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Kuk Ro Yoon - One of the best experts on this subject based on the ideXlab platform.
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Preparation and characterization of Manganese Oxide nanosheets for pseudocapacitor application
Journal of Energy Storage, 2019Co-Authors: Bal Sydulu Singu, Sang Eun Hong, Kuk Ro YoonAbstract:Abstract We have utilized the SILAR technique to prepare the Manganese Oxide nanosheets on SS substrates for binder free supercapacitor electrode. The Manganese Oxide nanosheets thin films were prepared and well structural characterized with Raman, XRD, XPS, FE-SEM, FE-TEM and EDAX mapping. The electrochemical properties of Manganese Oxide thin films were systematically studied with cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The Manganese Oxide nanosheets show the utmost capacitance of 398 F g–1, at the current density of 1 A g–1. The capacity retention was 91.3% after completion of 2000 cycles at 20 A g–1. The Manganese Oxide nanosheets display the maximum energy density of 35.4 Wh kg–1 and power density of 8000 W kg–1. These impressive results conclude the Manganese Oxide nanosheets was a promising electrode material for supercapacitor.
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Porous Manganese Oxide nanospheres for pseudocapacitor applications
Journal of Alloys and Compounds, 2017Co-Authors: Bal Sydulu Singu, Kuk Ro YoonAbstract:Abstract Mesoporous, uniform Manganese Oxide nanosphere thin films were grown on a stainless-steel substrate using the successive ionic layer adsorption and reaction (SILAR) method. The amorphous Manganese Oxide nanosphere thin films (AMONTFs) were characterized by grazing incidence X-ray diffraction (GI-XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The GI-XRD analysis reveals that the Manganese Oxide nanosphere thin films were present in the forms of α-MnO 2 and γ-MnO 2 . XPS demonstrates that the thin films contain a mixture of Manganese Oxides: MnO 2 (Mn 4+ ) and MnOOH (Mn 3+ ). The effect of the number of SILAR cycles on the morphology was observed systemically by FE-SEM and greatly influences the size of these unique nanospheres. The electrochemical properties of the AMONTF electrodes were analyzed by cyclic voltammetry (CV) and the galvanostatic charge-discharge (CD) method. The outcomes of the FE-SEM and electrochemical measurements reveal that the thin film obtained after 60 SILAR cycles has a uniform nanosphere size distribution and large specific capacitance. The Manganese Oxide thin films exhibit a maximum specific capacitance, energy, and power density of 262.0 F g −1 , 18.3 Wh kg −1 , and 7999.4 W kg −1 , respectively, in an aqueous 1 M Na 2 SO 4 electrolyte solution.
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Porous Manganese Oxide nanospheres for pseudocapacitor applications
Journal of Alloys and Compounds, 2017Co-Authors: Bal Sydulu Singu, Kuk Ro YoonAbstract:Abstract Mesoporous, uniform Manganese Oxide nanosphere thin films were grown on a stainless-steel substrate using the successive ionic layer adsorption and reaction (SILAR) method. The amorphous Manganese Oxide nanosphere thin films (AMONTFs) were characterized by grazing incidence X-ray diffraction (GI-XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The GI-XRD analysis reveals that the Manganese Oxide nanosphere thin films were present in the forms of α-MnO 2 and γ-MnO 2 . XPS demonstrates that the thin films contain a mixture of Manganese Oxides: MnO 2 (Mn 4+ ) and MnOOH (Mn 3+ ). The effect of the number of SILAR cycles on the morphology was observed systemically by FE-SEM and greatly influences the size of these unique nanospheres. The electrochemical properties of the AMONTF electrodes were analyzed by cyclic voltammetry (CV) and the galvanostatic charge-discharge (CD) method. The outcomes of the FE-SEM and electrochemical measurements reveal that the thin film obtained after 60 SILAR cycles has a uniform nanosphere size distribution and large specific capacitance. The Manganese Oxide thin films exhibit a maximum specific capacitance, energy, and power density of 262.0 F g −1 , 18.3 Wh kg −1 , and 7999.4 W kg −1 , respectively, in an aqueous 1 M Na 2 SO 4 electrolyte solution.
Hao Jiang - One of the best experts on this subject based on the ideXlab platform.
