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Articles 1 - 7 of 7
Full-Text Articles in Engineering Science and Materials
Electrochemical Syntheses Of Graphene And Its Composites, Bo Zhao, Li Jiang, Ming-Hui Yuen, Xian-Zhu Fu, Rong Sun, Ching-Ping Wong
Electrochemical Syntheses Of Graphene And Its Composites, Bo Zhao, Li Jiang, Ming-Hui Yuen, Xian-Zhu Fu, Rong Sun, Ching-Ping Wong
Journal of Electrochemistry
Graphene is a kind of ideal two-dimensional flat carbon nanomaterials which have unique chemical and physical properties. The attractive potential applications must be based on the high quality mass production of graphene. However, it remains a huge challenge.An electrochemical approach is a fast, environmental friendly and easy-operating method. single- or multi-layered graphene flakes can easily be produced in short periods of time. In this review, the structure, properties and preparation methods of graphene are first introduced. Accordingly, the electrochemical approaches used for the productions of graphene flakes，graphene/inorganic nanocomposites, graphene/polymer composites and graphene analogues are highlighted. Finally, challenges and opportunities are …
Synthesis And Electrochemical Performance Of Mn3O4/Graphene Composites, Shan-Shan Yang, Qian Zhang, Xiong-Gui Lin, Ming-Sen Zheng, Quan-Feng Dong
Synthesis And Electrochemical Performance Of Mn3O4/Graphene Composites, Shan-Shan Yang, Qian Zhang, Xiong-Gui Lin, Ming-Sen Zheng, Quan-Feng Dong
Journal of Electrochemistry
The Mn3O4/Graphene composites were synthesized by hydrothermal method with the in-situ redox reaction of graphene oxide (GO) and manganese acetate (Mn(Ac)2). The phase structures and morphologies of the materials were characterized by XRD, SEM and TEM. The XPS and IR techniques were used for studying the residual function groups of reduced graphene oxide (RGO). The electrochemical performances of the hybrids were tested in a coin cell. Results showed that the composites prepared with the addition of ammonia water (RM-A) have better performance. The graphenes in RM-A were better-reduced and the Mn3O4 particles were much …
Synthesis Of Graphene Wrapped Li-Rich Layered Metal Oxide And Its Electrochemical Performance, Meng-Yan Hou, Ke Wang, Xiao-Li Dong, Yong-Yao Xia
Synthesis Of Graphene Wrapped Li-Rich Layered Metal Oxide And Its Electrochemical Performance, Meng-Yan Hou, Ke Wang, Xiao-Li Dong, Yong-Yao Xia
Journal of Electrochemistry
In present work, lithium-rich layered transition metal oxide (LLO) was synthesized by a co-precipitation method in combination with a solid-state reaction. The graphene wrapped Li-rich layered oxide composite (LLO/Gra) was obtained by sintering the LLO/GO composite at 300 oC for 30 min in an air. The morphologies and the electrochemical performances were characterized by means of SEM, TEM, XRD, XPS, EIS and charge/discharge tests. The results indicated that the LLOe particles were uniformly wrapped with graphene. The resulting material exhibited better rate capability than that of pristine LLO since the wrapped graphene demonstrated the enhanced electronic conductivity. Accordingly, the …
Comparison In Factors Affecting Electrochemical Properties Of Thermal-Reduced Graphene Oxide For Supercapacitors, Peng Xiao, Da-Hui Wang, Jun-Wei Lang
Comparison In Factors Affecting Electrochemical Properties Of Thermal-Reduced Graphene Oxide For Supercapacitors, Peng Xiao, Da-Hui Wang, Jun-Wei Lang
Journal of Electrochemistry
