Physical Sciences and Mathematics Commons^™

Tillage System Effects On 15-Year Carbon-Based And Simulated N Budgets In A Tile-Drained Iowa Field, Douglas L. Karlen, Ajay Kumar, Ramesh S. Kanwar, Cynthia A. Cambardella, Thomas S. Colvin

Douglas L Karlen

Tillage influences N fate and transport by changing soil structure, aeration, macropore continuity, plant-residue placement, and organic-matter mineralization rates. Our objective was to use 15-year N budgets to compare four primary tillage treatments for continuous corn (Zea mays L.) production on tile-drained Aquic Hapludolls (FAO: Haplic Phaeozems) in northeastern Iowa, USA. A carbon-based N budget used annual grain yield, grain-N concentrations measured in 1992, changes in surface-soil C content between 1977 and 1988 or 1992, surface-soil C : N ratios, and measurements of NO3–N lost in tile-drainage water. It accounted for 98, 104, 99, and 99% of the fertilizer N …

Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace

Robert Gorkin III

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.

Kinetic Modeling Of Catalytic Aerogels, Yi Cao

Honors Theses

As pollution becomes an increasing concern globally, strict regulations have been set on vehicle pollutant emissions. The three-way catalytic converter is capable of converting toxic emissions such as carbon monoxide, unburned hydrocarbons and nitrogen oxides to less hazardous waste such as carbon dioxide, water, and nitrogen. Current catalysts employ platinum group metals, which are expensive and environmentally damaging to mine. Catalytically-active aerogels such as Co-Al, Cu-Al and V-Al aerogels have shown promise as alternatives to these metals. The work presented here adapts and extends a global kinetic model which predicts the conversion of hydrocarbons and carbon monoxide on platinum catalyst …

Stretchable, Weavable Coiled Carbon Nanotube/Mno2/Polymer Fiber Solid-State Supercapacitors, Changsoon Choi, Shi Hyeong Kim, Hyeon Jun Sim, Jae Ah Lee, A Young Choi, Youn Tae Kim, Xavier Lepro, Geoffrey M. Spinks, Ray H. Baughman, Seon Jeong Kim

Australian Institute for Innovative Materials - Papers

Fiber and yarn supercapacitors that are elastomerically deformable without performance loss are sought for such applications as power sources for wearable electronics, micro-devices, and implantable medical devices. Previously reported yarn and fiber supercapacitors are expensive to fabricate, difficult to upscale, or non-stretchable, which limits possible use. The elastomeric electrodes of the present solid-state supercapacitors are made by using giant inserted twist to coil a nylon sewing thread that is helically wrapped with a carbon nanotube sheet, and then electrochemically depositing pseudocapacitive MnO₂ nanofibers. These solid-state supercapacitors decrease capacitance by less than 15% when reversibly stretched by 150% in the …

Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov

Australian Institute for Innovative Materials - Papers

The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon …

Dual Yolk-Shell Structure Of Carbon And Silica-Coated Silicon For High-Performance Lithium-Ion Batteries, L Y. Yang, H Z. Li, Jun Liu, Ziqi Sun, S S. Tang, M Lei

Australian Institute for Innovative Materials - Papers

Silicon batteries have attracted much attention in recent years due to their high theoretical capacity, although a rapid capacity fade is normally observed, attributed mainly to volume expansion during lithiation. Here, we report for the first time successful synthesis of Si/void/SiO₂/void/C nanostructures. The synthesis strategy only involves selective etching of SiO₂ in Si/SiO₂/C structures with hydrofluoric acid solution. Compared with reported results, such novel structures include a hard SiO₂-coated layer, a conductive carbon-coated layer, and two internal void spaces. In the structures, the carbon can enhance conductivity, the SiO₂ layer has mechanically …

Uniform Yolk-Shell Iron Sulfide-Carbon Nanospheres For Superior Sodium-Iron Sulfide Batteries, Yunxiao Wang, Jianping Yang, Shulei Chou, Hua-Kun Liu, Weixian Zhang, Dongyuan Zhao, S X. Dou

Australian Institute for Innovative Materials - Papers

Sodium-metal sulfide battery holds great promise for sustainable and cost-effective applications. Nevertheless, achieving high capacity and cycling stability remains a great challenge. Here, uniform yolk-shell iron sulfide-carbon nanospheres have been synthesized as cathode materials for the emerging sodium sulfide battery to achieve remarkable capacity of ∼545 mA h g-1 over 100 cycles at 0.2 C (100 mA g-1), delivering ultrahigh energy density of ∼438 Wh kg-1. The proven conversion reaction between sodium and iron sulfide results in high capacity but severe volume changes. Nanostructural design, including of nanosized iron sulfide yolks (∼170 nm) with porous carbon shells (∼30 nm) and …

