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Full-Text Articles in Physical Sciences and Mathematics
Catechol Oxidation By Ozone And Hydroxyl Radicals At The Air-Water Interface, Elizabeth A. Pillar, Robert C. Camm, Marcelo I. Guzman
Catechol Oxidation By Ozone And Hydroxyl Radicals At The Air-Water Interface, Elizabeth A. Pillar, Robert C. Camm, Marcelo I. Guzman
Chemistry Faculty Publications
Anthropogenic emissions of aromatic hydrocarbons promptly react with hydroxyl radicals undergoing oxidation to form phenols and polyphenols (e.g., catechol) typically identified in the complex mixture of humic-like substances (HULIS). Because further processing of polyphenols in secondary organic aerosols (SOA) can continue mediated by a mechanism of ozonolysis at interfaces, a better understanding about how these reactions proceed at the air–water interface is needed. This work shows how catechol, a molecular probe of the oxygenated aromatic hydrocarbons present in SOA, can contribute interfacial reactive species that enhance the production of HULIS under atmospheric conditions. Reactive semiquinone radicals are quickly produced upon …
A Seemless Three-Dimensional Carbon Nanotube Graphene Hybrid Material, Yu Zhu, Lei Li, Gilberto Casillas, Zhengzong Sun, Zheng Yan, Gedeng Ruan, Zhiwei Peng, Abdul-Rahman Raji, Carter Kittrell, Robert Hauge, James Tour
A Seemless Three-Dimensional Carbon Nanotube Graphene Hybrid Material, Yu Zhu, Lei Li, Gilberto Casillas, Zhengzong Sun, Zheng Yan, Gedeng Ruan, Zhiwei Peng, Abdul-Rahman Raji, Carter Kittrell, Robert Hauge, James Tour
Yu Zhu
Graphene and single-walled carbon nanotubes are carbon materials that exhibit excellent electrical conductivities and large specific surface areas. Theoretical work suggested that a covalently bonded graphene/single-walled carbon nanotube hybrid material would extend those properties to three dimensions, and be useful in energy storage and nanoelectronic technologies. Here we disclose a method to bond graphene and single-walled carbon nanotubes seamlessly during the growth stage. The hybrid material exhibits a surface area 42,000m2 g1 with ohmic contact from the vertically aligned single-walled carbon nanotubes to the graphene. Using aberration-corrected scanning transmission electron microscopy, we observed the covalent transformation of sp2 carbon between …
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 …
Flexible Cellulose Based Polypyrrole-Multiwalled Carbon Nanotube Films For Bio-Compatible Zinc Batteries Activated By Simulated Body Fluids, Sha Li, Zai Ping Guo, Cai Yun Wang, Gordon G. Wallace, Hua-Kun Liu
Flexible Cellulose Based Polypyrrole-Multiwalled Carbon Nanotube Films For Bio-Compatible Zinc Batteries Activated By Simulated Body Fluids, Sha Li, Zai Ping Guo, Cai Yun Wang, Gordon G. Wallace, Hua-Kun Liu
Gordon Wallace
This work aims to develop biocompatible non-toxic materials for implantable bio-electronic cells. Polypyrrole (PPy)–carbon nanotube (CNT) composites with varied ratios of PPy to CNTs were chemically synthesized and used as cathodes with the support of cellulose paper. Zinc foil was used as the anode material due to its non-toxicity and moderate dissolution rate in aqueous solutions. Simulated body fluids (SBFs) with various protein concentrations were applied as electrolytes in this battery system. The PPy–CNT|Zn cell is capable of being discharged up to 24.5 hours at a current density of 60 μA cm−2 in a protein free SBF. The batteries have …
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 …
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.
