The Experts below are selected from a list of 25047 Experts worldwide ranked by ideXlab platform
Yibing Xie - One of the best experts on this subject based on the ideXlab platform.
-
Electrochemical Capacitance of a carbon quantum dots polypyrrole titania nanotube hybrid
RSC Advances, 2015Co-Authors: Yibing XieAbstract:A carbon quantum dots modified polypyrrole/titania (CQDs–PPy/TiO2) nanotube hybrid was designed as a supercapacitor electrode material for energy storage. CQDs–PPy/TiO2 was prepared by incorporating CQDs-hybridized PPy into a well-aligned titania nanotube array. CQDs–PPy/TiO2 exhibited a highly-ordered heterogeneous coaxial nanotube structure. A CQDs hybridized modification could improve the electrical conductivity of PPy. The charge transfer resistance decreased from 22.4 mΩ cm−2 to 9.3 mΩ cm−2 and the ohmic resistance decreased from 0.817 to 0.154 Ω cm−2 when PPy/TiO2 was converted into the CQDs–PPy/TiO2 nanotube hybrid. The specific Capacitance was accordingly enhanced from 482 F g−1 (or 161 mF cm−2) for PPy/TiO2 to 849 F g−1 (or 212 mF cm−2) for CQDs–PPy/TiO2 at a current density of 0.5 A g−1. The Capacitance retention was slightly increased from 78.5% to 89.3% after 2000 cycles at a high current density of 20 A g−1. The effective incorporation of CQDs into PPy could simultaneously increase the Electrochemical Capacitance and cycle stability of PPy, leading to a superior Electrochemical performance. A flexible solid-state supercapacitor based on the CQDs–PPy nanohybrid exhibited the stable capacitive performance in both planar and bent states. CQDs-hybridized PPy presented promising applications as a supercapacitor electrode material for energy storage.
-
Electrochemical Capacitance of polypyrrole titanium nitride and polypyrrole titania nanotube hybrids
New Journal of Chemistry, 2014Co-Authors: Yibing Xie, Chi Xia, Wei Wang, Fang TianAbstract:Both polypyrrole–titanium nitride (PPy–TiN) and polypyrrole–titania (PPy–TiO2) nanotube hybrids have been prepared by incorporating electroactive polypyrrole into well-aligned titanium nitride and titania nanotube arrays through a normal pulse voltammetry deposition process. Microstructure characterization shows that the polypyrroles have been fully coated on the titanium nitride and titania nanotube arrays to form coaxial heterogenous nanohybrids. The galvanostatic charge–discharge measurements indicate that the PPy–TiN and PPy–TiO2 nanotube hybrids have specific Capacitances of 1265 and 382 F g−1 at a current density of 0.6 A g−1. Both nanotube hybrids have similar cyclability, exhibiting stable Capacitances of 459 and 72 F g−1 after 2000 cycles at a high current density of 15 A g−1. The highly conductive titanium nitride substrate can promote the Electrochemical Capacitance of polypyrrole more significantly, as compared to the titania semiconductor, contributing to a higher superCapacitance performance of PPy–TiN. This indicates that PPy–TiN nanotube hybrids can be more suitable to act as supercapacitor electrode materials.
-
Electrochemical Capacitance of polypyrrole–titanium nitride and polypyrrole–titania nanotube hybrids
New Journal of Chemistry, 2014Co-Authors: Yibing Xie, Chi Xia, Wei Wang, Fang TianAbstract:Both polypyrrole–titanium nitride (PPy–TiN) and polypyrrole–titania (PPy–TiO2) nanotube hybrids have been prepared by incorporating electroactive polypyrrole into well-aligned titanium nitride and titania nanotube arrays through a normal pulse voltammetry deposition process. Microstructure characterization shows that the polypyrroles have been fully coated on the titanium nitride and titania nanotube arrays to form coaxial heterogenous nanohybrids. The galvanostatic charge–discharge measurements indicate that the PPy–TiN and PPy–TiO2 nanotube hybrids have specific Capacitances of 1265 and 382 F g−1 at a current density of 0.6 A g−1. Both nanotube hybrids have similar cyclability, exhibiting stable Capacitances of 459 and 72 F g−1 after 2000 cycles at a high current density of 15 A g−1. The highly conductive titanium nitride substrate can promote the Electrochemical Capacitance of polypyrrole more significantly, as compared to the titania semiconductor, contributing to a higher superCapacitance performance of PPy–TiN. This indicates that PPy–TiN nanotube hybrids can be more suitable to act as supercapacitor electrode materials.
