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Full-Text Articles in Engineering
Electron Tunneling And X-Ray Photoelectron Spectoscopy Studies Of The Superconductiong Properties Of Nitrogen-Doped Niobium Resonator Cavities, Eric M. Lechner, Basu Dev Oli, Junki Makita, Gianluigi Ciovati, Alex Gurevich, Maria Iavarone
Electron Tunneling And X-Ray Photoelectron Spectoscopy Studies Of The Superconductiong Properties Of Nitrogen-Doped Niobium Resonator Cavities, Eric M. Lechner, Basu Dev Oli, Junki Makita, Gianluigi Ciovati, Alex Gurevich, Maria Iavarone
Physics Faculty Publications
We use scanning tunneling microscopy (STM) and spectroscopy (STS), and x-ray photoelectron spectroscopy (XPS) to investigate the effect of nitrogen doping on the surface electronic and chemical structures of cutouts from superconducting Nb radio-frequency cavities. The goal of this work is to get insights into the fundamental physics and materials mechanisms behind the striking decrease of the surface resistance with the radio-frequency magnetic field, which has been observed on N-doped Nb cavities. Our XPS measurements reveal significantly more oxidized Nb 3d states and a thinner metallic suboxide layer on the N-doped Nb surfaces, which is also confirmed by tunneling spectroscopy …
Partial Carrier Freeze-Out At The Laalo3/Srtio3 Oxide Interface, Simon Meaney, Alexey Pan, Antony Jones, Sergey Fedoseev
Partial Carrier Freeze-Out At The Laalo3/Srtio3 Oxide Interface, Simon Meaney, Alexey Pan, Antony Jones, Sergey Fedoseev
Australian Institute for Innovative Materials - Papers
High quality robust two-dimensional electron gas (2DEG) LaAlO3/SrTiO3 (LAO/STO) interfaces are produced using pulsed laser deposition and an acid-free substrate Ti-Termination process, resulting in single unit cell terraces. Temperature dependent resistance measurements show two hysteresis anomalies around 80 K and 160 K. By using Hall measurements, we find an Arrhenius dependence in charge carrier density describing a partial carrier freeze-out below ∼80 K. We show that these two resistance anomalies are unrelated to the temperature dependence of the charge carrier density despite the tempting coincidence of the low temperature hysteresis feature and the freeze-out process. A two-carrier model is required …
Engineering Surface Amine Modifiers Of Ultrasmall Gold Nanoparticles Supported On Reduced Graphene Oxide For Improved Electrochemical Co2 Reduction, Yong Zhao, Caiyun Wang, Yuqing Liu, Douglas R. Macfarlane, Gordon G. Wallace
Engineering Surface Amine Modifiers Of Ultrasmall Gold Nanoparticles Supported On Reduced Graphene Oxide For Improved Electrochemical Co2 Reduction, Yong Zhao, Caiyun Wang, Yuqing Liu, Douglas R. Macfarlane, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Ultrasmall gold (Au) nanoparticles with high mass activity have great potential for practical applications in CO2electroreduction. However, these nanoparticles often suffer from poor product selectivity since their abundant low-coordinated sites are favorable for H2evolution. In this work, a catalyst, reduced graphene oxide supported ultrasmall Au nanoparticles (≈2.4 nm) is developed which delivers high Au-specific mass activities (>100 A g-1) and good Faradaic efficiencies (32-60%) for the CO2-to-CO conversion at moderate overpotentials (450-600 mV). The efficiencies can be improved to 59-75% while retaining the ultrahigh mass activities via a simple amine-modification strategy. In addition, an amine-structure-dependent effect is revealed: linear …
Strategies For Designing Metal Oxide Nanostructures, Ziqi Sun, Ting Liao, Liangzhi Kou
Strategies For Designing Metal Oxide Nanostructures, Ziqi Sun, Ting Liao, Liangzhi Kou
Australian Institute for Innovative Materials - Papers
There has been exponential growth in research activities on nanomaterials and nanotechnology for applications in emerging technologies and sustainable energy in the past decade. The properties of nanomaterials have been found to vary in terms of their shapes, sizes, and number of nanoscale dimensions, which have also further boosted the performance of nanomaterial-based electronic, catalytic, and sustainable energy conversion and storage devices. This reveals the importance and, indeed, the linchpin role of nanomaterial synthesis for current nanotechnology and high-performance functional devices. In this review, we provide an overview of the synthesis strategies for designing metal oxide nanomaterials in zero-dimensional (0D), …
