Preparation and Utilization of Jute-Derived Carbon: A Short Review

Advanced High-Energy All-Solid-State Hybrid Supercapacitor with Nickel-Cobalt-Layered Double Hydroxide Nanoflowers Supported on Jute Stick-Derived Activated Carbon Nanosheets

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.

Recent Progress in Polyaniline and its Composites for Supercapacitors

Polyaniline (PANI) has piqued the interest of nanotechnology researchers due to its potential as an electrode material for supercapacitors. Despite its ease of synthesis and ability to be doped with a wide range of materials, PANI's poor mechanical properties have limited its use in practical applications. To address this issue, researchers investigated using PANI composites with materials with highly specific surface areas, active sites, porous architectures, and high conductivity. The resulting composite materials have improved energy storage performance, making them promising electrode materials for supercapacitors. Here, we provide an overview of recent developments in PANI-based supercapacitors, focusing on using electrochemically active carbon and redox-active materials as composites. We discuss challenges and opportunities of synthesizing PANI-based composites for supercapacitor applications. Furthermore, we provide theoretical insights into the electrical properties of PANI composites and their potential as active electrode materials. The need for this review stems from the growing interest in PANI-based composites to improve supercapacitor performance. By examining recent progress in this field, we provide a comprehensive overview of the current state-of-the-art and potential of PANI-based composites for supercapacitor applications. This review adds value by highlighting challenges and opportunities associated with synthesizing and utilizing PANI-based composites, thereby guiding future research directions.

Metal Negatrode Supercapatteries: Advancements, Challenges, and Future Perspectives for High-Performance Energy Storage

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.

Advancements in Biomass-Derived Activated Carbon for Sustainable Hydrogen Storage: A Comprehensive Review

The increasing global energy demand, which is being driven by population growth and urbanization, necessitates the exploration of sustainable energy sources. While traditional energy generation predominantly relies on fossil fuels, it also contributes to alarming CO2 emissions. Hydrogen has emerged as a promising alternative energy carrier with its zero-carbon emission profile. However, effective hydrogen storage remains a challenge. When exposed to hydrogen, conventional metallic vessels, once considered to be the primary hydrogen carriers, are prone to brittleness-induced cracking. This has spurred interest in alternative storage solutions, particularly porous materials like metal-organic frameworks and activated carbon (AC). Among these, biomass-derived AC stands out for its eco-friendly nature, cost-effectiveness, and optimal adsorption properties. This review offers a comprehensive overview of recent advancements in the synthesis, characterization, and hydrogen storage capabilities of AC. The unique benefits of biomass-derived sources are highlighted, as is the pivotal role of chemical and physical activation processes. Furthermore, we identify existing challenges and propose future research directions in AC-based hydrogen storage. This compilation aims to serve as a foundation for potential innovations in sustainable hydrogen storage solutions.

A High-Energy Asymmetric Supercapacitor Based on Tomato-Leaf-Derived Hierarchical Porous Activated Carbon and Electrochemically Deposited Polyaniline Electrodes for Battery-Free Heart-Pulse-Rate Monitoring

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.

Cement Composites with Carbon-based Nanomaterials for 3D Concrete Printing Applications - A Review

3D concrete printing (3DCP) is an emerging additive manufacturing technology in the construction industry. Its challenges lie in the development of high-performance printable materials and printing processes. Recently developed carbon-based nanomaterials (CBNs) such as graphene, graphene oxide, graphene nanoplatelets, and carbon nanotubes, have various applications due to their exceptional mechanical, chemical, thermal, and electrical characteristics. CBNs also have found potential applications as a concrete ingredient as they enhance the microstructure and modify concrete properties at the molecular level. This paper focuses on state-of-the-art studies on CBNs, 3DCP technology, and CBNs in conventional and 3D printable cement-based composites including CBN dispersion techniques, concrete mixing methods, and fresh and hardened properties of concrete. Furthermore, the current limitations and future perspectives of 3DCP using CBNs to produce high-quality composite mixtures are discussed.

