Nanomaterials & Nanotechnology
S S Patil; V L Patil; AK Tawade; KK Sharma; TD Dongale; RM Mane; AK Bhosale; SA Vhanalkar
Abstract
Supercapacitors are emerging as an alternative to batteries due to their high-power density, low charging time, safety, electrochemical stability, and long cycle life and manganese dioxide (MnO2) is one of the best electrode materials to prepare supercapacitor. In this regard, the MnO2 as an electrode ...
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Supercapacitors are emerging as an alternative to batteries due to their high-power density, low charging time, safety, electrochemical stability, and long cycle life and manganese dioxide (MnO2) is one of the best electrode materials to prepare supercapacitor. In this regard, the MnO2 as an electrode material was synthesized by using the simplistic electrodeposition method and various characterization techniques were carried out to investigate their physicochemical properties. The scanning electron microscopy illustrates the interconnected nano-wall like morphology of MnO2 thin films, resulting in a larger surface area. This morphology is beneficial for providing more active sites for charge storage and hence leads to a higher capacitance. Therefore, the nano-wall like structure of MnO2 thin films were utilized for the electrochemical measurements and it revealed higher specific capacitance at about 465 F/g for low scan rate of 10 mV/s. Furthermore, even after 500 cycles of voltammetry, the MnO2-based supercapacitor exhibits a higher cycling stability of about 98%.

Biosensors, Bioelectronics and Biodevices
Nidhi Patel; Rahul Dev Bairwan; H.P.S. Abdul Khalil; Mardiana Idayu Ahmad; Esam Bashir Yahya; Soni Thakur; Kanchan Jha
Abstract
The planet must deal with the two main concerns of the twenty-first century: energy storage and protecting the environment. Energy storage systems urgently require green and sustainable electrode materials due to the rise in worldwide demand for energy and severe environmental damage. The biopolymer-based ...
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The planet must deal with the two main concerns of the twenty-first century: energy storage and protecting the environment. Energy storage systems urgently require green and sustainable electrode materials due to the rise in worldwide demand for energy and severe environmental damage. The biopolymer-based device reduces e-waste and environmental issues caused by conventional electronic devices. Nanocellulose is a solid choice for green electronics, due to its unique properties, like being eco-friendly, cost effective, biodegradable, having great mechanical strength, and remarkable optical clarity. With its exceptional qualities, sustainability and distinctive structures, nanocellulose has become a hopeful nanomaterial with enormous potential for creating useful energy storage systems. This review aims to offer novel viewpoints on flexible composites made of nanocellulose or nanocellulose-based materials for enhanced energy technologies. Initially, a brief introduction to the special structural features and attributes of nanocellulose is made. To improve these composites’ performances, the structure-property-application interactions must be addressed. The most recent uses of nanocellulose-based composites are then thoroughly reviewed. These include flexible solar cells, supercapacitors (SC), lithium-ion batteries and developing energy device innovations. Finally, nanocellulose-based composites for the next generation of energy devices are offered, along with their current difficulties and potential future developments.