Flexible Polycaprolactone (Pcl) Supercapacitor Based On Reduced Graphene Oxide (Rgo)/Single-Wall Carbon Nanotubes (Swnts) Composite Electrodes, Hyeon Taek Jeong, Yong-Ryeol Kim, Byung Chul Kim
Flexible Polycaprolactone (Pcl) Supercapacitor Based On Reduced Graphene Oxide (Rgo)/Single-Wall Carbon Nanotubes (Swnts) Composite Electrodes, Hyeon Taek Jeong, Yong-Ryeol Kim, Byung Chul Kim
Australian Institute for Innovative Materials - Papers
The reduced graphene oxide (rGO)/single-wall carbon nanotubes (SWNTs) composites are coated onto the polycaprolactone (PCL) substrate via spray coating technique to prepare a flexible supercapacitor. The electrochemical properties of the flexible PCL supercapacitor as a function of bending cycles and angles are evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge tests. The EIS and charge/discharge curves of the flexible PCL supercapacitor exhibit capacitive behavior even after prolonged bending cycles up to 500. The highest capacitance value of the unbent PCL supercapacitor is 52.5 F g-1 which retained 65% after 500 bending with 6000th galvanostatic charge/discharge cycles.
Two-Dimensional Cobalt-/Nickel-Based Oxide Nanosheets For High-Performance Sodium And Lithium Storage, Dan Zhang, Wenping Sun, Zhihui Chen, Yu Zhang, Wenbin Luo, Yinzhu Jiang, Shi Xue Dou
Two-Dimensional Cobalt-/Nickel-Based Oxide Nanosheets For High-Performance Sodium And Lithium Storage, Dan Zhang, Wenping Sun, Zhihui Chen, Yu Zhang, Wenbin Luo, Yinzhu Jiang, Shi Xue Dou
Australian Institute for Innovative Materials - Papers
Two-dimensional (2D) nanomaterials are one of the most promising types of candidates for energy-storage applications due to confined thicknesses and high surface areas, which would play an essential role in enhanced reaction kinetics. Herein, a universal process that can be extended for scale up is developed to synthesise ultrathin cobalt-/nickel-based hydroxides and oxides. The sodium and lithium storage capabilities of Co3O4 nanosheets are evaluated in detail. For sodium storage, the Co3O4 nanosheets exhibit excellent rate capability (e.g., 179 mA h g¿1 at 7.0 A g¿1 and 150 mA h g¿1 at 10.0 A g¿1) and promising cycling performance (404 mA …
Formation And Processability Of Liquid Crystalline Dispersion Graphene Oxide, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Joselito M. Razal, Simon E. Moulton, Gordon G. Wallace
Formation And Processability Of Liquid Crystalline Dispersion Graphene Oxide, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Joselito M. Razal, Simon E. Moulton, Gordon G. Wallace
Gordon Wallace
Rational control over the formation and processability, and consequently final properties of graphene oxide liquid crystalline dispersions has been a long-standing goal in the development of bottom-up device fabrication processes. Here we report, the principal conditions through which such levels of control can be exercised to fine-tune dispersion properties for further processing.
Graphene Oxide Dispersions: Tuning Rheology To Enable Fabrication, Sina Naficy, Rouhollah Jalili, Seyed Hamed Aboutalebi, Robert A. Gorkin Iii, Konstantin Konstantinov, Peter C. Innis, Geoffrey M. Spinks, Philippe Poulin, Gordon G. Wallace
Graphene Oxide Dispersions: Tuning Rheology To Enable Fabrication, Sina Naficy, Rouhollah Jalili, Seyed Hamed Aboutalebi, Robert A. Gorkin Iii, Konstantin Konstantinov, Peter C. Innis, Geoffrey M. Spinks, Philippe Poulin, Gordon G. Wallace
Robert Gorkin III
Here, we show that graphene oxide (GO) dispersions exhibit unique viscoelastic properties, making them a new class of soft materials. The fundamental insights accrued here provide the basis for the development of fabrication protocols for these two-dimensional soft materials, in a diverse array of processing techniques.
