BHU Institutional Repository :: Browsing by Author "Sonkar, Piyush Kumar"

Browsing by Author "Sonkar, Piyush Kumar"

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Carbon nanotubes-based electrochemical sensors for environmentally hazardous chemicals
(Apple Academic Press, 2022) Sonkar, Piyush Kumar; Narvadeshwar, X.
The environmental pollution of air, water, and natural resources has been increasing rapidly due to extensive industrialization and urbanization. The increasing level of pollution in the environment is the major global concern. It increases due to excessive use of pesticides, toxic wastes, synthetic fertilizers, biological warfare agents, etc. Monitoring of these pollutants is essential for sustainability of the environment. Electrochemical method is one of the important tools to determine the level of these toxic chemicals. Carbon nanotubes (CNTs)-based modified electrodes may play an essential role to monitor these environmental pollutants. By taking the advantages of extraordinary CNTs' physicochemical and electrocatalytic properties, a large number of electrochemical sensing platforms have been studied for sensing environmental pollutants. The detailed description of CNTs-based electrochemical sensors of different pollutants, such as heavy metals, pesticides, chemical fertilizers, food contaminants, microbial pollutants, etc. have been discussed in this chapter. Thus, this chapter provides a comprehensive overview of the recent development of CNTs-based modified electrodes for electrochemical sensing of environmentally hazardous chemicals and their future prospects. � 2023 by Apple Academic Press, Inc. All rights reserved.
Characteristics of carbon nanotubes and their nanocomposites
(Elsevier, 2021) Sonkar, Piyush Kumar; Narvdeshwar; Gupta, Pawan Kumar
Carbon nanotubes (CNTs) are one of the most significant allotropes of carbon. They are made of sp2-hybridized carbon with a hollow cylindrical tube structure. Based on the number of concentric cylinders, they may be single-walled CNTs, double-walled CNTs, or multiwalled CNTs. Based on their configuration, CNTs are of three types: chiral, zigzag, and armchair. CNTs have outstanding physical properties such as high tensile strength, high electrical conductivity, and thermal, chemical, and mechanical stability. These physical properties can be increased by the functionalization and formation of composite materials. Large numbers of CNT composites have been documented in the literature with a wide range of applications. CNTs and their composite materials can be analyzed using different microscopic techniques such as scanning electron microscopy, atomic force microscopy, transmission electron microscopy with energy-dispersive X-ray analysis (EDAX), and EDAX mapping. In addition, Raman spectroscopy is one of the most powerful tools for characterizing CNTs and their composite materials. CNTs and their composite materials have a wide range of applications in the fields of composite materials, nanoelectronics, drug delivery, pharmaceuticals, electrocatalysis, sensing, fuel cells, supercapacitors, hydrogen storage, water purification, and so on. Without doubt, CNTs and their composite materials have outstanding properties with significant applications in almost every branch of science and technology. � 2021 Elsevier Inc. All rights reserved.
Mesoporous carbon nitride supported 5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphine cobalt(ii) as a selective and durable electrocatalyst for the production of hydrogen peroxideviatwo-electron oxygen reduction
(Royal Society of Chemistry, 2021) Singh, Devesh Kumar; Ganesan, Vellaichamy; Yadav, Dharmendra Kumar; Yadav, Mamta; Sonkar, Piyush Kumar; Gupta, Rupali
Mesoporous carbon nitride (MCN) is synthesized using a mesoporous silica material (MCM-41) as a sacrificial template. 5,10,15,20-Tetrakis(4-methoxyphenyl)-21H,23H-porphine cobalt(ii) (cobalt tetramethoxyphenylporphyrin, CoTMPP), which consists of methoxy groups as the electron-rich center is integrated with MCN and the resulting composite material (CoTMPP@MCN) without any further heat treatment is used for the electrocatalytic reduction of oxygen. CoTMPP@MCN shows a higher onset potential (0.65 and 0.84 V, respectively, in 0.1 M HClO4and 0.1 M KOH) for the oxygen reduction reaction (ORR) than the bare MCN (0.34 and 0.60 V, respectively, in 0.1 M HClO4and 0.1 M KOH). The ORR onset potential exhibited by CoTMPP@MCN is comparable to several non-pyrolyzed mono-nuclear metal porphyrin integrated on carbon-based supports in both acidic and basic media. Kinetic measurements of CoTMPP@MCN show high selectivity for two-electron oxygen reduction to H2O2in both media. The H2O2yield in terms of faradaic efficiency is measured to be 87.6 and 89.0%, respectively, in 0.1 M HClO4and 0.1 M KOH. CoTMPP@MCN exhibits amazingly high durability (minute changes in the onset potential and current density at high reduction potentials after 3000 CV cycles) facilitated by the surface coordination of CoTMPP through the nitrogen present on the MCN surface. Being highly selective and outstandingly durable, CoTMPP@MCN fulfills all necessary requirements for an economically efficient electrocatalyst for industrial hydrogen peroxide synthesis and related commercial applications. � The Royal Society of Chemistry 2020.
