Harish Mudila; Sweta Rana; Mohammad G. H. Zaidi
Abstract
A series of Polyindole/Graphene nanocomposites (PGNCs) as electrochemical energy storage materials were fabricated at varying concentration (%, w/w) of graphene raging 3.0–9.0 in Polyindole (PIN) matrix in Supercritical CO2. The electrochemical behavior of PGNC prepared at different proportion ...
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A series of Polyindole/Graphene nanocomposites (PGNCs) as electrochemical energy storage materials were fabricated at varying concentration (%, w/w) of graphene raging 3.0–9.0 in Polyindole (PIN) matrix in Supercritical CO2. The electrochemical behavior of PGNC prepared at different proportion of graphene was investigated. The PGNC@9% has rendered specific capacitance of 389.17 F/g, along with energy and power densities of 13.51 Wh/kg and 511.95 W/kg respectively, which is greater as compared to graphene prepared through thermal reduction of graphene oxide. However, PIN comprises low capacitance of 24.48 F/g. Successive scans of PGNCs electrode for 1000 cycles at the scan rate of 0.1 V/s in KOH (1.0 M) shows a capacitive retention of ~98.6% indicating the electrochemical stability of the electrodes, with successive charge-discharge behavior. PGNCs display all the major peaks in Fourier Transform-Infrared and X-Ray diffraction spectra. Scanning electron micrograph in permutation with XRD spectra indicates the exfoliation of graphene into the matrix of PIN. Simultaneous TG-DSC reveals increased thermal stability of PGNCs with fractions of graphene. The good capacitive and charge-discharge performance indicates that supercritically fabricated PGNCs may serve as potential electrode materials for electrochemical energy storage devices.
Tatiana N. Myasoedova; Eugeniya N. Shishlyanikova; Tatiana A. Moiseeva; Maria Bzerzinskaya
Abstract
In the present work, the PANI and PANI/Zr composite powders were synthesized by the method of chemical polymerization in the inorganic acid medium. The morphology of prepared composites demonstrates fiber-like structure revealed by scanning electron microscopy. The value of the specific surface area ...
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In the present work, the PANI and PANI/Zr composite powders were synthesized by the method of chemical polymerization in the inorganic acid medium. The morphology of prepared composites demonstrates fiber-like structure revealed by scanning electron microscopy. The value of the specific surface area estimated by the BET technique depends on the type of the composite powder and was found to be 66.8 and 142.05 m 2 /g for PANI and PANI/Zr respectively. UV–Vis spectroscopy was employed to characterize the optical properties of the synthesized powder composites. The incorporation of zirconium gives rise to the red shift of π– π* transition of pristine PANI. The synthesized composite powders were used for preparation of PANI/PVA and PANI/Zr/PVA composites which electrochemical properties were compared in different electrolytes: 0.5 M KOH, 0.5 M NaCl and 0.5 M H2SO4. Excellent electrochemical reversibility was found out for both PANI/PVA and PANI/Zr/PVA composites. Effect of electrolyte type and current value on the specific capacitance of the prepared composites was observed.
Heon Lee; Sun-Jae Kim; Kay-Hyeok An; Jung-Sik Kim; Byung-Hoon Kim; Sang-Chul Jung
Abstract
The ruthenium oxide/activated carbon composite (RCC) were synthesized using an innovative plasma-in-liquid process, which is known as liquid phase plasma (LPP) process. This technique uses a single-step process for the synthesis of metal nanoparticles on supporting materials. LPP process led to simultaneous ...
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The ruthenium oxide/activated carbon composite (RCC) were synthesized using an innovative plasma-in-liquid process, which is known as liquid phase plasma (LPP) process. This technique uses a single-step process for the synthesis of metal nanoparticles on supporting materials. LPP process led to simultaneous precipitation of ruthenium and ruthenium oxide nanoparticles on the surface of activated carbon, which is then oxidized to ruthenium oxide during the thermal oxidation process. The specific capacitances of RCC electrodes prepared through the LPP and oxidation process were higher than that of bare AC. The specific capacitance increased with increasing LPP process duration and oxidation treatment. The specific capacitance of ruthenium oxide/carbon composite increased with increasing LPP process duration. The ruthenium oxide/carbon composite prepared through the LPP process and thermal oxidation showed smaller resistances and larger initial resistance slopes than bare activated carbon powder and this effect was intensified by increasing the LPP process duration. The RCC electrodes showed smaller resistances and larger initial resistance slopes than bare AC and this effect was intensified by increasing the LPP process duration and oxidation treatment.