Reduced Graphene Oxide And Polypyrrole/Reduced Graphene Oxide Composite Coated Stretchable Fabric Electrodes For Supercapacitor Application, Chen Zhao, Kewei Shu, Caiyun Wang, Sanjeev Gambhir, Gordon G. Wallace
Reduced Graphene Oxide And Polypyrrole/Reduced Graphene Oxide Composite Coated Stretchable Fabric Electrodes For Supercapacitor Application, Chen Zhao, Kewei Shu, Caiyun Wang, Sanjeev Gambhir, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
The advent of self-powered functional garments has given rise to a demand for stretchable energy storage devices that are amendable to integration into textile structures. The electromaterials (anode, cathode and separator) are expected to sustain a deformation of 3% to 55% associated with body movement. Here, we report a stretchable fabric supercapacitor electrode using commonly available nylon lycra fabric as the substrate and graphene oxide (GO) as a dyestuff. It was prepared via a facile dyeing approach followed by a mild chemical reduction. This reduced graphene oxide (rGO) coated fabric electrode retains conductivity at an applied strain of up to …
Synthesis Of Nitrogen-Doped Graphene Via Thermal Treatment Of Graphene Oxide Within Methylimidazole And Its Capacitance Performance As Electric Double Layer Capacitor, Md. Monirul Islam, Shaikh Nayeem Faisal, Anup Kumar Roy, Sonia Ansari, Dean Cardillo, Konstantin K. Konstantinov, Enamul Haque
Synthesis Of Nitrogen-Doped Graphene Via Thermal Treatment Of Graphene Oxide Within Methylimidazole And Its Capacitance Performance As Electric Double Layer Capacitor, Md. Monirul Islam, Shaikh Nayeem Faisal, Anup Kumar Roy, Sonia Ansari, Dean Cardillo, Konstantin K. Konstantinov, Enamul Haque
Australian Institute for Innovative Materials - Papers
Nitrogen-doped graphene was successfully synthesised from graphene oxide (GO) and 2-methylimidazole composite via thermal treatment under argon flow at 700oC within 1h. This synthesised N-doped graphene exhibits homogeneous nitrogen doping with concentration of ~5% in three different nitrogen configuration namelypyridinic N, pyrrolic N and graphitic N. The electric double layer capacitor (EDLC) made up with this N-doped graphene showed excellent specific capacitance 274 F/g at current density of 1A/g, which was ~7 times higher than GO. This EDLC capacitor showed excellent cyclic stability up to 5000 cycles with capacity retention of ~91%.
Protein Nanorings Organized By Poly(Styrene-Block-Ethylene Oxide) Self-Assembled Thin Films, Jenny Malmström, Akshita Wason, Fergus Roache, N. Amy Yewdall, Mazdak Radjainia, Shanghai Wei, Michael J. Higgins, David Williams, Juliet A. Gerrard, Jadranka Travas-Sejdic
Protein Nanorings Organized By Poly(Styrene-Block-Ethylene Oxide) Self-Assembled Thin Films, Jenny Malmström, Akshita Wason, Fergus Roache, N. Amy Yewdall, Mazdak Radjainia, Shanghai Wei, Michael J. Higgins, David Williams, Juliet A. Gerrard, Jadranka Travas-Sejdic
Australian Institute for Innovative Materials - Papers
This study explores the use of block copolymer self-assembly to organize Lsmα, a protein which forms stable doughnut-shaped heptameric structures. Here, we have explored the idea that 2-D crystalline arrays of protein filaments can be prepared by stacking doughnut shaped Lsmα protein into the poly(ethylene oxide) blocks of a hexagonal microphase-separated polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer. We were able to demonstrate the coordinated assembly of such a complex hierarchical nanostructure. The key to success was the choice of solvent systems and protein functionalization that achieved sufficient compatibility whilst still promoting assembly. Unambiguous characterisation of these structures is difficult; however AFM …
One-Pot Synthesis Of Ultra-Small Magnetite Nanoparticles On The Surface Of Reduced Graphene Oxide Nanosheets As Anodes For Sodium-Ion Batteries, Shaohua Zhang, Weijie Li, Bien Tan, Shulei Chou, Zhen Li, S X. Dou
One-Pot Synthesis Of Ultra-Small Magnetite Nanoparticles On The Surface Of Reduced Graphene Oxide Nanosheets As Anodes For Sodium-Ion Batteries, Shaohua Zhang, Weijie Li, Bien Tan, Shulei Chou, Zhen Li, S X. Dou
Australian Institute for Innovative Materials - Papers
Nanocomposites with ultra-small magnetite (Fe3O4) nanoparticles (approx. 3 nm) uniformly anchored on the surfaces of reduced graphene oxide (RGO) nanosheets were successfully synthesized for anodes in sodium-ion batteries by a novel single-step high-temperature coprecipitation approach. The best electrode delivers a reversible Na+ storage capacity of 204 mA h g-1 with excellent capacity retention, i.e., 98% of the second-cycle value was retained after 200 cycles.
