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Graphene

Materials Chemistry

2014

Articles 1 - 4 of 4

Full-Text Articles in Engineering Science and Materials

Comparison In Factors Affecting Electrochemical Properties Of Thermal-Reduced Graphene Oxide For Supercapacitors, Peng Xiao, Da-Hui Wang, Jun-Wei Lang Dec 2014

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 …


Preparation And Electrochemical Behavior Of Pbo/Gn/Ac, Yun-Fang Gao, Yan-Ping Wang, Qiu-Shi Yao, Fu-Hua Wang, Dong-Lei Ren, Xin Xu Oct 2014

Preparation And Electrochemical Behavior Of Pbo/Gn/Ac, Yun-Fang Gao, Yan-Ping Wang, Qiu-Shi Yao, Fu-Hua Wang, Dong-Lei Ren, Xin Xu

Journal of Electrochemistry

The lead oxide/graphene/activated carbon (PbO/GN/AC) composite materials were prepared by impregnating commercial activated carbon and graphene in saturated lead nitrate solution followed by calcination. The structures and morphologies of the composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that PbO crystals (about 200 nm) were dispersed uniformly on the surface of activated carbon and graphene. Electrochemical data indicate that the composite exhibited good electrochemical performances. The PbO/GN/AC composite possessed the higher over-potential of hydrogen evolution and the high specific capacitance of 312.6 F·g-1, while the internal resistance …


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 Oct 2014

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 Aug 2014

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.