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Graphene

Materials Chemistry

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Full-Text Articles in Engineering Science and Materials

Ordered Mesoporous Carbon/Graphene/Nickel Foam For Flexible Dopamine Detection With Ultrahigh Sensitivity And Selectivity, Lai-Yu Wang, Xin Xi, Dong-Qing Wu, Xiong-Yu Liu, Wei Ji, Rui-Li Liu Jun 2020

Ordered Mesoporous Carbon/Graphene/Nickel Foam For Flexible Dopamine Detection With Ultrahigh Sensitivity And Selectivity, Lai-Yu Wang, Xin Xi, Dong-Qing Wu, Xiong-Yu Liu, Wei Ji, Rui-Li Liu

Journal of Electrochemistry

Flexible biosensors have received intensive attentions for their potential applications in wearable electronics. To obtain flexible electrochemical dopamine (DA) sensors, the ordered mesoporous carbon/graphene/nickel foam (OMC/G/Ni) composite was fabricated in this work via the growth of graphene on Ni foam by chemical vapor deposition, and the formation of the OMC layer followed by the carbonization of co-assembled resol and block polymer., The monolithic Ni foam in the resultant OMC/G/Ni electrode provided an interconnected metal framework with high conductivity and good flexibility, while the OMC layer with the vertically aligned mesopore arrays rendered the composite a large electroactive surface with highly …


Electrochemical H2O2Sensor Based On The Co-Immobilization Of Phosphmolybdic Acid And Graphene On Pedot Film Electrode With Nafion, Hao-Xian Zhou, Jun-Ming Zhang, Zhi-Yu Qu, Pan-Yu Zhang, You-Jun Fan Feb 2016

Electrochemical H2O2Sensor Based On The Co-Immobilization Of Phosphmolybdic Acid And Graphene On Pedot Film Electrode With Nafion, Hao-Xian Zhou, Jun-Ming Zhang, Zhi-Yu Qu, Pan-Yu Zhang, You-Jun Fan

Journal of Electrochemistry

With a glassy carbon electrode (GCE) as the substrate, the poly(3,4-ethylenedioxythiophene) (PEDOT) film electrode was prepared through the electrochemical polymerization method, then a novel non-enzymatic electrochemical H2O2 sensor was fabricated by co-immobilizing phosphomolybdic acid and graphene with Nafion on the PEDOT/GCE electrode. The modified electrodes were characterized by scanning electron microscopy (SEM), while the responsive properties of the sensor to H2O2 were investigated by cyclic voltammetry and chronoamperometry. The results demonstrated that, under the optimized conditions, the sensor exhibited good electrocatalytic performance for H2O2 reduction. The current response of the sensor …


Electrochemical Syntheses Of Graphene And Its Composites, Bo Zhao, Li Jiang, Ming-Hui Yuen, Xian-Zhu Fu, Rong Sun, Ching-Ping Wong Feb 2016

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 Aug 2015

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 Jun 2015

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 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.


Preparation And Electrochemical Performance Of Tio2/Gns Nanocomposite As Anode Materials For Lithium-Ion Batteries, Lin-Lin Qin, Huan Zhang, Xiao-Jing Liu, Jian-Hui Xu, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong Jun 2012

Preparation And Electrochemical Performance Of Tio2/Gns Nanocomposite As Anode Materials For Lithium-Ion Batteries, Lin-Lin Qin, Huan Zhang, Xiao-Jing Liu, Jian-Hui Xu, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The honeycomb-like porous TiO2/graphenes (TiO2/GNs) nanocomposite was prepared by a reflux method. SEM and TEM results showed that nanosized anatase TiO2 (about 5~10 nm) were dispersed uniformly on the surface of the GNs. The TiO2/GNs composite showed excellent rate and cycling performance: A stable charge capacity of 169.5 mAh?g-1 was obtained at 30C, and can restore to 241.7 mAh?g-1 while current went back to 1C. The stable charge capacity of TiO2/GNs nanocomposite electrode up to 201.9 mAh?g-1 was achieved at 10C in the first cycle, and could be maintained at 181.4 mAh?g-1 after 300 times of cycling.


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 Apr 2012

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 …


Effects Of Graphene On Electrochemical Behaviors Of Ni(Oh)2 As Supercapacitor Material, Zhen-Zhen Zhao, Wen-Bin Ni, Neng-Yue Gao, Hong-Bo Wang, Jian-Wei Zhao Aug 2011

Effects Of Graphene On Electrochemical Behaviors Of Ni(Oh)2 As Supercapacitor Material, Zhen-Zhen Zhao, Wen-Bin Ni, Neng-Yue Gao, Hong-Bo Wang, Jian-Wei Zhao

Journal of Electrochemistry

The enhanced electrochemical properties of Ni(OH)2 by the oxidation defected graphene were studied by both experimental method and theoretical calculation. The composite material of nano-Ni(OH)2/graphene was prepared by potentiostatic deposition on the graphene substrate. Observed by TEM, the Ni(OH)2 nanoparticles were well dispersed on the graphene substrate with the diameter of 5.0±0.5 nm. The capacitance of the system measured by the electrochemical test was 1928 F?g-1. As indicated by the theoretical calculations, the composite material becomes conductive since Ni(OH)2 is combined with surface functional groups of the graphene through the strong chemical interaction. The electrons transfer from the graphene substrate …


Detection Of Acute Promyelocytic Leukemia Pml/Rarî± Fusion Gene Using Graphene Modified Glassy Carbon Electrode, Zhi-Xian Lian, Guang-Xian Zhong, Kun Wang, Ai-Lin Liu, Xin-Hua Lin, Yuan-Zhong Chen May 2011

Detection Of Acute Promyelocytic Leukemia Pml/Rarî± Fusion Gene Using Graphene Modified Glassy Carbon Electrode, Zhi-Xian Lian, Guang-Xian Zhong, Kun Wang, Ai-Lin Liu, Xin-Hua Lin, Yuan-Zhong Chen

Journal of Electrochemistry

A graphene modified glassy carbon electrode (GCE) was prepared by electrochemical reduction of graphite oxide fixed on the surface of GCE. Then, the amino-group modified probe of acute promyelocytic leukemia (APL) PML/RARα fusion gene fragment was immobilized onto surface of the graphene modified GCE by coupling activating agent. With methylene blue (MB) as a novel electrochemical indicator, artificial APL PML/RARα fusion gene fragment was measured by differential pulse voltammetry (DPV). The result indicated graphene nanomaterial showed good sensitization on the signal of MB. The relationship between the reduction peak current of MB and the concentration of complementary strand was linear …