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Articles 391 - 420 of 1524
Full-Text Articles in Physical Sciences and Mathematics
Thickness Dependence Of Dendritic Flux Avalanches In Yba2cu3o7-Xfilms, E Baruch-El, M Baziljevich, Tom H. Johansen, A Shaulov, Y Yeshurun
Thickness Dependence Of Dendritic Flux Avalanches In Yba2cu3o7-Xfilms, E Baruch-El, M Baziljevich, Tom H. Johansen, A Shaulov, Y Yeshurun
Australian Institute for Innovative Materials - Papers
By implementing a unique magneto-optical system with ultrafast magnetic-field ramping-rate capability (up to 3 kT/s), we have been able to routinely generate and image dendritic flux instabilities in YBa 2 Cu 3 O 7-x films. In the present work we study the effect of the film thickness on the dendritic instability. Dendritic avalanches in 50-600 nm thick films were magneto-optically imaged at 7 K, after ramping the magnetic field from zero to 60 mT at different rates. The data reveal a remarkable change in flux morphologies between the thin and the thicker films. While the former (50-250 nm) display well-developed …
Si Nanocrystal-Embedded Sioxnanofoils: Two-Dimensional Nanotechnology-Enabled High Performance Li Storage Materials, Hyundong Yoo, Eunjun Park, Juhye Bae, Jaewoo Lee, Dong Jae Chung, Yong Jo, Min-Sik Park, Jung Ho Kim, Shi Xue Dou, Young-Jun Kim, Hansu Kim
Si Nanocrystal-Embedded Sioxnanofoils: Two-Dimensional Nanotechnology-Enabled High Performance Li Storage Materials, Hyundong Yoo, Eunjun Park, Juhye Bae, Jaewoo Lee, Dong Jae Chung, Yong Jo, Min-Sik Park, Jung Ho Kim, Shi Xue Dou, Young-Jun Kim, Hansu Kim
Australian Institute for Innovative Materials - Papers
Silicon (Si) based materials are highly desirable to replace currently used graphite anode for lithium ion batteries. Nevertheless, its usage is still a big challenge due to poor battery performance and scale-up issue. In addition, two-dimensional (2D) architectures, which remain unresolved so far, would give them more interesting and unexpected properties. Herein, we report a facile, cost-effective, and scalable approach to synthesize Si nanocrystals embedded 2D SiO x nanofoils for next-generation lithium ion batteries through a solution-evaporation-induced interfacial sol-gel reaction of hydrogen silsesquioxane (HSiO 1.5 , HSQ). The unique nature of the thus-prepared centimeter scale 2D nanofoil with a large …
Creating Fast Ion Conducting Composites Via In-Situ Introduction Of Titanium As Oxygen Getter, Wenchao Zhang, Jianfeng Mao, Wei Kong Pang, Xing Wang, Zaiping Guo
Creating Fast Ion Conducting Composites Via In-Situ Introduction Of Titanium As Oxygen Getter, Wenchao Zhang, Jianfeng Mao, Wei Kong Pang, Xing Wang, Zaiping Guo
Australian Institute for Innovative Materials - Papers
Metal-ion batteries are promising for large-scale energy storage. Their potential commercialization not only depends on their superior electrochemical performance, but also on the large-scale synthesis cost of electrode materials. In the conventional industrial technology for producing non-oxides, argon protection is required to avoid oxidation, leading to additional costs and extra processing. We demonstrate, without protection gas, that ball milling in air with a small amount of Ti additive can be a cost-effective approach for preparing high-performance alloy anodes. Ti consumes the oxygen, forming TiO 2 ( < 10 nm) in situ with high ionic conductivity, while also preventing oxidation and sustaining the electrical conductivity of carbon. This strategy effectively promotes the rate capability (61% capacity retention from 60 to 3000 mA g −1 ) of SnSb/carbon-nanotube anode (over 204% better than without Ti additive).