-
Electrochemical Capacitance performance of titanium nitride nanoarray
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2013Co-Authors: Yibing Xie, Yong WangAbstract:Abstract In this study, titanium nitride (TiN) nanoarrays with a short nanotube and long nanopore structure have been prepared by an anodization process of ultra thin titanium foil in ethylene glycol (EG) solution containing ammonium fluoride, subsequent calcination process in an air atmosphere, and final nitridation process in an ammonia atmosphere. The morphology and microstructure characterization has been conducted using field emission scanning electron microscope and X-ray diffraction. The Electrochemical properties have been investigated through cyclic voltammetry and Electrochemical impedance spectrum measurements. The Electrochemical Capacitance performance has been investigated by galvanostatic charge–discharge measurements in the acidic, neural and alkali electrolyte solution. Well-defined TiN nanoarrays contribute a much higher Capacitance performance than titania (TiO 2 ) in the supercapacitor application due to the extraordinarily improved electrical conductivity. Such an Electrochemical Capacitance can be further enhanced by increasing aspect ratio of TiN nanoarray from short nanotubes to long nanopores. A flexible supercapacitor has been constructed using two symmetrical TiN nanoarray electrodes and a polyvinyl alcohol (PVA) gel electrolyte with H 2 SO 4 –KCl–H 2 O–EG. Such a supercapacitor has a highly improved potential window and still keeps good Electrochemical energy storage. TiN nanoarray with a high aspect ratio can act well as an ultra thin film electrode material of flexible supercapacitor to contribute a superior Capacitance performance.
-
Electrochemical Capacitance performance of polypyrrole–titania nanotube hybrid
Journal of Solid State Electrochemistry, 2012Co-Authors: Yibing XieAbstract:In this study, the polypyrrole–titania nanotube hybrid has been synthesized for an Electrochemical supercapacitor application. The highly ordered and independent titania nanotube array is fabricated by an electro-oxidation of titanium sheet through an Electrochemical anodization process in an aqueous solution containing ammonium fluoride, phosphoric acid and ethylene glycol. The polypyrrole–titania nanotube hybrid is then prepared by electrodepositing the conducting polypyrrole into well-aligned titania nanotubes through a normal pulse voltammetry deposition process in an organic acetonitrile solution containing pyrrole monomer and lithium perchlorate. The morphology and microstructure of polypyrrole–titania nanotube hybrid are characterized by scanning electron microscopy, infrared spectroscopy and Raman spectroscopy. The Electrochemical Capacitance performance is determined by cyclic voltammetry and charge/discharge measurement. It indicates that the polypyrrole film can been uniformly deposited on both surfaces of titania nanotube walls, demonstrating a heterogeneous coaxial nanotube structure. The specific Capacitance of polypyrrole–titania nanotube hybrid is determined to be 179 F g−1 based on the polypyrrole mass. The specific energy and specific power are 7.8 Wh kg−1 and 2.8 kW kg−1 at a constant charge/discharge current of 1.85 mA cm−2, respectively. The retained specific Capacitance still keeps 85% of the initial capacity even after 200 cycle numbers. This result demonstrates the satisfying stability and durability of PPy–TiO2 nanotube hybrid electrode in a cyclic charge/discharge process. Such a composite electrode material with highly ordered and coaxial nanotube hybrid structure can contribute high energy storage for supercapacitor applications.
Fang Tian - One of the best experts on this subject based on the ideXlab platform.
-
Electrochemical Capacitance of polypyrrole titanium nitride and polypyrrole titania nanotube hybrids
New Journal of Chemistry, 2014Co-Authors: Yibing Xie, Chi Xia, Wei Wang, Fang TianAbstract:Both polypyrrole–titanium nitride (PPy–TiN) and polypyrrole–titania (PPy–TiO2) nanotube hybrids have been prepared by incorporating electroactive polypyrrole into well-aligned titanium nitride and titania nanotube arrays through a normal pulse voltammetry deposition process. Microstructure characterization shows that the polypyrroles have been fully coated on the titanium nitride and titania nanotube arrays to form coaxial heterogenous nanohybrids. The galvanostatic charge–discharge measurements indicate that the PPy–TiN and PPy–TiO2 nanotube hybrids have specific Capacitances of 1265 and 382 F g−1 at a current density of 0.6 A g−1. Both nanotube hybrids have similar cyclability, exhibiting stable Capacitances of 459 and 72 F g−1 after 2000 cycles at a high current density of 15 A g−1. The highly conductive titanium nitride substrate can promote the Electrochemical Capacitance of polypyrrole more significantly, as compared to the titania semiconductor, contributing to a higher superCapacitance performance of PPy–TiN. This indicates that PPy–TiN nanotube hybrids can be more suitable to act as supercapacitor electrode materials.
-
Electrochemical Capacitance of polypyrrole–titanium nitride and polypyrrole–titania nanotube hybrids
New Journal of Chemistry, 2014Co-Authors: Yibing Xie, Chi Xia, Wei Wang, Fang TianAbstract:Both polypyrrole–titanium nitride (PPy–TiN) and polypyrrole–titania (PPy–TiO2) nanotube hybrids have been prepared by incorporating electroactive polypyrrole into well-aligned titanium nitride and titania nanotube arrays through a normal pulse voltammetry deposition process. Microstructure characterization shows that the polypyrroles have been fully coated on the titanium nitride and titania nanotube arrays to form coaxial heterogenous nanohybrids. The galvanostatic charge–discharge measurements indicate that the PPy–TiN and PPy–TiO2 nanotube hybrids have specific Capacitances of 1265 and 382 F g−1 at a current density of 0.6 A g−1. Both nanotube hybrids have similar cyclability, exhibiting stable Capacitances of 459 and 72 F g−1 after 2000 cycles at a high current density of 15 A g−1. The highly conductive titanium nitride substrate can promote the Electrochemical Capacitance of polypyrrole more significantly, as compared to the titania semiconductor, contributing to a higher superCapacitance performance of PPy–TiN. This indicates that PPy–TiN nanotube hybrids can be more suitable to act as supercapacitor electrode materials.
