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1.
Small ; 20(22): e2306665, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38150613

RESUMEN

Developing efficient, lightweight, and durable all-solid-state supercapacitors is crucial for future energy storage systems. The study focuses on optimizing electrode materials to achieve high capacitance and stability. This study introduces a novel two-step pyrolysis process to synthesize activated carbon nanosheets from jute sticks (JAC), resulting in an optimized JAC-2 material with a high yield (≈24%) and specific surface area (≈2600 m2 g-1). Furthermore, an innovative in situ synthesis approach is employed to synthesize hybrid nanocomposites (NiCoLDH-1@JAC-2) by integrating JAC nanosheets with nickel-cobalt-layered double hydroxide nanoflowers (NiCoLDH). These nanocomposites serve as positive electrode materials and JAC-2 as the negative electrode material in all-solid-state asymmetric hybrid supercapacitors (HSCs), exhibiting remarkable performance metrics. The HSCs achieve a specific capacitance of 750 F g-1, a specific capacity of 209 mAh g-1 (at 0.5 A g-1), and an energy density of 100 Wh kg-1 (at 250 W kg-1) using PVA/KOH solid electrolyte, while maintaining outstanding cyclic stability. Importantly, a density functional theory framework is utilized to validate the experimental findings, underscoring the potential of this novel approach for enhancing HSC performance and enabling the large-scale production of transition metal-based layered double hydroxides.

2.
Chem Rec ; 24(1): e202300239, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38050957

RESUMEN

Metal negatrode supercapattery (MNSC) is an emerging technology that combines the high energy storage capabilities of batteries with the high-power delivery of supercapacitors, thereby offering promising solutions for various applications, such as energy storage systems, electric vehicles, and portable electronics. This review article presents a comprehensive analysis of the potential of MNSCs as a prospective energy storage technology. MNSCs utilize a specific configuration in which the negatrode consists of a metal or metal-rich electrode, such as sodium, aluminum, potassium, or zinc, whereas the positrode functions as a supercapacitor electrode. The utilization of negatrodes with low electrochemical potential and high electrical conductivity is crucial for achieving high specific energy in energy storage devices, despite facing numerous challenges. The present study discusses the design and fabrication aspects of MNSCs, including the selection of appropriate metal negatrodes, electrolytes, and positrodes, alongside the fundamental operational mechanisms. Additionally, this review explores the challenges encountered in MNSCs and proposes solutions to enhance their performance, such as addressing dendrite formation and instability of metal electrodes.

3.
Chem Rec ; 24(1): e202300302, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38010947

RESUMEN

As supercapacitor (SC) technology continues to evolve, there is a growing need for electrode materials with high energy/power densities and cycling stability. However, research and development of electrode materials with such characteristics is essential for commercialization the SC. To meet this demand, the development of superior electrode materials has become an increasingly critical step. The electrochemical performance of SCs is greatly influenced by various factors such as the reaction mechanism, crystal structure, and kinetics of electron/ion transfer in the electrodes, which have been challenging to address using previously investigated electrode materials like carbon and metal oxides/sulfides. Recently, tellurium and telluride-based materials have garnered increasing interest in energy storage technology owing to their high electronic conductivity, favorable crystal structure, and excellent volumetric capacity. This review provides a comprehensive understanding of the fundamental properties and energy storage performance of tellurium- and Te-based materials by introducing their physicochemical properties. First, we elaborate on the significance of tellurides. Next, the charge storage mechanism of functional telluride materials and important synthesis strategies are summarized. Then, research advancements in metal and carbon-based telluride materials, as well as the effectiveness of tellurides for SCs, were analyzed by emphasizing their essential properties and extensive advantages. Finally, the remaining challenges and prospects for improving the telluride-based supercapacitive performance are outlined.