N.B. Arun Kumar; J. Sirajudeen; H.P. Nagaswarupa; C.R. Ravikumar; M.R. Anil Kumar; H.C. Ananda Murthy
Abstract
We report the successful synthesis of NiO nanomaterial by combustion method using Plectranthus amboinicus plant leaves extract. The diffraction pattern and image analysis confirmed the FCC lattice structure for green NiO nanomaterial (g-NONM) with spongy, agglomerated and porous nature. The average energy ...
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We report the successful synthesis of NiO nanomaterial by combustion method using Plectranthus amboinicus plant leaves extract. The diffraction pattern and image analysis confirmed the FCC lattice structure for green NiO nanomaterial (g-NONM) with spongy, agglomerated and porous nature. The average energy band gap of g-NONM was found to be 4.10 eV. The electrode made of g-NONM exhibited excellent stability in addition to its good reversibility. The g-NONM showed superior photo-decolarisation results for AO dye solution with 33.95 % dye decolorization at 405 nm. The obtained rate constant k value of g-NONM for AO dye is 0.002933 min −1 . The prepared g-NONM electrode showed a minimum charge-transfer resistance which is possibly due to its high conductivity as supported by electrochemical impedance studies. The NiO electrode also exhibited very high alcohol sensing ability in alkaline medium as revealed during CV measurement. The best part of the study was the fast reply (3 s) of the prepared electrode in sensing the drugs at 1 mM concentration solution. In addition, g-NONM can be easily fabricated into stable electrode material for supercapacitors applications. The results suggested that g-NONM can be an efficient and cheaper material for photocatalytic, sensor and supercapacitor applications.
Andrés Felipe Zapata-González; Julieth Carolina Cano-Franco; Mónica Lucía Álvarez-Láinez
Abstract
Due to the problems that exist on several systems that store energy, such as low energy density, low storage capacity and limited useful life; carbon nanofibers (CNFs) appear as an alternative to remedy such problems, due to their excellent properties, such as high electrical conductivity, high surface ...
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Due to the problems that exist on several systems that store energy, such as low energy density, low storage capacity and limited useful life; carbon nanofibers (CNFs) appear as an alternative to remedy such problems, due to their excellent properties, such as high electrical conductivity, high surface area and flexibility. However, there are some alternatives to reinforce their properties and optimize their application in energy storage systems. In this way, in our work, we look for an alternative to increase the capacitive properties of the CNFs. The hot drawing treatment was applied to the CNFs to improve their electrochemical performance for supercapacitor applications. First, non-woven polyacrylonitrile (PAN) membranes were manufactured by electrospinning, and then, the hot-drawing treatment was applied to promote molecular alignment. Prepared and stretched PAN membranes were carbonized at different temperatures to obtain CNFs. According to the applied hot drawing treatment and the increase in temperature, the crystalline structure of the CNFs was improved, which led to an increase in the electrochemical properties of the CNFs. The specific capacitance of the CNFs was increased by 88% when hot drawing process was applied and carbonized at 1000°C, compared to the sample without the application of the stretching treatment. Copyright © VBRI Press.

Ritu P. Mahore; Devendra K. Burghate; Subhash B. Kondawar; Ashish P.Mahajan; Deoram V. Nandanwar
Abstract
Due to the ever growing demand of energy for various applications attention of researchers is aroused by Supercapacitors due to its superior power, energy density and cyclic life. Electrode material mainly determines the performance of Supercapacitors. Conducting polymers, metal oxides and carbon based ...
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Due to the ever growing demand of energy for various applications attention of researchers is aroused by Supercapacitors due to its superior power, energy density and cyclic life. Electrode material mainly determines the performance of Supercapacitors. Conducting polymers, metal oxides and carbon based materials are mainly used as electrode materials in Supercapacitors. Among these three categories of materials, Conducting polymers and metal oxides shows pseudo-capacitance. This paper reported the synthesis of Pure Polypyrrole (PPy) and Polypyrrole/Manganese dioxide (PPy/MnO2) nanocomposites by in-situ chemical oxidative polymerization. The synthesized materials were tested as potential candidates for the electrodes of supercapacitor. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) revealed that nanoparticles of MnO2 are well incorporated into PPy matrix. Cyclic Voltammetry (CV) indicated that PPy/MnO2 nanocomposites have an ideal capacitive behaviour and an excellent cyclibility. Electrochemical impedance spectroscopy (EIS) and Galvanostatic charge-discharge (GCD) measurements proved that nanocomposite electrode with 10% MnO2 composition showed the smallest charge transfer resistance and highest specific capacitance compared to other compositions. The electrochemical studies of PPy/MnO2 nanocomposites showed that PPy/MnO2 nanocomposites are suitable advanced materials for electrodes of the supercapacitors. Copyright © 2018 VBRI Press.

Rickard Andersson; Amin M. Saleem; Ioanna Savva; Theodora Krasia-Christoforou; Peter Enoksson; Vincent Desmaris
Abstract
Carbon nanostructures are of great interest for a variety of applications, but their current processing throughput limits their industrial full scale deployment. This paper presents a cost effective and simple fabrication process, where vertically aligned carbon nanofibers are grown using DC-PECVD at ...
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Carbon nanostructures are of great interest for a variety of applications, but their current processing throughput limits their industrial full scale deployment. This paper presents a cost effective and simple fabrication process, where vertically aligned carbon nanofibers are grown using DC-PECVD at CMOS compatible temperatures from catalytic nanoparticles, spin-coated from stable polymer-nanoparticle colloidal suspensions. Two different catalysts, Co and Cu, are investigated by growing carbon nanofibers at temperatures ranging from 390°C to 550°C, using suspensions with various concentrations of nanoparticles. The length and morphology of the grown nanofibers are examined using SEM and the electrical properties are investigated using electrochemical measurements on samples arranged as supercapacitor devices. Vertically aligned CNFs are successfully grown from both types of catalyst. The Co-derived fibers are long and arranged in a denser carpet-like structure, while the Cu-derived fibers are shorter and in a sparser formation of free-standing individual fibers. All electrochemical measurements show typical supercapacitor behaviour even at high scan rates of 200 mVs -1 , with the fibers grown from Co showing great increase in capacitance over the bare chip reference device, including the samples grown at 390°C.