Recent advancements in lignocellulose biomass-based carbon fiber: Synthesis, properties, and applications

A growing need to reduce the global carbon footprint has prompted all sectors to make significant efforts in this direction. For example, there has been much focus on green carbon fiber sustainability. For example, it was found that the polyaromatic heteropolymer lignin might act as an intermediary in synthesising carbon fiber. Biomass is seen as a potential carbon accommodated solid natural sources that protects the nature and has a big overall supply and widespread distribution. With growing environmental concern in recent years, biomass has gained appeal as a raw material for production of carbon fibers. Especially, the positives of lignin material include its reasonable budget, sustainability, and higher carbon content, which makes it a dominating precursor. This review has examined a variety of bio precursors that help produce lignin and have higher lignin concentrations. In addition, there has been much research on plant sources, lignin types, factors affecting carbon fiber synthesis, spinning methods, stabilization, carbonization, and activation the characterisation techniques used for the lignin carbon fiber to comprehend the structure and features. In addition, an overview of the applications that use lignin carbon fiber has been provided.

Jute-Fiber Precursor-Derived Low-Cost Sustainable Hard Carbon with Varying Micro/Mesoporosity and Distinct Storage Mechanisms for Sodium-Ion and Potassium-Ion Batteries

Hard carbon (HC) remains the most viable choice as a negative electrode for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) owing to its higher energy density (discharge up to zero volts), higher capacity (distinct storage mechanisms), and cycling stability. Herein, a biomass jute fiber precursor HC anode (JPC) with varying porosity is reported for the first time as a low-cost and sustainable high-performance HC anode for SIBs and PIBs. Direct carbonization results in micro-meso porous HC (JPC-D), and micro-wave pretreated jute fiber results in ultramicroporous HC (JPC-M). The mesoporosity generated in JPC-D during synthesis outperforms the ultramicroporous JPC-M with a high reversible capacity of 328 mAh g^-1 (iCE = 66%) at a current density of 30 mA g^-1 (0.1C) with superior capacity retention of 84% after 100 cycles in SIBs. The Na⁺ ion and K⁺ ion storage in HCs, especially at lower voltages, shows distinct storage mechanisms that depend on the morphology and porosity of the material. JPC-D contributed 39% of its total capacity through the plateau region capacity (PRC), suggesting more pore filling from hierarchical porosity in SIBs. JPC-D and JPC-M exhibit more insertion-based capacity than pore-filling processes in PIBs. The presence of inorganic impurities (Ca, Si, Al, and Fe) encapsulated in the carbon structure plays a critical role in developing mesopores. The yield (%) of HC from direct carbonization per kilogram of jute is ∼34%, which makes it cheaper than HC from sugar-based precursors and 1.5 times more affordable than other biomass-derived HC. The jute-based micro-mesoporous HC is a novel, cost-effective, sustainable approach to designing HC for a PRC-based battery-type anode in SIBs and PIBs.

Preparation of Highly Stable and Electrochemically Active Three-dimensional Interconnected Graphene Frameworks from Jute Sticks

Over the past few years, the environmentally friendly synthesis of nanomaterials, including graphene using green chemistry, has attracted tremendous attention due to its easy handling, low cost, and biocompatibility. Here we demonstrate a facile and efficient green synthesis route for producing highly stable and electrochemically active three-dimensional interconnected graphene frameworks (3DIGF) from jute sticks. Initially, jute sticks derived three-dimensional amorphous activated carbon nanosheets (3DAACNs) were prepared at low temperatures (i.e., 850 °C) in an inert environment. The resultant 3DAACNs were then heat treated at a high temperature (i.e., 2700 °C) under an inert environment, resulting in 3DIGF. The prepared carbonaceous materials were fully characterized, and various experimental techniques confirmed the preparation of 3DIGF. The prepared 3DIGF shows a highly stable nature in thermal and chemical environments and demonstrates a highly dynamic nature for the electrooxidation of sulfide. This study could be considered a vital contribution towards the economic and simple approach for preparing 3DIGF from biomass.