4.
Molecules ; 29(9)2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38731570

RESUMEN

This comprehensive review addresses the need for sustainable and efficient energy storage technologies against escalating global energy demand and environmental concerns. It explores the innovative utilization of waste materials from oil refineries and coal processing industries as precursors for carbon-based electrodes in next-generation energy storage systems, including batteries and supercapacitors. These waste-derived carbon materials, such as semi-coke, coal gasification fine ash, coal tar pitch, petroleum coke, and petroleum vacuum residue, offer a promising alternative to conventional electrode materials. They present an optimal balance of high carbon content and enhanced electrochemical properties while promoting environmental sustainability through effectively repurposing waste materials from coal and hydrocarbon industries. This review systematically examines recent advancements in fabricating and applying waste-derived carbon-based electrodes. It delves into the methodologies for converting industrial by-products into high-quality carbon electrodes, with a particular emphasis on carbonization and activation processes tailored to enhance the electrochemical performance of the derived materials. Key findings indicate that while higher carbonization temperatures may impede the development of a porous structure, using KOH as an activating agent has proven effective in developing mesoporous structures conducive to ion transport and storage. Moreover, incorporating heteroatom doping (with elements such as sulfur, potassium, and nitrogen) has shown promise in enhancing surface interactions and facilitating the diffusion process through increased availability of active sites, thereby demonstrating the potential for improved storage capabilities. The electrochemical performance of these waste-derived carbon materials is evaluated across various configurations and electrolytes. Challenges and future directions are identified, highlighting the need for a deeper understanding of the microstructural characteristics that influence electrochemical performance and advocating for interdisciplinary research to achieve precise control over material properties. This review contributes to advancing electrode material technology and promotes environmental sustainability by repurposing industrial waste into valuable resources for energy storage. It underscores the potential of waste-derived carbon materials in sustainably meeting global energy storage demands.

5.
Small ; 19(33): e2300258, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37093224

RESUMEN

A simple and scalable method to fabricate a novel high-energy asymmetric supercapacitor using tomato-leaf-derived hierarchical porous activated carbon (TAC) and electrochemically deposited polyaniline (PANI) for a battery-free heart-pulse-rate monitor is reported. In this study, TAC is prepared by simple pyrolysis, exhibiting nanosheet-type morphology and a high specific surface area of ≈1440 m2 g-1 , and PANI is electrochemically deposited onto carbon cloth. The TAC- and PANI- based asymmetric supercapacitor demonstrates an electrochemical performance superior to that of symmetric supercapacitors, delivering a high specific capacitance of 248 mF cm-2 at a current density of 1.0 mA cm-2 . The developed asymmetric supercapacitor shows a high energy density of 270 µWh cm-2 at a power density of 1400 µW cm-2 , as well as an excellent cyclic stability of ≈95% capacitance retention after 10 000 charging-discharging cycles while maintaining ≈98% Coulombic efficiency. Impressively, the series-connected asymmetric supercapacitors can operate a battery-free heart-pulse-rate monitor extremely efficiently upon solar-panel charging under regular laboratory illumination.

6.
Chem Rec ; 22(7): e202200018, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35426239

RESUMEN

Due to advancements in technology, the energy demand is becoming more intense with time. The rapid fossil fuels consumption and environmental concerns triggered intensive research for alternative renewable energy resources, including sunlight and wind. Yet, due to their time-dependent operations, significant electric energy storage systems are required to store substantial energy. In this regard, electrochemical energy storage devices, like batteries and supercapacitors (SCs), have recently attracted much research attention. Recent developments in SCs demonstrated that hybrid SCs (HSCs), which combine the excellent properties of batteries and SCs, increase the specific energy, specific power, specific capacitance, and life span. Carbonaceous and redox-active materials have been explored as efficient electrode materials for applications in HSCs, ultimately enhancing their electrochemical performances. The HSCs performance significantly depends on the porosity, specific surface area, and conductivity of the electrode materials. This review article gives an overview of recent advances in developing HSCs with high specific power, specific energy, and long cyclic-life. The fabrication of various HSCs materials using carbonaceous and redox-active nanoarchitectures and their characterization are explored in-depth, including electrode development, basic principles, and device engineering. A proper investigation has been conducted regarding state-of-the-art materials as HSC electrodes. This review focuses on the most up-to-date, cutting-edge, electrode materials for HSCs and their performance. The possibilities for novel electrode materials and their impact on the HSCs performance for future energy storage are also discussed.

