Preparation of Graphene–Polypyrrole Hollow Sphere by Pickering Emulsion Method and Their Electrochemical Performances as Supercapacitor Electrode

NANO ◽  
2019 ◽  
Vol 14 (05) ◽  
pp. 1950056
Author(s):  
Sai Wu ◽  
Jie Tian ◽  
Xianglu Yin ◽  
Wei Wu
Keyword(s):  
Graphene Oxide ◽  
Hollow Sphere ◽  
Pickering Emulsion ◽  
Electrochemical Performances ◽  
Test Results ◽  
Supercapacitor Electrode ◽  
Emulsion Method ◽  
Pickering Emulsion Polymerization ◽  
First Time ◽  
A Current

Graphene–polypyrrole hollow sphere composite was synthesized for the first time via Pickering emulsion polymerization using graphene oxide as Pickering stabilizer. It was found that polypyrrole and graphene were well hybrid and all graphene–polypyrrole composites had a uniform hollow sphere structure, whose diameters gradually decreased as the pyrrole content decreased. The electrochemical properties of the composites as supercapacitor electrode were investigated. The test results displayed that the specific capacitance of the optimal ratio of composite could reach 238[Formula: see text]F/g at a current density of 1[Formula: see text]A/g, and a 90.7% capacitance retention could be achieved after 1500 cycles, which was a significant improvement compared with the 62.2% retention of pure polypyrrole.

Graphene oxide as a sacrificial material for fabricating molecularly imprinted polymers via Pickering emulsion polymerization

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74654-74661 ◽  
Author(s):  
Yuqing Li ◽  
Yanhua Sun ◽  
Jian Chen ◽  
Xiaohong Zhu ◽  
Hui Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Emulsion Polymerization ◽  
Molecularly Imprinted Polymers ◽  
Pickering Emulsion ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Pickering Emulsion Polymerization ◽  
Sacrificial Material ◽  
First Time

Graphene oxide (GO) was introduced as a sacrificial material, for the first time, to fabricate a hollow molecularly imprinted polymer (HMIP) via Pickering emulsion polymerization.

Pickering emulsion polymerization of graphene oxide-stabilized styrene

2013 ◽  
Vol 291 (7) ◽  
pp. 1631-1639 ◽  
Author(s):  
Pengfei Xie ◽  
Xueping Ge ◽  
Bin Fang ◽  
Zhi Li ◽  
Ying Liang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Emulsion Polymerization ◽  
Pickering Emulsion ◽  
Pickering Emulsion Polymerization

scholarly journals GRAPHENE OXIDE MICROCAPSULES (GOMs) WITH LINSEED OIL CORE VIA PICKERING EMULSION METHOD: EFFECT OF DISPERSE SPEED

2021 ◽  
Vol 22 (1) ◽  
pp. 213-222
Author(s):  
Nurul Nadiah Sahir ◽  
Noor Azlina Hassan ◽  
Norita Binti Hassan ◽  
Norhasnidawani Binti Johari
Keyword(s):  
Graphene Oxide ◽  
Phase Separation ◽  
Linseed Oil ◽  
Pickering Emulsion ◽  
Optical Microscope ◽  
Coating System ◽  
Self Healing ◽  
Promising Candidate ◽  
Emulsion Method ◽  
Method Effect

Graphene oxide microcapsules (GOMs) have been prepared through Pickering emulsion method by varying the disperse speed to study its effect on the GOM’s size. The GOMs were characterized through phase separation observation, polarized optical microscope (POM), and particle size analyser (PSA). Phase separation observation showed more viscous and cloudy emulsion was produced when the disperse speed was increased. After 24 hours, only 800 rpm emulsion did not show any phase separation. POM characterization depicted that increasing the emulsification energy led to the finer emulsion with the 1200 rpm sample showing the smallest microcapsule size of around 8 ?m. However, PSA analysis suggested that although the disperse speed controls the GOMs size, the amount of GO in the emulsion plays an important role for the microcapsule to maintain its stability. Emulsion produced at 800 rpm possesses satisfactory stability with GOMs diameter of 11.15 ?m. The result also suggested that graphene oxide encapsulated linseed oil may act as a promising candidate for healing microcapsules in a self-healing coating system. ABSTRAK: Mikrokapsul graphene oksida (GOMs) telah dihasilkan melalui kaedah emulsifikasi Pickering dengan memvariasikan tenaga pengemulsi untuk mengkaji kesannya terhadap saiz GOMs. GOMs dicirikan melalui pemerhatian pemisahan fasa, mikroskop optik polarisasi (POM) dan penganalisis saiz zarah (PSA). Pemerhatian pemisahan fasa menunjukkan emulsi yang lebih likat dan keruh dihasilkan apabila kelajuan pengemulsi meningkat. Selepas 24 jam, hanya emulsi 800 rpm tidak menunjukkan pemisahan fasa. Pencirian POM meunjukkan bahawa peningkatan tenaga pengemulsi menghasilkan emulsi yang lebih halus dengan sampel 1200 rpm menunjukkan saiz mikrokapsul terkecil, sekitar 8 ?m. Walau bagaimanapun, analisis PSA mencadangkan bahawa walaupun kelajuan pengemulsi mengawal saiz GOMs, jumlah GO dalam emulsi memainkan peranan penting untuk mengekalkan kestabilan mikrokapsul. Emulsi yang dihasilkan pada 800 rpm mempunyai kestabilan yang memuaskan dengan purata saiz GOMs sekitar 11.15 ?m. Berdasarkan dapatan kajian, graphene oksida yang terkandung minyak biji rami boleh menjadi salah satu mikrokapsul penyembuh dalam sistem cat auto-sembuh.

