The surface area of a single graphene sheet is 2630 m(2)/g, substantially higher than values derived from BET measurements activated carbons used in current electrochemical double layer capacitors. Our group has pioneered new carbon material that we call chemically modified (CMG). CMG materials are made 1-atom thick sheets carbon, functionalized as needed, and here demonstrate an ultracapacitor cell their performance. Specific capacitances 135 99 F/g aqueous organic electrolytes,...

Activated microwave-exfoliated graphite oxide combined with an ionic liquid can be used to make enhanced capacitor.

Graphene, a two-dimensional monolayer of sp2-bonded carbon atoms, has been attracting great interest due to its unique transport properties. One the promising applications graphene is as transparent conductive electrode owing high optical transmittance and conductivity. In this paper, we report on an improved transfer process large-area grown Cu foils by chemical vapor deposition. The transferred films have electrical conductivity that make them suitable for applications. processes will also...

Reduced graphene oxide/Fe(2)O(3) composite was prepared using a facile two-step synthesis by homogeneous precipitation and subsequent reduction of the G-O with hydrazine under microwave irradiation to yield reduced oxide (RG-O) platelets decorated Fe(2)O(3) nanoparticles. As an anode material for Li-ion batteries, RG-O/Fe(2)O(3) exhibited discharge charge capacities 1693 1227 mAh/g, respectively, normalized mass in (and ∼1355 982 based on total composite), good cycling performance rate...

Graphene monolayer has been grown by chemical vapor deposition on copper and then suspended over a hole. By measuring the laser heating monitoring Raman G peak, we obtain room-temperature thermal conductivity interface conductance of (370 + 650/−320) W/m K (28 16/−9.2) MW/m2 for supported graphene. The graphene exceeds (2500 1100/−1050) near 350 becomes (1400 500/−480) at about 500 K.

We present a novel method to prepare highly conductive, free-standing, and flexible porous carbon thin films by chemical activation of reduced graphene oxide paper. These possess very high specific surface area 2400 m(2) g(-1) with in-plane electrical conductivity 5880 S m(-1). This is the highest for free-standing film reported date. A two-electrode supercapacitor using these as electrodes demonstrated an excellent high-frequency response, extremely low equivalent series resistance on order...

The fundamental properties of graphene are making it an attractive material for a wide variety applications. Various techniques have been developed to produce and recently we discovered the synthesis large area by chemical vapor deposition (CVD) methane on Cu foils. We also showed that growth is surface-mediated process films were polycrystalline with domains having tens square microns. In this paper report effect parameters such as temperature, flow rate partial pressure rate, domain size,...

Graphite oxide was exfoliated and dispersed in propylene carbonate (PC) by bath sonication. Heating the graphene suspensions at 150 °C significantly reduced platelets; paper samples comprising such platelets had an electrical conductivity of 5230 S/m. By adding tetraethylammonium tetrafluoroborate (TEA BF4) to oxide/PC slurry making a two-cell ultracapacitor, specific capacitance values about 120 F/g were obtained.

We report the deposition of films composed overlapped and stacked platelets graphene oxide (G-O) reduced by an electrophoretic (EPD) process. The oxygen functional groups G-O were significantly removed EPD process, as-deposited film showed improved electrical conductivity (1.43 × 104 S·m−1) over papers made filtration method (0.53 10−3 S·m−1). This for reducing without added agents has potential high-yield, large-area, low-cost, environmentally friendly production platelets.

A method for reducing graphite oxide using a variety of commercially available alcohols is described. The carbon products were found to exhibit high C : O ratios (up 30 1, as determined by elemental combustion analysis), conductivities 4600 S m−1), and good specific capacitances 35 F g−1) when tested electrode materials in ultracapacitors.

A hierarchical porous carbon is fabricated by introducing a polyurethane sponge to template graphene oxide into 3D interconnected structure, while KOH activation generates abundant micropores in its backbone. Supercapacitors assembled with this achieve high energy density of 89 W h kg−1 (64 L−1) and outstanding power due the shortened ion-transport distance 3D. As service our authors readers, journal provides supporting information supplied authors. Such materials are peer reviewed may be...

