The Experts below are selected from a list of 57795 Experts worldwide ranked by ideXlab platform
James L. Gole - One of the best experts on this subject based on the ideXlab platform.
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Formation of ferromagnetic Ni/SiO2 Nanospheres
Materials Letters, 2002Co-Authors: S. M. Prokes, W. E. Carlos, Lenward Seals, Stephen E. Lewis, James L. GoleAbstract:Abstract Dispersed SiO 2 Nanospheres have been nickel-plated using an electroless-plating solution. Magnetic resonance (MR) experiments have been performed on these samples. The MR signals demonstrate the presence of Ni +2 and Ni +3 paramagnetic centers, which are most easily seen below 40 K, and ferromagnetic metallic Ni, which can be readily seen above 40 K. The MR results also indicate only the presence of paramagnetic Ni +3 in a dried sample of the Ni-plating solution that does not contain any SiO 2 Nanospheres. These results suggest that an interfacial reaction at the surface of the SiO 2 Nanospheres leads to the formation of ferromagnetic Ni, which deposits onto the spheres and forms a Ni/SiO 2 Nanosphere composite.
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Formation of ferromagnetic Ni/SiO2 Nanospheres
Materials Letters, 2002Co-Authors: S. M. Prokes, W. E. Carlos, Lenward Seals, Stephen Lewis, James L. GoleAbstract:Dispersed SiO2 Nanospheres have been nickel-plated using an electroless-plating solution. Magnetic resonance (MR) experiments have been performed on these samples. The MR signals demonstrate the presence of Ni+2 and Ni+3 paramagnetic centers, which are most easily seen below 40 K, and ferromagnetic metallic Ni, which can be readily seen above 40 K. The MR results also indicate only the presence of paramagnetic Ni+3 in a dried sample of the Ni-plating solution that does not contain any SiO2 Nanospheres. These results suggest that an interfacial reaction at the surface of the SiO2 Nanospheres leads to the formation of ferromagnetic Ni, which deposits onto the spheres and forms a Ni/SiO2 Nanosphere composite. ?? 2002 Elsevier Science B.V. All rights reserved.
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direct synthesis of silicon nanowires silica Nanospheres and wire like Nanosphere agglomerates
Applied Physics Letters, 2000Co-Authors: James L. Gole, John D Stout, William L Rauch, Zhong Lin WangAbstract:Elevated temperature synthesis has been used to generate virtually defect free SiO2 sheathed crystalline silicon nanowires and silica (SiO2) Nanospheres which can be agglomerated to wire-like configurations impregnated with crystalline silicon. The SiO2 passivated (sheathed) crystalline silicon nanowires, generated with a modified approach using a heated Si–SiO2 mix, with their axes parallel to 〈111〉 are found to be virtually defect free. Modifications to the system allow the simultaneous formation of SiO2 Nanospheres (d∼10–30 nm) as virtually monodisperse gram quantity powders which form large surface area catalysts for the selective conversion of ethanol to acetaldehyde.
Weixin Zhang - One of the best experts on this subject based on the ideXlab platform.
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controllable preparation of multishelled nio hollow Nanospheres via layer by layer self assembly for supercapacitor application
Journal of Power Sources, 2014Co-Authors: Zeheng Yang, Feifei Xu, Weixin ZhangAbstract:Abstract In this work, we demonstrate a facile layer-by-layer (LBL) self-assembly method for controllable preparation of single-, double-, and triple-shelled NiO hollow Nanospheres by calcining Ni(OH)2/C precursors formed at different stage. It is observed that the external nanoflakes of the NiO hollow Nanospheres are inherited from the Ni(OH)2 precursors organized on the surface of carbon spheres via a self-assembly growth process and the inner shells result from the formation of different Ni(OH)2 layers within the carbon spheres during different preparation cycles. Supercapacitive performance of the three types of NiO hollow Nanospheres as active electrode materials has been evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge. The results indicate that double-shelled NiO hollow Nanosphere sample with largest surface area (92.99 m2 g−1) exhibits the best electrochemical properties among the three NiO hollow Nanosphere samples. It delivers a high capacitance of 612.5 F g−1 at 0.5 A g−1 and demonstrates a superior long-term cyclic stability, with over 90% specific capacitance retention after 1000 charge–discharge cycles. This excellent performance is ascribed to the short diffusion path and large surface area of the unique hollow structure with nanoflake building blocks for bulk accessibility of faradaic reaction.
Weiguo Song - One of the best experts on this subject based on the ideXlab platform.