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high rate electrochemical capacitors from highly graphitic carbon tipped Manganese Oxide mesoporous carbon Manganese Oxide hybrid nanowires
Energy and Environmental Science, 2011Co-Authors: Hao Jiang, Liping Yang, Chaoyi Yan, Pooi See LeeAbstract:In this paper, using Manganese Oxide as an example, we report the successful design and synthesis of a novel one-dimensional highly graphitic carbon-tipped Manganese Oxide/mesoporous carbon/Manganese Oxide hybrid nanowire. The unique structure significantly improves the conductivity of metal Oxide materials, which is a key limitation in pseudocapacitors. The hybrid nanowire with optimal carbon content, when applied as an electrode, exhibits superior capacitive properties in 1 M Na2SO4 aqueous solution, such as high specific capacitance (266 F g−1 at 1 A g−1), excellent rate capability (56.4% capacity retention at 60 A g−1) and outstanding cycling stability (without degradation after 1200 cycles). The energy densities achieved can be as high as 20.8 W h kg−1, at a power density of 30 kW kg−1. The results demonstrated that the Manganese Oxide in our hybrid nanomaterial was efficiently utilized with the assistance of the highly conductive graphitic carbon-tipped mesoporous carbon shell. It is reckoned that the present low-cost novel hybrid nanowire can serve as a promising electrode material for supercapacitors and other electrochemical devices.
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High–rate electrochemical capacitors from highly graphitic carbon–tipped Manganese Oxide/mesoporous carbon/Manganese Oxide hybrid nanowires
Energy and Environmental Science, 2011Co-Authors: Hao Jiang, Liping Yang, Chunzhong Li, Jan MaAbstract:In this paper, using Manganese Oxide as an example, we report the successful design and synthesis of a novel one-dimensional highly graphitic carbon-tipped Manganese Oxide/mesoporous carbon/Manganese Oxide hybrid nanowire. The unique structure significantly improves the conductivity of metal Oxide materials, which is a key limitation in pseudocapacitors. The hybrid nanowire with optimal carbon content, when applied as an electrode, exhibits superior capacitive properties in 1 M Na2SO4 aqueous solution, such as high specific capacitance (266 F g−1 at 1 A g−1), excellent rate capability (56.4% capacity retention at 60 A g−1) and outstanding cycling stability (without degradation after 1200 cycles). The energy densities achieved can be as high as 20.8 W h kg−1, at a power density of 30 kW kg−1. The results demonstrated that the Manganese Oxide in our hybrid nanomaterial was efficiently utilized with the assistance of the highly conductive graphitic carbon-tipped mesoporous carbon shell. It is reckoned that the present low-cost novel hybrid nanowire can serve as a promising electrode material for supercapacitors and other electrochemical devices.
Bal Sydulu Singu - One of the best experts on this subject based on the ideXlab platform.
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Preparation and characterization of Manganese Oxide nanosheets for pseudocapacitor application
Journal of Energy Storage, 2019Co-Authors: Bal Sydulu Singu, Sang Eun Hong, Kuk Ro YoonAbstract:Abstract We have utilized the SILAR technique to prepare the Manganese Oxide nanosheets on SS substrates for binder free supercapacitor electrode. The Manganese Oxide nanosheets thin films were prepared and well structural characterized with Raman, XRD, XPS, FE-SEM, FE-TEM and EDAX mapping. The electrochemical properties of Manganese Oxide thin films were systematically studied with cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The Manganese Oxide nanosheets show the utmost capacitance of 398 F g–1, at the current density of 1 A g–1. The capacity retention was 91.3% after completion of 2000 cycles at 20 A g–1. The Manganese Oxide nanosheets display the maximum energy density of 35.4 Wh kg–1 and power density of 8000 W kg–1. These impressive results conclude the Manganese Oxide nanosheets was a promising electrode material for supercapacitor.
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Porous Manganese Oxide nanospheres for pseudocapacitor applications
Journal of Alloys and Compounds, 2017Co-Authors: Bal Sydulu Singu, Kuk Ro YoonAbstract:Abstract Mesoporous, uniform Manganese Oxide nanosphere thin films were grown on a stainless-steel substrate using the successive ionic layer adsorption and reaction (SILAR) method. The amorphous Manganese Oxide nanosphere thin films (AMONTFs) were characterized by grazing incidence X-ray diffraction (GI-XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The GI-XRD analysis reveals that the Manganese Oxide nanosphere thin films were present in the forms of α-MnO 2 and γ-MnO 2 . XPS demonstrates that the thin films contain a mixture of Manganese Oxides: MnO 2 (Mn 4+ ) and MnOOH (Mn 3+ ). The effect of the number of SILAR cycles on the morphology was observed systemically by FE-SEM and greatly influences the size of these unique nanospheres. The electrochemical properties of the AMONTF electrodes were analyzed by cyclic voltammetry (CV) and the galvanostatic charge-discharge (CD) method. The outcomes of the FE-SEM and electrochemical measurements reveal that the thin film obtained after 60 SILAR cycles has a uniform nanosphere size distribution and large specific capacitance. The Manganese Oxide thin films exhibit a maximum specific capacitance, energy, and power density of 262.0 F g −1 , 18.3 Wh kg −1 , and 7999.4 W kg −1 , respectively, in an aqueous 1 M Na 2 SO 4 electrolyte solution.