Nanocomposites Of Silicon And Carbon Derived From Coal Tar Pitch: Cheap Anode Materials For Lithium-Ion Batteries With Long Cycle Life And Enhanced Capacity, Yun-Xiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Nanocomposites Of Silicon And Carbon Derived From Coal Tar Pitch: Cheap Anode Materials For Lithium-Ion Batteries With Long Cycle Life And Enhanced Capacity, Yun-Xiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
From energy and environmental consideration, an industrial waste product, coal tar pitch (CTP), is used as the carbon source for Si/AC composite. We exploited a facile sintering method to largely scale up Si/amorphous carbon nanocomposite. The composites with 20 wt.% silicon with PVdF binder exhibited stable lithium storage ability for prolonged cycling. The composite anode delivered a capacity of 400.3 mAh g−1 with a high capacity retention of 71.3% after 1000 cycles. Various methods are used to investigate the reason for the outstanding cyclability. The results indicate that the silicon nanoparticles are wrapped by amorphous SiOx and AC in Si/AC …
A Triblock-Copolymer-Templating Route To Carbon Spheres@Sba-15 Large Mesopore Core-Shell And Hollow Structures, Jianping Yang, Xianghong Qian, Minjun Chen, Jianwei Fan, Hua-Kun Liu, Weixian Zhang
A Triblock-Copolymer-Templating Route To Carbon Spheres@Sba-15 Large Mesopore Core-Shell And Hollow Structures, Jianping Yang, Xianghong Qian, Minjun Chen, Jianwei Fan, Hua-Kun Liu, Weixian Zhang
Australian Institute for Innovative Materials - Papers
The fabrication of mesoporous core-shell and hollow spheres with ordered mesostructures and tunable large pore sizes is highly desirable for fundamental research and practical applications. A direct triblock-copolymer-templating coating approach has been provided for the synthesis of carbon sphere@mesoporous silica core-shell (CS@SBA-15) and hollow structures in an acidic medium at room temperature. These CS@SBA-15 core-shell structures possess large mesopores (6.3-8.4 nm), high surface areas (318.1-438.4 m2 g-1) and large pore volumes (0.31-0.36 cm3 g-1). The corresponding hollow mesoporous silica spheres (HMSS) with controllable mesopores (6.0-8.2 nm), high surface areas (239.9-326.5 m2 g-1 …
Na3v2(Po4)3 Particles Partly Embedded In Carbon Nanofibers With Superb Kinetics For Ultra-High Power Sodium Ion Batteries, Junghoon Yang, Dongwook Han, Mi Ru Jo, Kyeongse Song, Yongil Kim, Shulei Chou, Hua-Kun Liu, Yong-Mook Kang
Na3v2(Po4)3 Particles Partly Embedded In Carbon Nanofibers With Superb Kinetics For Ultra-High Power Sodium Ion Batteries, Junghoon Yang, Dongwook Han, Mi Ru Jo, Kyeongse Song, Yongil Kim, Shulei Chou, Hua-Kun Liu, Yong-Mook Kang
Australian Institute for Innovative Materials - Papers
We here describe the extraordinary performance of NASICON Na3V2(PO4)3-carbon nanofiber (NVP-CNF) composites with ultra-high power and excellent cycling performance. NVP-CNFs are composed of CNFs at the center part and partly embedded NVP nanoparticles in the shell. We first report this unique morphology of NVP-CNFs for the electrode material of secondary batteries as well as for general energy conversion materials. Our NVP-CNFs show not only a high discharge capacity of approx. 88.9 mA h g-1 even at a high current density of 50 C but also approx. 93% cyclic retention property after …
Microwave Autoclave Synthesized Multi-Layer Graphene/Single-Walled Carbon Nanotube Composites For Free-Standing Lithium-Ion Battery Anodes, Chao Zhong, Jia-Zhao Wang, David Wexler, Hua-Kun Liu
Microwave Autoclave Synthesized Multi-Layer Graphene/Single-Walled Carbon Nanotube Composites For Free-Standing Lithium-Ion Battery Anodes, Chao Zhong, Jia-Zhao Wang, David Wexler, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
