Browse
Submit Data
Databases
API
Help

Dataset Information

14 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Synergistic Effects of Fe₂O₃ Nanotube/Polyaniline Composites for an Electrochemical Supercapacitor with Enhanced Capacitance.

ABSTRACT: α-Fe₂O₃, which is an attractive material for supercapacitor electrodes, has been studied to address the issue of low capacitance through structural development and complexation to maximize the use of surface pseudocapacitance. In this study, the limited performance of α-Fe₂O₃ was greatly improved by optimizing the nanotube structure of α-Fe₂O₃ and its combination with polyaniline (PANI). α-Fe₂O₃ nanotubes (α-NT) were fabricated in a form in which the thickness and inner diameter of the tube were controlled by Fe(CO)₅ vapor deposition using anodized aluminum oxide as a template. PANI was combined with the prepared α-NT in two forms: PANI@α-NT-a enclosed inside and outside with PANI and PANI@α-NT-b containing PANI only on the inside. In contrast to α-NT, which showed a very low specific capacitance, these two composites showed significantly improved capacitances of 185 Fg^-1 for PANI@α-NT-a and 62 Fg^-1 for PANI@α-NT-b. In the electrochemical impedance spectroscopy analysis, it was observed that the resistance of charge transfer was minimized in PANI@α-NT-a, and the pseudocapacitance on the entire surface of the α-Fe₂O₃ nanotubes was utilized with high efficiency through binding and conductivity improvements by PANI. PANI@α-NT-a exhibited a capacitance retention of 36% even when the current density was increased 10-fold, and showed excellent stability of 90.1% over 3000 charge-discharge cycles. This approach of incorporating conducting polymers through well-controlled nanostructures suggests a solution to overcome the limitations of α-Fe₂O₃ electrode materials and improve performance.

SUBMITTER: Azimov F

PROVIDER: S-EPMC8231785 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Synthesis and Supercapacitor Performance of Polyaniline/Nitrogen-Doped Ordered Mesoporous Carbon Composites.

Project description:The electrochemical property of ordered mesoporous carbon (OMC) can be changed significantly due to the incorporating of electron-donating heteroatoms into OMC. Here, we demonstrate the successful fabrication of nitrogen-doped ordered mesoporous carbon (NOMC) materials to be used as carbon substrates for loading polyaniline (PANI) by in situ polymerization. Compared with NOMC, the PANI/NOMC prepared with a different mass ratio of PANI and NOMC exhibits remarkably higher electrochemical specific capacitance. In a typical three-electrode configuration, the hybrid has a specific capacitance about 276.1 F/g at 0.2 A/g with a specific energy density about 38.4 Wh/kg. What is more, the energy density decreases very slowly with power density increasing, which is a different phenomenon from other reports. PANI/NOMC materials exhibit good rate performance and long cycle stability in alkaline electrolyte (~ 80% after 5000 cycles). The fabrication of PANI/NOMC with enhanced electrochemical properties provides a feasible route for promoting its applications in supercapacitors.

| S-EPMC5968012 | biostudies-literature

Hydrothermal synthesis of nanostructured graphene/polyaniline composites as high-capacitance electrode materials for supercapacitors.

Project description:As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of supercapacitors. Specifically, ultrathin PANi layers with total thickness of 10-20 nm are uniformly composited with GNS by a two-step hydrothermal-assistant chemical oxidation polymerization process; while PANi nanofibers with diameter of 50~100 nm are obtained by a one-step direct hydrothermal process. Benefitting from the ultrathin layer and porous structure, the sheet-like GNS/PANi composites can deliver specific capacitances of 532.3 to 304.9 F/g at scan rates of 2 to 50 mV/s. And also, this active material showed very good stability with capacitance retention as high as ~99.6% at scan rate of 50 mV/s, indicating a great potential for using in supercapacitors. Furthermore, the effects of hydrothermal temperatures on the electrochemical performances were systematically studied and discussed.

| S-EPMC5349513 | biostudies-literature

Boosting the Utilization and Electrochemical Performances of Polyaniline by Forming a Binder-Free Nanoscale Coaxially Coated Polyaniline/Carbon Nanotube/Carbon Fiber Paper Hierarchical 3D Microstructure Composite as a Supercapacitor Electrode.