High Acetic Acid Production Rate Obtained By Microbial Electrosynthesis From Carbon Dioxide, Ludovic Jourdin, Timothy Grieger, Juliette Monetti, Victoria Flexer, Stefano Freguia, Yang Lu, Jun Chen, Mark S. Romano, Gordon G. Wallace, Jurg Keller

Australian Institute for Innovative Materials - Papers

High product specificity and production rate are regarded as key success parameters for large-scale applicability of a (bio)chemical reaction technology. Here, we report a significant performance enhancement in acetate formation from CO2, reaching comparable productivity levels as in industrial fermentation processes (volumetric production rate and product yield). A biocathode current density of -102 ± 1 A m-2 and an acetic acid production rate of 685 ± 30 (g m-2 day-1) have been achieved in this study. High recoveries of 94 ± 2% of the CO2 supplied as the sole carbon source and 100 ± 4% of electrons into the final …

One Dimensional Graphitic Carbon Nitrides As Effective Metal-Free Oxygen Reduction Catalysts, Muhammad Nawaz Tahir, Nasir Mahmood, Jinghan Zhu, Asif Mahmood, Faheem K. Butt, Syed Rizwan, Imran Aslam, M Tanveer, Faryal Idrees, Imran Shakir, Chuanbao Cao, Yanglong Hou

Australian Institute for Innovative Materials - Papers

To explore the effect of morphology on catalytic properties of graphitic carbon nitride (GCN), we have studied oxygen reduction reaction (ORR) performance of two different morphologies of GCN in alkaline media. Among both, tubular GCN react with dissolved oxygen in the ORR with an onset potential close to commercial Pt/C. Furthermore, the higher stability and excellent methanol tolerance of tubular GCN compared to Pt/C emphasizes its suitability for fuel cells.

Yolk-Shell Silicon-Mesoporous Carbon Anode With Compact Solid Electrolyte Interphase Film For Superior Lithium-Ion Batteries, Jianping Yang, Yunxiao Wang, Shulei Chou, Renyuan Zhang, Yanfei Xu, Jianwei Fan, Weixian Zhang, Hua-Kun Liu, Dongyuan Zhao, S X. Dou

Australian Institute for Innovative Materials - Papers

Silicon as an electrode suffers from short cycling life, as well as unsatisfactory rate-capability caused by the large volume expansion (~400%) and the consequent structural degradation during lithiation/delithiation processes. Here, we have engineered unique void-containing mesoporous carbon-encapsulated commercial silicon nanoparticles (NPs) in yolk-shell structures. In this design, the silicon NPs yolk are wrapped into open and accessible mesoporous carbon shells, the void space between yolk and shell provides enough room for Si expansion, meanwhile, the porosity of carbon shell enables fast transport of Li+ ions between electrolyte and silicon. Our ex-situ characterization clearly reveals for the first time that a …

A New Strategy For Achieving A High Performance Anode For Lithium Ion Batteries-Encapsulating Germanium Nanoparticles In Carbon Nanoboxes, Dan Li, Hongqiang Wang, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel strategy to improve the electrochemical performance of a germanium anode is proposed via encapsulating germanium nanoparticles in carbon nanoboxes by carbon coating the precursor, germanium dioxide cubes, and then subjecting them to a reduction treatment. The complete and robust carbon boxes are shown to not only provide extra void space for the expansion of germanium nanoparticles after lithium insertion but also offer a large reactive area and reduced distance for the lithium diffusion. Furthermore, the thus-obtained composite, composed of densely stacked carbon nanoboxes encapsulating germanium nanoparticles (germanium at carbon cubes (Ge at CC)), exhibits a high tap density …

Hollow Carbon Spheres With Encapsulated Germanium As An Anode Material For Lithium Ion Batteries, Dan Li, Chuanqi Feng, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel composite consisting of hollow carbon spheres with encapsulated germanium (Ge@HCS) was synthesized by introducing a germanium precursor into the porous-structured hollow carbon spheres. The carbon spheres not only function as a scaffold to hold the germanium and thus maintain the structural integrity of the composite, but also increase the electrical conductivity. The voids and vacancies that are formed after the reduction of germanium dioxide to germanium provide free space for accommodating the volume changes during discharging-charging processes, thus preventing pulverization. The obtained Ge@HCS composite exhibits excellent lithium storage performance, as revealed by electrochemical evaluation.