Study of MnO2-Graphene Oxide nanocomposites for supercapacitor applications

MRS Advances ◽  
2019 ◽  
Vol 4 (13) ◽  
pp. 777-782 ◽  
Author(s):  
Rahul Singhal ◽  
Justin Fagnoni ◽  
David Thorne ◽  
Peter K. LeMaire ◽  
Xavier Martinez ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Characterizations ◽  
Average Diameter ◽  
Deionized Water ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercapacitor Applications ◽  
A Current ◽  
Charge Discharge

ABSTRACTGraphene oxide (GO)/MnO2 nanocomposites were synthesized by adding KMnO4 in a solution of water and ethanol (3:1), containing 10 mg of GO. Brown precipitates were obtained after a continuous stirring for 1 hr. The precipitates were then washed with deionized water (DI) water and dried to obtain the MnO2-GO nanocomposites. Pure MnO2 was also synthesized using the same method without GO for the comparison. X-ray diffraction pattern confirm δ-MnO2 type of MnO2 with birnessite type MnO2 structure. The TEM images show the average diameter of MnO2 nanorods as 15 nm. Electrochemical characterizations were carried out in an aqueous solution of 3M KOH. Charge-discharge studies were carried out between 1A/g to 20 A/g current range. The MnO2-GO nanocomposites showed improved electrochemical performances. The capacitance of MnO2 and MnO2-GO electrodes was found to be as 300 F/g, and 350 F/g, respectively at a current of 0.5 A/g.

One-pot hydrothermal synthesis of polyaniline nanofibers/reduced graphene oxide nanocomposites and their supercapacitive properties

2019 ◽  
Vol 31 (9-10) ◽  
pp. 1238-1247 ◽  
Author(s):  
Shanxin Xiong ◽  
Yuancheng Wang ◽  
Jia Chu ◽  
Xiaoqin Wang ◽  
Runlan Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrochemical Performances ◽  
One Pot ◽  
Raman Analysis ◽  
Polyaniline Nanofibers ◽  
Reduced Graphene ◽  
A Current ◽  
Charge Discharge

In this article, polyaniline nanofibers/reduced graphene oxide (PANI-NFs/rGO) nanocomposites were prepared by a one-pot hydrothermal method. Under the condition of high temperature and high pressure, graphene oxide (GO) was reduced to rGO and aniline was in-situ polymerized to form PANI-NFs using ammonium persulfate as oxidant. The morphologies and structures of PANI-NFs/rGO nanocomposites were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and Raman analysis. The results show that PANI-NFs uniformly grow on the surfaces of rGO sheets, which can act as spacers to prevent the aggregation of rGO. Combining with FTIR and Raman analysis, it can be concluded that PANI-NFs/rGO nanocomposites are successfully prepared. The electrochemical performances of PANI-NFs/rGO nanocomposites were tested by cyclic voltammetry and galvanostatic charge–discharge. The PANI-NFs/rGO nanocomposites exhibit superior electrochemical performances compared to the PANI-NFs. With 10 wt% of GO loaded, the PANI-NFs/rGO nanocomposite exhibits highest specific capacitance of 942 F g−1 at a current density of 1 A g−1. The PANI-NFs/rGO nanocomposites also demonstrate good rate capacity and high cycling stability under the high discharging current density (10 A g−1), the specific capacitance can still reach to 680 F g−1. After 1000 charge–discharge cycling at a current density of 5 A g−1, 78% of specific capacitance can be retained. The enhanced capacitive performances can be attributed to the facile electron conduction pathway brought by the even distribution of highly conductive rGO nanosheets.

Hydrothermal Synthesis and Electrochemical Properties of CoS2–Reduced Graphene Oxide Nanocomposite for Supercapacitor Application

2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760020 ◽  
Author(s):  
Sandhya Venkateshalu ◽  
Dinesh Rangappa ◽  
Andrews Nirmala Grace
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Properties ◽  
Reduced Graphene Oxide ◽  
Test Results ◽  
Supercapacitor Application ◽  
Cobalt Disulfide ◽  
Reduced Graphene ◽  
Uniform Deposition ◽  
A Current ◽  
Charge Discharge

A Cobalt disulfide–reduced graphene oxide (CoS2-RGO) nanocomposite was prepared by a simple hydrothermal method and the prepared nanocomposite was characterized using various techniques like XRD, SEM and FTIR. The results of these techniques indicated the uniform deposition of CoS2 nanoparticles on Graphene sheets. Further, the prepared nanocomposites were tested for its activity towards energy storage and the test results showed a specific capacitance of 28[Formula: see text]F/g in an aqueous 20% KOH electrolyte at a current density of 0.5[Formula: see text]A/g. All these materials showed highly reversible charge–discharge cycles. The overall electrochemical performance of this composite is shown to be drastically improved when compared to bare CoS2 nanoparticles. Thus with the good electrochemical properties, CoS2–RGO nanocomposites could be effectively used as an electrode material for supercapacitors.

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