gas response because of the larger specific surface area.In the letter, nanoneedle-assembled SnO2 and nanosheet-assembled-SnO2 were synthesized via a hydrothermal method. And nanoneedle-assembled SnO2 shows quicker gas response and recovery while nanosheet-assembled SnO2 exhibits higher gas response.
Co-reporter:Hongbing Chen, Tianmo Liu, Yin Zhang, Bo Song, Dewen Hou, Fusheng Pan
Materials Science and Engineering: A 2016 Volume 652() pp:167-174
Publication Date(Web):15 January 2016
DOI:10.1016/j.msea.2015.11.092
This study aims to investigate the tension and compression properties and precipitation behavior of pre-twinned ZK60 alloys. It was found that aging treatment can effectively reduce the tension–compression yield asymmetry of pre-twinned ZK60 alloy. For the pre-twinned sample with 10 h aging treatment, the yield asymmetry ratio is nearly equal to 1. Precipitate behavior in {10–12} extension twins of ZK60 Mg alloy were characterized by TEM. Three different morphologies of precipitates, [0001]twin rods, (0001)twin plates and [11–20]twin laths were observed in {10–12} extension twins. The precipitates constituted Mg4Zn7 or MgZn2 phases. The Mg4Zn7 phases have two variant orientations of the [010] zone axis, [010]Mg4Zn7 ‖ [0001]twin and (−201)Mg4Zn7 ‖ (‐12‐10)twin or (−201)Mg4Zn7 ‖ (10–10)twin, while the MgZn2 phases have an orientation of [‐12‐10]MgZn2 ‖ [0001]twin and (10–12)MgZn2 ‖ (10–10)twin. [11–20]twin laths as a new morphology of the precipitates have been found in ZK60 alloy, which have an orientation relationship of [010] Mg4Zn7 ‖ [0001] twin and (−201)Mg4Zn7 ‖ (‐12‐10)twin. Finally, the influences of aging treatment on yield asymmetry of pre-twinned ZK60 alloy are addressed and discussed.
Co-reporter:Huicong Chen, Tianmo Liu, Dewen Hou, Dongfeng Shi
Materials Science and Engineering: A 2016 Volume 667() pp:402-408
Publication Date(Web):14 June 2016
DOI:10.1016/j.msea.2016.05.006
Continuous {101̅2} twin bands across neighboring grains was observed in a hot rolled AZ31 during the interrupted compression along the rolling direction. The variant selection in paired twins was studied by Schmid factor (SF) and geometric misorientation relationship. The results show that most mated twins possess high rank Schmid factors (SFs), however, they does not share the same twin variant. Furthermore, EBSD analysis indicates that the formation of paired twins is correlated with the orientation relationship between adjacent grains. Based on these observation and analysis, the mechanism of “sequential twinning” nucleation and synergetic growth during deformation are proposed. Above all, this twinning behavior is capable of transmitting the localized shear and releasing stress at the former twin-termination interfaces, which plays an important role in accommodating plastic strain and mediating multiple grains' deformation
Co-reporter:Dewen Hou, Tianmo Liu, Dongfeng Shi, Huicong Chen, Hongbing Chen
Materials Science and Engineering: A 2016 Volume 653() pp:108-114
Publication Date(Web):20 January 2016
DOI:10.1016/j.msea.2015.12.011
In this paper rolled AZ31 magnesium alloy was deformed by interrupted in situ compressive tests. Compressive and re-compressive tests were conducted along rolling direction (RD). It is discovered that the yield strength of re-compression is enhanced due to grain refinement by {10–12} tensile twins. Twinning activation and evolution are evidenced by electron backscatter diffraction. Correlations with grain orientation and boundary misorientation are observed in the region of twins that arise at grain boundaries. The distributions of grain boundary misorientation associated with twin nucleation are mapped. It is found that nucleation of twin is mainly controlled by the initial texture, and is more easy at low misorientation grain boundaries. The growth of twins depend on two modes: the thickening of the existing twin lamellae and new twins is nucleated at grain boundary. With increasing compressive strain, the growth and coalescence of twins eventually encompassed the whole grain. Meanwhile, the basal texture is weaker after compression due to the propagation and coalescence of tensile twins.
Co-reporter:Tengfei Li, Liyang Lin, Hongmei Wei, Guoqiang Liang, Xinliang Kuang, Tianmo Liu
Physica E: Low-dimensional Systems and Nanostructures 2016 Volume 76() pp:198-202
Publication Date(Web):February 2016
DOI:10.1016/j.physe.2015.10.029
•Uniform BiOCl microspheres have been synthesized via a solvothermal route.•BiOCl microspheres possessed a superstructure.•These microspheres were of hollow structures.•BiOCl microspheres showed good photocatalytic performance.Uniform BiOCl microspheres have been synthesized via a facile solvothermal route. The structural features of the as-prepared BiOCl samples were systematically characterized by the X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The SEM characterization results indicated that BiOCl microspheres possessed a superstructure composed of several hierarchical microspheres, which were assembled by numerous two dimensional nanosheets. This kind of special BiOCl 3D microstructure exhibited a large BET surface area of about 14.24 m2 g−1. Besides, the photocatalytic properties of BiOCl hollow microsphere sample and sheet-like sample were investigated in detail. Significantly, BiOCl hollow microsphere sample presented faster degradation rate toward RhB even under visible light, which should be attributed to the unique BiOCl nanosheets self-assembled hollow microspheres.
Co-reporter:Dongfeng Shi, Tianmo Liu, Liqiong Zhang, Dewen Hou, Huicong Chen, Fusheng Pan, Liwei Lu
Materials Science and Engineering: A 2016 Volume 667() pp:132-138
Publication Date(Web):14 June 2016
DOI:10.1016/j.msea.2016.04.063
A novel finding of this study is that localised de-twining caused by shear banding induced by uniaxial compression deformation was first found through in situ EBSD observation. The twinning deformation process showed in this paper consists of the following three steps: twinning, de-twinning and re-twinning, which needs more energy and larger load than the process of twin growth and coalescence and complete consumption. It is believed that localised de-twining deformation mechanism is one of the strengthening mechanisms in magnesium alloy. More interestingly, twinning and de-twinning deformation operate simultaneously in a single twinning system, which was not in good agreement with the prediction of previous reports [1]. It is the first time that such unusual deformation mechanism has been found in experimental results. According to the results and combining with theoretical analysis, uncertain local stress states in individual grains is the cause of unusual experimental phenomena. The back stress induced in a twin by the surrounding matrix plays an important role in localised de-twining during uniaxial compression.