Metal oxide-carbon nanotubes nanocomposite-modified electrochemical sensors for toxic chemicals
(Elsevier, 2021) Sonkar, Piyush Kumar; Ganesan, Vellaichamy
Nanocomposites based on metal oxides (MOs) have attracted the attention of researchers worldwide due to their significant properties such as high active surface area, high porosity, and electrical conductivity. On the other hand, carbon nanotubes (CNTs) are important materials due to their high surface area, ease of functionalization, and high electrical communication. Nanocomposites-based MOs and CNTs (MOs-CNTs) act synergistically to increase electrochemical activity for the sensing of toxic chemicals. Electrochemical sensor-based MOs-CNTs composites are widely used for the determination of chemical processes, air�water impurities, and toxic ingredients in the environment. A number of MOs-CNTs nanocomposites have been reported for electrochemical sensing such as nickel oxide nanoparticles-decorated CNTs nanocomposites for 4-aminophenol chemical sensors, multiwalled CNTs NiO nanoparticles composites as enzyme-free electrochemical glucose sensors, phenolic sensor development based on chromium oxide-decorated CNTs for environmental safety, etc. Conclusively, MOs-CNTs are an excellent class of nanocomposites for the development of effective, reliable, cost-effective, and durable electrochemical sensors for toxic chemicals significant for environmental, biological, pathological, and pharmaceutical samples. � 2021 Elsevier Inc. All rights reserved.
Nanomaterials for Sustainable Energy Applications
(CRC Press, 2023) Sonkar, Piyush Kumar; Ganesan, Vellaichamy
This book provides a detailed overview of different devices and nanomaterials for energy storage applications. The application of each nanomaterial is discussed for fuel cells, metal�air batteries, supercapacitors, solar cells, regenerative fuel cells, hydrogen energy, batteries, and redox flow batteries to understand the reaction process and material performance improvement for energy storage devices. In addition, major challenges, case studies, historical, and future perspective are summarized. Features: Summarizes state-of-the-art nanomaterials for energy storage and conversion applications Comprehensive coverage of a wide range of nanomaterials, including synthesis and characterization Details different energy storage devices, construction, working principles, and major challenges Covers specific reactions, nanomaterials, and nanocomposites via audio-video slides/short films Includes case studies pertaining to development of energy storage devices and major challenges This book is aimed at researchers and graduate students in chemical engineering, chemical sciences, nanomaterials, and energy engineering/conversion. � 2024 selection and editorial matter, Piyush Kumar Sonkar and Vellaichamy Ganesan; individual chapters, the contributors.
