Tao Tao

Deakin University, Geelong, Victoria, Australia

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Publications (20)73.03 Total impact

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    ABSTRACT: We report sub-nanometre modification enabled by an ultrafine helium ion beam. By adjusting ion dose and the beam profile, structural defects were controllably introduced in a few-layer molybdenum disulphide (MoS2) sample and its stoichiometry was modified by preferential sputtering of sulphur at a few-nanometre scale. Localised tuning of MoS2's resistivity was demonstrated and semiconducting, metallic-like or insulating material was obtained by irradiation with different doses of He(+). Amorphous MoS with metallic behaviour has been demonstrated for the first time. Fabrication of MoS2 nanostructures with 7 nm dimensions and pristine crystal structure was also achieved. The damage at the edges of these nanostructures was typically confined to within 1 nm. Nanoribbons with widths as small as 1 nm were reproducibly fabricated. This nanoscale modification technique is a generalised approach which can be applied to various two-dimensional (2D) materials to produce a new range of 2D metamaterials.
    No preview · Article · Jul 2015 · Nano Letters
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    ABSTRACT: Composite LiFe0.4Mn0.6PO4/C microspheres are considered advanced cathode materials for electric vehicles and other high-energy density applications due to the advantages of high energy density and excellent cycling stability. LiFe0.4Mn0.6PO4/C microspheres have been produced using a double carbon coating process employing traditional industrial techniques (ball milling, spray-drying and annealing). The obtained LiFe0.4Mn0.6PO4 microspheres exhibit a high discharge capacity of around 166 mAh g-1 at 0.1 C and excellent rate capabilities of 132, 103, and 72 mAh g-1 at 5, 10, and 20 C, respectively. A reversible capacity of about 152 mAh g-1 after 500 cycles at a current density of 1 C indicates an outstanding cycling stability. The excellent electrochemical performance is attributed to the micrometer-sized spheres of double carbon-coated LiFe0.4Mn0.6PO4 nanoparticles with improved electric conductivity and higher Li ion diffusion coefficients, ensuring full redox reactions of all nanoparticles. The results show that the advanced high-energy density cathode materials can be produced using existing industry techniques.
    Full-text · Article · Sep 2014
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    ABSTRACT: Nitrogen doped SnO2 polycrystalline nanostructures were produced from commercial SnO powders in a new system that combines a low-temperature plasma with heating. The method has the potential to improve the initial efficiency and the cycling performance of SnO2 anodes in Li-ion batteries. With this system, the temperature of the SnO to SnO2 conversion was lowered from 430 to 320 degrees C, up to 5 at% of doped nitrogen was detected and a nano-scale polycrystalline structure was observed in the product. Combining heat and low-pressure plasma is a promising approach for the production and treatment of enhanced energy storage materials.
    Full-text · Article · Sep 2014 · Plasma Processes and Polymers
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    ABSTRACT: Back Cover: The combination of cold plasma with thermal treatment enables doping and changed growth of semiconductors that cannot be achieved by either treatment alone. The combination applied to commercial SnO powder produced SnO2 with a nano-scale polycrystalline structure and controllable nitrogen doping of up to 5 at. %. This product has potential as an improved anode material for Li-ion batteries. Further details can be found in the article Xiujuan J. Dai et al. on page 897.
    No preview · Article · Sep 2014 · Plasma Processes and Polymers
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    ABSTRACT: Some of the prospective electrode materials for lithium-ion batteries are known to have electronic transport limitations preventing them from being used in the electrodes directly. In many cases, however, these materials may become practical if they are applied in the form of nanocomposites with a carbon component, e.g. via incorporating nanoparticles of the phase of interest into a conducting network of carbon nanotubes. A simple way to prepare oxide–carbon nanotube composites suitable for the electrodes of lithium-ion batteries is presented in this paper. The method is based on low-energy ball milling. An electrochemically active but insulating phase of LiFeTiO4 is used as a test material. It is demonstrated that the LiFeTiO4 –carbon nanotube composite is not only capable of having significantly higher capacity (~105–120 mA h g-1 vs. the capacity of ~65–70 mA h g-1 for the LiFeTiO4 nanoparticles) at a slow current rate but may also operate at reasonably high current rates.
    Full-text · Article · Aug 2014 · RSC Advances