7.
Chem Rec ; 22(7): e202100278, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34862719

RESUMEN

The fabrication of smart, efficient, and innovative devices critically needs highly refined thin-film nanomaterials; therefore, facile, scalable, and economical methods of thin films production are highly sought-after for the sustainable growth of the hi-tech industry. The chemical vapor deposition (CVD) technique is widely implemented at the industrial level due to its versatile features. However, common issues with a precursor, such as reduced volatility and thermal stability, restrict the use of CVD to produce novel and unique materials. A modified CVD approach, named aerosol-assisted CVD (AACVD), has been the center of attention due to its remarkable tendency to fabricate uniform, homogenous, and distinct nano-architecture thin films in an uncomplicated and straightforward manner. Above all, AACVD can utilize any custom-made or commercially available precursors, which can be transformed into a transparent solution in a common organic solvent; thus, a vast array of compounds can be used for the formation of nanomaterial thin films. This review article highlights the importance of AACVD in fabricating heterobimetallic oxide thin films and their potential in making energy production (e. g., photoelectrochemical water splitting), energy storage (e. g., supercapacitors), and environmental protection (e. g., electrochemical sensors) devices. A heterobimetallic oxide system involves two metallic species either in a composite, solid solution, or metal-doped metal oxides. Moreover, the AACVD tunable parameters, such as temperature, deposition time, and precursor, which drastically affect thin films microstructure and their performance in device applications, are also discussed. Lastly, the key challenges and issues of scaling up AACVD to the industrial level and processing for emerging functional materials are also highlighted.

8.
Chem Rec ; 22(7): e202200041, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35426220

RESUMEN

As the world moves towards renewable and sustainable energy sources, the need for systems that can quickly and safely store this energy is also rising. Supercapacitors (SCs) are among the most promising alternatives to conventional lithium-ion batteries. SCs are more stable, have higher-power densities, and can be charged much faster. However, SCs have their issues, and three of the main drawbacks of current SCs are 1) lower energy densities, 2) high cost of production, and 3) safety concerns in wearable devices. In this review, we discuss recent progress made in supramolecule-based SCs (SSCs). In supramolecular systems, molecules are held stable using non-covalent-type bonds. This allows for a flexible system in which the molecular interaction sites can easily break and reform at low energy, allowing for exposure of highly active sites and self-healing. When heterometal atoms are introduced into these supramolecular systems, this allows for further activation of the metal sites through the metal-metal interaction along with the metal-ligand interactions. This review discusses different types of SSCs (carbon-based and metal-incorporated) that have been utilized in recent years depending on their synthesis process. The working principle of SSCs and the utilization of different supramolecular elements that enhance the performance of SCs have also been discussed.

9.
Chem Rec ; 22(11): e202200134, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35832015

RESUMEN

Emerging demands to achieve zero carbon emissions and develop renewable energy resources necessitate the development of appropriate energy storage systems. To achieve this, several alternatives to conventional energy storage devices, such as Li-ion batteries or capacitors to more sustainable and scalable energy storage systems, are being explored. Supercapacitors, possess unique characteristics that include high power, long life, and environmental-friendly design. They may be used to bridge the energy-power gap between typical capacitors and fuel cells/batteries. Recently, structural supercapacitors being capable of storing electrochemical energy besides bearing mechanical load have caught the attention of researchers. As such, efforts have been made worldwide to study both the fundamental and applied aspects of structural supercapacitors. Further, the possibility of using construction materials for interdisciplinary applications is being studied because they are relatively cheap and easily available. Thus, construction materials can be considered as potential candidates for the development of structural supercapacitors. Herein an overview on the use of construction materials, such as Portland cement concrete, geopolymer concrete, and bricks, as a component of structural supercapacitors has been presented.

10.
Chem Rec ; 22(7): e202200013, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35313076

RESUMEN

The demand for energy storage devices with high energy and power densities has increased tremendously in this rapidly growing world. Conventional capacitors, fuel cells, and lithium-ion batteries have been used as energy storage devices for the long term. However, supercapacitors are one of the most promising energy storage devices because of their high specific capacitance, high power density, and longer cycle life. Recent research has focused on synthesizing transition-metal oxides/hydroxides, carbon materials, and conducting polymers as supercapacitor electrode materials. The performance of supercapacitors can be improved by altering electrolytes, electrode materials, current collectors, experimental temperatures, and film thickness. Thousands of papers on supercapacitors have already been published, reflecting the significance and elucidating how much demanding such energy storage devices for this fast-growing generation. This review aims to illustrate the electrode materials loaded on various conductive substrates by electrochemical deposition employed for supercapacitors to provide broad knowledge on synthetic pathways, which will pave the way for future research. We also discussed the basic parameters involved in supercapacitor studies and the advantages of the electrochemical deposition techniques through literature analysis. Finally, future trends and directions on exploring metals/metal composites toward designing and constructing viable, high-class, and even newly featured flexible energy storage materials, electrodes, and systems are presented.