Significantly Enhanced Critical Current Density In Nano-Mgb2 Grains Rapidly Formed At Low Temperature With Homogeneous Carbon Doping, Yongchang Liu, Feng Lan, Zongqing Ma, Ning Chen, Huijun Li, Shaon Barua, Dipakkumar Patel, Md S. Hossain, S Acar, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

High performance MgB₂ bulks using carbon-coated amorphous boron as a boron precursor were fabricated by Cu-activated sintering at low temperature (600 °C, below the Mg melting point). Dense nano-MgB₂ grains with a high level of homogeneous carbon doping were formed in these MgB₂ samples. This type of microstructure can provide a stronger flux pinning force, together with depressed volatility and oxidation of Mg owing to the low-temperature Cu-activated sintering, leading to a significant improvement of critical current density (J_c) in the as-prepared samples. In particular, the value of J_c for the carbon-coated (Mg …

Efficient, Absorption-Powered Artificial Muscles Based On Carbon Nanotube Hybrid Yarns, Marcio D. Lima, Mohammad W. Hussain, Geoffrey M. Spinks, Sina Naficy, Daniela Hagenasr, Julia S. Bykova, Derrick Tolly, Ray H. Baughman

Australian Institute for Innovative Materials - Papers

A new type of absorption-powered artificial muscle provides high performance without needing a temperature change. These muscles, comprising coiled carbon nanotube fibers infiltrated with silicone rubber, can contract up to 50% to generate up to 1.2 kJ kg⁻¹. The drive mechanism for actuation is the rubber swelling during exposure to a nonpolar solvent. Theoretical energy efficiency conversion can be as high as 16%.

Nano-Carbon Electrodes For Thermal Energy Harvesting, Mark S. Romano, Joselito M. Razal, Dennis Antiohos, Gordon G. Wallace, Jun Chen

Australian Institute for Innovative Materials - Papers

Thermogalvanic cells are capable of converting waste heat (generated as a by-product of almost all human activity) to electricity. These devices may alleviate the problems associated with the use of fossil fuels to meet the world's current demand for energy. This review discusses the developments in thermogalvanic systems attained through the use of nano-carbons as the electrode materials. Advances in cell design and electrode configuration that improve performance of these thermo converters and make them applicable in a variety of environments are also summarized. It is the aim of this review to act as a channel for further developments in …

Hierarchically Porous Carbon-Zirconium Carbide Spheres As Potentially Reusable Transmutation Targets, Nicholas Scales, Jun Chen, Tracey L. Hanley, Daniel P. Riley, Gregory R. Lumpkin, Vittorio Luca

Australian Institute for Innovative Materials - Papers

The preparation of hierarchically porous phase-pure carbon-zirconium carbide spheres with surface areas upwards of 70 m²/g and diameters in the 1-2 mm range has been achieved. The zirconium carbide beads were prepared through carbothermal reduction of polyacrylonitrile-zirconium composites prepared via three different routes including infiltration of a zirconium precursor into preformed polyacrylonitrile (PAN) beads and two one-pot co-precipitation methods. Depending on the route used to prepare the composites, relatively high surface area phase-pure zirconium carbides with the radial macroporous internal structure of the PAN template could be prepared. The adsorption of the elements U, Mo, Cs and Sr …

Carbon Fibre Microelectrodes For Neuroscience Applications, Jian Fang, Zhigang Xie, Gordon G. Wallace, Xungai Wang

Australian Institute for Innovative Materials - Papers

Microelectrodes have shown outstanding performance in neural signal recording, neural stimulation and electrochemical sensing1,2. Compared with their micro-sized counterparts, microelectrodes normally exhibit improved signal-to-noise ratio, fast response time and can work with limited sample volumes. Microelectrodes are required to have good biocompatibility, low electrical impedance and long-term stability in many biomedical applications. Carbon fibres are manufactured from polymeric precursor fibres through carbonization, and high carbon content makes carbon fibres electrically conductive, corrosion resistant, biologically safe and inert3. Therefore, carbon fibre has been considered as an ideal candidate for making microelectrodes.

In this work, single carbon fibres were loaded into capillary …

Large-Scale Synthesis Of Ordered Mesoporous Carbon Fiber And Its Application As Cathode Material For Lithium-Sulfur Batteries, Hongqiang Wang, Chaofeng Zhang, Zhixin Chen, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel type of one-dimensional ordered mesoporous carbon fiber has been prepared via the electrospinning technique by using resol as the carbon source and triblock copolymer Pluronic F127 as the template. Sulfur is then encapsulated in this ordered mesoporous carbon fibers by a simple thermal treatment. The interwoven fibrous nanostructure has favorably mechanical stability and can provide an effective conductive network for sulfur and polysulfides during cycling. The ordered mesopores can also restrain the diffusion of long-chain polysulfides. The resulting ordered mesoporous carbon fiber sulfur (OMCF-S) composite with 63% S exhibits high reversible capacity, good capacity retention and enhanced rate …

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

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

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

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

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

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

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

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

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

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

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

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 …