Multi-layer graphene sheets have been synthesized by a time-efficient microwave autoclave method and used to form composites in situ with single-walled carbon nanotubes. The application of these composites as flexible free-standing film electrodes was then investigated. According to the transmission electron microscopy and X-ray diffraction characterizations, the average d-spacing of the graphene-single-walled carbon nanotube composites was 0.41 nm, which was obviously larger than that of the as-prepared pure graphene (0.36 nm). The reversible Li-cycling properties of the free-standing films have been evaluated by galvanostatic discharge-charge cycling and electrochemical impedance spectroscopy. Results showed that the free-standing composite film with 70 wt% …
A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu
A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
Paper-like free-standing germanium (Ge) and single-walled carbon nanotube (SWCNT) composite anodes were synthesized by the vacuum filtration of Ge/SWCNT composites, which were prepared by a facile aqueous-based method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Electrochemical measurements demonstrate that the Ge/SWCNT composite paper anode with the weight percentage of 32% Ge delivered a specific discharge capacity of 417 mA h g−1 after 40 cycles at a current density of 25 mA g−1, 117% higher than the pure SWCNT paper anode. The SWCNTs not only function as a flexible mechanical support for …
A Computational Study Of Carbon Dioxide Adsorption On Solid Boron, Qiao Sun, Meng Wang, Zhen Li, Aijun Du, Debra J. Searles
A Computational Study Of Carbon Dioxide Adsorption On Solid Boron, Qiao Sun, Meng Wang, Zhen Li, Aijun Du, Debra J. Searles
Australian Institute for Innovative Materials - Papers
Capturing and sequestering carbon dioxide (CO2) can provide a route to partial mitigation of climate change associated with anthropogenic CO2 emissions. Here we report a comprehensive theoretical study of CO2 adsorption on two phases of boron, α-B12 and γ-B28. The theoretical results demonstrate that the electron deficient boron materials, such as α-B12 and γ-B 28, can bond strongly with CO2 due to Lewis acid-base interactions because the electron density is higher on their surfaces. In order to evaluate the capacity of these boron materials for CO2 capture, we also performed calculations with various degrees of CO2 coverage. The computational results …
Highly Conductive Carbon Nanotube-Graphene Hybrid Yarn, Javad Foroughi, Geoffrey M. Spinks, Dennis Antiohos, Azadehsadat Mirabedini, Sanjeev Gambhir, Gordon G. Wallace, Shaban Reza Ghorbani, Germanas Peleckis, Mikhail Kozlov, Marcio Lima, Ray Baughman
Highly Conductive Carbon Nanotube-Graphene Hybrid Yarn, Javad Foroughi, Geoffrey M. Spinks, Dennis Antiohos, Azadehsadat Mirabedini, Sanjeev Gambhir, Gordon G. Wallace, Shaban Reza Ghorbani, Germanas Peleckis, Mikhail Kozlov, Marcio Lima, Ray Baughman
Australian Institute for Innovative Materials - Papers
An efficient procedure for the fabrication of highly conductive carbon nanotube/graphene hybrid yarns has been developed. To start, arrays of vertically aligned multi-walled carbon nanotubes (MWNT) are converted into indefinitely long MWNT sheets by drawing. Graphene flakes are then deposited onto the MWNT sheets by electrospinning to form a composite structure that is transformed into yarn filaments by twisting. The process is scalable for yarn fabrication on an industrial scale. Prepared materials are characterized by electron microscopy, electrical, mechanical, and electrochemical measurements. It is found that the electrical conductivity of the composite MWNT-graphene yarns is over 900 S/cm. This value …
Dispersion And Characterization Of Arc Discharge Single-Walled Carbon Nanotubes-Towards Conducting Transparent Films, Benedikt Rosner, Dirk Guldi, Jun Chen, Andrew Minett, Rainer H. Fink
Dispersion And Characterization Of Arc Discharge Single-Walled Carbon Nanotubes-Towards Conducting Transparent Films, Benedikt Rosner, Dirk Guldi, Jun Chen, Andrew Minett, Rainer H. Fink