Co-reporter:Shuoqing Zhao;Yu Zhang
Journal of Materials Science: Materials in Electronics 2016 Volume 27( Issue 4) pp:3265-3270
Publication Date(Web):2016 April
DOI:10.1007/s10854-015-4154-1
Cr-doped MnO2 nanostructure has been fabricated via a facile hydrothermal method and its morphology and electrochemical properties was discussed systematically. In this process, flower-like MnO2 transforms into the self-assembled orchid structure under the influence of Cr-doped. Moreover, electrochemical behaviors of the Cr-doped MnO2 nanostructure electrode were clarified by cyclic voltammograms, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy, which shows a high specific capacitance of 202.5 F g−1 and superior cycling stability (6.8 % capacitance decay after 1000 cycling test). These remarkable and excellent results prove it has a great potential of application in future energy storage device.
Co-reporter:Liyang Lin, Jianlin Liu, Tianmo Liu, Jinghua Hao, Kemeng Ji, Rong Sun, Wen Zeng and Zhongchang Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 34) pp:17652-17658
Publication Date(Web):20 Jul 2015
DOI:10.1039/C5TA04054J
We report a synthesis of NiCo2S4 nanosheet arrays with self-decorated nanoneedles on nickel foams by a facile and efficient two-step hydrothermal approach. We demonstrate that the morphologies of various three-dimensional nanostructures such as nanoneedle arrays, nanosheet arrays, and nanoneedle-decorated nanosheet arrays can be manipulated by tuning the amount of additive ammonium fluoride alone in the reaction. The unusual nanostructure of nanoneedles grown on the surface of NiCo2S4 nanosheet arrays shows a large electroactive surface area and superior electrochemical properties. The electrode made of the NiCo2S4 nanosheet arrays with self-decorated nanoneedles shows greatly improved electrochemical performances with an ultrahigh specific capacitance of 2617.6 F g−1 at a current density of 15 mA cm−2 and of 2051.0 F g−1 even at a current density of 30 mA cm−2. The electrode also exhibits an excellent cycling stability by retaining 93.2% of its original state after 5000 cycles, rendering the NiCo2S4 nanosheet arrays with self-decorated nanoneedles a potential electrode material for high-performance supercapacitors.
Co-reporter:Yu Zhang, Tianmo Liu, Jinghua Hao, Liyang Lin, Wen Zeng, Xianghe Peng, Zhongchang Wang
Applied Surface Science 2015 Volume 357(Part A) pp:31-36
Publication Date(Web):1 December 2015
DOI:10.1016/j.apsusc.2015.08.170
Highlights
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The sunflower-like ZnO nanostructures reveal superior NH3 sensing performance than ZnO nanoparticles.
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The ZnO nanoflowers, looking like a sunflower with six petals and one pistil, consist of single crystalline nanotriangles and nanosphere.
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The sensitivity of ZnO nanoflowers exposure to NH3 is up to 49.5 under the concentration of 50 ppm, which is better than that reported in the literatures.
Co-reporter:Shuoqing Zhao, Tianmo Liu, Dewen Hou, Wen Zeng, Bin Miao, Shahid Hussain, Xianghe Peng, Muhammad Sufyan Javed
Applied Surface Science 2015 Volume 356() pp:259-265
Publication Date(Web):30 November 2015
DOI:10.1016/j.apsusc.2015.08.037
Highlights
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Hierarchical MnO2 nanoflower was synthesized via a hydrothermal process.
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The possible formation mechanism of the nanoflower MnO2 was proposed.
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The evolution of the MnO2 nanoflower nanostructure due to the change of reactant concentration.
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The Hierarchical MnO2 nanoflower exhibits high specific capacitance of 197.3 F g−1.
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The Hierarchical MnO2 nanoflower shows 94.6% capacitance retention after 1000 cycles.
Co-reporter:Xinliang Kuang, Tianmo Liu, Yangyang Zhang, Wenxia Wang, Mingping Yang, Wen Zeng, Shahid Hussain, Xianghe Peng
Materials Letters 2015 Volume 161() pp:153-156
Publication Date(Web):15 December 2015
DOI:10.1016/j.matlet.2015.08.090
•Urchin-like SnO2 nanoflowers were fabricated via hydrothermal process.•A growth mechanism is proposed based on comparative studies.•Urchin-like SnO2 microstructures showed the excellent properties.Novel urchin-like SnO2 nanostructures were prepared by a facile hydrothermal process. The well-defined nanostructures were composed of numerous one-dimensional nanowires with a diameter of ∼8–10 nm. Based on comparative studies, a possible formation mechanism was proposed in detail. It was believed that the nucleation was initiated by formation of ZnSn(OH)6. Furthermore, gas-sensing measurement indicated that the urchin-like SnO2 nanoflowers showed excellent gas-sensing properties.In this work, we prepare urchin-like SnO2 nanoflowers via hydrothermal synthesis, and report their growth formation mechanism and gas sensing properties.
Co-reporter:Sufen Li, Tianmo Liu, Yu Zhang, Wen Zeng, Fusheng Pan, Xianghe Peng
Materials Letters 2015 Volume 143() pp:12-15
Publication Date(Web):15 March 2015
DOI:10.1016/j.matlet.2014.12.053
•Unusual ZnO sealed nanotubes were synthesized through hydrothermal methods.•A possible growth mechanism for the specific morphology was proposed.•The sample showed excellent gas-sensitivities to gas with low concentration.In this article, a sealed nanotube of ZnO was successfully obtained by a simple hydrothermal technique, which employed Hexamethylene tetramine (HMT) and Fluorinion (F−) as the active agents. The rod-like nanotubes structures were observed through field-emission scanning electron microscopy. The high-resolution transmission electron microscope exhibited a shell-enclosed nanotube structures. On the basis of experimental observations, including temperature, pH of the solution and acting agents, a growth mechanism was proposed. The as-prepared nanostructures showed excellent gas sensitivities to different gases (ethanol, ammonia gas, formaldehyde gas) with a quite low concentration respectively.