One step synthesis of a bimetallic (Ni and Co) metal-organic framework for the efficient electrocatalytic oxidation of water and hydrazine
(Royal Society of Chemistry, 2022) Singh, Smita; Yadav, Mamta; Singh, Devesh Kumar; Yadav, Dharmendra Kumar; Sonkar, Piyush Kumar; Ganesan, Vellaichamy
A series of metal-organic frameworks (MOFs) with varying Ni : Co ratios are synthesized by an easy one-step solvothermal method using trimesic acid as an organic linker. Physicochemical characterization of the synthesized MOFs was done by high-resolution transmission electron microscopy, energy dispersive X-Ray, powder X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis, which depicts that the monometallic and bimetallic MOFs have a similar crystal structure. Among the synthesized MOFs, NiCo-MOF (1 : 1) (where the 1 : 1 ratio indicates Ni : Co ratio) exhibits efficient bifunctional electrocatalytic properties, i.e. it electrocatalytically oxidizes water and hydrazine (HZ). Electrocatalytic water oxidation leading to oxygen evolution can be exploited in the production of green hydrogen. NiCo-MOF (1 : 1) exhibits a low overpotential of 330 mV at a current density of 10 mA cm?2, a low Tafel slope of 32 mV dec?1, and high stability for water oxidation. Electrocatalytic oxidation of HZ leads to its sensitive amperometric determination in real samples. For the electrochemical detection of HZ, NiCo-MOF (1 : 1) displays a low limit of detection (1.1 ?M), broad linear range (1-2000 ?M) and high selectivity and stability. Thus, the present results demonstrate a new scheme to fabricate an economical and high-performance oxygen evolution catalyst and HZ sensor. � 2022 The Royal Society of Chemistry.
Phenosafranine encapsulated mesoporous silica as efficient electrocatalyst for Cr(VI) reduction and its subsequent sensitive determination
(Elsevier Inc., 2023) Gupta, Rupali; Ganesan, Vellaichamy; Sonkar, Piyush Kumar; Yadav, Dharmendra Kumar; Yadav, Mamta
This work presents an easy, highly specific, and sensitive route for the electrochemical reduction of Cr(VI) by phenosafranine (PSF+) integrated sulfonic acid functionalized mesoporous silica microspheres (MS-SO3?), denoted as PSF+-MS-SO3?. The synthesized material is characterized using various spectroscopic and microscopic methods. The glassy carbon electrode (GCE) is modified with this material (represented as GCE/PSF+-MS-SO3?) and employed for electroanalytical applications. The electrochemical characteristics of PSF+-MS-SO3? are established by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. Further, it is exploited for the electrocatalytic reduction of, Cr(VI). Superior electron transfer kinetics and stable electrochemical response for Cr(VI) are observed at the GCE/PSF+-MS-SO3? electrode. Moreover, the quantitative estimation of Cr(VI) at the GCE/PSF+-MS-SO3? done using linear sweep voltammetry (LSV). Dual linear calibration ranges (1 to 20 �M and 20 to 100 �M) is obtained from the LSV response. A low limit of detection (0.5 �M) and superior sensitivity (1.1 �A �M?1 cm?2) are recognized at this electrode. In addition, significant selectivity in the existence of other interfering ions is also shown by fabricated sensing scaffold. The precise measurement of Cr(VI) in spiked water samples with simple matrix is also demonstrated successfully with sufficient durability and reproducibility. � 2023 Elsevier B.V.