Australian Institute for Innovative Materials - Papers
This study addresses a combination of a well-developed and mild dispersion method and high-quality arc discharge single-walled carbon nanotubes (SWCNTs) as starting materials. Thus, we advance in fabrication of transparent, conducting films with extraordinary low material loss during SWCNT processing. The starting material was characterized by means of thermogravimetric analysis, high-resolution transmission electron microscopy and Raman spectroscopy. The quality of the starting material and produced dispersions was evaluated by ultraviolet and visible light absorption spectroscopy and Raman spectroscopy. A transparent conductive film was fabricated by drop-casting, whereas films were obtained with electrical to optical conductivity ratios (σDC/σOp) as high as …
Current-Voltage Characteristics Of Nb-Carbon-Nb Junctions, I P. Nevirkovets, S E. Shafranjuk, O Chernyashevskyy, Nandhag Masilamani, J Ketterson
Current-Voltage Characteristics Of Nb-Carbon-Nb Junctions, I P. Nevirkovets, S E. Shafranjuk, O Chernyashevskyy, Nandhag Masilamani, J Ketterson
Australian Institute for Innovative Materials - Papers
We report on properties of Nb(/Ti)-carbon-(Ti/)Nb junctions fabricated on graphite flakes using e-beam lithography. The devices were characterized at temperatures above 1.8 K where a Josephson current was not observed, but the differential conductivity revealed features below the critical temperature of Nb, and overall metallic conductivity, in spite of a high-junctions resistance. Since the conductivity of graphite along the planes is essentially two-dimensional (2D), we use a theoretical model developed for metal/graphene junctions for interpretation of the results. The model involves two very different graphene "access" lengths. The shorter length characterizes ordinary tunneling between the three-dimensional Nb(/Ti) electrode and 2D …
A Novel Carbon Nanotube Modified Scaffold As An Efficient Biocathode Material For Improved Microbial Electrosynthesis, Ludovic Jourdin, Stefano Freguia, Bogdan C. Donose, Jun Chen, Gordon G. Wallace, Jurg Keller, Victoria Flexer
A Novel Carbon Nanotube Modified Scaffold As An Efficient Biocathode Material For Improved Microbial Electrosynthesis, Ludovic Jourdin, Stefano Freguia, Bogdan C. Donose, Jun Chen, Gordon G. Wallace, Jurg Keller, Victoria Flexer
Australian Institute for Innovative Materials - Papers
We report on a novel biocompatible, highly conductive three-dimensional cathode manufactured by direct growth of flexible multiwalled carbon nanotubes on reticulated vitreous carbon (NanoWeb-RVC) for the improvement of microbial bioelectrosynthesis (MES). NanoWeb-RVC allows for an enhanced bacterial attachment and biofilm development within its hierarchical porous structure. 1.7 and 2.6 fold higher current density and acetate bioproduction rate normalized to total surface area were reached on NanoWeb-RVC versus a carbon plate control for the microbial reduction of carbon dioxide by mixed cultures. This is the first study showing better intrinsic efficiency as biocathode material of a three-dimensional electrode versus a flat …
Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace
Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
In this report single-wall carbon nanotubes (SWNTs) were coated onto latex using spray coating to produce a stretchable electrode. The electrochemical properties of the electrode were determined using cyclic voltammetry and electrochemical impedance spectroscopy and galvanostatic charge/discharge tests were also carried out. The impedance and charge/discharge curves of the latex/SWNTs electrode showed good capacitive behavior even after repetitive stretching to 100% strain. The highest capacitance value obtained for the unstretched SWNTs electrode was 119 F g−1 in 1 M Na2SO4 at 5 mV s−1. After the 100th stretch ≈ 80% of the original capacitance value was retained.