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microwave assisted gas liquid interfacial synthesis of flowerlike nio hollow Nanosphere precursors and their application as supercapacitor electrodes
Journal of Materials Chemistry, 2011Co-Authors: Weiguo SongAbstract:A rapid method based on an efficient gas/liquid interfacial microwave-assisted process has been developed to synthesize flowerlike NiO hollow Nanosphere precursors, which were then transformed to NiO by simple calcinations. The wall of the sphere is composed of twisted NiO nanosheets that intercalated with each other. Such hollow structure is different from widely reported flowerlike nanostructures with solid cores. An Ostwald ripening mechanism was proposed for the formation of the hollow nanostructures. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution TEM, energy-dispersive X-ray analysis, and N2adsorption-desorption methods. These flowerlike NiO hollow Nanospheres have high surface area of 176 m2 g−1. Electrochemical properties show a high specific capacitance of 585 F g−1 at a discharge current of 5 A g−1 and excellent cycling stability, suggesting its promising potentials in supercapacitors.
S. M. Prokes - One of the best experts on this subject based on the ideXlab platform.
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Formation of ferromagnetic Ni/SiO2 Nanospheres
Materials Letters, 2002Co-Authors: S. M. Prokes, W. E. Carlos, Lenward Seals, Stephen E. Lewis, James L. GoleAbstract:Abstract Dispersed SiO 2 Nanospheres have been nickel-plated using an electroless-plating solution. Magnetic resonance (MR) experiments have been performed on these samples. The MR signals demonstrate the presence of Ni +2 and Ni +3 paramagnetic centers, which are most easily seen below 40 K, and ferromagnetic metallic Ni, which can be readily seen above 40 K. The MR results also indicate only the presence of paramagnetic Ni +3 in a dried sample of the Ni-plating solution that does not contain any SiO 2 Nanospheres. These results suggest that an interfacial reaction at the surface of the SiO 2 Nanospheres leads to the formation of ferromagnetic Ni, which deposits onto the spheres and forms a Ni/SiO 2 Nanosphere composite.
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Formation of ferromagnetic Ni/SiO2 Nanospheres
Materials Letters, 2002Co-Authors: S. M. Prokes, W. E. Carlos, Lenward Seals, Stephen Lewis, James L. GoleAbstract:Dispersed SiO2 Nanospheres have been nickel-plated using an electroless-plating solution. Magnetic resonance (MR) experiments have been performed on these samples. The MR signals demonstrate the presence of Ni+2 and Ni+3 paramagnetic centers, which are most easily seen below 40 K, and ferromagnetic metallic Ni, which can be readily seen above 40 K. The MR results also indicate only the presence of paramagnetic Ni+3 in a dried sample of the Ni-plating solution that does not contain any SiO2 Nanospheres. These results suggest that an interfacial reaction at the surface of the SiO2 Nanospheres leads to the formation of ferromagnetic Ni, which deposits onto the spheres and forms a Ni/SiO2 Nanosphere composite. ?? 2002 Elsevier Science B.V. All rights reserved.
Zhihao Wu - One of the best experts on this subject based on the ideXlab platform.
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ag nanoparticle zno hollow Nanosphere arrays large scale synthesis and surface plasmon resonance effect induced raman scattering enhancement
Journal of Materials Chemistry, 2012Co-Authors: Yashu Zang, Jing Li, Zhiming Wu, Suntao Wu, Zhihao WuAbstract:ZnO hollow Nanosphere (HNS) arrays decorated with Ag nanoparticles (NPs) were fabricated on silicon substrates using self-assembled monolayer polystyrene (PS) Nanospheres as the template. The O2 plasma etching was introduced to manipulate the diameters of the ZnO HNSs. This fabrication method has the advantages of simplicity, large scale production, easy size and shape manipulations, low cost and bio-compatibility. Scanning electron microscopy (SEM) images show that the obtained Ag NP–ZnO HNS hybrid structures are hexagonally arranged, with the uniform size and shape, and the X-ray diffraction (XRD) pattern shows that the ZnO HNS arrays are of high crystal quality and have a dominant orientation of direction. Resonant Raman scattering spectra reveal the multiphonon A1 (LO) modes of ZnO hollow Nanospheres at 574, 1147 and 1725 cm−1. Enhanced resonant Raman scattering from the Ag NP modified ZnO HNSs was observed, indicating a strong energy coupling effect located at the metal/semiconductor interface. Surface enhanced Raman scattering (SERS) application for the Ag NP decorated ZnO HNS arrays was verified using a Rhodamine 6G (R6G) chromophore as a standard analyte, which is proved to be an effective SERS template for Raman signal detection. SERS substrates with different structures have been compared, and the Ag NP modified ZnO HNS system exhibits superior Raman scattering enhancements induced by the local surface plasmon resonance (LSPR) effect. The SERS mechanism was well explained by theoretical calculation results. This study is helpful to fabricate controllable Ag NP arrays using the ZnO HNS as the supporting structure and to understand the mechanism of bio-sensing enhancements due to the LSPR effect originated from the metal NPs and metal/semiconductor interface.