Frequency And Wavenumber Selective Excitation Of Spin Waves Through Coherent Energy Transfer From Elastic Waves, Yusuke Hashimoto, Davide Bossini, Tom H. Johansen, Eiji Saitoh, Andrei Kirilyuk, Theo Rasing
Frequency And Wavenumber Selective Excitation Of Spin Waves Through Coherent Energy Transfer From Elastic Waves, Yusuke Hashimoto, Davide Bossini, Tom H. Johansen, Eiji Saitoh, Andrei Kirilyuk, Theo Rasing
Australian Institute for Innovative Materials - Papers
Using spin-wave tomography (SWaT), we have investigated the excitation and the propagation dynamics of optically excited magnetoelastic waves, i.e., hybridized modes of spin waves and elastic waves, in a garnet film. By using time-resolved SWaT, we reveal the excitation dynamics of magnetoelastic waves through coherent-energy transfer between optically excited pure-elastic waves and spin waves via magnetoelastic coupling. This process realizes frequency and wavenumber selective excitation of spin waves at the crossing of the dispersion relations of spin waves and elastic waves. Finally, we demonstrate that the excitation mechanism of the optically excited pure-elastic waves, which are the source of the …
Three-Dimensional Printing And Cell Therapy For Wound Repair, Sylvia Van Kogelenberg, Zhilian Yue, Jeremy Dinoro, Christopher Baker, Gordon G. Wallace
Three-Dimensional Printing And Cell Therapy For Wound Repair, Sylvia Van Kogelenberg, Zhilian Yue, Jeremy Dinoro, Christopher Baker, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Significance: Skin tissue damage is a major challenge and a burden on healthcare systems, from burns and other trauma to diabetes and vascular disease. Although the biological complexities are relatively well understood, appropriate repair mechanisms are scarce. Three-dimensional bioprinting is a layer-based approach to regenerative medicine, whereby cells and cell-based materials can be dispensed in fine spatial arrangements to mimic native tissue. Recent Advances: Various bioprinting techniques have been employed in wound repair-based skin tissue engineering, from laser-induced forward transfer to extrusion-based methods, and with the investigation of the benefits and shortcomings of each, with emphasis on biological compatibility and …
Carbon Hollow Nanobubbles On Porous Carbon Nanofibers: An Ideal Host For High-Performance Sodium-Sulfur Batteries And Hydrogen Storage, Guanglin Xia, Lijun Zhang, Xiaowei Chen, Yuqin Huang, Dalin Sun, Fang Fang, Zaiping Guo, Xuebin Yu
Carbon Hollow Nanobubbles On Porous Carbon Nanofibers: An Ideal Host For High-Performance Sodium-Sulfur Batteries And Hydrogen Storage, Guanglin Xia, Lijun Zhang, Xiaowei Chen, Yuqin Huang, Dalin Sun, Fang Fang, Zaiping Guo, Xuebin Yu
Australian Institute for Innovative Materials - Papers
One-dimensional (1D) carbon nanostructures have been intensively investigated because of their intriguing features and great potential for practical application in various fields. This paper reports the controllable fabrication of carbon hollow nanobubbles on porous carbon nanofibers (CHNBs@PCNFs) through a general electrospinning strategy, with metal azides serving as both a bubbling and a porogen reagent. The strong repulsive forces resulting from the intense release of N 2 from the decomposition of metal azides upon carbonization leads to the uniform formation of porous carbon nanofibers (PCNFs), which could be facile tuned by heating rates and the amount of the bubbling reagent, simultaneously …
Measuring The Effective Area And Charge Density Of Platinum Electrodes For Bionic Devices, Alexander R. Harris, C Newbold, P Carter, R Cowan, Gordon G. Wallace
Measuring The Effective Area And Charge Density Of Platinum Electrodes For Bionic Devices, Alexander R. Harris, C Newbold, P Carter, R Cowan, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Objective. Neural stimulation is usually performed with fairly large platinum electrodes. Smaller electrodes increase the applied charge density, potentially damaging the electrode. Greater understanding of the charge injection mechanism is required for safe neural stimulation. Approach. The charge injection mechanism and charge injection capacity were measured by cyclic voltammetry. Electrodes were cleaned mechanically or by potential cycling in acidic solutions. The effective electrode area was measured by hydrogen adsorption or reduction of Ru(NH3) 3+ 6 . Main results. The water window and safe potential window were affected by changes to electrolyte, electrode size, polishing method and oxygen concentration. Capacitance and …