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Porous Manganese Oxide nanospheres for pseudocapacitor applications
Journal of Alloys and Compounds, 2017Co-Authors: Bal Sydulu Singu, Kuk Ro YoonAbstract:Abstract Mesoporous, uniform Manganese Oxide nanosphere thin films were grown on a stainless-steel substrate using the successive ionic layer adsorption and reaction (SILAR) method. The amorphous Manganese Oxide nanosphere thin films (AMONTFs) were characterized by grazing incidence X-ray diffraction (GI-XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The GI-XRD analysis reveals that the Manganese Oxide nanosphere thin films were present in the forms of α-MnO 2 and γ-MnO 2 . XPS demonstrates that the thin films contain a mixture of Manganese Oxides: MnO 2 (Mn 4+ ) and MnOOH (Mn 3+ ). The effect of the number of SILAR cycles on the morphology was observed systemically by FE-SEM and greatly influences the size of these unique nanospheres. The electrochemical properties of the AMONTF electrodes were analyzed by cyclic voltammetry (CV) and the galvanostatic charge-discharge (CD) method. The outcomes of the FE-SEM and electrochemical measurements reveal that the thin film obtained after 60 SILAR cycles has a uniform nanosphere size distribution and large specific capacitance. The Manganese Oxide thin films exhibit a maximum specific capacitance, energy, and power density of 262.0 F g −1 , 18.3 Wh kg −1 , and 7999.4 W kg −1 , respectively, in an aqueous 1 M Na 2 SO 4 electrolyte solution.
Hongmin Chen - One of the best experts on this subject based on the ideXlab platform.
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facile synthesis of monodisperse Manganese Oxide nanostructures and their application in water treatment
Journal of Physical Chemistry C, 2008Co-Authors: Hongmin ChenAbstract:Different Manganese Oxide nanomaterials were prepared by treating their precursor, which had been prepared by mixing KMnO4 solution and oleic acid at room temperature, at low temperatures (≤200 °C). While the hierarchical morphology was kept, the phase structure was transformed from layered Manganese Oxide to tetragonal hausmannite. The Manganese Oxide nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and nitrogen adsorption−desorption measurements. These nanostructures showed better adsorption capacity of organic polluents (methylene blue) than existing MCM-22, Red mud, and other synthesized Manganese Oxide (including α-, β-, and γ-) materials. The adsorption capacity of the nanomaterials did not largely depend on their surface area. The possible adsorption mechanisms are also discussed.
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self assembly of novel mesoporous Manganese Oxide nanostructures and their application in oxidative decomposition of formaldehyde
Journal of Physical Chemistry C, 2007Co-Authors: Hongmin Chen, Changbin Zhang, Junhui He, Hong HeAbstract:Monodisperse Manganese Oxide honeycomb and hollow nanospheres have been prepared facilely at room temperature by varying the molar ratio of KMnO4 and oleic acid. These new nanomaterials were characterized by XRD, SEM, EDS, TEM, and BET measurements. They had robust nanostructures and were stable even after ultrasonic treatment (40 kHz, 120 W) for 30 min. A plausible mechanism of the formation of Manganese Oxide nanostructures was proposed. The Manganese Oxide nanomaterials showed high catalytic activities for oxidative decomposition of formaldehyde at low temperatures. Complete conversion of formaldehyde to CO2 and H2O could be achieved, and harmful byproducts were not detected in effluent gases. The catalytic activity of Manganese Oxide hollow nanospheres was much higher than that of honeycomb nanospheres, although the surface area of the latter was nearly 2 times as high as that of the former. The mechanism of such morphology-dependent catalytic activity was discussed in detail. The catalytic activities...
Jan Ma - One of the best experts on this subject based on the ideXlab platform.
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High–rate electrochemical capacitors from highly graphitic carbon–tipped Manganese Oxide/mesoporous carbon/Manganese Oxide hybrid nanowires
Energy and Environmental Science, 2011Co-Authors: Hao Jiang, Liping Yang, Chunzhong Li, Jan MaAbstract:In this paper, using Manganese Oxide as an example, we report the successful design and synthesis of a novel one-dimensional highly graphitic carbon-tipped Manganese Oxide/mesoporous carbon/Manganese Oxide hybrid nanowire. The unique structure significantly improves the conductivity of metal Oxide materials, which is a key limitation in pseudocapacitors. The hybrid nanowire with optimal carbon content, when applied as an electrode, exhibits superior capacitive properties in 1 M Na2SO4 aqueous solution, such as high specific capacitance (266 F g−1 at 1 A g−1), excellent rate capability (56.4% capacity retention at 60 A g−1) and outstanding cycling stability (without degradation after 1200 cycles). The energy densities achieved can be as high as 20.8 W h kg−1, at a power density of 30 kW kg−1. The results demonstrated that the Manganese Oxide in our hybrid nanomaterial was efficiently utilized with the assistance of the highly conductive graphitic carbon-tipped mesoporous carbon shell. It is reckoned that the present low-cost novel hybrid nanowire can serve as a promising electrode material for supercapacitors and other electrochemical devices.