Co-reporter:Zhixiang Long;Jiejun He
Journal of Materials Engineering and Performance 2015 Volume 24( Issue 1) pp:16-23
Publication Date(Web):2015 January
DOI:10.1007/s11665-014-1284-1
In present work, pre-compression along the transverse direction and the normal direction (ND) was conducted on the rolled AZ31Mg alloy. Subsequently, the pre-compressed samples were annealed at 250 °C for different times. The effects of pre-compression and post-annealing on the yielding behavior during subsequent compression along ND were investigated. The results revealed that a lot of non-recrystallized extension twin remained in 5% PT sample after annealing for 4 h, while no twin was observed in the 5% PN sample, under the same annealing time. Along with, no prominent changes occurred in the texture of post-annealed as compared to pre-compressed samples. Due to the grain refinement caused by static recrystallization, yield strength increase of 5% PNA sample is found for an annealing time of 30 min. For the 5% PTA sample, the strength increase is attributed to annealing hardening (i.e., annealing retards the detwinning activity and consequently increase the yield strength).
Co-reporter:Jianping Zhang;Yu Zhang
Journal of Materials Science: Materials in Electronics 2015 Volume 26( Issue 3) pp:1347-1353
Publication Date(Web):2015 March
DOI:10.1007/s10854-014-2545-3
ZnO nanostructures with four different morphologies (nanoparticles, nanorods, mixtures of nanoparticles and nanorods as well as nanoflowers aggregated by nanoparticles and nanorods) were synthesized successfully via simple hydrothermal method. The crystalline structures of ZnO samples were characterized by the X-ray diffraction and the microscopic morphologies of ZnO samples were observed by the scanning electron microscopy. Besides, the probable growth mechanisms of ZnO nanostructures with four different morphologies were proposed. We found that Hexamethylenetetramine (HMT), the halogen ion F− and the concentration of OH− played a significant role in the morphology of ZnO nanocrystalline. In addition, further gas sensitivity measurements revealed that all the as-synthesized ZnO performed gas-sensing properties towards the ethanol gas with very low concentration. Furthermore, the gas-sensing properties of nanoflowers were much more excellent than the other three low-dimension nanostructures, which indicated that the splendid gas-sensing properties of ZnO nanoflowers were contributed to their large specific area.
Co-reporter:Yanqiong Li, Tianmo Liu, Tianming Li, Xianghe Peng
Materials Letters 2015 140() pp: 48-50
Publication Date(Web):
DOI:10.1016/j.matlet.2014.10.153
Co-reporter:Shixiu Cao, Tianmo Liu, Shahid Hussain, Wen Zeng, Xianghe Peng, Fusheng Pan
Physica E: Low-dimensional Systems and Nanostructures 2015 Volume 68() pp:171-175
Publication Date(Web):April 2015
DOI:10.1016/j.physe.2014.12.029
•Nano-sized WS2 doped TiO2 composite was synthesized via a facile hydrothermal route.•The polyporous and loose WS2/TiO2 nanospheres consisted of many nanoparticles.•The nano-WS2/TiO2 nanocomposite exhibited a wide range of visible light absorption.•The nanocomposite may have potential application as visible light photocatalysis.Nanosized tungsten disulfide (WS2) sensitized titanium dioxide (TiO2) was successfully prepared via a simple yet facile hydrothermal process. The nanocomposite exhibited a wide and intensive absorption in the visible light region of 400–700 nm, and may have a potential application as a visible photocatalyst. In addition, the sensitization mechanism of the nano-WS2 was proposed to elaborate the wide visible light absorption of the WS2/TiO2 nanocomposites.Experimental study on the morphologies and the UV–visible absorption of nano-WS2/TiO2 composite and its sensitization mechanism were presented in the current work.
Co-reporter:Shahid Hussain, Tianmo Liu, M. Kashif, Liyang Lin, Shufang Wu, Weiwei Guo, Wen Zeng, U. Hashim
Materials Science in Semiconductor Processing 2014 Volume 18() pp:52-58
Publication Date(Web):February 2014
DOI:10.1016/j.mssp.2013.10.028
Morphological transformation was achieved from ZnO hexagonal needle-like rods to hexagonal flower-like rods by varying the reaction growth time using the hydrothermal method. Optical bandgap energies were calculated from the absorption spectra using UV‐vis spectroscopy. Gas sensing properties of flower-like hexagonal ZnO structures at 50 ppm for ethanol (C2H5OH) and nitrogen dioxide (NO2) at different temperatures were analyzed. The sensor showed a higher response toward C2H5OH than NO2 gas at 350 °C.
Co-reporter:Shahid Hussain, Tianmo Liu, M. Kashif, Bin Miao, Jiejun He, Wen Zeng, Yu Zhang, U. Hashim, Fusheng Pan
Materials Letters 2014 Volume 118() pp:165-168
Publication Date(Web):1 March 2014
DOI:10.1016/j.matlet.2013.12.068
•Preparation of ZnO nanodisks by using SDS and CTAB separately.•Preparation of twinned ZnO nanodisks by using same surfactants together.•Investigation and characterization of the structural and growth mechanism.Regular hexagonal twinned ZnO nanodisks were successfully prepared from nanodisks using a controlled hydrothermal method with the assistance of double surfactants. The products were characterized using X-ray powder diffraction. The morphologies of ZnO nanostructures were characterized in detail using field-emission scanning electron microscopy and high-resolution transmission electron microscopy. Based on the experimental results, a growth mechanism for hexagonal structure was proposed.For the first time after using double surfactant, we prepared twinned ZnO nanodisks. Before twinning, both the surfactants were used to make nanodisk structures, then assembled to twin the nanodisks by a controlled hydrothermal method.
Co-reporter:Shahid Hussain, Tianmo Liu, M. Kashif, Shixiu Cao, Wen Zeng, Sibo Xu, Khalid Naseer, Uda Hashim
Materials Letters 2014 Volume 128() pp:35-38
Publication Date(Web):1 August 2014
DOI:10.1016/j.matlet.2014.04.115
•Preparation of ZnO nanocones by using double anionic surfactants.•Investigating and characterizing the anionic surfactant effects on structural and growth mechanism.•Exposing the as prepared nanostructures to formaldehyde for gas sensing properties.Hexagonal ZnO nanocones were successfully prepared using a controlled hydrothermal method with the assistance of double anionic surfactants. The products were characterized using X-ray powder diffraction. The morphologies of ZnO nanostructures were characterized using field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The effects of the addition of one anionic to another anionic reagent in the crystal structure formation were discussed in detail. The gas sensing properties were measured for formaldehyde.For the first time using double surfactant, we prepared twinned ZnO Nanocones. Before twinning, both the surfactants were used to make nanodisk structures, and then assembled to twin the nanodsiks by a controlled hydrothermal method.