Coercivity Degradation Caused By Inhomogeneous Grain Boundaries In Sintered Nd-Fe-B Permanent Magnets, Hansheng Chen, Fan Yun, Jiangtao Qu, Yingfei Li, Zhenxiang Cheng, Ruhao Fang, Zhixiao Ye, Simon Peter Ringer, Rongkun Zheng
Coercivity Degradation Caused By Inhomogeneous Grain Boundaries In Sintered Nd-Fe-B Permanent Magnets, Hansheng Chen, Fan Yun, Jiangtao Qu, Yingfei Li, Zhenxiang Cheng, Ruhao Fang, Zhixiao Ye, Simon Peter Ringer, Rongkun Zheng
Australian Institute for Innovative Materials - Papers
Quantitative correlation between intrinsic coercivity and grain boundaries in three dimensions is critical to further improve the performance of sintered Nd-Fe-B permanent magnets. Here, we quantitatively reveal the local composition variation across and especially along grain boundaries using the powerful atomic-scale analysis technique known as atom probe tomography. We also estimate the saturation magnetization, magnetocrystalline anisotropy constant, and exchange stiffness of the grain boundaries on the basis of the experimentally determined structure and composition. Finally, using micromagnetic simulations, we quantify the intrinsic coercivity degradation caused by inhomogeneous grain boundaries. This approach can be applied to other magnetic materials for the …
In Situ Construction Of Yolk-Shell Zinc Cobaltite With Uniform Carbon Doping For High Performance Asymmetric Supercapacitors, Xiaoya Chang, Lei Zang, Song Liu, Mengying Wang, Huinan Guo, Caiyun Wang, Yijing Wang
In Situ Construction Of Yolk-Shell Zinc Cobaltite With Uniform Carbon Doping For High Performance Asymmetric Supercapacitors, Xiaoya Chang, Lei Zang, Song Liu, Mengying Wang, Huinan Guo, Caiyun Wang, Yijing Wang
Australian Institute for Innovative Materials - Papers
Zinc cobaltite (ZnCo 2 O 4 ) is a promising material for supercapacitors with appreciable theoretical capacitance. However, it suffers from poor electrical conductivity and large volume expansion during charge-discharge processes. In this work, a novel material, ZnCo 2 O 4 /C microspheres in a yolk-shell structure, is fabricated by a facile refluxing process in combination with a calcination treatment. Carbon is in situ formed via the pyrolysis of polyvinyl pyrrolidone and uniformly dispersed both in the core and the shell. Benefiting from the unique structure and the synergistic effect of the two components, this material exhibits remarkable electrochemical properties …
High Performance Mno@C Microcages With A Hierarchical Structure And Tunable Carbon Shell For Efficient And Durable Lithium Storage, Chuanxin Hou, Zhixin Tai, Lanling Zhao, Yanjie Zhai, Yue Hou, Yuqi Fan, Feng Dang, Jun Wang, Hua-Kun Liu
High Performance Mno@C Microcages With A Hierarchical Structure And Tunable Carbon Shell For Efficient And Durable Lithium Storage, Chuanxin Hou, Zhixin Tai, Lanling Zhao, Yanjie Zhai, Yue Hou, Yuqi Fan, Feng Dang, Jun Wang, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
A MnO@C microcage with a multi-structure and tunable carbon shell was fabricated through a facile bio-inspired synthesis strategy for highly reversible Li storage. Micrometer-sized MnO unit aggregates were covered with a porous carbon shell outside with a thickness of about 0.2 μm, and a graphene-analogous carbon network inside the MnO@C microcages. The carbon shell could be tunable by a graphene-base shell. The unique double-carbon-coating structure of the MnO@C microcages enabled realizing the high Li-storage performance of the MnO particles with a micrometer size. The electrode containing the MnO@C microcages delivered a high reversible capacity of 1450.5 mA h g -1 …
Recent Progress On Liquid Metals And Their Applications, Guyue Bo, Long Ren, Xun Xu, Yi Du, Shi Xue Dou
Recent Progress On Liquid Metals And Their Applications, Guyue Bo, Long Ren, Xun Xu, Yi Du, Shi Xue Dou
Australian Institute for Innovative Materials - Papers
Gallium-based liquid metals show excellent thermal and electrical conductivities with low viscosity and non-toxicity. Their melting points are either lower than or close to room temperature, which endows them with additional advantages in comparison to the solid metals; for example, they are flexible, stretchable and reformable at room temperature. Recently, great improvements have been achieved in developing multifunctional devices by using Ga-based liquid metals, including actuators, flexible circuits, bio-devices and self-healing superconductors. Here, we review recent research progress on Gallium-based liquid metals, especially on the applications aspects. These applications are mainly based on the unique properties of liquid metals, including …