Sensing of mercury ion using light induced aqueous leaf extract mediated green synthesized silver nanoparticles of Cestrum nocturnum L
(Springer Science and Business Media Deutschland GmbH, 2022) Kumar, Pradeep; Sonkar, Piyush Kumar; Tiwari, Kavindra Nath; Singh, Amit Kumar; Mishra, Sunil Kumar; Dixit, Jyoti; Ganesan, Vellaichamy; Singh, Jasmeet
In this study, a simple, one-pot, and eco-friendly biosynthesis of silver nanoparticles (AgNPs) was accomplished with the use of aqueous leaves extract of�Cestrum nocturnum L.(AECN). Different techniques like ultraviolet�visible (UV�Vis) spectrophotometry, Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning area electron diffraction were used to investigate the optical, operational, and physical properties of the green synthesized AECN-AgNPs.The AECN-AgNPs were further used for the detection of Hg2+ by UV�Vis and electrochemical methods. The disintegration of the AECN-AgNPs solution caused the formation of an Ag-Hg amalgam, which caused discoloration of the solution. Sensing performance for a variety of metals such as Na+, K+, Mg2+, Ca2+, Ni2+, Cu 2+, Fe3+, Zn2+, Co2+, Cd2+, Pb2+, As3+, and Mn2+ at 10-mM concentrations was measured in order to determine the selectivity of the sensor towards the Hg2+. For the electrochemical determination of 2 +�Hg2+ , AECN-AgNPs were immobilized on a glassy carbon (GC) electrode, and the resulting modified electrode (GC/AECN-AgNPs) was characterized by cyclic voltammetry. This phenomenon is advantageously used for the sensitive determination of trace level Hg2+. GC/AECN-AgNPs demonstrated a linear calibration range of 100�nM to 10�?M and a limit of detection of 21�nM for Hg2+ determination. � 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Signal generation in MIP sensors
(Elsevier, 2023) Sonkar, Piyush Kumar; Jaiswal, Amit; Kumar, Ranjeet; Maurya, Angesh Kumar; Narvadeshwar; Verma, Amit Kumar
Signal generation from the sensors is based on three compartments: a reactor, a transducer, and a detector. Transducers mediate the signals generated from the reactor to detectors. It plays a crucial role in sensing devices. The use of molecularly imprinted polymers (MIPs) in sensor development is increasing due to their high selectivity and sensitivity. The most difficult aspect is creating MIP sensors with the right transducers to provide measurable signals. The fundamentals of signal creation, their improvement to reduce noise levels, and other challenges associated with signals when converting to detectors will all be covered in this chapter. This chapter's conclusion will also maintain a futuristic perspective. � 2023 Elsevier Inc. All rights reserved.
Ultrafast detection of ammonia at room temperature and subsequent electrochemical water splitting via the ionic liquid templated nano nickel oxide
(Elsevier Ltd, 2022) Joy, Miji E.; Sah, Neeraj Kumar; Phukan, Shankab Jyoti; Ganesan, Vellaichamy; Roy, Manas; Sonkar, Piyush Kumar; Garai, Somenath; Sankaranarayanan, Kamatchi
In this work, biopolymers like chitosan and Bovine Serum Albumin (BSA) templated and ionic liquid (IL)-driven synthesis of crystalline NiO nanoparticles for ultrafast room temperature detection of ammonia together with its semi-empirical mechanistic details are reported. The XRD results have revealed the crystalline nature of synthesized NiO nanoparticles; the contact angle measurements for the adhesive nature of the NiO nanoparticles have been carried out and the films have been subjected to gas sensing studies by chemo-resistive method. The as-prepared BSA templated ionic liquid driven NiO based thin film sensor displays an ultrafast response for the room temperature detection of ammonia with an excellent response and recovery times of 38 and 13 s, respectively, towards a lower detection limit up to 1 ppm. The ultrafast sensing mechanism of the ammonia has been deduced with the aid of X-ray Photoelectron Spectroscopy (XPS) analysis. Furthermore, as-synthesized BSA/BSA-IL templated NiO electrodes have displayed excellent electrocatalytic water oxidation in alkaline media, with a collective water-splitting stable current density of 10 mA?cm?2. We have observed the HOMO-LUMO gap and the Valence Band/Conduction Band (VB/CB) position from the Bredas method calculations which clarifies the highest aptitude of NiO prepared with BSA-IL template for superfast ammonia gas sensing as the CB energy is significantly lower than that of NiO synthesized via the BSA template. The dual approach of multifarious applications for the ultrafast ammonia sensing and the corresponding electrochemical water oxidation through the bio-inspired NiO-nanoparticles is in fact one of the novel applications being cited in this paper. The results highlight the grave implications of as-synthesized NiO-nanoparticles as a brilliant cost-effective gas sensor and as an effective alternative electrode for sustainable energy harvesting. � 2022 Elsevier B.V.

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