Browsing by Author "Bhawna Verma"

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Advances in Semiconducting Fibers
(CRC Press, 2024) Sanjeev Verma; Tapas Das; Shivani Verma; Ram K. Gupta; Bhawna Verma
The development of semiconductor fiber technology in recent years has been accelerated by improvements in fabrication and post-processing methods. Numerous opportunities, including solar energy harvesting, photodetection, signal modulation, and in-fiber frequency generation, have been made possible by combining the electronic and optical functions of fiber-structured semiconductor materials. An outline of the most recent developments in semiconductor material fibers, such as manufacturing and after-processing techniques, optical characteristics and different materials, is provided in this chapter. Applications for lasers, multimaterial functional fibers, optical–electrical conversion and nonlinear optics are also presented. © 2025 selection and editorial matter, Ram K. Gupta; individual chapters, the contributors.
Char Reduction for Pyrolysis of Lignocellulosic Biomass
(Taylor and Francis Ltd., 2018) Arun Kumar Gautam; Bhawna Verma
Thermal decomposition of biomass in controlled environment produces bio-oil, which can serve as an alternative to diesel and gasoline. Alongwith bio-oil, the by-product char is also produced which affects the yield of bio-oil. Hence the present work is focused to the control the amount of char by varying the heat regulation rate and different chemical and microwave pretreatments of the biomass (rice husk). Extract of the treated biomass, biomass samples and the char was studied in different characterization techniques, such as Thermo Gravimetry (TGA), Thermal Differential Analysis (DTA), Fourier Transform Infrared Spectroscopy (FT-IR), Elemental Analyser (CHNS), Inductively Coupled Argon Plasma (ICP). Thermal analysis showed the rate of weight loss was high at higher heating rates. Two different degradation temperatures were observed for Cellulose and lignin in biomass which was not disturbed by acid treatment, representing no significant loss in cellulose and hemicellulose structure, while alkali treated sample approached to a unique temperature representing significant loss/removal of lignin and some portion of hemicellulose/cellulose. Microwave treatment resulted in the cleavage of glycosidic linkage of cellulose resulting in monosaccharides, xylose, and other sugar forms. © 2018 Har Krishan Bhalla & Sons.
Future outlook and challenges for supercapacitors
(Bentham Science Publishers, 2024) Vikas Kumar Pandey; Bhawna Verma
The contemporary research environment calls for developing nextgeneration devices using cutting-edge technologies for energy storage applications. Supercapacitors are becoming burgeoning contenders in the energy sector due to their increased durability and quicker charge storage capacity. In contrast to batteries and fuel cells, supercapacitors are a less realistic solution for practical applications. Additionally, there is a pressing need for fabrication techniques that must be addressed to deliver an appropriate supercapacitor electrode. The book chapter will better describe the difficulties encountered during various supercapacitor research, development, and commercial application phases. Finally, a conclusive prognosis has been given on how the discussion above will deliver essential insights and create chances to expand the possible application of new-generation supercapacitors. © 2024 Bentham Science Publishers. All rights reserved.
Graphene-based nanocomposites: An efficient detoxification agent for heavy metal removal from wastewater
(National Institute of Science Communication and Policy Research, 2023) Sanjeev Verma; Shivani Verma; Tapas Das; Bhawna Verma
Numerous scientific and technological developments in wastewater treatment procedures are brought on by the shortage of clean water supplies. Heavy metals' recalcitrance in wastewater has been shown to be a difficult issue. Further, drinking water quality must be at its highest for human health to be at its best; nevertheless, a number of human activities are continuously degrading it, which has an effect on human health either directly or indirectly. Because heavy metals are the primary causes of many chronic illnesses and have a tendency to bio accumulate, they are giving rise to a lot of worries. Technologies from all over the world are being developed to address the demand for clean drinking water. The objective of the current study is to raise awareness of the need to remove dangerous dense metals from various types of wastewater and the application of modified graphene nanocomposite for their adsorption-based removal. Graphene-based nanocomposite materials have been picked for this application due to their large surface area, superior mechanical strength, and reactivity towards polar and nonpolar contaminants for the electrostatic emission of the heavy metal ions arsenic (As), chromium (Cr), copper (Cu), and lead (Pb). © 2023, National Institute of Science Communication and Policy Research. All rights reserved.
Grossly Polluting Industries and Their Effect on Water Resources in India
(wiley, 2021) Zeenat Arif; Naresh Kumar Sethy; Swati; Pradeep Kumar Mishra; Bhawna Verma
Industrialization is considered as the pillar of economic development and human welfare in India. Since the previous decade, industrial development has greatly affected water resources like rivers, lakes, groundwater, and so on. This is mainly due to the increase in the percentage of grossly polluting industries (GPIs) such as textiles, tannery, distillery, and drug industries. Since 2011, the number of GPIs increased from 1162â€‰units over 22 states/union territories (UTs) to 2743â€‰units over 36 states/UTs as per the Central Pollution Control Board (CPCB) report, of which about 84% of the GPIs are located in four states, viz. Uttar Pradesh (1218), Haryana (660), Andhra Pradesh (198), and Gujarat (191). According to the National Mission for Clean Ganga (NMCG), the wastewater generated by GPIs is 45% of total water consumption. This is mostly due to small-scale industries having a lack of effluent treatment plants (ETPs). These industries produce major pollutants like Cr from tanneries, organic pollutants from distilleries, dyes from textiles, and other toxic chemicals from drug and hazardous chemical industries, which affect both surface and groundwater resources. This has an adverse effect on aquatic ecosystems and human health both directly and indirectly. There are many initiatives and measures taken by central government like national water policies, revised effluent standards, establishing more common effluent treatment plants (CETPs), adopting projects like zero liquid discharge (ZLD) (reuse and recycling of entire industrial wastewater), and so on. Proper management and monitoring of these measures and policies would help in reducing surface and groundwater pollution. Hence, this chapter is focused on GPIs and their effect on water resources and the management of their discharging effluents. © 2021 John Wiley & Sons Ltd. All rights reserved.