Soft, Flexible Freestanding Neural Stimulation And Recording Electrodes Fabricated From Reduced Graphene Oxide, Nicholas V. Apollo, Matias I. Maturana, Wei Tong, David A. X Nayagam, Mohit N. Shivdasani, Javad Foroughi, Gordon G. Wallace, Steven Prawer, Michael R. Ibbotson, David J. Garrett
Soft, Flexible Freestanding Neural Stimulation And Recording Electrodes Fabricated From Reduced Graphene Oxide, Nicholas V. Apollo, Matias I. Maturana, Wei Tong, David A. X Nayagam, Mohit N. Shivdasani, Javad Foroughi, Gordon G. Wallace, Steven Prawer, Michael R. Ibbotson, David J. Garrett
Australian Institute for Innovative Materials - Papers
There is an urgent need for conductive neural interfacing materials that exhibit mechanically compliant properties, while also retaining high strength and durability under physiological conditions. Currently, implantable electrode systems designed to stimulate and record neural activity are composed of rigid materials such as crystalline silicon and noble metals. While these materials are strong and chemically stable, their intrinsic stiffness and density induce glial scarring and eventual loss of electrode function in vivo. Conductive composites, such as polymers and hydrogels, have excellent electrochemical and mechanical properties, but are electrodeposited onto rigid and dense metallic substrates. In the work described here, strong …
Towards The Knittability Of Graphene Oxide Fibres, Shayan Seyedin, Mark S. Romano, Andrew I. Minett, Joselito M. Razal
Towards The Knittability Of Graphene Oxide Fibres, Shayan Seyedin, Mark S. Romano, Andrew I. Minett, Joselito M. Razal
Australian Institute for Innovative Materials - Papers
Recent developments in graphene oxide fibre (GO) processing include exciting demonstrations of hand woven textile structures. However, it is uncertain whether the fibres produced can meet the processing requirements of conventional textile manufacturing. This work reports for the first time the production of highly flexible and tough GO fibres that can be knitted using textile machinery. The GO fibres are made by using a dry-jet wet-spinning method, which allows drawing of the spinning solution (the GO dispersion) in several stages of the fibre spinning process. The coagulation composition and spinning conditions are evaluated in detail, which led to the production …
One-Dimensional Manganese-Cobalt Oxide Nanofibres As Bi-Functional Cathode Catalysts For Rechargeable Metal-Air Batteries, Kyu-Nam Jung, Soomin Hwang, Min-Sik Park, Ki Jae Kim, Jae-Geun Kim, S X. Dou, Jung Ho Kim, Jongwon Lee
One-Dimensional Manganese-Cobalt Oxide Nanofibres As Bi-Functional Cathode Catalysts For Rechargeable Metal-Air Batteries, Kyu-Nam Jung, Soomin Hwang, Min-Sik Park, Ki Jae Kim, Jae-Geun Kim, S X. Dou, Jung Ho Kim, Jongwon Lee
Australian Institute for Innovative Materials - Papers
Rechargeable metal-air batteries are considered a promising energy storage solution owing to their high theoretical energy density. The major obstacles to realising this technology include the slow kinetics of oxygen reduction and evolution on the cathode (air electrode) upon battery discharging and charging, respectively. Here, we report non-precious metal oxide catalysts based on spinel-type manganese-cobalt oxide nanofibres fabricated by an electrospinning technique. The spinel oxide nanofibres exhibit high catalytic activity towards both oxygen reduction and evolution in an alkaline electrolyte. When incorporated as cathode catalysts in Zn-air batteries, the fibrous spinel oxides considerably reduce the discharge-charge voltage gaps (improve the …