Ultra-Small Nanocluster Mediated Synthesis Of Nd3+-Doped Core-Shell Nanocrystals With Emission In The Second Near-Infrared Window For Multimodal Imaging Of Tumor Vasculature, Feng Ren, Lihua Ding, Hanghang Liu, Qian Huang, Hao Zhang, Lijuan Zhang, Jianfeng Zeng, Qiao Sun, Zhen Li, Mingyuan Gao
Ultra-Small Nanocluster Mediated Synthesis Of Nd3+-Doped Core-Shell Nanocrystals With Emission In The Second Near-Infrared Window For Multimodal Imaging Of Tumor Vasculature, Feng Ren, Lihua Ding, Hanghang Liu, Qian Huang, Hao Zhang, Lijuan Zhang, Jianfeng Zeng, Qiao Sun, Zhen Li, Mingyuan Gao
Australian Institute for Innovative Materials - Papers
In-vivo intravital short wavelength infrared (SWIR, 1000-2300 nm) fluorescence imaging has attracted considerable attention in the imaging of tumor vasculature due to its low background, high sensitivity, and deep penetration. It can noninvasively provide dynamic feedback on the tumorigenesis, growth, necrosis and metastasis. Herein, monodisperse Nd3+-doped core-shell downconversion luminescent nanocrystals with strong emission in the second near-infrared (NIR II) window, strong temperature-dependent paramagnetism and fast attenuation to X-rays were prepared from ultra-small nanoclusters. The use of nanoclusters resulted in very uniform bright nanocrystals with a relative quantum yield comparable to the standard dye IR-26. These bright NIR nanocrystals were modified …
Soft-Templated Synthesis Of Mesoporous Nickel Oxide Using Poly(Styrene-Block-Acrylic Acid-Block-Ethylene Glycol) Block Copolymers, Hamzeh Qutaish, Shunsuke Tanaka, Yusuf Valentino Kaneti, Jianjian Lin, Yoshio Bando, Abdulmohsen Alshehri, Shin-Ichi Yusa, Yusuke Yamauchi, Md. Shahriar Al Hossain, Jeonghun Kim
Soft-Templated Synthesis Of Mesoporous Nickel Oxide Using Poly(Styrene-Block-Acrylic Acid-Block-Ethylene Glycol) Block Copolymers, Hamzeh Qutaish, Shunsuke Tanaka, Yusuf Valentino Kaneti, Jianjian Lin, Yoshio Bando, Abdulmohsen Alshehri, Shin-Ichi Yusa, Yusuke Yamauchi, Md. Shahriar Al Hossain, Jeonghun Kim
Australian Institute for Innovative Materials - Papers
In this work, we report the soft-templated preparation of mesoporous nickel oxide using an asymmetric poly(styrene-block-acrylic acid-block-ethylene glycol) (PS-b-PAA-b-PEG) triblock copolymer. This block copolymer forms a micelle consisting of a PS core, a PAA shell and a PEG corona in aqueous solutions, which can serve as a soft template. Specifically, the PS block forms the core of the micelles on the basis of its lower solubility in water. The anionic PAA block interacts with the cationic Ni 2+ ions present in the solution to generate the shell. The PEG block forms the corona of the micelles and stabilizes the micelles …
S-P Orbital Hybridization: A Strategy For Developing Efficient Photocatalysts With High Carrier Mobility, Zhongfei Xu, Kang Xu, Haifeng Feng, Yi Du, Weichang Hao
S-P Orbital Hybridization: A Strategy For Developing Efficient Photocatalysts With High Carrier Mobility, Zhongfei Xu, Kang Xu, Haifeng Feng, Yi Du, Weichang Hao
Australian Institute for Innovative Materials - Papers
Photocatalysis has not only invigorated the field of energy conversion materials, but also is leading to bright prospects for application in the environmental purification field [1]. Akira Fujishima and Kenichi Honda [2] first reported photocatalytic water splitting on a TiO2 semiconductor electrode under ultraviolet (UV) light in 1972. In semiconductor photocatalysts, electrons are excited from valence band maximum (VBM) to conduction band minimum (CBM) under light irradiation, and then trigger the photocatalytic process [3]. Considering solar-light-driven photocatalysis, semiconductor photocatalysts should possess a narrow band gap and appropriate band positions [4]. It was also found that photoinduced charge generation, separation, and …
Harvesting Electrical Energy From Torsional Thermal Actuation Driven By Natural Convection, Shi Hyeong Kim, Hyeon Jun Sim, Jae Hyeon, Dongseok Suh, Geoffrey M. Spinks, Ray H. Baughman, Seon Jeong Kim
Harvesting Electrical Energy From Torsional Thermal Actuation Driven By Natural Convection, Shi Hyeong Kim, Hyeon Jun Sim, Jae Hyeon, Dongseok Suh, Geoffrey M. Spinks, Ray H. Baughman, Seon Jeong Kim
