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Full-Text Articles in Nanoscience and Nanotechnology

Cobalt-Doped Ceria/Reduced Graphene Oxide Nanocomposite As An Efficient Oxygen Reduction Reaction Catalyst And Supercapacitor Material, Shaikh Parwaiz, Kousik Bhunia, Ashok Kumar Das, Mohammad Mansoob Khan Dr, Debabrata Pradhan Aug 2017

Cobalt-Doped Ceria/Reduced Graphene Oxide Nanocomposite As An Efficient Oxygen Reduction Reaction Catalyst And Supercapacitor Material, Shaikh Parwaiz, Kousik Bhunia, Ashok Kumar Das, Mohammad Mansoob Khan Dr, Debabrata Pradhan

Dr. Mohammad Mansoob Khan

 Design and development of highly active and durable oxygen reduction reaction (ORR) catalyst to replace Pt- and Pt-based materials are present challenges in fuel cell research including direct methanol fuel cells (DMFC). The methanol crossover and its subsequent oxidation at the cathode is another unwanted issue that reduces the efficiency of DMFC. Herein we report cobalt-doped ceria (Co-CeO2) as a promising electrocatalyst with competent ORR kinetics mainly through a four-electron reduction pathway, and it surpasses Pt/C by a great margin in terms of stability and methanol tolerance. The Co-CeO2 nanoparticles of diameter 4–7 nm were uniformly …


Visible-Light-Responsible Co-Catalysts Enhanced By Graphene For Solar Energy Harvesting, Chen Ying Apr 2016

Visible-Light-Responsible Co-Catalysts Enhanced By Graphene For Solar Energy Harvesting, Chen Ying

Masters Theses & Specialist Projects

This study focuses on the visible light response of hetero-structures of TiO2-graphene- MoS2 for solar energy harvestings. The commercial P25 TiO2 nano-particles, and selfprepared layered reduced graphene oxides (RG) and MoS2 were assembled for the targeted hetero-structure materials as visible-light responsible solar harvesting cocatalysts. The hydrothermal method was applied for nano-material synthesis, the reduction of graphene oxides, and bonding formation. Multiple characterization methods (SEM-TEM, XRD, XPS, UV-VIS, PL, FT-IR, TGA) have been applied to understand the electron-hole pair separation and recombination, and performance tuning in their visible-light photo-catalysis rhodamine B (Rh.B) degradations process

Compared to TiO2, an obvious red shift …


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 Properties Of Graphene/Porous Nano-Silicon Anode, Chun-Li Li, Guang Yang, Ping Zhang, Zhi-Yu Jiang Dec 2015

Electrochemical Properties Of Graphene/Porous Nano-Silicon Anode, Chun-Li Li, Guang Yang, Ping Zhang, Zhi-Yu Jiang

Journal of Electrochemistry

Porous nano-silicon (Si) was prepared by acid etching Al-Si alloy powder method, and used as an active material for fabricating a grapene/porous nano-Si electrode. The results of SEM and TEM measurements indicated that porous nano-Si powder was uniformly mixed with graphene by emulsification dispersion-ultrasonication method. As an anode for lithium ion battery, the graphene/porous nano-Si electrode presented relatively high performance in 1 mol•L-1 LiPF6/EC:DMC = 1:1(by volume) + 1.5% (by mass) VC solution. At the charge and discharge current densities of 0.5A•g-1, the first discharge capacity was 1768.6 mAh•g-1 with coulombic efficiency of 68.3%. The discharge …


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 …


Fabrication And Electrochemical Properties Of Graphene-Zno Nanocomposite, Chuan-Ling Men, Wan Wang, Jun Cao Apr 2014

Fabrication And Electrochemical Properties Of Graphene-Zno Nanocomposite, Chuan-Ling Men, Wan Wang, Jun Cao

Journal of Electrochemistry

In this work, the graphene-ZnO nanocomposite was successfully synthesized through a one-step solvothermal approach, using ethylene glycol as the solvent and reducing agent. The ZnO particles could be attached to the surfaces and edges of graphene sheet. The electrochemical performance of the nanocomposite was investigated by performing cyclic voltammetry, A.C. impedance and chronopotentiometry tests in 6 mol·L-1 KOH. The results showed that the graphene-ZnO nanocomposite exhibited a nice electrochemical specific capacitance of 115 F·g-1 determined in cyclic voltammetry test, or 71 F·g-1 evaluated in chronopotentiometry test and good reversible charge/discharge behavior.


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.