Capacitive Performance of Reduced Graphene Oxide Modified Sodium Ion-Intercalated Manganese Oxide Composite Electrode

Abstract The reduced graphene oxide modified sodium ion-intercalated manganese oxide (RGO-NaxMnO2) is designed as a supercapacitor electrode material. The layered intercalation compound NaxMnO2 is prepared through a solid-state reaction process. RGO-NaxMnO2 is then formed by the chemical reduction of graphene oxide coated NaxMnO2 through a hydrothermal process. RGO-NaxMnO2 is supported on the substrate of nickel form (NF) and titanium nitride (TiN) to form RGO-NaxMnO2/NF and RGO-NaxMnO2/TiN composite electrodes. NaxMnO2 has a particle aggregate structure with the individual particle size of 1–2 µm. RGO-NaxMnO2 composite shows the densely packed arrangement of particles with the particle aggregate size of 8 µm. RGO modification can well improve the electrical conductivity of RGO-NaxMnO2. The current response is highly enhanced from 0.127 A g−1 for NaxMnO2/NF to 0.372 A g−1 for RGO-NaxMnO2/NF at 2 mV s−1. Furthermore, the TiN substrate with superior electrical conductivity and electrochemical anti-corrosion contributes to improving the electrochemical capacitance and cycle stability of RGO-NaxMnO2. RGO-NaxMnO2/TiN reveals higher specific capacitance (244.2 F g−1 at 2.0 A g−1) and higher cycling capacitance retention (99.7%) after 500 cycles at 2.0 A g−1 than RGO-NaxMnO2/NF (177.1 F g−1, 43.6%). So, RGO-NaxMnO2/TiN exhibits much higher capacitive performance than RGO-NaxMnO2/NF, which presents a potential application for electrochemical energy storage.

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Sulfur-Doped Reduced Graphene Oxide for Enhanced Sodium Ion Pseudocapacitance

Nanomaterials ◽

10.3390/nano9050752 ◽

2019 ◽

Vol 9 (5) ◽

pp. 752 ◽

Cited By ~ 4

Author(s):

Yiting Wang ◽

Mingxiang Hu ◽

Desheng Ai ◽

Hongwei Zhang ◽

Zheng-Hong Huang ◽

...

Keyword(s):

Graphene Oxide ◽

Energy Density ◽

Electrochemical Properties ◽

Reduced Graphene Oxide ◽

High Performance ◽

Large Scale ◽

Hydrothermal Process ◽

Sodium Ion ◽

Sulfur Source ◽

Reduced Graphene

Sodium-ion capacitors (NICs) are considered an important candidate for large-scale energy storage in virtue of their superior energy–power properties, as well as availability of rich Na+ reserves. To fabricate high-performance NIC electrode material, a hydrothermal method was proposed to synthesize sulfur-doped reduced graphene oxide (SG), which exhibited unique layered structures and showed excellent electrochemical properties with 116 F/g capacitance at 1 A/g as the cathode of NICs from 1.6 V to 4.2 V. At the power–energy density over 5000 W/kg, the SG demonstrated over 100 Wh/kg energy density after 3500 cycles, which indicated its efficient durability and superior power–energy properties. The addition of a sulfur source in the hydrothermal process led to the higher specific surface area and more abundant micropores of SG when compared with those of reduced graphene oxide (rGO), thus SG exhibited much better electrochemical properties than those shown by rGO. Partially substituting surface oxygen-containing groups of rGO with sulfur-containing groups also facilitated the enhanced sodium-ion storage ability of SG by introducing sufficient pseudocapacitance.

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Coexistence of electrical conductivity and ferromagnetism in a hybrid material formed from reduced graphene oxide and manganese oxide

Dalton Transactions ◽

10.1039/c5dt00299k ◽

2015 ◽

Vol 44 (11) ◽

pp. 5049-5052 ◽

Cited By ~ 5

Author(s):

Yusuke Murashima ◽

Ryo Ohtani ◽

Takeshi Matsui ◽

Hiroshi Takehira ◽

Ryotaro Yokota ◽

...