B. C. Cavenett - One of the best experts on this subject based on the ideXlab platform.
-
Electrical characterization of zinc oxide thin films by Electrochemical Capacitance-voltage profiling
Applied Physics Letters, 2004Co-Authors: Xiaodong Tang, Kevin Alan Prior, A. Clauzonnier, H. I. Campbell, B. C. CavenettAbstract:The growth of ZnO by epitaxial techniques is important for the development of new optoelectronic devices. In order to establish control over the growth, it is important to be able to measure dopant profiles through the layers to supplement Hall effect data. A standard method for many semiconductors is by Electrochemical Capacitance–voltage (C–V) profiling. In this letter, C–V profiles from metal organic chemical vapor deposition grown ZnO thin films are presented. It is shown that carrier density profiles can be obtained routinely and reproducibly by using 0.1 M ZnCl2.
-
Electrochemical Capacitance‐voltage profiling of n‐type molecular beam epitaxy ZnSe layers
Applied Physics Letters, 1992Co-Authors: S. Y. Wang, J. Simpson, Kevin Alan Prior, Frank M. Haran, H. Stewart, J.m. Wallace, B. C. CavenettAbstract:We report the use of Electrochemical Capacitance‐voltage profiling of n‐type ZnSe layers by the use of NaOH electrolyte. Samples with both uniform and staircase doping profiles have been measured with concentrations ranging over 1016–1019 cm−3. The profiling technique has revealed in some samples regions of lower carrier concentration at the surface and at the ZnSe/GaAs interface. Our results demonstrate that this powerful technique can now be used for assessing the growth parameters of wideband gap II‐VI materials in the same way that is widely accepted for III‐V semiconductors.
-
Electrochemical Capacitance‐voltage profiling of n‐type ZnSe
Journal of Applied Physics, 1992Co-Authors: S. Y. Wang, J. Simpson, Kevin Alan Prior, B. C. CavenettAbstract:In this article we report the first detailed study of Electrochemical Capacitance‐voltage profiling of ZnSe. An electrolyte consisting of 1 M sodium hydroxide and 1 M sodium sulphite has been developed that does not deposit selenium while etching the surface of n‐type ZnSe during C‐V profiling. The dissolution number of the electrolyte/ZnSe system is a function of the strength of electrolyte and the etching current and in order to obtain an accurate etching depth a constant etching current mode was used. A wide range of doping concentrations including both uniformly doped and staircase structures have been measured demonstrating that the Electrochemical C‐V profiler can now be a routine tool for assessing the growth parameters of ZnSe.
Zhang Xiaogang - One of the best experts on this subject based on the ideXlab platform.
-
preparation and Electrochemical Capacitance of ruo2 tio2 nanotubes composites
Electrochimica Acta, 2004Co-Authors: Wang Yonggang, Zhang XiaogangAbstract:Abstract In this paper, RuO2/TiO2 nanotubes composites were synthesized by loading various amounts of RuO2 on TiO2 nanotubes. The symmetric supercapacitors based on these nanocomposites were fabricated by using gel polymer PVA–H3PO4–H2O as electrolyte. The Electrochemical Capacitance performance of the nanocomposites in these supercapacitors was investigated by current–potential responses, galvanostatic charge–discharge tests and Electrochemical impedance spectroscopy. The results show that the three dimensional nanotube network of TiO2 offers a solid support structure for active materials RuO2, allows the active material to be readily accessible (available) for Electrochemical reactions, and improves the efficiency of the active materials. A maximum specific Capacitance of 1263 F/g was obtained for the RuO2 which was loading on TiO2 nanotubes.
Zhang Xiao-gang - One of the best experts on this subject based on the ideXlab platform.
-
Preparation and Electrochemical Capacitance of RuO2/TiO2 nanotubes composites
Electrochimica Acta, 2004Co-Authors: Wang Yong-gang, Zhang Xiao-gangAbstract:Abstract In this paper, RuO2/TiO2 nanotubes composites were synthesized by loading various amounts of RuO2 on TiO2 nanotubes. The symmetric supercapacitors based on these nanocomposites were fabricated by using gel polymer PVA–H3PO4–H2O as electrolyte. The Electrochemical Capacitance performance of the nanocomposites in these supercapacitors was investigated by current–potential responses, galvanostatic charge–discharge tests and Electrochemical impedance spectroscopy. The results show that the three dimensional nanotube network of TiO2 offers a solid support structure for active materials RuO2, allows the active material to be readily accessible (available) for Electrochemical reactions, and improves the efficiency of the active materials. A maximum specific Capacitance of 1263 F/g was obtained for the RuO2 which was loading on TiO2 nanotubes.