11.
Chemistry ; 27(23): 6973-6984, 2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33609404

RESUMEN

Tungsten oxide/graphene hybrid materials are attractive semiconductors for energy-related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG//m-WO3 ASC), fabricated from monoclinic tungsten oxide (m-WO3 ) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material. The supercapacitor performance of the prepared electrodes was evaluated in an aqueous electrolyte (1 m H2 SO4 ) using three- and two-electrode systems. The HRG//m-WO3 ASC exhibits a maximum specific capacitance of 389 F g-1 at a current density of 0.5 A g-1 , with an associated high energy density of 93 Wh kg-1 at a power density of 500 W kg-1 in a wide 1.6 V operating potential window. In addition, the HRG//m-WO3 ASC displays long-term cycling stability, maintaining 92 % of the original specific capacitance after 5000 galvanostatic charge-discharge cycles. The m-WO3 nanoplates were prepared hydrothermally while HRG was synthesized by a modified Hummers method.

12.
Chem Rec ; 21(1): 204-238, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33200874

RESUMEN

Due to their potential applications in industry and potent toxicity to the environment, sulfides and their detection have attracted the attention of researchers. To date, a large number of controlled-potential techniques for electrochemical sulfide sensors have been developed, thanks to their simplicity, reasonable limit of detection (LOD), and good selectivity. Different researchers have applied different strategies for developing selective and sensitive sulfide sensors. However, there has been no systematic review on controlled-potential techniques for sulfide sensing. In light of this absence, the main aim of this review article is to summarize various strategies for detecting sulfide in different media. The efficiencies of the developed sulfide sensors for detecting sulfide in its various forms are determined, and the essential parameters, including sensing strategies, working electrodes, detection media, pH, LOD, sensitivity, and linear detection range, are emphasized in particular. Future research in this area is also recommended. It is expected that this review will act as a basis for further research on the fabrication of sulfide sensors for practical applications.

13.
Chem Rec ; 21(7): 1631-1665, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34132038

RESUMEN

Nanotechnology has transformed the world with its diverse applications, ranging from industrial developments to impacting our daily lives. It has multiple applications throughout financial sectors and enables the development of facilitating scientific endeavors with extensive commercial potentials. Nanomaterials, especially the ones which have shown biomedical and other health-related properties, have added new dimensions to the field of nanotechnology. Recently, the use of bioresources in nanotechnology has gained significant attention from the scientific community due to its 100 % eco-friendly features, availability, and low costs. In this context, jute offers a considerable potential. Globally, its plant produces the second most common natural cellulose fibers and a large amount of jute sticks as a byproduct. The main chemical compositions of jute fibers and sticks, which have a trace amount of ash content, are cellulose, hemicellulose, and lignin. This makes jute as an ideal source of pure nanocellulose, nano-lignin, and nanocarbon preparation. It has also been used as a source in the evolution of nanomaterials used in various applications. In addition, hemicellulose and lignin, which are extractable from jute fibers and sticks, could be utilized as a reductant/stabilizer for preparing other nanomaterials. This review highlights the status and prospects of jute in nanotechnology. Different research areas in which jute can be applied, such as in nanocellulose preparation, as scaffolds for other nanomaterials, catalysis, carbon preparation, life sciences, coatings, polymers, energy storage, drug delivery, fertilizer delivery, electrochemistry, reductant, and stabilizer for synthesizing other nanomaterials, petroleum industry, paper industry, polymeric nanocomposites, sensors, coatings, and electronics, have been summarized in detail. We hope that these prospects will serve as a precursor of jute-based nanotechnology research in the future.


Asunto(s)
Celulosa/química , Corchorus/química , Lignina/química , Nanocompuestos/química , Nanotecnología/tendencias , Animales , Catálisis , Celulosa/aislamiento & purificación , Humanos , Lignina/aislamiento & purificación , Nanopartículas del Metal/química , Oxidación-Reducción
14.
Chem Res Toxicol ; 33(6): 1292-1311, 2020 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-31884781

RESUMEN

The optoelectrical and magnetic characteristics of naturally existing iron-based nanostructures, especially hematite and magnetite nanoparticles (H-NPs and M-NPs), gained significant research interest in various applications, recently. The main purpose of this Review is to provide an overview of the utilization of H-NPs and M-NPs in various environmental remediation. Iron-based NPs are extensively explored to generate green energy from environmental friendly processes such as water splitting and CO2 conversion to hydrogen and low molecular weight hydrocarbons, respectively. The latter part of the Review provided a critical overview to use H-NPs and M-NPs for the detection and decontamination of inorganic and organic contaminants to counter the environmental pollution and toxicity challenge, which could ensure environmental sustainability and hygiene. Some of the future perspectives are comprehensively presented in the final portion of the script, optimiztically, and it is supported by some relevant literature surveys to predict the possible routes of H-NPs and M-NPs modifications that could enable researchers to use these NPs in more advanced environmental applications. The literature collection and discussion on the critical assessment of reserving the environmental sustainability challenges provided in this Review will be useful not only for experienced researchers but also for novices in the field.