Keyword(s):

Electrical Conductivity ◽

Graphene Oxide ◽

Manganese Oxide ◽

Reduced Graphene Oxide ◽

Hybrid Material ◽

Reduced Graphene

The coexistence of electrical conductivity and ferromagnetism has been achieved in a reduced graphene oxide and manganese oxide hybrid (rGO–Mn).

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Graphene Oxide: A Smart (Starting) Material for Natural Methylxanthines Adsorption and Detection

Molecules ◽

10.3390/molecules24234247 ◽

2019 ◽

Vol 24 (23) ◽

pp. 4247 ◽

Cited By ~ 5

Author(s):

Rita Petrucci ◽

Isabella Chiarotto ◽

Leonardo Mattiello ◽

Daniele Passeri ◽

Marco Rossi ◽

...

Keyword(s):

Electrical Conductivity ◽

Graphene Oxide ◽

Nucleic Acids ◽

Reduced Graphene Oxide ◽

Electrochemical Sensors ◽

Enzymatic Digestion ◽

Biologically Active ◽

Polar Solvents ◽

Dna And Rna ◽

Reduced Graphene

Natural methylxanthines, caffeine, theophylline and theobromine, are widespread biologically active alkaloids in human nutrition, found mainly in beverages (coffee, tea, cocoa, energy drinks, etc.). Their detection is thus of extreme importance, and many studies are devoted to this topic. During the last decade, graphene oxide (GO) and reduced graphene oxide (RGO) gained popularity as constituents of sensors (chemical, electrochemical and biosensors) for methylxanthines. The main advantages of GO and RGO with respect to graphene are the easiness and cheapness of synthesis, the notable higher solubility in polar solvents (water, among others), and the higher reactivity towards these targets (mainly due to – interactions); one of the main disadvantages is the lower electrical conductivity, especially when using them in electrochemical sensors. Nonetheless, their use in sensors is becoming more and more common, with the obtainment of very good results in terms of selectivity and sensitivity (up to 5.4 × 10−10 mol L−1 and 1.8 × 10−9 mol L−1 for caffeine and theophylline, respectively). Moreover, the ability of GO to protect DNA and RNA from enzymatic digestion renders it one of the best candidates for biosensors based on these nucleic acids. This is an up-to-date review of the use of GO and RGO in sensors.

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Chemically reduced graphene oxide-coated knitted fabric imparted conductivity and outstanding hydrophobicity

Textile Research Journal ◽

10.1177/0040517521995471 ◽

2021 ◽

pp. 004051752199547

Author(s):

Min Hou ◽

Xinghua Hong ◽

Yanjun Tang ◽

Zimin Jin ◽

Chengyan Zhu ◽

...

Keyword(s):

Electrical Conductivity ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Chemical Reduction ◽

Knitted Fabric ◽

Mesh Structure ◽

Reduced Graphene ◽

Chemically Reduced Graphene Oxide ◽

Modified Hummers Method

Functionalized knitted fabric, as a kind of flexible, wearable, and waterproof material capable of conductivity, sensitivity and outstanding hydrophobicity, is valuable for multi-field applications. Herein, the reduced graphene oxide (RGO)-coated knitted fabric (polyester/spandex blended) is prepared, which involves the use of graphite oxide (GO) by modified Hummers method and in-situ chemical reduction with hydrazine hydrate. The treated fabric exhibits a high electrical conductivity (202.09 S/cm) and an outstanding hydrophobicity (140°). The outstanding hydrophobicity is associated with the morphology of the fabric and fiber with reference to pseudo-infiltration. These properties can withstand repeated bending and washing without serious deterioration, maintaining good electrical conductivity (35.70 S/cm) and contact angle (119.39°) after eight standard washing cycles. The material, which has RGO architecture and continuous loop mesh structure, can find wide use in smart garment applications.

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