An Experimental Investigation Towards Improvement Of Thermoelectric Properties Of Strontium Titanate Ceramics, Arash Mehdizadeh Dehkordi
An Experimental Investigation Towards Improvement Of Thermoelectric Properties Of Strontium Titanate Ceramics, Arash Mehdizadeh Dehkordi
All Dissertations
The direct energy conversion between heat and electricity based on thermoelectric effects is a topic of long-standing interest in condensed matter materials science. Experimental and theoretical investigations in order to understand the mechanisms involved and to improve the materials properties and conversion efficiency have been ongoing for more than half a century. While significant achievements have been accomplished in improving the properties of conventional heavy element based materials (such as Bi$_2$Te$_3$ and PbTe) as well as the discovery of new materials systems for the close-to-room temperature and intermediate temperatures, high-temperature applications of thermoelectrics is still limited to one materials system, …
Quantitative Analysis Of Structure And Bandgap Changes In Graphene Oxide Nanoribbons During Thermal Annealing, Yu Zhu, Xianyu Li, Qinjia Cai, Zhengzong Sun, Gilberto Casillas, Miguel Jose-Yacaman, Rafael Verduzco, James Tour
Quantitative Analysis Of Structure And Bandgap Changes In Graphene Oxide Nanoribbons During Thermal Annealing, Yu Zhu, Xianyu Li, Qinjia Cai, Zhengzong Sun, Gilberto Casillas, Miguel Jose-Yacaman, Rafael Verduzco, James Tour
Yu Zhu
Graphene oxide nanoribbons (GONRs) are wide bandgap semiconductors that can be reduced to metallic graphene nanoribbons. The transformation of GONRs from their semiconductive to the metallic state by annealing has attracted significant interest due to its simplicity. However, the detailed process by which GONRs transform from widebandgap semiconductors to semimetals with a near zero bandgap is unclear. As a result, precise control of the bandgap between these two states is not currently achievable. Here, we quantitatively examine the removal of oxygen-containing groups and changes in the bandgap during thermal annealing of GONRs. X-ray photoelectron spectroscopy measurements show the progressive removal …
Aqueous Dispersions Of Reduced Graphene Oxide And Multi Wall Carbon Nanotubes For Enhanced Glucose Oxidase Bioelectrode Performance, Willo Grosse, Joffrey Champavert, Sanjeev Gambhir, Gordon G. Wallace, Simon E. Moulton
Aqueous Dispersions Of Reduced Graphene Oxide And Multi Wall Carbon Nanotubes For Enhanced Glucose Oxidase Bioelectrode Performance, Willo Grosse, Joffrey Champavert, Sanjeev Gambhir, Gordon G. Wallace, Simon E. Moulton
Gordon Wallace
Aqueous dispersions of reduced graphene oxide (rGO) and multi walled carbon nanotubes (MWCNT) were fabricated through a modified chemical reduction method. The significant advantage of the method developed here is the omission of any stabilising compound or organic solvent to obtain stable rGO-MWCNT dispersions. Significantly biological entities, in this case the enzyme glucose oxidase (GOx), can be successfully incorporated into the dispersion. These dispersions were characterised using XPS, SEM, zeta potential and particle size measurements which showed that the dispersion stability is not sacrificed with the addition of GOx, and significantly, the electrical properties of the rGO and MWCNTs are …