Sandip Maiti; Ranadip Bera;Bhanu B. Khatua; Sumanta K. Karan; Amit K. Das
Abstract
Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared ...
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Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared through simple and cost-effective method via in-situ polymerization of aniline in presence of CNH and TiO2 nanoparticles. Thus, as prepared active electrode material provides high specific capacitance value of 1068 F/g at current density of 3 A/g. The existence TiO2 nanoparticle in the ternary hybrid leads to enhancement of capacitance value through synergistic effect compared to the pure components (e.g., PANI and CNH are 335 F/g and 240 F/g, respectively at same current density). As morphological analysis says, TiO2 nanoparticles are observed to be coated by CNH nanofiller and PANI fiber in the hybrid, which plays a key role to enhance the capacitance value of hybrid making it highly promising electrode material for energy storage in the next-generation power supply.

Xun Xu; Fangwang Ming; Jinqing Hong; Zhoucheng Wang
Abstract
Graphene-based aerogels with porous structure and three-dimensional (3D) network have attracted plentiful interests recently because they could exhibit as an excellent matrix for various kinds of nanoparticles, thus providing a potential prospect in a variety of applications. In this report, 3D composite ...
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Graphene-based aerogels with porous structure and three-dimensional (3D) network have attracted plentiful interests recently because they could exhibit as an excellent matrix for various kinds of nanoparticles, thus providing a potential prospect in a variety of applications. In this report, 3D composite aerogel with poriferous structure assembly of bismuth tungstate sheets and graphene nanosheets has been prepared by a simple hydrothermal process. The 3D multihole structure of the hybrid aerogel could not only provide enormous surface area, but also facilitate electron transfer and ion transmission which could decrease the electrode internal resistance and consequently improve the capacitive property. As a result, the Bi2WO6/graphene hybrid aerogel achieves a large specific capacitance of 714 F g -1 at the current density of 4 A g -1 . The hybrid aerogel could provide a new method for developing high-performance energy storage materials.

Vardhaman V. Khedekar; Shaikh Mohammed Zaeem; Santanu Das
Abstract
Graphene-Metal oxide nanocomposites have been extensively investigated due to their potential applications in the fields of energy devices, including, solar cells, fuel cells, batteries, sensors, electro-catalysis, and photo-catalysis. Among them, several researches have been performed on supercapacitors, ...
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Graphene-Metal oxide nanocomposites have been extensively investigated due to their potential applications in the fields of energy devices, including, solar cells, fuel cells, batteries, sensors, electro-catalysis, and photo-catalysis. Among them, several researches have been performed on supercapacitors, which could be best used with devices that require high current for short duration of time. Here, in this article, we present a brief review on the recent advances on the graphene-metal oxide nanocomposites for supercapacitor technologies and the future perspective of this field of research. A wide range of graphene-metal oxide synthesis techniques have been discussed with a focus on the advancement of nanocomposites with controlled features, including, particle size, morphologies, surface structures, pore size, pore-distributions, etc. Specifically, various nanocomposites and their role in supercapacitor electrodes are discussed with their explicit electrochemical charge-storage mechanisms along with charge-transfer techniques. Furthermore, this analysis demonstrates current trends and future directions in research on graphene-metal oxide nanocomposite electrodes for the performance enhancement in next-generation supercapacitor devices.