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    ABSTRACT: Li0.5Fe2.5O4 nanoparticles of about 80 nm were synthesized through a hydrothermal method, followed by a solid state reaction between LiOH·H2O and Fe2O3. The Li0.5Fe2.5O4 nanoparticles exhibit a remarkable high capacity (up to 1124 mA h g−1), a good cycle stability (650 mA h g−1 after 50 cycles) and excellent coulombic efficiency.
    Full-text · Article · May 2014 · RSC Advances
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    ABSTRACT: The electrochemical reactivity of the ball-milled ilmenite FeTiO3 and ilmenite nanoflowers with lithium has been investigated. The electrode assembled with the ilmenite nanoflowers delivers better electrochemical performance than that of the milled material during charging and discharging in the potential range of 0.01 and 3 V vs. Li/Lit(+). The ilmenite nanoflowers demonstrate the capacity of ca. 650 mAh g(-1) during the first discharge, and a reversible capacity of approximately 200 mAh g(-1) in the course of the first 50 cycles. The possible reaction mechanism between ilmenite and lithium was studied using cyclic voltammetry and transmission electron microscopy. The first discharge involves the formation of an irreversible phase, which is either LiTiO2 or LiFeO2. Subsequently, the extraction-insertion of lithium happens in a reversible manner. It was also observed that the lithium storage might be significantly improved if the electrode was prepared in the form of a nanocomposite of FeTiO3 with carbon. Crown Copyright
    Preview · Article · Oct 2013 · Electrochimica Acta
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    ABSTRACT: EVWUDFW SiO nanowires have been synthesized on SiC substrates with liquid phase Fe as a novel catalyst at 1300 -1400ć. The length of SiO nanowires is in the range of several tens to hundreds of micrometers, and the diameters are 40-230 nm. Energy dispersive X-ray analysis shows the element ratio Si: O nanowires as 1:1. However, X-ray-diffraction reveals amorphous structure in SiO nanowires. The formation process of SiO nanowires is related to the solid-liquid-solid growth mechanism. FTIR spectra of SiO nanowires demonstrate two peaks at 1066 and 800 nm, which are different from those of SiO 2 nanowires. Meanwhile, Raman spectrum also shows that the characteristic SiO nanowires (321 and 378 nm) is different from the traditional SiO 2 nanowires. Photoluminescence spectrum of SiO nanowires shows strong absorption peaks at 421 and 520 nm. results indicate SiO nanowires having potential application in the optical field. In recent years, one-dimensional nano-sized materials, such as nanowires, nanoroads and nanotubes, have been investigated extensively due to their particular properties and great potential applications [1]. Silicon and silica nanostructures have attracted considerable attention because of their 1671 The 8 th Pacific Rim International Congress on Advanced Materials and Processing Edited by: Fernand Marquis TMS (The Minerals, Metals & Materials Society), 2013
    Full-text · Conference Paper · Aug 2013
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    ABSTRACT: EVWUDFW Magnetic, magnetocaloric, electrical properties of nanocrystalline and coarse-grained gadolinium (Gd) metals were compared in the present work. The bulk nanocrystalline matels have been consolidated from Gd nanoparticles using spark plasma sintering technique. With the decrease of Gd grain size from micrometer to nanometer range, Curie temperature of the nanocrystalline Gd shifts by more than 6 K below that of coarse-grained and the magnetic moment per Gd atom at 5 K dropped noticeably from 7.81u B to 6.31u B . Magnetic entropy change of crystalline Gd drops surprising from 10.07 to 4.47 Jkg -1 gK -1 at ႤH=5 T; adiabatic temperature change drops from 3.5 K to 1.1 K with ႤH=1.5 T. However, magnetocaloric effect of the nanocrystalline metals exhibit a more constant tendency. The room temperature electrical resistivity increases from 209.68 to 333.04 uΩ cm, while the low temperature electrical resistivity is found to increase surprisingly from 16.51 to 126.30 uΩ cm. .H\ZRUGV ˖ Magnetic properties; magnetocaloric properties; electrical properties; nanocrystalline metals; Gd 1729 The 8 th Pacific Rim International Congress on Advanced Materials and Processing Edited by: Fernand Marquis TMS (The Minerals, Metals & Materials Society), 2013
    Full-text · Conference Paper · Aug 2013
  • Tao Tao · Ying Chen
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    ABSTRACT: Rutile TiO2 nanorods were directly synthesized from natural mineral ilmenite via a simple two-step process, including ball milling and wet chemistry treatments. The morphological and structural characterizations reveal that the nanorods with length of 50–100 nm, width of 5–20 nm and thickness of 2–5 nm possess a large specific surface area (97 m2/g). The obtained rutile TiO2 nanorods show excellent electrochemical properties, such as large reversible charge–discharge capacity, good cycling stability and high rate performance, when used as anode materials for lithium ion batteries. Moreover, their electrochemical performance is better than that of two commercial samples including commercial annatase and rutile TiO2.