Facile Synthesis Of Reduced Graphene Oxide/Mwnts Nanocomposite Supercapacitor Materials Tested As Electrophoretically Deposited Films On Glassy Carbon Electrodes, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Byung C. Kim, Rao Yepuri, Anthony C. Romeo, Gordon G. Wallace
Facile Synthesis Of Reduced Graphene Oxide/Mwnts Nanocomposite Supercapacitor Materials Tested As Electrophoretically Deposited Films On Glassy Carbon Electrodes, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Byung C. Kim, Rao Yepuri, Anthony C. Romeo, Gordon G. Wallace
Gordon Wallace
This paper reports on a facile synthesis method for reduced graphene oxide (rGO)/multi-walled carbon nanotubes (MWNTs) nanocomposites. The initial step involves the use of graphene oxide to disperse the MWNTs, with subsequent reduction of the resultant graphene oxide/MWNTs composites using l-ascorbic acid (LAA) as a mild reductant. Reduction by LAA preserves the interaction between the rGO sheets and MWNTs. The dispersion-containing rGO/MWNTs composites was characterized and electrophoretically deposited anodically onto glassy carbon electrodes to form high surface area films for capacitance testing. Pseudo capacitance peaks were observed in the rGO/MWNTs composite electrodes, resulting in superior performance with capacitance values up …
Scalable One-Step Wet-Spinning Of Graphene Fibers And Yarns From Liquid Crystalline Dispersions Of Graphene Oxide: Towards Multifunctional Textiles, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Roderick L. Shepherd, Jun Chen, Sima Aminorroaya-Yamini, Konstantin Konstantinov, Andrew I. Minett, Joselito M. Razal, Gordon G. Wallace
Scalable One-Step Wet-Spinning Of Graphene Fibers And Yarns From Liquid Crystalline Dispersions Of Graphene Oxide: Towards Multifunctional Textiles, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Roderick L. Shepherd, Jun Chen, Sima Aminorroaya-Yamini, Konstantin Konstantinov, Andrew I. Minett, Joselito M. Razal, Gordon G. Wallace
Gordon Wallace
Key points in the formation of liquid crystalline (LC) dispersions of graphene oxide (GO) and their processability via wet-spinning to produce long lengths of micrometer-dimensional fibers and yarns are addressed. Based on rheological and polarized optical microscopy investigations, a rational relation between GO sheet size and polydispersity, concentration, liquid crystallinity, and spinnability is proposed, leading to an understanding of lyotropic LC behavior and fiber spinnability. The knowledge gained from the straightforward formulation of LC GO "inks" in a range of processable concentrations enables the spinning of continuous conducting, strong, and robust fibers at concentrations as low as 0.075 wt%, eliminating …
Carbon Nanotube-Reduced Graphene Oxide Composites For Thermal Energy Harvesting Applications, Mark S. Romano, Na Li, Dennis Antiohos, Joselito M. Razal, Andrew Nattestad, Stephen Beirne, Shaoli Fang, Yongsheng Chen, Rouhollah Jalili, Gordon G. Wallace, Ray Baughman, Jun Chen
Carbon Nanotube-Reduced Graphene Oxide Composites For Thermal Energy Harvesting Applications, Mark S. Romano, Na Li, Dennis Antiohos, Joselito M. Razal, Andrew Nattestad, Stephen Beirne, Shaoli Fang, Yongsheng Chen, Rouhollah Jalili, Gordon G. Wallace, Ray Baughman, Jun Chen
Gordon Wallace
By controlling the SWNT-rGO electrode composition and thickness to attain the appropriate porosity and tortuosity, the electroactive surface area is maximized while rapid diffusion of the electrolyte through the electrode is maintained. This leads to an increase in exchange current density between the electrode and electrolyte which results in enhanced thermocell performance.