Asunto(s)
Restauración y Remediación Ambiental , Compuestos Férricos , Óxido Ferrosoférrico , Nanoestructuras , Contaminación Ambiental/prevención & control , Compuestos Férricos/química , Óxido Ferrosoférrico/química , Nanoestructuras/química , Energía Renovable
15.
Chem Rec ; 20(9): 1074-1098, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32794376

RESUMEN

This article summarizes the preparation and applications of carbon derived from jute sticks and fibers that are low-cost, widely available, renewable, and environmentally friendly. Both the fibers and sticks are considered ideal candidates of carbon preparation because they are composed of cellulose, hemicelluloses, and lignin, and contain negligible ash content. Various carbon preparation methods including simple pyrolysis, pyrolysis with chemical and physical activations are discussed. The impacts of several parameters including types of activating agents, impregnation ratio, and temperature on their morphology, surface area, pore size, crystallinity, and surface functional groups are also emphasized. Various treatments to endow functionalization for increasing the practical applicability, such as chemical, physical, and physico-chemical methods, are discussed. In addition, applications of jute-derived carbon in various practical areas, including energy storage, water treatment, and sensors, are also highlighted in this report. Due to the porous fine structure and a large specific surface area, the jute-derived carbon could be considered as a powerful candidate material for various industrial applications. Finally, possible future prospects of jute-derived carbon for various applications are pointed out.


Asunto(s)
Carbono/química , Celulosa/química , Lignina/química , Polisacáridos/química , Técnicas Electroquímicas/métodos , Pirólisis , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
16.
Chem Asian J ; : e202301039, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38324734

RESUMEN

In the realm of renewable energy technologies, the development of efficient and durable electrocatalysts is paramount, especially for applications like electrochemical water splitting. This research focuses on synthesizing a novel bimetallic metal-organic framework (BMMOF11) using earth-abundant elements, cobalt (Co) and cadmium (Cd). BMMOF11 showcases a distinctive structure with distorted octahedral chains of CoO and CdO, linked by benzene tricarboxylic acid (BTC). Our study primarily investigates the electrocatalytic efficiency of BMMOF11, particularly in water oxidation reactions. For practical analysis, BMMOF11 was anchored onto nickel foam, forming BMMOF11/NF, to evaluate its electrocatalytic properties. Electrochemical testing revealed that BMMOF11/NF begins water oxidation at an onset potential of 1.62 V versus RHE, demonstrating high activity with a lower overpotential of 0.4 V to achieve a current density of 10 mA/cm2 . Moreover, BMMOF11/NF maintained stable water splitting performance, sustaining a current density of approximately 70 mA/cm2 under a voltage of 1.9 V relative to RHE. These findings indicate that BMMOF11/NF is a promising candidate for large-scale electrochemical water splitting, offering a blend of high activity and stability.

17.
Chem Asian J ; : e202400314, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39014972

RESUMEN

Stainless steel mesh (SSM) has emerged as a cornerstone in electrochemical applications owing to its exemplary versatility, electrical conductivity, mechanical robustness, and corrosion resistance. This state-of-the-art review delves into the diverse roles of SSM across a spectrum of electrochemical domains, including energy conversion and storage devices, water treatment technologies, electrochemical sensors, and catalysis. We meticulously explore its deployment in supercapacitors, batteries, and fuel cells, highlighting its utility as a current collector, electrode, and separator. The review further discusses the critical significance of SSM in water treatment processes, emphasizing its efficacy in supporting membranes and facilitating electrocoagulation, as well as its novel uses in electrochemical sensing and catalysis, which include electrosynthesis and bioelectrochemistry. Each section delineates the recent advancements, identifies the inherent challenges, and suggests future directions for leveraging SSM in electrochemical technologies. This comprehensive review showcases the current state of knowledge and articulates the novel integration of SSM with emerging materials and technologies, thereby establishing a new paradigm for sustainable and efficient electrochemical applications. Through critical analysis and insightful recommendations, this review positions itself as a seminal contribution, paving the way for researchers and practitioners to harness the full potential of SSM in advancing the electrochemistry frontiers.