In this paper, thermal-reduced graphene oxide (T-RGO) materials are synthesized by modified Hummer’s method, followed by thermal reduction under argon atmosphere at different temperatures. Electrochemical investigations show that, for T-RGO electrodes, good electrical conductivity is necessary and the surface functional groups play more significant role than the specific surface area in determining the electrochemical capacitance. The T-RGO obtained at 900 °C (T-RGO900) with a relatively high Brunauer-Emmett-Teller (BET) surface area (314 m2·g-1) and a high electrical conductivity (2421 S·m-1) shows a low specific capacitance of 56 F·g-1. In comparison, the T-RGO obtained …
Boosting Electrocatalytic Activity Of Nitrogen-Doped Graphene/Carbon Nanotube Composite For Oxygen Reduction Reaction, Yu Zhang, Jin-Song Hu, Wen-Jie Jiang, Lin Guo, Zi-Dong Wei, Li-Jun Wan
Boosting Electrocatalytic Activity Of Nitrogen-Doped Graphene/Carbon Nanotube Composite For Oxygen Reduction Reaction, Yu Zhang, Jin-Song Hu, Wen-Jie Jiang, Lin Guo, Zi-Dong Wei, Li-Jun Wan
Journal of Electrochemistry
Developing low-cost catalysts with high electrocatalytic activity for oxygen reduction reaction (ORR) has recently attracted much attention because the sluggish ORR currently limits the performance and commercialization of fuel cells and metal-air batteries as well. Nitrogen doped carbon materials have been considered as a promising candidate for the replacement of high-cost and scarce Pt-based catalysts although their electrocatalytic activity still needs to be much improved. In this work, an improved nitrogen-doped graphene/carbon nanotubes composite (N-rGO/CNT) was developed as an efficient ORR electrocatalyst. It was found that the ORR activity of N-rGO/CNT composite could be significantly enhanced by introducing iron in …
Preparation Of Pt-Tio2/Graphene Composites With High Catalytic Activity Towards Methanol Oxidation And Oxygen Reduction Reaction, Li Qi, Ying Yin, Wen-Guang Tu, Bing-Bing Wu, Zhao-Sheng Wang, Jian-Guo Liu, Jun Gu, Zhi-Gang Zou
Preparation Of Pt-Tio2/Graphene Composites With High Catalytic Activity Towards Methanol Oxidation And Oxygen Reduction Reaction, Li Qi, Ying Yin, Wen-Guang Tu, Bing-Bing Wu, Zhao-Sheng Wang, Jian-Guo Liu, Jun Gu, Zhi-Gang Zou
Journal of Electrochemistry
A series of graphene-supported TiO2 nanoparticles (TiO2/G) with different TiO2 contents were prepared by a facile hydrothermal method, and then the Pt-TiO2/G catalysts were successfully prepared by reducing Pt-precursor with microwave technique. Compared with Pt-G catalysts, the catalytic performance toward oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) of Pt-TiO2/G catalysts was improved due to the addition of TiO2. However, the excessive TiO2 would lead to a poor catalytic performance of Pt-TiO2/G catalysts because of the low electrical conductivity of TiO2.
Synthesis And Electrochemical Properties Of Lifeso4f/Graphene Composite As Cathode Material For Lithium-Ion Batteries, Wei Guo, Ya-Xia Yin, Li-Jun Wan, Yu-Guo Guo
Synthesis And Electrochemical Properties Of Lifeso4f/Graphene Composite As Cathode Material For Lithium-Ion Batteries, Wei Guo, Ya-Xia Yin, Li-Jun Wan, Yu-Guo Guo
Journal of Electrochemistry
The LiFeSO4F was successfully synthesized from the reactions of FeSO4?xH2O (x=1, 4, 7) with LiF in tetraethylene glycol media through a facile low temperature method. The structures and microscopic features of the products were characterized by XRD, SEM and TEM. TGA result shows the good thermal stability of the as-prepared LiFeSO4F. No diffraction peaks of the FeSO4 are observed in the as-prepared products with the starting material of either FeSO4?4H2O or FeSO4?7H2O, which should be ascribed to delaying the release of H2O from the hydrated compounds. Cyclic voltammetry (CV) curves and electrochemical impedance spectroscopy (EIS) results prove that the LiFeSO4F/graphene …