    No preview · Article · May 2013 · Materials Letters
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    ABSTRACT: A novel nanocomposite architecture of a Fe2O3-SnO2-C anode, based on clusters of Fe2O3 and SnO2 nanoparticles dispersed along the conductive chains of Super P Li™ carbon black (Timcal Ltd.), is presented as a breathable structure in this paper for lithium-ion batteries. The synthesis of the nanocomposite is achieved by combining a molten salt precipitation process and a ball milling method for the first time. The crystalline structure, morphology, and electrochemical characterization of the synthesised product are investigated systematically. Electrochemical results demonstrate that the reversible capacity of the composite anode is 1110 mA h g(-1) at a current rate of 158 mA g(-1) with only 31% of initial irreversible capacity in the first cycle. A high reversible capacity of 502 mA h g(-1) (higher than the theoretical capacity of graphite, ∼372 mA h g(-1)) can be obtained at a high current rate of 3950 mA g(-1). The electrochemical performance is compared favourably with those of Fe2O3-SnO2 and Fe2O3-SnO2-C composite anodes for lithium-ion batteries reported in the literature. This work reports a promising method for the design and preparation of nanocomposite electrodes for lithium-ion batteries.
    Preview · Article · Apr 2013 · Nanoscale
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    ABSTRACT: The mineral ilmenite is one of the most abundant ores in the Earth's crust and it is the main source for the industrial production of bulk titanium oxide. At the same time, methods to convert ilmenite into nanostructures of TiO(2) (which are required for new advanced applications, such as solar cells, batteries, and photocatalysts) have not been explored to any significant extent. Herein, we describe a simple and effective method for the preparation of rutile TiO(2) nanorods from ball-milled ilmenite. These nanorods have small dimensions (width: 5-20 nm, length: 50-100 nm, thickness: 2-5 nm) and possess large specific surface areas (up to 97 m(2)  g(-1) ). Dissolution/hydrolysis/precipitation is proposed as a growth mechanism. The nanorods were found to have attractive photocatalytic properties in the degradation of oxalic acid. Their photocatalytic activity is close to that of the benchmark Degussa P25 material and better than that of a commercial high-surface-area rutile powder.
    Full-text · Article · Jan 2013 · Chemistry - A European Journal
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    ABSTRACT: A new combination method consisting of ball milling, carbothermic reduction and hydrochloric acid leaching was proposed for the preparation of nanosized synthetic rutile from natural ilmenite. The ball milling was employed to grind ilmenite into small particles. The carbothermic reduction was carried out to yield a high titanium slag, which would be easily purified by subsequent leaching procedure. Factors affecting the hydrochloric acid process, namely the leaching time, temperature, and acid concentration, were studied. After leaching and calcining the milled and annealed mixture of FeTiO3/C under the optimal conditions, the TiO2 nanoparticles with size of 10-200 nm and purity>98.0% were obtained.
    No preview · Article · May 2012 · Transactions of Nonferrous Metals Society of China
  • Tao Tao · QiYuan Chen · HuiPing Hu · Ying Chen
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    ABSTRACT: A highly uniform nanocomposite of MoO3 and carbon with a weight ratio of 1:1 is prepared by employing a simple procedure of ball milling. Such composite as electrochemical pseudocapacitor materials for potential energy storage applications exhibits a high specific capacitance of ~ 179 F/g at a charge and discharge current density of 50 mA/g with excellent cycling ability over 1000 cycles. Compared with the capacitance of pure milled graphite (~ 22 F/g) and MoO3 (< 10 F/g), an enhanced electrochemical performance of the composite with a weight ratio of 1:1 is attributed to its unique structure, in which MoO3 nanoparticles (with a size range of 1–180 nm) are uniformly dispersed in an electrically conductive carbon host.
    No preview · Article · Jan 2012 · Materials Letters
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    ABSTRACT: Pronounced and stable pseudocapacitance has been found in flowerlike FeTiO3 nanostructures that were synthesized from ball-milled ilmenite (natural mineral) under mild hydrothermal conditions. Each nanoflower is composed of many thin petals with a thickness of 5–20 nm and a width of 100–200 nm. The formation of these flowerlike nanostructures is attributed to a dissolution–precipitation mechanism involving an intermediate sodium-containing phase. Electrochemical properties of the obtained FeTiO3 nanostructures are evaluated in aqueous electrolytes. The capacitance of 122 ± 14.5 F/g is measured in 1 M KOH aqueous electrolyte at the current rate of 500 mA/g, and 50 ± 6 F/g is retained at 5 A/g. The material has good long-term cycling stability. According to our data, FeTiO3 nanostructures show functionality as an electrode material for supercapacitors.