Co-reporter:Shixiu Cao, Tianmo Liu, Shahid Hussain, Wen Zeng, Xianghe Peng, Fusheng Pan
Materials Letters 2014 Volume 129() pp:205-208
Publication Date(Web):15 August 2014
DOI:10.1016/j.matlet.2014.05.013
•WS2 nanostructures were successfully synthesized through a hydrothermal method.•Different nanostructures were obtained by controlling surfactants concentration.•Surfactants play an important role in the formation of the WS2 nanostructures.•This research is important for the preparations of other metal sulfide materials.We report a successful fabrication of tungsten disulfide (WS2) nanostructures with different morphologies including rod-like, sheet-like and fiber-like ones via a simple yet facile hydrothermal process by adding surfactants cetyltrimethyl ammonium bromide (CTAB) and polyethylene glycol (PEG). The structural features of the as-prepared WS2 are characterized systematically by the X-ray powder diffraction and scanning electron microscopy. We find that the surfactants play a critical role in producing low dimensional WS2 structures with different morphologies. We also propose growth mechanisms for the various WS2 morphologies. The simple fabrication of WS2 nanostructures can also be applied for the synthesis of other transition metal sulfides with novel nanostructures.
Co-reporter:Shixiu Cao;Wen Zeng
Journal of Materials Science: Materials in Electronics 2014 Volume 25( Issue 10) pp:4300-4305
Publication Date(Web):2014 October
DOI:10.1007/s10854-014-2164-z
Flower-like WS2 nanospheres with high purity were successfully synthesized via a facile surfactant-assisted hydrothermal route. The products were characterized by X-ray powder diffraction and scanning electron microscopy. The flower-like WS2 nanospheres, consisting of numerous aggregate nanosheets with the width of 300–500 nm, had uniform sizes with a mean diameter about 5 μm. Further comparative experiments showed that the surfactant cetyltrimethyl ammonium bromide (CTAB) played a critical role as templates to promote the growth of WS2 nanosheets and accelerate the assembling of nanosheets into flower-like nanosphere. Interaction forces inside the CTAB made the flower-like nanospheres grow uniformly and dispersedly. Moreover, the WS2 nanoflowers exhibited excellent visible-absorption ability and may have a potential application as a visible photocatalyst.
Co-reporter:Shahid Hussain;M. Kashif
Journal of Materials Science: Materials in Electronics 2014 Volume 25( Issue 11) pp:4725-4729
Publication Date(Web):2014 November
DOI:10.1007/s10854-014-2223-5
ZnO nanodisks exhibiting regular hexagonal structures were successfully synthesized using two surfactants via a hydrothermal method. The surfactants, namely, cetyltrimethylammonium bromide and sodium dodecyl sulfate, had vital functions in the formation of nanodisk structures. The fabricated ZnO nanodisk-based sensor was exposed to reductive gases. The performance of the developed gas sensor to formaldehyde was superior than that to ethanol. The highest sensitivity values for formaldehyde and ethanol (150 ppm) were 81.6 and 43.2, respectively, at an optimal temperature of 300 °C.
Co-reporter:Shun Xu, Tianmo Liu, Xuezheng Ding, Wen Zeng
Materials Science and Engineering: A 2014 Volume 592() pp:230-235
Publication Date(Web):13 January 2014
DOI:10.1016/j.msea.2013.08.073
In the current paper, pre-compression is performed along the rolling direction (RD). Subsequently, the samples are deformed in plane-strain compression along the transverse direction (TD) and not allowed to expand in the normal direction (ND). The effect of plane-strain compression on the texture and anisotropy modification of a pre-twinned hot-rolled Mg–3Al–1Zn alloy is investigated by EBSD observation. The results reveal that the generation of {101¯2}−{101¯2} double twins in the previous {101¯2} twins dominates the plane-strain pre-compression along TD while the {101¯2} twinning is difficult to occur in the matrix due to the constraint along ND. Additionally, the {101¯2}−{101¯2} double twins generated in the previously formed {101¯2} twins effectively modify the compression behavior and enhance the compressive yield strength of the pre-compressed samples along ND. The anisotropy along RD, TD and ND is decreased.
Co-reporter:Jiejun He, Tianmo Liu, Yin Zhang, Jun Tan
Journal of Alloys and Compounds 2013 Volume 578() pp:536-542
Publication Date(Web):25 November 2013
DOI:10.1016/j.jallcom.2013.07.001
•Samples perpendicular to ED exhibit lower yield stress than these parallel to ED.•Yield stress of sample perpendicular to ED increases if pre-compressed along ED.•The change of orientation leads to a different twin characteristic.The twin characteristics and flow stress evolution in the extruded magnesium alloy AZ31 under prior compression parallel to extrusion direction (ED) and then compression perpendicular to ED at room temperature was investigated. Because of the role of activated basal slip, samples parallel to the extrusion radial direction exhibit lower yield stress than these parallel to the ED. However, the compressive yield stress of the sample parallel to the extrusion radial direction increases when there is pre-compression along ED. Twins produced under the load parallel to ED are nearly parallel to each other in a grain, but the twin morphologies are multiple in the sample parallel to extrusion radial direction. Schmid factor was conducted to explain the twin characteristics and flow stress evolution under these stress condition.
Co-reporter:Yong Chen, Tianmo Liu, Chunlin Chen, Weiwei Guo, Rong Sun, Shuhui Lv, Mitsuhiro Saito, Susumu Tsukimoto, Zhongchang Wang
Ceramics International 2013 Volume 39(Issue 6) pp:6607-6610
Publication Date(Web):August 2013
DOI:10.1016/j.ceramint.2013.01.096
Abstract
We report a synthesis of two types of CeO2 nano-rods via the facile and efficient hydrothermal process free from any surfactant and template. The synthesized nano-rods are chemically identified as CeO2 with the standard fluorite structure but their morphologies are different. The nano-rods prepared with cerium nitrate hexahydrate and sodium phosphate are thicker and shorter with diameter of ∼30 nm and length of ∼100 nm, and those prepared with cerium acetate hydrate and dibasic sodium phosphate are thinner and longer with ∼10 nm in diameter and ∼400 nm in length. Microstructural analyses reveal that the two species of nano-rods have low-energy {111} surfaces and grow along the 〈112〉 direction. As a consequence of their morphologies, the two types of synthesized nano-rods exhibit excellent UV-absorption ability in comparison to the irregular CeO2 nanoparticles.