Australian Institute for Innovative Materials - Papers
The development of practical, cost-efective systems for the conversion of low-grade waste heat to electrical energy is an important area of renewable energy research. We here demonstrate a thermal energy harvester that is driven by the small temperature fuctuations provided by natural convection. This harvester uses coiled yarn artifcial muscles, comprising well-aligned shape memory polyurethane (SMPU) microfbers, to convert thermal energy to torsional mechanical energy, which is then electromagnetically converted to electrical energy. Temperature fuctuations in a yarn muscle, having a maximum hot-to-cold temperature diference of about 13°C, were used to spin a magnetic rotor to a peak torsional rotation …
Hierarchical Porous Pani/Mil-101 Nanocomposites Based Solid-State Flexible Supercapacitor, Qian Wang, Liang Shao, Zhonglei Ma, Juanjuan Xu, Ying Li, Caiyun Wang
Hierarchical Porous Pani/Mil-101 Nanocomposites Based Solid-State Flexible Supercapacitor, Qian Wang, Liang Shao, Zhonglei Ma, Juanjuan Xu, Ying Li, Caiyun Wang
Australian Institute for Innovative Materials - Papers
Metal-Organic Frameworks (MOFs) have attracted increasing attention in the field of energy storage owing to their high porosity, high specific surface area, high charge storage. However, the poor conductivity in most MOFs largely hinders their electrical properties. In this work, we developed an effective strategy to grow the conductive polyaniline (PANI) inside the pores of MIL-101 (labeled as PANI/MIL-101) to form a fixed interpenetrating network structure. The electron-rich imine group in PANI is chelated with the coordinatively unsaturated metal sites (CUS) in MIL-101 to form a relatively strong bonded complex and through other synergistic effects to enhance the conductivity and …
Electrical Stimulation With A Conductive Polymer Promotes Neurite Outgrowth And Synaptogenesis In Primary Cortical Neurons In 3d, Qingsheng Zhang, Stephen T. Beirne, Kewei Shu, Dorna Esrafilzadeh, Xu-Feng Huang, Gordon G. Wallace
Electrical Stimulation With A Conductive Polymer Promotes Neurite Outgrowth And Synaptogenesis In Primary Cortical Neurons In 3d, Qingsheng Zhang, Stephen T. Beirne, Kewei Shu, Dorna Esrafilzadeh, Xu-Feng Huang, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Deficits in neurite outgrowth and synaptogenesis have been recognized as an underlying developmental aetiology of psychosis. Electrical stimulation promotes neuronal induction including neurite outgrowth and branching. However, the effect of electrical stimulation using 3D electrodes on neurite outgrowth and synaptogenesis has not been explored. This study examined the effect of 3D electrical stimulation on 3D primary cortical neuronal cultures. 3D electrical stimulation improved neurite outgrowth in 3D neuronal cultures from both wild-Type and NRG1-knockout (NRG1-KO) mice. The expression of synaptophysin and PSD95 were elevated under 3D electrical stimulation. Interestingly, 3D electrical stimulation also improved neural cell aggregation as well as …
Dirac Signature In Germanene On Semiconducting Substrate, Jincheng Zhuang, Chen Liu, Zhiyong Zhou, Gilberto Casillas, Haifeng Feng, Xun Xu, Jiaou Wang, Weichang Hao, Xiaolin Wang, Shi Xue Dou, Zhenpeng Hu, Yi Du
Dirac Signature In Germanene On Semiconducting Substrate, Jincheng Zhuang, Chen Liu, Zhiyong Zhou, Gilberto Casillas, Haifeng Feng, Xun Xu, Jiaou Wang, Weichang Hao, Xiaolin Wang, Shi Xue Dou, Zhenpeng Hu, Yi Du
Australian Institute for Innovative Materials - Papers
2D Dirac materials supported by nonmetallic substrates are of particular interest due to their significance for the realization of the quantum spin Hall effect and their application in field-effect transistors. Here, monolayer germanene is successfully fabricated on semiconducting germanium film with the support of a Ag(111) substrate. Its linear-like energy-momentum dispersion and large Fermi velocity are derived from the pronounced quasiparticle interference patterns in a √3 x √3 superstructure. In addition to Dirac fermion characteristics, the theoretical simulations reveal that the energy gap opens at the Brillouin zone center of the √3 x √3 restructured germanene, which is evoked by …
Nanocrystalline Cellulose For Anisotropic Magnetoelectric Composites, Yan Zong, Zhilian Yue, Michael J. Higgins