Abstract A method for growing polymers directly from the surface of graphene oxide is demonstrated. The technique involves covalent attachment an initiator followed by polymerization styrene, methyl methacrylate, or butyl acrylate using atom transfer radical (ATRP). resulting materials were characterized a range techniques and found to significantly improve solubility properties oxide. surface‐grown saponified also characterized. Based on these results, ATRP reactions determined proceed in...

By dissolving carbon atoms decomposed from methane in a metal substrate at high temperatures, large area uniform few-layer graphene (FLG)/graphite films were precipitated on surfaces upon cooling. The thickness could be controlled by varying the amount of metal. Such transferred to glass slides after an aqueous solution Fe(NO3)3. Sheet resistances as low 200 Ω/◻ with transmittance 85% obtained FLG films. resistance and can changed over one order magnitude, making such potentially useful for...

Manganese dioxide (MnO2) particles 2–3 nm in size were deposited onto a porous "activated microwave expanded graphite oxide" (aMEGO) carbon scaffold via self-controlled redox process. Symmetric electrochemical capacitors fabricated that yielded specific capacitance of 256 F/g (volumetric: 640 F/cm3) and retention 87.7% after 1000 cycles 1 M H2SO4; when normalized to MnO2, the was 850 F/g. Asymmetric also with aMEGO/MnO2 as positive electrode aMEGO negative had power density 32.3 kW/kg (for...

Abstract Graphene is considered a promising material for industrial application based on the intensive laboratory-scale research in fields of physics, chemistry, materials science and engineering, biology over last decade. Many companies have thus started to pursue graphene scale tons (for flake material) or hundreds thousands square meters film applications. Though industry still its early stages, very significant progress mass production certain applications has become obvious. In this...

A flexible and free‐standing porous carbon nanofibers/selenium composite electrode (Se@PCNFs) is prepared by infiltrating Se into mesoporous nanofibers (PCNFs). The with optimized mesopores for accommodating can synergistically suppress the active material dissolution provide mechanical stability needed film. Se@PCNFs exhibits exceptional electrochemical performance both Li‐ion Na‐ion storage. In case of storage, it delivers a reversible capacity 516 mAh g −1 after 900 cycles without any...

The interfacial capacitance of large area, single layer graphene was directly measured with electrolyte accessing both sides the sheet. PMMA and photoresist patterns were used as supports to suspend CVD grown in during electrochemical testing. Both one two films compared. results show that area normalized charge can be stored simultaneously on is significantly lower than could just side graphene, consistent storage having a quantum component. These measurements are also specific materials...

High-performance yet flexible micro-supercapacitors (MSCs) hold great promise as miniaturized power sources for increasing demand of integrated electronic devices. Herein, this study demonstrates a scalable fabrication multilayered graphene-based MSCs (MG-MSCs), by direct laser writing (DLW) stacked graphene films made from industry-scale chemical vapor deposition (CVD). Combining the dry transfer CVD films, DLW allows highly efficient large-areal with exceptional flexibility, diverse planar...

There are significant controversies on the antibacterial properties of graphene oxide (GO): GO was reported to be bactericidal in saline, whereas its activity nutrient broth controversial. To unveil mechanisms underlying these contradictions, we performed assays under comparable conditions. In bare sheets were intrinsically bactericidal, yielding a bacterial survival percentage <1% at 200 μg/mL. Supplementing saline with ≤10% Luria–Bertani (LB) broth, however, progressively deactivated...

A 3D current collector made of covalently connected carbon nanostructures is presented, which can significantly improve battery performance when used as the cathode and/or anode. Li–S cell assembled using these collectors, with loaded elemental sulfur and anode lithium metal, delivers a high-rate capacity 860 mA h g−1 at 12 C. As service to our authors readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be re-organized for online...