Co-reporter:Yong Chen, Tianmo Liu, Chunlin Chen, Weiwei Guo, Rong Sun, Shuhui Lv, Mitsuhiro Saito, Susumu Tsukimoto, Zhongchang Wang
Materials Letters 2013 Volume 96() pp:210-213
Publication Date(Web):1 April 2013
DOI:10.1016/j.matlet.2013.01.069
We report the synthesis of three kinds of hybrid architectures with two different types of ceria nanoparticles, the nano-rods and nano-octahedrons, within one step via a facile yet efficient hydrothermal process. We demonstrate that morphology of the synthesized CeO2 nanomaterials can be manipulated via tuning the type and concentration of the mineralizer. The synthesis mechanism and chemical evolution of the harvested nanomaterials are also discussed in light of the role played by the mineralizer. Such a simple method to synthesize the functional nano-crystallites with tunable morphology by tailoring the concentration of mineralizer alone should be applicable to other types of nanomaterials and significant for a wide range of applications.Highlights► A facile method was used to fabricate hybrid architectures. ► The method is surfactant and template free. ► The systems show morphology of CeO2 nano-rods mixed with nano-octahedrons. ► The simple approach is applicable to other types of nanomaterials.
Co-reporter:Liyang Lin, Tianmo Liu, Yu Zhang, Shahid Hussain, Shufang Wu, Wen Zeng
Materials Letters 2013 Volume 108() pp:231-234
Publication Date(Web):1 October 2013
DOI:10.1016/j.matlet.2013.06.065
•The synthesized NiO sample presents chrysanthemum-like morphology which was much less reported.•Doping the WO3·0.33H2O into the NiO to form a special p–n heterojunction was never reported before.•The composite exhibited outstanding ethanol-sensing performance.•Schematic model for the doped sensor was built to make the response process clear.Tungsten doped chrysanthemum-like NiO composite was successfully prepared via the hydrothermal process, then the calcination after mixing. Three relative samples (WO3·0.33H2O–NiO, NiO, WO3·0.33H2O) were tested and confirmed by X-ray diffraction. At the meantime, the Energy Dispersive Spectrometer (EDS) was used to prove that the dopant, tungsten, had been doped into the NiO. The morphologies of NiO and WO3·0.33H2O–NiO were characterized by field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). Significantly, the comparation of ethanol-sensing performances among the above three samples was disscussed in detail revealing that the doping of tungsten enhanced the gas-sensing property extremely. In addition, the doping model and gas-sensing mechanism were proposed to elaborate the high improvement of the sensor response to the ethanol.
Co-reporter:Yong Chen, Tianmo Liu, Chunlin Chen, Rong Sun, Shuhui Lv, Mitsuhiro Saito, Susumu Tsukimoto, Zhongchang Wang
Materials Letters 2013 Volume 92() pp:7-10
Publication Date(Web):1 February 2013
DOI:10.1016/j.matlet.2012.10.068
A hybrid architecture comprising two types of cerium compound nanoparticles is synthesized via a facile surfactant- and template-free hydrothermal process. The prepared hybrid materials show an unusual morphology with small hexagonal nano-disks dispersed on relatively larger frustum pyramids. Microscopic analyses identify the chemical composition of the nano-disks as CeF3 and the frustum pyramids as CeO2. Apart from absorption on the CeO2 supports, the CeF3 nano-disks are self-assembled as well to form ordered one-dimensional chain nanostructure. Such unique hybrid architecture may open an avenue for the scientific and technological application in the rapidly emerging catalytic field.Highlights► Simple method was used to fabricate a hybrid CeF3/CeO2 system. ► Method is surfactant and template free. ► System shows a unique architecture of CeF3 nano-disks on CeO2 frustum pyramid. ► Hybrid architecture is promising for catalytic applications.
Co-reporter:Liyang Lin, Tianmo Liu, Bin Miao, Wen Zeng
Materials Letters 2013 Volumes 102–103() pp:43-46
Publication Date(Web):July 2013
DOI:10.1016/j.matlet.2013.03.103
•The synthesized NiO sample presents perfect regular hexagonal nanosheet which was much less reported.•The concentration of ammonia solution and the additive of EG were controlled in the synthesis processing.•It was the first to illustrate the growth mechanism for this hexagonal structure by the crystal structure theory.•The hexagonal NiO nanosheets were promising sensing materials for alcohol among various gases.Uniform hexagonal NiO nanosheets were perfectly prepared by a controlled hydrothermal method followed by calcination. The as-prepared products were characterized by X-ray powder diffraction (XRD), which illustrated the precursor Ni(OH)2 and the final product NiO. The morphologies of NiO were characterized in detail by field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). The SAED pattern is detected from a sampling area covering a collection of constituent nanoparticles. Based on the experimental results and the crystal structure theory, the chemical reaction processes and the growth mechanism for hexagonal structure were proposed. In addition, the gas-sensing performances of uniform hexagonal NiO were investigated toward 50 ppm of several reductive gases including ethanol, CO, H2S, CH4 and NH3 at different working temperatures.Graphical abstract(a) The FE-SEM image shows the as-synthesized NiO product presents uniform hexagonal nanosheets, and (b) the HRTEM image gives a special feature of a perfect hexagonal nanosheet.
Co-reporter:Shun Xu, Tianmo Liu, Huicong Chen, Zichun Miao, Zheng Zhang, Wen Zeng
Materials Science and Engineering: A 2013 Volume 565() pp:96-101
Publication Date(Web):10 March 2013
DOI:10.1016/j.msea.2012.11.127
Co-reporter:Liyang Lin, Tianmo Liu, Weijie Yu, Zhongping Gou, Wen Zeng
Materials Research Bulletin 2013 48(7) pp: 2730-2736
Publication Date(Web):
DOI:10.1016/j.materresbull.2013.04.004
Co-reporter:Jiejun He, Tianmo Liu, Shun Xu, Yin Zhang
Materials Science and Engineering: A 2013 Volume 579() pp:1-8
Publication Date(Web):1 September 2013
DOI:10.1016/j.msea.2013.04.115
The effects of compressive pre-deformation along extrusion direction (ED) on yield asymmetry between tension and compression in hot-extruded Mg–3Al–1Zn (AZ31) alloy was investigated in this paper. {10–12}-type twinning occurred when samples were subjected to compressive pre-deformation. The compressive yield strength of sample with compressive pre-deformation increased gradually with the increase in compressive prestrain. The tensile yield strength of the sample decreased rapidly with the increase in compressive prestrain from zero to ~1.7%, but it was nearly unaltered when compressive prestrain was higher than ~1.7%. Detwinning occurred in the twinned regions played roles in the subsequent tensile process so that the yield stress was lower than sample without prestrain. Yield asymmetry between tension and compression decreased gradually when compressive prestrain was lower than ~1.1%, but it began to increase after that. It suggests that yield asymmetry can be effectively controlled by appropriate pre-deformation.