Current Development and Future Perspective on Natural Jute Fibers and Their Biocomposites

The increasing trend of the use of synthetic products may result in an increased level of pollution affecting both the environment and living organisms. Therefore, from the sustainability point of view, natural, renewable and biodegradable materials are urgently needed to replace environmentally harmful synthetic materials. Jute, one of the natural fibers, plays a vital role in developing composite materials that showed potential in a variety of applications such as household, automotive and medical appliances. This paper first reviews the characterization and performance of jute fibers. Subsequently, the main focus is shifted towards research advancements in enhancing physical, mechanical, thermal and tribological properties of the polymeric materials (i.e., synthetic or biobased and thermoplastic or thermoset plastic) reinforced with jute fibers in a variety of forms such as particle, short fiber or woven fabric. It is understood that the physio-mechanical properties of jute-polymer composites largely vary based on the fiber processing and treatment, fiber shape and/or size, fabrication processes, fiber volume fraction, layering sequence within the matrix, interaction of the fiber with the matrix and the matrix materials used. Furthermore, the emerging research on jute fiber, such as nanomaterials from jute, bioplastic packaging, heavy metal absorption, electronics, energy device or medical applications and development of jute fiber composites with 3D printing, is explored. Finally, the key challenges for jute and its derivative products in gaining commercial successes have been highlighted and potential future directions are discussed.

Recent Advancements in Electrochemical Deposition of Metal-Based Electrode Materials for Electrochemical Supercapacitors

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.

Preparation of Sulfur-doped Carbon for Supercapacitor Applications: A Review

Electrochemical capacitors, also known as supercapacitors (SCs), have lately played an important role in energy storage and conversion systems due to their specific characteristics such as high strength, durability, and environmental friendliness. A wide range of materials is used as electrodes for SC applications because the electrochemical efficiency is primarily determined by the electrode materials used. Carbonaceous materials with unique surface, chemical, electrochemical, and electronic characteristics have become attractive for energy storage research, but they cannot meet the rising need for high specific energy and specific power. Besides, heteroatom-doped carbon materials have shown pseudocapacitance characteristics and improved specific energy, specific power, and conductivity. This makes them more adaptable in SC application. Among different heteroatom doping of carbon, S-doped carbon has gained considerable attention in SC applications due to its unpaired electrons and easily polarizable nature. S-doped carbon materials-based SCs have demonstrated enhanced surface wettability, improved conductivity, and induced pseudocapacitance effect, thereby delivering improved specific energy and specific power. Many reports on S-doped carbon for SC applications have been published, but there is no specific Review on the preparation of S-doped carbon for SC applications. This Review focuses on recent developments in the field of SC electrodes made from S-doped carbon materials. Herein, the preparation methods and applications of S-doped carbon for SCs were summarized following a brief discussion of different electrochemical characterization techniques of SCs. Finally, the challenges of S-doped carbon materials and their potential prospects were discussed to give crucial insights into the favorable factors for future innovations of SC electrodes. This Review aims to provide insight for further research on the preparation of S-doped carbon for electrochemical energy storage applications.

Recent Advances in Processing and Applications of Heterobimetallic Oxide Thin Films by Aerosol-assisted Chemical Vapor Deposition

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.