Anna Batlle
Abstract
Wearable devices requires from macroscopic mechanical properties laying in macro-scale in comparison with chemical processes that requires from material design in the nanoscale. Besides, such reactions and phenomena involves charge transfer, and therefore a charge transducer in mean scale is required. ...
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Wearable devices requires from macroscopic mechanical properties laying in macro-scale in comparison with chemical processes that requires from material design in the nanoscale. Besides, such reactions and phenomena involves charge transfer, and therefore a charge transducer in mean scale is required. In this paper we propose a flexible and wearable supercapacitor that takes advantage of a conductive fabric current collector that is coated by electrospray with MnO2-decorated carbon nanofibers (CNF). The results point out that a high capacitance is obtained due to the pseudocapacitive reactions in MnO2; moreover, the long and conductive structure of CNF allow transferring charge to conductive fabric, keeping a low equivalent serial resistance (ESR). The results indicate a specific capacitance on fabric collector of (226.40 ± 0.3) F/g, about 10 times higher than on aluminum foil collector, with a similar ESR which indicates a suitable way to wearable devices. The proposed technique is scalable, and can be easily applied in the industry.
Surjit Sahoo; Chandra Sekhar Rout
Abstract
In the present work, we report the hydrothermal synthesis of NiCo2O4/Single walled carbon nanotubes (SWNTs) nanocomposites for supercapacitor applications. The SWNTs provided the conductive network and favored the growth of NiCo2O4 nanoparticles on its surface to facilitate the collection and transportation ...
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In the present work, we report the hydrothermal synthesis of NiCo2O4/Single walled carbon nanotubes (SWNTs) nanocomposites for supercapacitor applications. The SWNTs provided the conductive network and favored the growth of NiCo2O4 nanoparticles on its surface to facilitate the collection and transportation of electrons during the electrochemical charge storage performance. Due to the improved conductivity and higher surface area of the NiCo2O4/SWNTs nanocomposites as compared to pure NiCo2O4 nanorods, it exhibited a specific capacitance of 1623 F/g and 1098 F/g at 1mV/s scan rate and 1A/g current density. Obtained energy density and power density of the NiCo2O4/SWNTs nanocomposites were 56.19 Wh/Kg and 9.824 kW/kg respectively. These results demonstrated that the nanocomposites could be a promising candidate for future high performance energy storage devices.
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.
Ritu P. Mahore; Devendra K. Burghate; Subhash B. Kondawar
Abstract
Supercapacitors are recognized as one of the most promising energy storage devices for a wide range of civilian and military applications in electric vehicles, uninterruptible power supplies. Conducting polymer nanocomposites are new functional materials suitable for supercapacitors due to synergistic ...
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Supercapacitors are recognized as one of the most promising energy storage devices for a wide range of civilian and military applications in electric vehicles, uninterruptible power supplies. Conducting polymer nanocomposites are new functional materials suitable for supercapacitors due to synergistic effect of individual components. In present work, polypyrrole/CNT nanocomposites have been prepared by an in-situ chemical polymerization method and studied for supercapacitor. CNTs were well functionalized using 3:1 ratio of H2SO4 and HNO3 before polymerizing the pyrrole. Analytical techniques such as SEM, UV-VIS and FTIR were used to characterize the synthesized materials. The SEM images reveal that the materials have rough and granular morphology. The composites showed good interaction based on the shift to longer wavelengths in the electronic transition, indicating the interaction between PPy and functionalized CNTs as observed in their UV-VIS and FTIR spectra. The electrochemical performance was evaluated by using cyclic voltammetry (CV) in 1M Na2SO4 electrolyte and specific capacitance was obtained at 0.5 V/s for pure polypyrrole and PPy/CNT nanocomposites. Nanocomposite showed the enhanced electrochemical performance as compared to that of pure polypyrrole. The specific capacitance obtained at the scan rate 0.5V/s was found to be 0.825 F/cm -2 for pure polypyrrole and 1.0619 F/cm -2 for PPy/CNT nanocomposite material respectively, indicates that PPy/CNT nanocomposite is suitable material as electrode for supercapacitor as compoared to pure polypyrrole.
Ashok K. Sharma; Yashpal Sharma; Rajesh Malhotra; J.K. Sharma
Abstract
Composites of polyaniline and multiwalled carbon nanotube were prepared by in- situ chemical oxidative polymerization of the aniline monomer in 1M HCl and 1M HCl with 20% ethanol as solvent. The PANI-CNT composites were characterized by FTIR and XRD method. The surface morphology characterization of ...
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Composites of polyaniline and multiwalled carbon nanotube were prepared by in- situ chemical oxidative polymerization of the aniline monomer in 1M HCl and 1M HCl with 20% ethanol as solvent. The PANI-CNT composites were characterized by FTIR and XRD method. The surface morphology characterization of the composites was done by using scanning electron microscopy (SEM). Electrochemical behavior of prepared PANI-CNT composites was investigated by means of cyclic voltammetry. Specific capacitance of PANI-CNT composite using 0.02M aniline in 1M HCl (20% ethanol) and 1M HCl was 597.82 and 484.49 F/g respectively at scan rate of 2mV/s in 1M H2SO4.