Nanocrystalline Cellulose For Anisotropic Magnetoelectric Composites, Yan Zong, Zhilian Yue, Michael J. Higgins
Australian Institute for Innovative Materials - Papers
The emergence of piezoelectric polymers in magnetoelectric (ME) composites enables flexible and low-cost device fabrication though notably gives rise to the highest ME output voltages to date. Accordingly, the highest piezoresponsive polymers, poly(vinylidene fluoride) (PVDF) and its copolymers, are exclusively studied despite an inventory of unexplored piezoelectric polymers such as naturally occurring cellulose, that is only recently demonstrated in ME composites. Herein, the development of nanocrystalline cellulose (CNC)-based ME composites is reported on. Two types of CNC, nanospheres and nanowhiskers, are synthesized and incorporated in laminate composite, which exhibit a giant α ME ( > 1 V cm -1 Oe -1 …
Discovery Of A Voltage-Stimulated Heartbeat Effect In Droplets Of Liquid Gallium, Zhenwei Yu, Yuchen Chen, Fei Yun, David L. Cortie, Lei Jiang, Xiaolin Wang
Discovery Of A Voltage-Stimulated Heartbeat Effect In Droplets Of Liquid Gallium, Zhenwei Yu, Yuchen Chen, Fei Yun, David L. Cortie, Lei Jiang, Xiaolin Wang
Australian Institute for Innovative Materials - Papers
Chemomechanical effects are known to initiate fluid oscillations in certain liquid metals; however, they typically produce an irregular motion that is difficult to deactivate or control. Here we show that stimulating liquid gallium with electrochemistry can cause a metal drop to exhibit a heart beating effect by shape shifting at a telltale frequency. Unlike the effects reported in the past for mercury, the symmetry-breaking forces generated by using gallium propel the drop several millimeters with velocities of the order of 1 cm per second. We demonstrate pulsating dynamics between 0 and 610 beats per minute for 50-150 μL droplets in …
Defect Electrocatalytic Mechanism: Concept, Topological Structure And Perspective, Yi Jia, Jun Chen, Xiangdong Yao
Defect Electrocatalytic Mechanism: Concept, Topological Structure And Perspective, Yi Jia, Jun Chen, Xiangdong Yao
Australian Institute for Innovative Materials - Papers
Carbon-based materials have been attracting intense interest for electrocatalysis due to their various merits, such as abundance, low cost, high conductivity and tunable molecular structures. However, to date, the electrochemical activities of these electrocatalysts are mainly attributed to different active dopants (e.g. N, B, P or S), leading to a common concept that heteroatom doping is essential for carbon-based electrocatalysts. Recently, we presented a new concept where the specific topological defects could activate the oxygen reduction reaction (ORR) and developed a facile method to create such unique defects. Subsequent research has extended this new mechanism to other reactions, such as …
A "Tandem" Strategy To Fabricate Flexible Graphene/Polypyrrole Nanofiber Film Using The Surfactant-Exfoliated Graphene For Supercapacitors, Kewei Shu, Yunfeng Chao, Shulei Chou, Caiyun Wang, Tian Zheng, Sanjeev Gambhir, Gordon G. Wallace
A "Tandem" Strategy To Fabricate Flexible Graphene/Polypyrrole Nanofiber Film Using The Surfactant-Exfoliated Graphene For Supercapacitors, Kewei Shu, Yunfeng Chao, Shulei Chou, Caiyun Wang, Tian Zheng, Sanjeev Gambhir, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
The surfactant-assisted liquid-phase exfoliation of expanded graphite can produce graphene sheets in large quantities with minimal defects. However, it is difficult to completely remove the surfactant from the final product, thus affecting the electrochemical properties of the produced graphene. In this article, a novel approach to fabricate flexible graphene/polypyrrole film was developed: using surfactant cetyltrimethylammonium bromide as a template for growth of polypyrrole nanofibers (PPyNFs) instead of removal after the exfoliation process; followed by a simple filtration method. The introduction of PPyNF not only increases the electrochemical performance, but also ensures flexibility. This composite film electrode offers a capacitance up …
Controlled Synthesis Of Mesoporous Nitrogen-Doped Carbons With Highly Ordered Two-Dimensional Hexagonal Mesostructures And Their Chemical Activation, Abeer Enaiet Allah, Haibo Tan, Xingtao Xu, Ahmed Farghali, Mohamed Khedr, Abdulmohsen Alshehri, Yoshio Bando, Nanjundan Kumar, Yusuke Yamauchi