Advanced strategies in Metal-Organic Frameworks for CO2 Capture and Separation

The continuous carbon dioxide (CO₂ ) gas emissions associated with fossil fuel production, valorization, and utilization are serious challenges to the global environment. Therefore, several developments of CO₂ capture, separation, transportation, storage, and valorization have been explored. Consequently, we documented a comprehensive review of the most advanced strategies adopted in metal-organic frameworks (MOFs) for CO₂ capture and separation. The enhancements in CO₂ capture and separation are generally achieved due to the chemistry of MOFs by controlling pore window, pore size, open-metal sites, acidity, chemical doping, post or pre-synthetic modifications. The chemistry of defects engineering, breathing in MOFs, functionalization in MOFs, hydrophobicity, and topology are the salient advanced strategies, recently reported in MOFs for CO₂ capture and separation. Therefore, this review summarizes MOF materials' advancement explaining different strategies and their role in the CO₂ mitigations. The study also provided useful insights into key areas for further investigations.

Lignin Derived Porous Carbons: Synthesis Methods and Supercapacitor Applications

Lignin, one of the renewable constituents in natural plant biomasses, holds great potential as a sustainable source of functional carbon materials. Tremendous research efforts have been made on lignin-derived carbon electrodes for rechargeable batteries. However, lignin is considered as one of the most promising carbon precursors for the development of high-performance, low-cost porous carbon electrode materials for supercapacitor applications. Yet, these efforts have not been reviewed in detail in the current literature. This review, therefore, offers a basis for the utilization of lignin as a pivotal precursor for the synthesis of porous carbons for use in supercapacitor electrode applications. Lignin chemistry, the synthesis process of lignin-derived porous carbons, and future directions for developing better porous carbon electrode materials from lignin are systematically reviewed. Technological hurdles and approaches that should be prioritized in future research are presented.

Preparation, Characterization, and Evaluation of the Anticorrosion Performance of Submicron/Nanocarbon from Jute Sticks

Jute stick, one of the most commonly and abundantly available agricultural waste product, was converted to a value-added submicron/nano jute carbon by using pyrolysis and high-energy ball milling techniques. The submicron/nano jute carbon was characterized using FE-SEM, TEM, EDS, XRD, XPS and Raman spectroscopy. The anticorrosive performance of the submicron/nano jute carbon was investigated through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and salt spray techniques, on mild steel plates coated with a mixture of epoxy resin and the submicron/nano jute carbon. The electrochemical impedance of the steel coated with the composite coating was two orders of magnitudes higher than that of the specimen coated with neat epoxy. Consequently, the corrosion rate of specimens coated with composite coating was 13-20 times higher than that of steel coated with neat epoxy coating. The salt spray results also indicate an improvement in the corrosion resistance performance of the composite coating compared to the neat epoxy. The uniform distribution of the submicron/nano jute carbon particles in the epoxy resin improved the denseness of the composite coating by acting as a barrier against the diffusion of chloride, moisture, and oxygen, thus, improving the corrosion resistance of the developed coating.

Graphene and Carbon Nanotube-based Electrochemical Sensing Platforms for Dopamine

Dopamine (DA) is an important neurotransmitter, which is created and released from the central nervous system. It plays a crucial role in human activities, like cognition, emotions, and response to anything. Maladjustment of DA in human blood serum results in different neural diseases, like Parkinson's and Schizophrenia. Consequently, researchers have started working on DA detection in blood serum, which is undoubtedly a hot research area. Electrochemical sensing techniques are more promising to detect DA in real samples. However, utilizing conventional electrodes for selective determination of DA encounters numerous problems due to the coexistence of other materials, such as uric acid and ascorbic acid, which have an oxidation potential close to DA. To overcome such problems, researchers have put their focus on the modification of bare electrodes. The aim of this review is to present recent advances in modifications of most used bare electrodes with carbonaceous materials, especially graphene, its derivatives, and carbon nanotubes, for electrochemical detection of DA. A brief discussion about the mechanistic phenomena at the electrode interface has also been included in this review.