Organic Solvent-Based Graphene Oxide Liquid Crystals: A Facile Route Toward The Next Generation Of Self-Assembled Layer-By-Layer Multifunctional 3d Architectures, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Simon E. Moulton, Joselito M. Razal, Gordon G. Wallace
Organic Solvent-Based Graphene Oxide Liquid Crystals: A Facile Route Toward The Next Generation Of Self-Assembled Layer-By-Layer Multifunctional 3d Architectures, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Simon E. Moulton, Joselito M. Razal, Gordon G. Wallace
Gordon Wallace
We introduce soft self-assembly of ultralarge liquid crystalline (LC) graphene oxide (GO) sheets in a wide range of organic solvents overcoming the practical limitations imposed on LC GO processing in water. This expands the number of known solvents which can support amphiphilic self-assembly to ethanol, acetone, tetrahydrofuran, N-dimethylformamide, N-cyclohexyl-2-pyrrolidone, and a number of other organic solvents, many of which were not known to afford solvophobic self-assembly prior to this report. The LC behavior of the as-prepared GO sheets in organic solvents has enabled us to disperse and organize substantial amounts of aggregate-free single-walled carbon nanotubes (SWNTs, up to 10 wt …
Manganosite-Microwave Exfoliated Graphene Oxide Composites For Asymmetric Supercapacitor Device Applications, Dennis Antiohos, Kanlaya Pingmuang, Mark Romano, Stephen Beirne, Tony C. Romeo, Phil Aitchison, Andrew I. Minett, Gordon G. Wallace, Sukon Phanichphant, Jun Chen
Manganosite-Microwave Exfoliated Graphene Oxide Composites For Asymmetric Supercapacitor Device Applications, Dennis Antiohos, Kanlaya Pingmuang, Mark Romano, Stephen Beirne, Tony C. Romeo, Phil Aitchison, Andrew I. Minett, Gordon G. Wallace, Sukon Phanichphant, Jun Chen
Gordon Wallace
Graphene based materials coupled with transition metal oxides are promising electrode materials in asymmetric supercapacitors owing to their unique properties which include high surface area, good chemical stability, electrical conductivity, abundance, and lower cost profile over time. In this paper a composite material consisting of graphene oxide exfoliated with microwave radiation (mw rGO), and manganosite (MnO) is synthesised in order to explore their potential as an electrode material. The composite material was characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to explore …
Cation Exchange At Semiconducting Oxide Surfaces: Origin Of Light-Induced Performance Increases In Porphyrin Dye-Sensitized Solar Cells, Matthew J. Griffith, Kenji Sunahara, Akihiro Furube, Attila J. Mozer, David L. Officer, Pawel Wagner, Gordon G. Wallace, Shogo Mori
Cation Exchange At Semiconducting Oxide Surfaces: Origin Of Light-Induced Performance Increases In Porphyrin Dye-Sensitized Solar Cells, Matthew J. Griffith, Kenji Sunahara, Akihiro Furube, Attila J. Mozer, David L. Officer, Pawel Wagner, Gordon G. Wallace, Shogo Mori
Gordon Wallace
The origin of simultaneous improvements in the short-circuit current density (Jsc) and open-circuit voltage (Voc) of porphyrin dye-sensitized TiO2 solar cells following white light illumination was studied by systematic variation of several different device parameters. Reduction of the dye surface loading resulted in greater relative performance enhancements, suggesting open space at the TiO2 surface expedites the process. Variation of the electrolyte composition and subsequent analysis of the conduction band potential shifts suggested that a light-induced replacement of surface-adsorbed lithium (Li+) ions with dimethylpropylimidazolium (DMPIm+) ions was responsible for an increased electron lifetime by decreasing the recombination with the redox mediator. …
Reduced Graphene Oxide With Superior Cycling Stability And Rate Capability For Sodium Storage, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Reduced Graphene Oxide With Superior Cycling Stability And Rate Capability For Sodium Storage, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
Sodium ion battery is a promising electrical energy storage system for sustainable energy storage applications due to the abundance of sodium resources and their low cost. In this communication, the electrochemical properties of sodium ion storage in reduced graphene oxide (RGO) were studied in an electrolyte consisting of 1 M NaClO4 in propylene carbonate (PC). The experimental results show that the RGO anode allowed significant sodium ion insertion, leading to higher capacity at high current density compared to the previously reported results for carbon materials. This is due to the fact that RGO possesses higher electrical conductivity and is a …
A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou
A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
Transition metal oxide (Mn3O4, Fe2O3, Co3O4, and ZnO) and reduced graphene oxide (RGO) composites were successfully synthesized via a hydrothermal method using the direct reaction between the corresponding metal powder and graphene oxide (GO). In this process, the GO can be reduced by transition metal powder in water, and the nanosized metal oxide can be obtained, and homogeneously mixed with and wrapped by RGO to form a metal oxide/RGO composite at the same time. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy were used to characterize the as-prepared materials. The different experimental parameters, including reactants, …
The Electrochemical Properties Of High-Capacity Sulfur/Reduced Graphene Oxide With Different Electrolyte Systems, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
The Electrochemical Properties Of High-Capacity Sulfur/Reduced Graphene Oxide With Different Electrolyte Systems, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
The lithium/sulfur battery is a promising electrochemical system with high capacity, which is well-known to undergo a complex multistep reaction during the discharge process. Two types of electrolytes including poly (ethylene glycol) dimethyl ether (PEGDME)-based and 1.3 - dioxolane (DOL)/ dimethoxyethane (DME)-based electrolytes were investigated here. Furthermore, LiNO3 additive was introduced into the electrolyte in order to effectively eliminate the overcharge effect. The lithium sulfur battery with 1.0 M LiN(CF3SO2)2 in PEGME with 0.1 M LiNo3 shows highly stable reversible capacity of 624.8 mAh g-1 after 200 cycles and improved average coulombic efficiency of 98 percent.