Fabrication Of Free-Standing Hierarchical Carbon Nanofiber/Graphene Oxide/Polyaniline Films For Supercapacitors, Dongdong Xu, Qun Xu, Kaixi Wang, Jun Chen, Zhimin Chen
Fabrication Of Free-Standing Hierarchical Carbon Nanofiber/Graphene Oxide/Polyaniline Films For Supercapacitors, Dongdong Xu, Qun Xu, Kaixi Wang, Jun Chen, Zhimin Chen
Australian Institute for Innovative Materials - Papers
A hierarchical high-performance electrode with nanoacanthine-style polyaniline (PANI) deposited onto a carbon nanofiber/graphene oxide (CNF/GO) template was successfully prepared via an in situ polymerization process. The morphology analysis shows that introducing one-dimensional (1D) CNF could significantly decrease/inhibit the staking of laminated GO to form an open-porous CNF/GO architecture. Followed with in situ facial deposition of PANI, the as-synthesized PANI modified CNF/GO exhibits three-dimensional (3D) hierarchical layered nanoarchitecture, which favors the diffusion of the electrolyte ions into the inner region of active materials. The hierarchical free-standing electrodes were directly fabricated into sandwich structured supercapacitors using 1 M H2SO4 as the electrolyte …
A New Strategy For Integrating Abundant Oxygen Functional Groups Into Carbon Felt Electrode For Vanadium Redox Flow Batteries, Ki Jae Kim, Seung-Wook Lee, Taeeun Yim, Jae-Geun Kim, Jang Wook Choi, Jung Ho Kim, Min-Sik Park, Young-Jun Kim
A New Strategy For Integrating Abundant Oxygen Functional Groups Into Carbon Felt Electrode For Vanadium Redox Flow Batteries, Ki Jae Kim, Seung-Wook Lee, Taeeun Yim, Jae-Geun Kim, Jang Wook Choi, Jung Ho Kim, Min-Sik Park, Young-Jun Kim
Australian Institute for Innovative Materials - Papers
The effects of surface treatment combining corona discharge and hydrogen peroxide (H2O2) on the electrochemical performance of carbon felt electrodes for vanadium redox flow batteries (VRFBs) have been thoroughly investigated. A high concentration of oxygen functional groups has been successfully introduced onto the surface of the carbon felt electrodes by a specially designed surface treatment, which is mainly responsible for improving the energy efficiency of VRFBs. In addition, the wettability of the carbon felt electrodes also can be significantly improved. The energy efficiency of the VRFB cell employing the surface modified carbon felt electrodes is improved by 7% at high …
Fabrication Of Graphene Foam Supported Carbon Nanotube/Polyaniline Hybrids For High-Performance Supercapacitor Applications, Hongxia Yang, Nan Wang, Qun Xu, Zhimin Chen, Yumei Ren, Joselito M. Razal, Jun Chen
Fabrication Of Graphene Foam Supported Carbon Nanotube/Polyaniline Hybrids For High-Performance Supercapacitor Applications, Hongxia Yang, Nan Wang, Qun Xu, Zhimin Chen, Yumei Ren, Joselito M. Razal, Jun Chen
Australian Institute for Innovative Materials - Papers
A large-scale, high-powered energy storage system is crucial for addressing the energy problem. The development of high-performance materials is a key issue in realizing the grid-scale applications of energy-storage devices. In this work, we describe a simple and scalable method for fabricating hybrids (graphenepyrrole/ carbon nanotube-polyaniline (GPCP)) using graphene foam as the supporting template. Graphene-pyrrole (G-Py) aerogels are prepared via a green hydrothermal route from two-dimensional materials such as graphene sheets, while a carbon nanotube/polyaniline (CNT/PANI) composite dispersion is obtained via the in situ polymerization method. The functional nanohybrid materials of GPCP can be assembled by simply dipping the prepared …