18.
Chem Asian J ; 19(9): e202400074, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38545693

RESUMEN

This work demonstrates the use of jute stick extract as a reducing and stabilizing agent for the synthesis of spherical gold nanoparticles (AuNPs). In UV-Vis spectroscopy, peak at 550 nm was used to confirm the formation of AuNPs. The spherical surface morphology of AuNPs was determined through SEM and TEM analysis. While XRD investigation revealed the crystallinity of the prepared AuNPs. To ensure the biocompatibility of synthesized AuNPs, a bacterial investigation was conducted with negative results towards bacterial strain. The, modified FTO with AuNPs were able to detect glucose in CV analysis and the constructed sensor displayed a wide linear range of 50 µM to 40 mM with a detection limit of 20 µM. Scan rate analysis was performed to determine the charge transfer coefficient (0.42) and Tafel slope (102 mV/decade). Furthermore, the interfacial surface mechanism is illustrated to understand the interaction of glucose with the electrode surface in an alkaline medium and the product formation through the dehydrogenation and hydrolysis process. The prepared sensor also showed good stability, reproducibility, and anti-interference capabilities. In the case of real sample analysis, we used a blood serum sample. A low RSD value (<10 %) suggests the practical use of AuNPs/FTO in real-life applications.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Electrodos , Flúor , Oro , Nanopartículas del Metal , Compuestos de Estaño , Oro/química , Nanopartículas del Metal/química , Flúor/química , Compuestos de Estaño/química , Materiales Biocompatibles/química , Materiales Biocompatibles/síntesis química , Glucosa/análisis , Propiedades de Superficie , Humanos , Glucemia/análisis , Tamaño de la Partícula
19.
Chem Asian J ; 18(4): e202201223, 2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36576425

RESUMEN

Energy storage is one of the most stimulating requirements to keep civilization on the wheel of progress. Supercapacitors generally exhibit a high-power density, have a maximum life cycle, quick charging time, and are eco-friendly. Polyaniline (PANI), a conductive polymer, is considered an efficacious electrode material for supercapacitors due to its good electroactivity, including pseudocapacitive behavior. Here, we present the fabrication of a symmetric supercapacitor device based on steel mesh electrodeposited with PANI. Due to its effective conductivity, porous nature, and low cost, steel mesh is a good choice as a current collector to fabricate a high-performance supercapacitor at a low cost. The optimum fabricated supercapacitor has a high specific capacitance of ∼353 mF cm-2 . Furthermore, the supercapacitor obtained an energy density of ∼26.4 µW h cm-2 at a power density of ∼400 µW cm-2 . The fabricated supercapacitor shows high stability, as the initial capacitance remained almost the same after 1000 charge/discharge cycles. PANI is a promising candidate for mass production and wide applications due to its low cost and high performance.

20.
Environ Sci Pollut Res Int ; 30(12): 34904-34914, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36525190

RESUMEN

Nitrate is a water-soluble toxic pollutant that needs to be excluded from the environment. For this purpose, several electrochemical studies have been conducted but most of them focused on the nitrate reduction reaction (NRR) in alkaline and acidic media while insignificant research is available in neutral media with Pt electrode. In this work, we explored the effect of three coinage metals (Cu, Ag, and Au) on Pt electrode for the electrochemical reduction of nitrate in neutral solution. Among the three electrodes, Pt-Cu exhibited the best catalytic activity toward NRR, whereas Pt-Au electrode did not show any reactivity. An activity order of Pt-Cu > Pt-Ag > Pt-Au was observed pertaining to NRR. The Pt-Ag electrode produces nitrite ions by reducing nitrate ions ([Formula: see text]. Meanwhile, at Pt-Cu electrode, nitrate reduction yields ammonia via both direct ([Formula: see text] and indirect ([Formula: see text] reaction pathways depending on the potential. The cathodic transfer coefficients were estimated to be ca. 0.40 and ca. 0.52, while the standard rate constants for nitrate reduction were calculated as ca. 2.544 × 10-2 cm.s-1 and ca. 1.453 × 10-2 cm.s-1 for Pt-Cu and Pt-Ag electrodes, respectively. Importantly, Pt-Cu and Pt-Ag electrodes execute NRR in the neutral medium between their respective Hydrogen-Evolution Reaction (HER) and Open-Circuit Potential (OCP), implying that on these electrodes, HER and NRR do not compete and the latter is a corrosion-free process.


Asunto(s)
Nitratos , Platino (Metal) , Nitritos , Electrodos
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