Liquid Crystalline Graphene Oxide/Pedot: Pss Self-Assembled 3d Architecture For Binder-Free Supercapacitor Electrodes, Md. Monirul Islam, Alfred T. Chidembo, Seyed Hamed Aboutalebi, Dean Cardillo, Hua-Kun Liu, Konstantin K. Konstantinov, S X. Dou
Liquid Crystalline Graphene Oxide/Pedot: Pss Self-Assembled 3d Architecture For Binder-Free Supercapacitor Electrodes, Md. Monirul Islam, Alfred T. Chidembo, Seyed Hamed Aboutalebi, Dean Cardillo, Hua-Kun Liu, Konstantin K. Konstantinov, S X. Dou
Australian Institute for Innovative Materials - Papers
Binder-free self-assembled 3D architecture electrodes have been fabricated by a novel convenient method. Liquid crystalline graphene oxide was used as precursor to interact with poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in dispersion in order to form a conductive polymer entrapped, self-assembled layer-by-layer structure. This advanced network containing PEDOT:PSS enabled us to ascribe the superior electrochemical properties of particular graphene sheets. This layer-by-layer self-assembled 3D architecture of best performing composite (reduced graphene oxide-PEDOT:PSS 25) showed excellent electrochemical performance of 434 F g−1 through chemical treatment. To highlight these advances, we further explored the practicality of the as-prepared electrode by varying the composite material content. …
Formation And Processability Of Liquid Crystalline Dispersion Graphene Oxide, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Joselito M. Razal, Simon E. Moulton, Gordon G. Wallace
Formation And Processability Of Liquid Crystalline Dispersion Graphene Oxide, Rouhollah Jalili, Seyed Hamed Aboutalebi, Dorna Esrafilzadeh, Konstantin Konstantinov, Joselito M. Razal, Simon E. Moulton, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Rational control over the formation and processability, and consequently final properties of graphene oxide liquid crystalline dispersions has been a long-standing goal in the development of bottom-up device fabrication processes. Here we report, the principal conditions through which such levels of control can be exercised to fine-tune dispersion properties for further processing.
In Situ Engineering Of Urchin-Like Reduced Graphene Oxide-Mn 2o3-Mn3o4 Nanostructures For Supercapacitors, Alfred Tawirirana Chidembo, Seyed Hamed Aboutalebi, Konstantin Konstantinov, Charl Jeremy Jafta, Hua-Kun Liu, Kenneth Ikechukwu Ozoemena
In Situ Engineering Of Urchin-Like Reduced Graphene Oxide-Mn 2o3-Mn3o4 Nanostructures For Supercapacitors, Alfred Tawirirana Chidembo, Seyed Hamed Aboutalebi, Konstantin Konstantinov, Charl Jeremy Jafta, Hua-Kun Liu, Kenneth Ikechukwu Ozoemena
Australian Institute for Innovative Materials - Papers
We report the use of a spray pyrolysis method to synthesize high surface area (BET surface area of 139 m2 g-1) self-organized, micron sized urchin-like composites made up of reduced graphene oxide and needle-shaped manganese oxide (rGO-Mn2O3-Mn 3O4). Maximum capacitances of 425 Fg-1 at 5 mV s-1 from a three electrode set up and 133 Fg-1 at a current density of 0.2 Ag-1 were recorded using an asymmetric two electrode set up with graphene as the anode. The composite material also showed a capacitance retention of 83% over 1000 cycles. We attribute this remarkable performance to the high specific surface …