Project description:Nanoscale polyaniline (PANI) is formed on a hierarchical 3D microstructure carbon nanotubes (CNTs)/carbon fiber paper (CFP) substrate via a one-step electrochemical polymerization method. The chemical and structural properties of the binder-free PANI/CNTs/CFP electrode are characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The specific capacitance of PANI/CNTs/CFP tested in a symmetric two-electrode system reaches 731.6 mF·cm-2 (1354.7 F·g-1) at a current density of 1 mA·cm-2 (1.8 A·g-1). The symmetric supercapacitor device demonstrates excellent cycling performance up to 10,000 cycles with a capacitance retention of 81.4% at a current density of 1 mA·cm-2 (1.8 A·g-1). The results demonstrate that the binder-free CNTs/CFP composite is a strong backbone for depositing ultrathin PANI layers at a high mass loading. The hierarchical 3D microstructure PANI/CNTs/CFP provides enough space and transporting channels to form an efficient electrode-electrolyte interface for the supercapacitance reaction. The formed nanoscale PANI film coaxially coated on the sidewalls of CNTs enables efficient charge transfer and a shortened diffusion length. Hence, the utilization efficiency and electrochemical performances of PANI are significantly improved. The rational design strategy of a CNT-based binder-free hierarchical 3D microstructure can be used in preparing various advanced energy-storage electrodes for electrochemical energy-storage and conversion systems.

| S-EPMC7482095 | biostudies-literature

Measurement of the combined quantum and electrochemical capacitance of a carbon nanotube.

Project description:The nature of the electronic interface between a nanotube and solvated ions in a liquid electrolyte is governed by two distinct physical phenomena: quantum and chemical. The quantum component arises from the sharply varying electronic density of states and the chemical component arises from ion screening and diffusion. Here, using an integrated on-chip shield technology, we measure the capacitance of one to a few nanotubes quantitatively as a function of both bias potential (from -0.7 V to 0.3 V) and ionic concentration (from 10 mM to 1 M KCl) at room temperature. We determine the relative contributions of the quantum and electrochemical capacitance, and confirm the measurements with theoretical models. This represents an important measurement of the quantum effects on capacitance in reduced dimensional systems in contact with liquid electrolytes, an important and emerging theme in the interface between nanotechnology, energy, and life.

| S-EPMC6689019 | biostudies-literature

High-Performance Gas Sensor of Polyaniline/Carbon Nanotube Composites Promoted by Interface Engineering.

Project description:Inspired by the enhanced gas-sensing performance by the one-dimensional hierarchical structure, one-dimensional hierarchical polyaniline/multi-walled carbon nanotubes (PANI/CNT) fibers were prepared. Interestingly, the simple heating changed the sensing characteristics of PANI from p-type to n-type and n-type PANI and p-type CNTs form p-n hetero junctions at the core-shell interface of hierarchical PANI/CNT composites. The p-type PANI/CNT (p-PANI/CNT) and n-type PANI/CNT (n-PANI/CNT) performed the higher sensitivity to NO2 and NH3, respectively. The response times of p-PANI/CNT and n-PANI/CNT to 50 ppm of NO2 and NH3 are only 5.2 and 1.8 s, respectively, showing the real-time response. The estimated limit of detection for NO2 and NH3 is as low as to 16.7 and 6.4 ppb, respectively. After three months, the responses of p-PANI/CNT and n-PANI/CNT decreased by 19.1% and 11.3%, respectively. It was found that one-dimensional hierarchical structures and the deeper charge depletion layer enhanced by structural changes of PANI contributed to the sensitive and fast responses to NH3 and NO2. The formation process of the hierarchical PANI/CNT fibers, p-n transition, and the enhanced gas-sensing performance were systematically analyzed. This work also predicts the development prospects of cost-effective, high-performance PANI/CNT-based sensors.

| S-EPMC6982802 | biostudies-literature

Two-dimensional ?-MnO? nanowire network with enhanced electrochemical capacitance.

Project description:Conventional crystalline ?-MnO2 usually exhibits poor electrochemical activities due to the narrow tunnels in its rutile-type structure. In this study, we synthesized a novel 2D ?-MnO2 network with long-range order assembled by ?-MnO2 nanowires and demonstrated that the novel 2D ?-MnO2 network exhibits enhanced electrochemical performances. The 2D network is interwoven by crossed uniform ?-MnO2 nanowires and the angle between the adjacent nanowires is about 60°. Such a novel structure makes efficient contact of ?-MnO2 with electrolyte during the electrochemical process, decreases the polarization of the electrode and thus increases the discharge capacity and high-rate capability. The specific capacitance of the obtained 2D ?-MnO2 network is 453.0 F/g at a current density of 0.5 A/g.

| S-EPMC3709167 | biostudies-literature

Use of facile mechanochemical method to functionalize carbon nanofibers with nanostructured polyaniline and their electrochemical capacitance.