    Full-text · Article · Aug 2011 · The Journal of Physical Chemistry C
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    ABSTRACT: A MoO3-carbon nanocomposite was synthesized from a mixture of MoO3 and graphite by a controlled ball milling procedure. The as-prepared product consists of nanosized MoO3 particles (2-180 nm) homogeneously distributed in carbon matrix. The nanocomposite acts as a high capacity anode material for lithium-ion batteries and exhibits good cyclic behavior. Its initial capacity exceeds the theoretical capacity of 745 mA h g-1 in a mixture of MoO3 and graphite (1 : 1 by weight), and the stable capacity of 700 mA h g-1 (94% of the theoretical capacity) is still retained after 120 cycles. The electrode performance is linked with the unique nanoarchitecture of the composite and is compared with the performance of MoO3-based anode materials reported in the literature previously (nanoparticles, ball milled powders, and carbon-coated nanobelts). The high value of capacity and good cyclic stability of MoO3-carbon nanocomposite are attractive in respect to those of the reported MoO3 electrodes.
    Full-text · Article · Jul 2011 · Journal of Materials Chemistry
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    ABSTRACT: Tree-like SnO2 nanowires have been grown by a vapor–solid process using a milled SnO2 powder as the evaporation source. Phase, structural evolution and chemical composition were investigated using X-ray diffraction (XRD), X-ray spectrometry (EDS), and scanning electron microscopy (SEM). The process yields a large proportion of ultra-long rutile nanowires of 50–150nm diameter and lengths up to several tens of micrometers. High-resolution transmission electron microscopy (HRTEM) shows that the SnO2 nanowires are single crystals in the (101) growth direction with scattered smaller crystals or nanowires as the tree branches. The SnO2 nanostructures were also examined using Fourier transform infra-red (FT-IR) and photoluminescence (PL) spectroscopy. A strong emission band centered at 548nm dominated the PL spectrum of the tree-like nanowires.
    No preview · Article · Mar 2011 · Materials Chemistry and Physics
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    ABSTRACT: The evaporation behaviour of a ball milled SnO2 powder has been investigated. It is observed that the milled powder starts to evaporate at the temperatures above 950 °C while the unmilled SnO2 powder does not generate any vapor at this temperature. The effect is likely to be related to structural changes in the milled material and, particularly, a certain degree of reduction of the SnO2 powder in the course of milling. The milled powder can be used as a vapor source for producing various types of nanostructures of SnO2.
    No preview · Article · Aug 2010 · Journal of Alloys and Compounds
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    ABSTRACT: SnO2 nanoribbons have been synthesized by annealing of a milled SnO2 powder, which is able to evaporate efficiently at the temperature as low as 1100 degrees C due to the metastable structure created by ball milling treatment. When the milled powder was annealed in an assembly of two combustion boats, SnO2 nanoribbons formed on the surface of the milled powder. The nanoribbons tend to grow along the [101] crystallographic direction and their side surfaces are represented by +/- (010) and +/- (101) facets. The oxygen plays an important role in enhancing their formation.
    No preview · Article · Aug 2010 · Journal of Nanoscience and Nanotechnology
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    ABSTRACT: Ilmenite (FeTiO3) is an inexpensive abundant natural mineral and it would be a perfect precursor for the production of porous TiO2 if a suitable synthesis method was developed. A new method combining a series of processing steps of ball milling, high-temperature annealing, selective chemical leaching and final calcining in air is proposed in this paper. The resulting TiO2 is a porous material with a bimodal pore structure. The pore size distribution has two clear maxima corresponding to small mesopores (2–30 nm) and large meso- and macropores (centered at around 50–80 nm). It was found that the duration of the annealing step could alter the contribution of each type of pores. A short annealing time (0.5 h) lead to the preferential formation of pores within 2–30 nm while pores centered at 50–80 nm dominated the pore size distribution after a relatively long annealing (1.5 h). The obtained porous rutileTiO2 shows a better photocatalytic activity than that of a commercial rutileTiO2 powder.
    Full-text · Article · Jan 2010 · CrystEngComm

Publication Stats

172 Citations
73.03 Total Impact Points

Institutions

  • 2010-2015
    • Deakin University
      • • Institute for Frontier Materials (IFM)
      • • Institute for Technology Research and Innovation
      Geelong, Victoria, Australia
  • 2012-2014
    • University of Vic
      Vic, Catalonia, Spain
  • 2011-2012
    • Central South University
      • Department of Chemistry Engineering
      Ch’ang-sha-shih, Hunan, China