Controlled Synthesis Of Mesoporous Nitrogen-Doped Carbons With Highly Ordered Two-Dimensional Hexagonal Mesostructures And Their Chemical Activation, Abeer Enaiet Allah, Haibo Tan, Xingtao Xu, Ahmed Farghali, Mohamed Khedr, Abdulmohsen Alshehri, Yoshio Bando, Nanjundan Kumar, Yusuke Yamauchi
Australian Institute for Innovative Materials - Papers
Ordered mesoporous nitrogen-doped carbon (OMNC) materials are considered as the most promising material for supercapacitors. In this study, a highly ordered two-dimensional (2D) hexagonal mesostructured polymer was synthesized through a facile assembly of triblock polymer micelles and phenol-melamine/formaldehyde resin via an organic-organic assembly process in aqueous solution. After calcination, the novel OMNC materials with 2D hexagonal mesostructures were obtained. By further KOH activation, the surface area and the porosity of the OMNC significantly improved, and the internal mesoporous structures were maintained. The activated OMNC-800A displayed a specific capacitance as high as 475.75 F g-1at 0.5 A g-1with an outstanding cycling …
Fe-Doped Phosphorene For The Nitrogen Reduction Reaction, Zengxi Wei, Yuefeng Zhang, Shuangyin Wang, Caiyun Wang, Jianmin Ma
Fe-Doped Phosphorene For The Nitrogen Reduction Reaction, Zengxi Wei, Yuefeng Zhang, Shuangyin Wang, Caiyun Wang, Jianmin Ma
Australian Institute for Innovative Materials - Papers
The nitrogen-to-ammonia conversion is one of the most important and challenging processes in chemistry. We have employed spin-polarized density functional theory to propose Fe-doped monolayer phosphorene (Fe-P) as a new catalyst for the N2reduction reaction at room temperature. Our results show that single-atom Fe is the active site, cooperating with P to activate the inert N-N triple bond and reduce N2to NH3via three reliable pathways. Our findings provide a new avenue for single atom catalytic nitrogen fixation under ambient conditions.
Cose2/Mose2heterostructures With Enriched Water Adsorption/Dissociation Sites Towards Enhanced Alkaline Hydrogen Evolution Reaction, Guoqiang Zhao, Peng Li, Kun Rui, Yaping Chen, Shi Xue Dou, Wenping Sun
Cose2/Mose2heterostructures With Enriched Water Adsorption/Dissociation Sites Towards Enhanced Alkaline Hydrogen Evolution Reaction, Guoqiang Zhao, Peng Li, Kun Rui, Yaping Chen, Shi Xue Dou, Wenping Sun
Australian Institute for Innovative Materials - Papers
Transition-metal dichalcogenides (TMDs) are promising electrocatalysts toward the hydrogen evolution reaction (HER) in acid media, but they show significantly inferior activity in alkaline media due to the extremely sluggish water dissociation kinetics. Herein, CoSe2/MoSe2heterostructures with CoSe2quantum dots anchored on MoSe2nanosheets are synthesized towards enhanced alkaline HER catalytic activity. The incorporation of CoSe2is intended to construct additional water adsorption sites on the basal planes of MoSe2to promote water dissociation. The CoSe2/MoSe2heterostructures show substantially enhanced activity over MoSe2and CoSe2in 1 m KOH. The optimal overpotential required to reach a current density of 10 mA cm−2is merely 218 mV, which is more than …
Ion Selective Separators Based On Graphene Oxide For Stabilizing Lithium Organic Batteries, Yuede Pan, Junran Hao, Xuanbo Zhu, Yahong Zhou, Shulei Chou
Ion Selective Separators Based On Graphene Oxide For Stabilizing Lithium Organic Batteries, Yuede Pan, Junran Hao, Xuanbo Zhu, Yahong Zhou, Shulei Chou
Australian Institute for Innovative Materials - Papers
Ion selective membranes exist widely in the biological world and have been mimicked by scientists and engineers for the purpose of manipulating ion flow. For instance, polymers with sulfonate groups like Nafion are applied in proton exchange membrane fuel cells for facilitating proton transport whilst blocking other species. Herein, ion selective separators composed of graphene oxide (GO) and Super P (or graphene) are applied for stabilizing lithium organic batteries. The reconstructed GO sheets form numerous negatively charged nanochannels, which selectively allow the transport of lithium ions and reject the electroactive organic anions. Meanwhile, Super P (or graphene) on top of …
Vacancy-Induced Sodium-Ion Storage In N-Doped Carbon Nanofiber@Mos2nanosheet Arrays, Jiaojiao Liang, Zengxi Wei, Caiyun Wang, Jianmin Ma
Vacancy-Induced Sodium-Ion Storage In N-Doped Carbon Nanofiber@Mos2nanosheet Arrays, Jiaojiao Liang, Zengxi Wei, Caiyun Wang, Jianmin Ma