Project description:A facile approach to functionalize carbon nanofibers [CNFs] with nanostructured polyaniline was developed via in situ mechanochemical polymerization of polyaniline in the presence of chemically treated CNFs. The nanostructured polyaniline grafting on the CNF was mainly in a form of branched nanofibers as well as rough nanolayers. The good dispersibility and processability of the hybrid nanocomposite could be attributed to its overall nanostructure which enhanced its accessibility to the electrolyte. The mechanochemical oxidation polymerization was believed to be related to the strong Lewis acid characteristic of FeCl3 and the Lewis base characteristic of aniline. The growth mechanism of the hierarchical structured nanofibers was also discussed. After functionalization with the nanostructured polyaniline, the hybrid polyaniline/CNF composite showed an enhanced specific capacitance, which might be related to its hierarchical nanostructure and the interaction between the aromatic polyaniline molecules and the CNFs.

| S-EPMC3305476 | biostudies-literature

Polyaniline/Titania Nanotube-Based Biosensor Strip for Sensitive and Specific Electrochemical Detection of SARS-CoV-2.

Project description:This study showcases the creation of a biosensor strip designed for the rapid, precise, and highly sensitive electrochemical detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These biosensor strips were crafted by affixing a monoclonal antibody (mAb) specific to SARS-CoV-2 onto the surface of a commercially screen-printed carbon electrode (SPCE) modified with polyaniline-titania nanotubes (PANi-TNT). The transportable sensing device was constructed by pairing the mAb functionalized strip with a portable potentiostat wirelessly connected to either a Windows or Android device. Fast and specific conjugation between spike protein of SARS-CoV-2 and immobilized anti-SARS-CoV-2 triggered a change in the charge and electron mobility in the biosensing layer of the strip to produce detectable current during chronoamperometric scanning in the presence of a phosphate buffer solution (PBS). The excellent sensitivity and specificity of the sensor toward SARS-CoV-2 were detected as analytical analysis demonstrated linearity in the range of 80 to 200 copies/μL with a limit of detection of 25.59 copies/μL from the dose-response and standard fitted curve. Through experimental validation, the sensor strip's ability to specifically detect SARS-CoV-2 was established, distinguishing it from human coronavirus-OC43 (HCoV-OC43), HCoV-NL63, HCoV-229E, and adenovirus. The results from these tests indicate that these strips possess the potential for the future creation of dependable and easily transportable point-of-care diagnostic devices, enabling swift, sensitive, and precise detection of SARS-CoV-2 in the saliva or nasopharyngeal fluid of individuals infected with the virus.

| S-EPMC10702311 | biostudies-literature

TiO<sub>2</sub> Nanomembranes Fabricated by Atomic Layer Deposition for Supercapacitor Electrode with Enhanced Capacitance.

Project description:TiO2 is a promising environment friendly, low cost, and high electrochemical performance material. However, impediments like high internal ion resistance and low electrical conductivity restrict its applications as electrode for supercapacitor. In the present work, atomic layer deposition was used to fabricate TiO2 nanomembranes (NMs) with accurately controlled thicknesses. The TiO2 NMs were then used as electrodes for high-performance pseudocapacitors. Experimental results demonstrated that the TiO2 NM with 100 ALD cycles had the highest capacitance of 2332 F/g at 1 A/g with energy density of 81 Wh/kg. The enhanced performance was ascribed to the large surface area and the interconnectivity in the case of ultra-thin and flexible NMs. Increased ALD cycles led to stiffer NMs and decreased capacitance. Moreover, one series of two supercapacitors can light up one light-emitting diode with a working voltage of ~ 1.5 V, sufficiently describing its application values.

| S-EPMC6419636 | biostudies-literature

Quantum capacitance mediated carbon nanotube optomechanics.

Project description:Cavity optomechanics allows the characterization of a vibration mode, its cooling and quantum manipulation using electromagnetic fields. Regarding nanomechanical as well as electronic properties, single wall carbon nanotubes are a prototypical experimental system. At cryogenic temperatures, as high quality factor vibrational resonators, they display strong interaction between motion and single-electron tunneling. Here, we demonstrate large optomechanical coupling of a suspended carbon nanotube quantum dot and a microwave cavity, amplified by several orders of magnitude via the nonlinearity of Coulomb blockade. From an optomechanically induced transparency (OMIT) experiment, we obtain a single photon coupling of up to g0 = 2π ⋅ 95 Hz. This indicates that normal mode splitting and full optomechanical control of the carbon nanotube vibration in the quantum limit is reachable in the near future. Mechanical manipulation and characterization via the microwave field can be complemented by the manifold physics of quantum-confined single electron devices.

| S-EPMC7118114 | biostudies-literature