Strategies for Improved Electrochemical CO2 Reduction to Value-added Products by Highly Anticipated Copper-based Nanoarchitectures

Uncontrolled CO₂ emission from various industrial and domestic sources is a considerable threat to environmental sustainability. Scientists are trying to develop multiple approaches to not only reduce CO₂ emissions but also utilize this potent pollutant to get economically feasible products. The electrochemical reduction of CO₂ (ERC) is one way to effectively convert CO₂ to more useful products (ranging from C1 to C5). Nevertheless, this process is kinetically hindered and less selective towards a specific product and, consequently, requires an efficient electrocatalyst with characteristics like selectivity, stability, reusability, low cost, and environmentally benign. Owing to specified commercial features, copper (Cu)-based materials are highly anticipated and widely investigated for the last two decades. However, their non-modified polycrystalline Cu forms usually lack selectivity and lower overpotential of CO₂ reduction. Therefore, extensive research is in progress to induce various alterations ranging from morphological and surface chemistry tuning to structural and optoelectrical characteristics modifications. This review provides an overview of those strategies to improve the CO₂ conversion efficiency through Cu-based ERC into valuable C1, C2_, and higher molecular weight hydrocarbons. The thermodynamics and kinetics of CO₂ reduction via Cu-based electrocatalysts are discussed in detail with the support of the first principle DFT-based models. In the last portion of the review, the reported mechanisms for various products are summarized, with a short overview of the outlook. This review is expected to provide important basics as well as advanced information for experienced as well as new researchers to develop various strategies for Cu and related materials to achieve improved ERC.

Electrochemical Reduction of CO2: A Review of Cobalt Based Catalysts for Carbon Dioxide Conversion to Fuels

Electrochemical CO2 reduction reaction (CO2RR) provides a promising approach to curbing harmful emissions contributing to global warming. However, several challenges hinder the commercialization of this technology, including high overpotentials, electrode instability, and low Faradic efficiencies of desirable products. Several materials have been developed to overcome these challenges. This mini-review discusses the recent performance of various cobalt (Co) electrocatalysts, including Co-single atom, Co-multi metals, Co-complexes, Co-based metal-organic frameworks (MOFs), Co-based covalent organic frameworks (COFs), Co-nitrides, and Co-oxides. These materials are reviewed with respect to their stability of facilitating CO2 conversion to valuable products, and a summary of the current literature is highlighted, along with future perspectives for the development of efficient CO2RR.

Present Status and Future Prospects of Jute in Nanotechnology: A Review

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.

A Review on Heavy Metal Ions and Containing Dyes Removal Through Graphene Oxide-Based Adsorption Strategies for Textile Wastewater Treatment

Textile wastewater heavy metal pollution has become a severe environmental problem worldwide. Metal ion inclusion in a dye molecule exhibits a bathochromic shift producing deeper but duller shades, which provides excellent colouration. The ejection of a massive volume of wastewater containing heavy metal ions such as Cr (VI), Pb (II), Cd (II) and Zn (II) and metal-containing dyes are an unavoidable consequence because the textile industry consumes large quantities of water and all these chemicals cannot be combined entirely with fibres during the dyeing process. These high concentrations of chemicals in effluents interfere with the natural water resources, cause severe toxicological implications on the environment with a dramatic impact on human health. This article reviewed the various metal-containing dye types and their heavy metal ions pollution from entryway to the wastewater, which then briefly explored the effects on human health and the environment. Graphene-based absorbers, specially graphene oxide (GO) benefits from an ordered structured, high specific surface area, and flexible surface functionalization options, which are indispensable to realize a high performance of heavy metal ion removal. These exceptional adsorption properties of graphene-based materials support a position of ubiquity in our everyday lives. The collective representation of the textile wastewater's effective remediation methods is discussed and focused on the GO-based adsorption methods. Understanding the critical impact regarding the GO-based materials established adsorption portfolio for heavy metal ions removal are also discussed. Various heavy-metal ions and their pollutant effect, ways to remove such heavy metal ions and role of graphene-based adsorbent including their demand, perspective, limitation, and relative scopes are discussed elaborately in the review.

Controlled-Potential-Based Electrochemical Sulfide Sensors: A Review

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.