Australian Institute for Innovative Materials - Papers
As a promising material for sodium-ion batteries, molybdenum disulphide (MoS2) affords excellent electrochemical performance owing to its large surface area and the accelerated electron transport within individual layers. However, it suffers from slow reaction kinetics and agglomeration owing to low conductivity and high surface energy. In this work, nitrogen-doped carbon nanofiber@MoS2nanosheets arrays with S-vacancies (NC@MoS2-VS) are developed via a process involving electrospining, hydrothermal and annealing. When served as an anode material for SIBs, this material displays a superior capacity of 495 mAh g−1over 100 charge/discharge cycles at a current density of 100 mA g−1, and the pseudocapacitive contribution is up …
The Charge Transport Mechanisms In Conducting Polymer Polypyrrole Films And Fibers, Reza Ghanbari, Shaban Reza Ghorbani, Hadi Arabi, Javad Foroughi
The Charge Transport Mechanisms In Conducting Polymer Polypyrrole Films And Fibers, Reza Ghanbari, Shaban Reza Ghorbani, Hadi Arabi, Javad Foroughi
Australian Institute for Innovative Materials - Papers
Smart materials based on inherently conducting polymers are of practical interest and extend the advantages of electromaterials from the nanoscale to macroscale applications. However understanding mechanisms of the their electrical properties are still remained challanging. Herein, we report the transport properties of chemically and electrochemically preapred conducting polymer polypyrrole films and fibers. Conduction mechanisms of the as-prepared polypyrrole (PPy) were investigated using their electrical properties as a function of temperature (7-300 K). The results of the PPy resistivity were evaluated using a linear combination of Mott's and Efros-Shklovskii's Variable- Range Hopping (Mott-VRH and ES-VRH) models. It was found that the …
Enhancement Of Thermoelectric Figure Of Merit By The Insertion Of Multi-Walled Carbon Nanotubes In Α-Mgagsb, Jingdan Lei, De Zhang, Weibao Guan, Zheng Ma, Zhenxiang Cheng, Chao Wang, Yuanxu Wang
Enhancement Of Thermoelectric Figure Of Merit By The Insertion Of Multi-Walled Carbon Nanotubes In Α-Mgagsb, Jingdan Lei, De Zhang, Weibao Guan, Zheng Ma, Zhenxiang Cheng, Chao Wang, Yuanxu Wang
Australian Institute for Innovative Materials - Papers
Hybrid materials provide an efficient alternative route on improving the thermoelectric performance compared with doping elements. Especially, the insertion of carbon nanotubes plays an effective role in modulating the electrical transport properties and phonon scattering simultaneously. We fabricated a multi-walled carbon nanotube (MWCNTs) doped α-MgAgSb-based hybrid material and researched its thermoelectric properties in detail. The introduced MWCNTs enhanced carrier transport due to the metallic character of MWCNTs and phonon dispersion by the additional interfaces of insertions. The results showed that the electrical conductivity in α-MgAgSb/CNTs was remarkably enhanced especially at MgAg0.97Sb0.99/0.15 wt. % CNTs boosting to 1.6 times than that …
Coordination Of Atomic Co-Pt Coupling Species At Carbon Defects As Active Sites For Oxygen Reduction Reaction, Longzhou Zhang, Julia Fischer, Yi Jia, Xuecheng Yan, Wei Xu, Xiyang Wang, Jun Chen, Dongjiang Yang, Hongwei Liu, Linzhou Zhuang, Marlies Hankel, Debra J. Searles, Keke Huang, Shouhua Feng, Christopher L. Brown, Xiangdong Yao
Coordination Of Atomic Co-Pt Coupling Species At Carbon Defects As Active Sites For Oxygen Reduction Reaction, Longzhou Zhang, Julia Fischer, Yi Jia, Xuecheng Yan, Wei Xu, Xiyang Wang, Jun Chen, Dongjiang Yang, Hongwei Liu, Linzhou Zhuang, Marlies Hankel, Debra J. Searles, Keke Huang, Shouhua Feng, Christopher L. Brown, Xiangdong Yao
Australian Institute for Innovative Materials - Papers
Platinum (Pt) is the state-of-the-art catalyst for oxygen reduction reaction (ORR), but its high cost and scarcity limit its large-scale use. However, if the usage of Pt reduces to a sufficiently low level, this critical barrier may be overcome. Atomically dispersed metal catalysts with high activity and high atom efficiency have the possibility to achieve this goal. Herein, we report a locally distributed atomic Pt-Co nitrogen-carbon-based catalyst (denoted as A-CoPt-NC) with high activity and robust durability for ORR (267 times higher than commercial Pt/C in mass activity). The A-CoPt-NC shows a high selectivity for the 4e-pathway in ORR, differing from …