Lignocellulosic Biomass-Derived Graphene: Fabrication, Challenges and Its Potential for Hydrogen Storage Application
(John Wiley and Sons Inc, 2024) Anjali Singh; Aman John Tudu; Basant Lal; Shafiul Haque; Bhawna Verma
This review explores the utilization of lignocellulosic biomass (LCB) waste in the fabrication of graphene and its applications in hydrogen storage. Several LCB wastes, such as rice straws, coconut shells, wheat straws, and sugarcane bagasse, along with the methodology used and the characteristics of the final graphene, have been discussed in detail. It was found that the coconut shells produced crumpled multilayered graphene, rice husks (RHs) provided a mix of graphene layers and amorphous carbon, wheat straw yielded few-layered graphene, and sugarcane bagasse contributed to different graphene-like materials. This review has also focused on the various synthesis processes, such as carbonization, hydrothermal carbonization (HTC), chemical activation, pyrolysis, chemical vapor deposition (CVD), and Hummers' method for graphene fabrication from LCB waste, along with their advantages and disadvantages, for a better understanding. Various results have been discussed exploring the use of lignocellulosic biomass-derived graphene (LCB-G) and its various modified forms for hydrogen storage applications. Various challenges in graphene fabrication from LCB, such as low yield, product quality, scalability, use of expensive synthesis methods, and toxic chemicals, along with some potential solutions, have been mentioned. Finally, the review concludes with insights into the future of LCB-G and its role in hydrogen storage while identifying some gaps, such as scalability and product quality, for further research and development. © 2024 John Wiley & Sons Ltd.
Nanowires for Flexible Electrochemical Energy Devices
(CRC Press, 2023) Tapas Das; Sanjeev Verma; Vikas Kumar Pandey; Bhawna Verma
The demand for flexible electronics devices has been increasing due to their excessive use in implantable medical equipment, artificial skins, roll-up displays, and wearable devices. Huge specific energy and specific power flexible energy storage backup systems are required to operate the flexible devices. Nanowire is such a type of one-dimensional material, which can provide flexibility and mechanical stability to an energy storage device. Nanowires provide direct pathways to current flow, resulting in facilitation of electron movement more than other structures. The large specific surface area of nanowires enhances the contact area between electrode-electrolyte and as a result, the specific capacitance, energy, and power energy storage device increases. This chapter covers the use of nanowires in flexible energy storage devices, like supercapacitors, lithium-ion, sodium-ion, metal-air batteries, etc. Different types of carbon, polymer, organic, inorganic, and composite nanowires have been discussed briefly. Finally, the existing issues along with the current outlook have been addressed in this chapter. © 2023 selection and editorial matter, Ram K. Gupta.
Nanowires for Supercapacitors
(CRC Press, 2023) Sanjeev Verma; Shivani Verma; Saurabh Kumar; Bhawna Verma
Nanomaterials have various preferable properties for supercapacitor applications because of their nanosize, which is different from other sizes such as micron sizes and bulky behavior. Nanowires are one-dimensional (1D) materials, in which atoms grew in 1D only. 1D inherent morphologies of nanowires give a quick path for effective ion movement. Their high length/diameter ratio, large surface area, ease of electrode-electrolyte interaction, and easy adsorption of ions pay much attention to supercapacitor materials. In this chapter, we discuss the various synthesis approaches with current prospects of research in the field of nanowire-based supercapacitor electrode materials. It includes electric double layer capacitance (EDLC), pseudocapacitance, and hybrid-type nanowire materials in the supercapacitor field. And we also discuss symmetric and asymmetric nanowire systems. Furthermore, the advantages and disadvantages of nanowire-based materials in supercapacitors are also addressed. Finally, we examine the prime areas in research and development for commercializing nanowire-based supercapacitors. © 2023 selection and editorial matter, Ram K. Gupta.
Pseudocapacitive Materials-Based Metal-Air Batteries
(Springer Science and Business Media Deutschland GmbH, 2024) Sanjeev Verma; Vikas Kumar Pandey; Ram K. Gupta; Shivani Verma; Bhawna Verma
Researchers’ attraction has been sparked by the fabrication of green and renewable energy-storage innovations in view of the increasing hurdle around the needs of energy and environmental concerns. MABs (Metal-air batteries), mainly rechargeable MABs, are seen as a viable energy storage/conversion solution because of their high energy density and specific power, lower price, as well as its safety. Moreover, the fabrication of MABs is significantly hindered by their lower rate ability, corrosion, and dendrite formation between the electrochemical actions, less active material synthesis strategies expansion, slower oxygen reaction kinetics at cathode surface, electrolyte and electrode refinement, and a proper separator selection. This chapter goes into great detail to help readers understand many types of MABs, the fundamentals of electrode reactions and battery configurations, the function of electrode active materials, separators, and electrolytes, as well as future scenarios. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.