Co-reporter:Yong Chen, Tianmo Liu, Chunlin Chen, Weiwei Guo, Rong Sun, Shuhui Lv, Mitsuhiro Saito, Xianghe Peng, Susumu Tsukimoto, Zhongchang Wang
Physica E: Low-dimensional Systems and Nanostructures 2013 Volume 48() pp:181-186
Publication Date(Web):February 2013
DOI:10.1016/j.physe.2013.01.006
We report the preparation of cerium-containing nanoparticles by a simple yet efficient hydrothermal synthesis process using cerium resource and NaF mineralizer with no surfactant or template. We demonstrate that morphology and chemistry of the synthesized CeO2 and CeF3 nanomaterials can be manipulated via tuning concentration of the mineralizer NaF alone. The synthesis mechanism, chemical evolution, and optical properties of the harvested nanomaterials have also been investigated. The ceria and its hybrid system are found to exhibit an excellent UV-shielding capability, which provides further evidence that the mineralizer NaF is critical for governing the morphology and properties of the cerium-containing nanomaterials. Such a facile method to synthesize the functional nano-crystallites with tunable morphology and chemistry by tailoring the concentration of mineralizer alone should be applicable to other types of nanomaterials and relevant for a wide range of applications.Graphical abstractWe report the preparation of cerium-containing nanoparticles by a simple yet efficient hydrothermal synthesis process without any surfactants or templates. The morphology and chemistry of the fabricated CeO2 and CeF3 nanomaterials can be manipulated via tuning concentration of a mineralizer NaF alone. The hybrid systems exhibit an excellent UV-shielding capability. Such a facile method is applicable to other types of nanomaterials for a wide range of applications.Highlights► A simple hydrothermal process is used to synthesize cerium-related nanomaterials. ► No surfactant or template is applied. ► The morphology and chemistry can be tuned by concentration of mineralizer alone. ► The ceria and hybrid system show an excellent UV-shielding ability.
Co-reporter:Shun Xu, Tianmo Liu, Jiejun He, Liwei Lu, Wen Zeng
Materials & Design 2013 45() pp: 166-170
Publication Date(Web):
DOI:10.1016/j.matdes.2012.08.074
Co-reporter:Weiwei Guo, Tianmo Liu, Rong Sun, Yong Chen, Wen Zeng, Zhongchang Wang
Sensors and Actuators B: Chemical 2013 178() pp: 53-62
Publication Date(Web):
DOI:10.1016/j.snb.2012.12.073
Co-reporter:Liyang Lin, Tianmo Liu, Bin Miao, Wen Zeng
Materials Research Bulletin 2013 48(2) pp: 449-454
Publication Date(Web):
DOI:10.1016/j.materresbull.2012.10.046
Co-reporter:Weiwei Guo, Tianmo Liu, Rong Sun, Yong Chen, Wen Zeng, Zhongchang Wang
Materials Letters 2012 Volume 89() pp:5-8
Publication Date(Web):15 December 2012
DOI:10.1016/j.matlet.2012.08.055
Nanomaterials with unusual architectures or morphologies often exhibit novel functional properties. Here, we apply a simple two-step solution method to synthesize the ZnO/SnO2 microspheres with an average size of 1–2 μm, which exhibit a unique core–shell architecture with a uniform dispersion of SnO2 nanoparticles on surfaces of spherical ZnO cores. We further investigate in detail the morphology evolution with reaction time, based upon which a likely growth mechanism is proposed. In property, the prepared core–shell structural ZnO/SnO2 microspheres show excellent gas-sensing functions to ethanol gas of 50 ppm at an optimal temperature as low as 250 °C, rendering the hybrid microspheres a promising gas-sensing material for the on-site detection of ethanol.Highlights► A simple method was used to synthesize the ZnO/SnO2 microspheres. ► The microspheres show a unique core–shell architecture. ► Gas-sensing functions are enhanced greatly due to the unique structures. ► The hybrid microspheres are promising for on-site detection of ethanol.
Co-reporter:Liwei Lu, Tianmo Liu, Yong Chen, Zhongchang Wang
Materials Characterization 2012 Volume 67() pp:93-100
Publication Date(Web):May 2012
DOI:10.1016/j.matchar.2012.02.023
Grains inside extruded Mg alloys AZ31 are usually elongated along the < 112¯0 > crystal direction with their c axis perpendicular to extrusion direction, which often affects mechanical properties of the AZ31 alloys significantly. Here, we conduct cold compressive and tensile deformation tests to the as-extruded AZ31 alloys, aimed at investigating the role played by elongated grains in deformation and understanding the origin of fracture propagation. Using several analytic techniques, we characterize the fracture features thoroughly and identify the fracture propagation mechanism as the dimpled rupture during cold tensile deformation. We also investigate the fundamental impact of the elongated grains, twins, inclusions, and secondary phase on the crack propagation, and propose an effective way in modifying or even enhancing mechanical properties of the engineering important Mg alloys AZ31.Highlights► Facture propagation mechanism is identified as dimpled rupture during deformation. ► The original elongated coarse grains are unable to coordinate plastic deformation. ► Contraction twins locate at boundary of elongated grains and interact with cracks. ► Suppressing elongated grains, inclusions and pores enhances plasticity of Mg alloys.
Co-reporter:Dejun Liu, Tianmo Liu, Hejing Zhang, Chengling Lv, Wen Zeng, Jianyue Zhang
Materials Science in Semiconductor Processing 2012 Volume 15(Issue 4) pp:438-444
Publication Date(Web):August 2012
DOI:10.1016/j.mssp.2012.02.015
Doping often plays a critical role in governing gas sensing properties of nanomaterials. Different levels of cerium (Ce) doped-tin oxide (SnO2) nanomaterials are synthesized by a hydrothermal method in order to improve its sensor performance. X-ray diffraction and field emission scanning electronic microscopy are employed to examine the chemical composition and microstructures. It is found that Ce4+ doping can suppress the growth of large SnO2 crystallites and assist a uniform growth of large agglomeration spheres. The gas sensing properties is also investigated. By considering a variety of volatile organic compound gas and gas concentration, 2% Ce-doped SnO2 is found to exhibit the best gas sensing properties with excellent response and fast response-recovery even at low gas concentration of 10 ppm. Further comparative studies attribute this to enhanced capability of adsorbing oxygen on the surface. It is proposed that the main oxygen species on the surface of SnO2 is O2−, but O− may play a more important role in improving gas response.
Co-reporter:Hejing Zhang, Tianmo Liu, Long Huang, Weiwei Guo, Dejun Liu, Wen Zeng
Physica E: Low-dimensional Systems and Nanostructures 2012 Volume 44(7–8) pp:1467-1472
Publication Date(Web):April–May 2012
DOI:10.1016/j.physe.2012.03.013
Unique assembled sphere-like WO3 architectures were successfully synthesized through a facile hydrothermal method in the presence of malic acid followed by subsequent heat treatment. We found that malic acid played a significant role in governing morphologies of WO3·xH2O precursors during hydrothermal process. A possible formation mechanism was also proposed in detail. Experimental results showed that the optimized hydrothermal precursor could be dehydrated to mixed composition of hexagonal and monoclinic WO3 with the unique sphere-like porous architecture after being annealed at 400 °C for 2.5 h. Besides, gas-sensing measurement indicated that the well-defined 3D assembled sphere-like architectures exhibited the highest sensor response to ethanol at the optimal temperature of 250 °C among the samples.Graphical abstractWe have prepared unique three-dimensional assembled sphere-like WO3 architectures successfully via a facile hydrothermal method followed by a subsequent heat treatment. The well-defined porous structures exhibit novel gas-sensing properties to ethanol.Highlights► Unique assembled sphere-like WO3 architectures are successfully obtained. ► Malic acid is introduced as an assembling and structure-directing agent to controllable synthesis of WO3 architectures. ► The well-defined sphere-like WO3 architectures exhibit excellent gas-sensing properties to ethanol. ► The malic acid presented in current experiment may provide inspiration for controllably synthesizing other metals oxide.
Co-reporter:Cheng Chen, Tianmo Liu, Chengling Lv, Liwei Lu, Dongzhi Luo
Materials Science and Engineering: A 2012 Volume 539() pp:223-229
Publication Date(Web):30 March 2012
DOI:10.1016/j.msea.2012.01.084
Co-reporter:Long Huang;Hejing Zhang
Journal of Materials Science: Materials in Electronics 2012 Volume 23( Issue 11) pp:2024-2029
Publication Date(Web):2012 November
DOI:10.1007/s10854-012-0697-6
A type of titanium precursor, H-exchanged titanate nanobelts, was used to prepare nanosized anatase titanium dioxide (TiO2) with various morphologies by hydrothermal method. Nanorods, nanobelts, nano-polyhedrons and nanoparticles were successfully synthesized. We found that CTAB and EDTA-4Na+ play critical roles in synthesizing the nanorods and nano-polyhedrons. All the samples exhibit rapid response and recovery time to ethanol, but Nanorods, nanobelts and nano-polyhedrons show lager response than nanoparticles.
Co-reporter:Chengling Lv, Tianmo Liu, Dejun Liu, Shan Jiang, Wen Zeng
Materials & Design 2012 33() pp: 529-533
Publication Date(Web):
DOI:10.1016/j.matdes.2011.04.060
Co-reporter:Liwei Lu, Tianmo Liu, Ming-Jen Tan, Jian Chen, Zhongchang Wang
Materials & Design 2012 39() pp: 131-139
Publication Date(Web):
DOI:10.1016/j.matdes.2012.02.035
Co-reporter:Liwei Lu, Tianmo Liu, Yong Chen, Liguang Wang, Zhongchang Wang
Materials & Design 2012 35() pp: 138-143
Publication Date(Web):
DOI:10.1016/j.matdes.2011.09.039
Co-reporter:Jian Chen, Tianmo Liu, Liwei Lu, Yueyang Zhang, Wen Zeng
Materials & Design 2012 36() pp: 577-583
Publication Date(Web):
DOI:10.1016/j.matdes.2011.12.002
Co-reporter:Liwei Lu, Tianmo Liu, Jian Chen, Zhongchang Wang
Materials & Design 2012 36() pp: 687-693
Publication Date(Web):
DOI:10.1016/j.matdes.2011.12.023
Co-reporter:Weiwei Guo, Tianmo Liu, Wen Zeng, Dejun Liu, Yong Chen, Zhongchang Wang
Materials Letters 2011 Volume 65(23–24) pp:3384-3387
Publication Date(Web):December 2011
DOI:10.1016/j.matlet.2011.07.059
New morphologies often play a critical role in governing properties of nano-materials. Here, using hydrothermal method and reagents of sodium citrate and polyethylene glycol (PEG), we synthesize the ZnO nano-crystals and find that they exhibit hierarchical flower-like architectures assembled by nanosheets. Further comparative studies demonstrate that the sodium citrate assists a uniform growth of the nanosheets, and the PEG provides nucleation sites for the assembling of the nanosheets, both of which play a critical role in producing such unique flower-like architectures. Consequently, this sample is found to show excellent sensing performances to the target ethanol owing to its largest amount of petals, intervals, and pores. Such an unexpected morphology holds substantial promise for rendering ZnO as a potential gas-sensing material for a broad range of future sensor applications.Highlights► The ZnO nanocrystals show flower-like architectures assembled by nanosheets. ► Sodium citrate and PEG are important for producing flower-like architectures. ► Gas sensing properties are enhanced significantly due to the unique structures. ► Such morphology makes ZnO promising for a wide range of future sensor applications.
Co-reporter:Jinxing Wang, Tianmo Liu, Zhongchang Wang, Eberhard Bugiel, Apurba Laha, Tatsuro Watahiki, Roman Shayduk, Wolfgang Braun, Andreas Fissel, Hans Jörg Osten
Materials Letters 2010 Volume 64(Issue 7) pp:866-868
Publication Date(Web):15 April 2010
DOI:10.1016/j.matlet.2010.01.045
New gate dielectric substitute for high-k application requires well matched lattice parameters and an atomically defined interface with Si for optimal performance. Using molecular beam epitaxy technique, we have grown on Si(111) crystalline rare-earth oxide ultrathin films, (GdxNd1 − x)2O3 (GNO), a multi-component material that is superior to either of its binary host oxides. By carefully characterizing its crystal structure, we have found that the epitaxial GNO film exhibits a single bixbyite cubic structure with ultralow lattice mismatch to Si, which is indistinguishable even by the powerful synchrotron radiation. This structural perfection could make the GNO a promising high-k material in future devices.
Co-reporter:Liwei Lu, Tianmo Liu, Shan Jiang, Fushen Pan, Qing Liu, Zhongchang Wang
Materials Science and Engineering: A 2010 527(16–17) pp: 4050-4055
Publication Date(Web):
DOI:10.1016/j.msea.2010.03.009
Co-reporter:Dewen Hou, Tianmo Liu, Longjing Luo, Liwei Lu, Huicong Chen, Dongfeng Shi
Materials Characterization (February 2017) Volume 124() pp:122-128
Publication Date(Web):February 2017
DOI:10.1016/j.matchar.2016.11.046
Co-reporter:Wen Zeng, Tianmo Liu, Zhongchang Wang
Physica E: Low-dimensional Systems and Nanostructures (December 2010) Volume 43(Issue 2) pp:633-638
Publication Date(Web):1 December 2010
DOI:10.1016/j.physe.2010.10.010
Most of volatile organic compounds (VOCs) are often harmful or even toxic for environment, which require in situ detection. Here, we demonstrate that the TiO2 additive can enhance significantly gas-sensing properties of the SnO2-based sensor to VOCs, independent of its content and the concentration of tested gases. The improved gas-sensing quantities of matter, i.e., maximum sensitivity, minimum gas concentration, optimal operating temperature, and response and recovery times, are found to satisfy the basic needs for a practical application, which renders the TiO2–SnO2 composite material promising for the development of sensor devices to VOCs.Graphical abstractResearch Highlights► TiO2 additive enhances significantly gas-sensing properties of SnO2-based sensor to volatile organic compounds. ► Property improvement is independent of operating temperature and gas concentration. ► Enhanced key gas-sensing properties meet basic needs for practical applications. ► TiO2–SnO2 composite is promising for development of sensors to volatile organic compounds.
Co-reporter:Shuoqing Zhao, Tianmo Liu, Le Yu, Wen Zeng, Yangyang Zhang, Bin Ke, Shahid Hussain, Liyang Lin, Xianghe Peng
Ceramics International (15 February 2017) Volume 43(Issue 3) pp:
Publication Date(Web):15 February 2017
DOI:10.1016/j.ceramint.2016.11.047
Ternary metal oxides have great potential for chemical storage devices because of their outstanding synergistic effects as well as rich redox reactions. However, there are limited reports of 3D structure BiCoO3 materials and relevant electrochemical properties. Meanwhile, the study of BiCoO3 is reasonably important for underlying metal oxides researches. In this work, we have successfully developed a 3D urchin-like BiCoO3 material without using any template and surfactant. For the supercapacitor application, the BiCoO3 material showed a specific capacitance of 152 F g−1 at the current density of 1 A g −1, and this value exhibited a rate capability of 82.3% at a high current density of 10 A g −1. Furthermore, the sample showed the ideal cycling stability (92.7% retention after 5000 times cycles at the current density of 1 A g −1 and nearly invariable specific capacitance during different current density cycles). These results suggest that the obtained urchin-like BiCoO3 sample has superb electrochemical performances which suggest its promising applications as renewable and clean energy storage devices electrode materials in the future.
Co-reporter:Longjing Luo, Tianmo Liu, Shuo Zhang, Bin Ke, Le Yu, Shahid Hussain, Liyang Lin
Ceramics International (15 April 2017) Volume 43(Issue 6) pp:
Publication Date(Web):15 April 2017
DOI:10.1016/j.ceramint.2017.01.022
To improve the electrochemical properties of Co3O4 for supercapacitors application, a hierarchical Co3O4@ZnWO4 core/shell nanowire arrays (NWAs) material is designed and synthesized successfully via a facile two-step hydrothermal method followed by the heat treatment. Co3O4@ZnWO4 NWAs exhibits excellent electrochemical performances with areal capacitance of 4.1 F cm−2 (1020.1 F g−1) at a current density of 2 mA cm−2 and extremely good cycling stability (99.7% of the initial capacitance remained even after 3000 cycles). Compared with pure Co3O4 electrodes, the results prove that this unique hierarchical hybrid nanostructure and reasonable assembling of two electrochemical pseudocapacitor materials are more advantageous to enhance the electrochemical performance. Considering these remarkable capacitive behaviors, the hierarchical Co3O4@ZnWO4 core/shell NWAs nanostructure electrode can be revealed promising for high-performance supercapacitors.
Co-reporter:Liyang Lin, Jianlin Liu, Tianmo Liu, Jinghua Hao, Kemeng Ji, Rong Sun, Wen Zeng and Zhongchang Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 34) pp:NaN17658-17658
Publication Date(Web):2015/07/20
DOI:10.1039/C5TA04054J
We report a synthesis of NiCo2S4 nanosheet arrays with self-decorated nanoneedles on nickel foams by a facile and efficient two-step hydrothermal approach. We demonstrate that the morphologies of various three-dimensional nanostructures such as nanoneedle arrays, nanosheet arrays, and nanoneedle-decorated nanosheet arrays can be manipulated by tuning the amount of additive ammonium fluoride alone in the reaction. The unusual nanostructure of nanoneedles grown on the surface of NiCo2S4 nanosheet arrays shows a large electroactive surface area and superior electrochemical properties. The electrode made of the NiCo2S4 nanosheet arrays with self-decorated nanoneedles shows greatly improved electrochemical performances with an ultrahigh specific capacitance of 2617.6 F g−1 at a current density of 15 mA cm−2 and of 2051.0 F g−1 even at a current density of 30 mA cm−2. The electrode also exhibits an excellent cycling stability by retaining 93.2% of its original state after 5000 cycles, rendering the NiCo2S4 nanosheet arrays with self-decorated nanoneedles a potential electrode material for high-performance supercapacitors.
