Browsing by Author "B.C. Yadav"

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Comparative study on humidity sensing abilities of synthesized mono and poly rhodium acryl amide tin oxide (RhAAm/SnO2) nanocomposites
(Elsevier B.V., 2021) Lava Kumar Gupta; Kuldeep Kumar; B.C. Yadav; T.P. Yadav; G.I. Dzhardimalieva; I.E. Uflyand; Shripal
The present work details the comparative study on humidity detection abilities of the Rhodium Acrylamide SnO2 (RhAAm/SnO2) and frontal polymerized RhAAm/SnO2 nanocomposites. The synthesized monomer and polymer were characterized with Scanning electron microscopy, Energy dispersive X-ray analysis, Particle size analyzer, X-ray diffraction, Fourier transform infra-red and UV–vis spectroscopies for the surface morphological studies, elemental mapping, analysis of particle size, structural analysis, vibrations stretching present among the constituent elements and optical energy band gap respectively. The porous structures were observed along with the presence of the Rh and SnO2 metal nanoparticles in the monomer and polymer. The minimum particle sizes were found to be 74 and 50 nm for monomer and polymer respectively which were observed by the dynamic light scattering technique. BET surface area analysis presents that the synthesized materials are a combination of micro and mesoporous materials. However, the Debye-Scherrer formula confirms that the average crystallite size of the monomer and polymer nanocomposites are 60 and 17 nm respectively. FTIR analysis suggests the presence of acrylamide. The hygrometric detection properties were studied for both materials. Better sensitivity, good repeatability along with low response and recovery time for the synthesized monomer as compared with the polymer-based humidity sensor were found. © 2021 Elsevier B.V.
Fabrication and characterization of nanostructured indium tin oxide film and its application as humidity and gas sensors
(Springer New York LLC, 2016) B.C. Yadav; Kaushlendra Agrahari; Satyendra Singh; T.P. Yadav
This paper reports the synthesis and characterization of nanocrystalline indium tin oxide (ITO) and its application as humidity and gas sensors. The structure and crystallite size of the synthesized powder were determined by X-ray diffraction. The minimum crystallite size was found 5 nm by Debye–Scherrer equation and confirmed by transmission electron microscopy image. Optical characterizations of ITO were studied using UV–visible absorption spectroscopy and Fourier transforms infrared spectroscopy. Thermal analysis was carried out by differential scanning calorimetry. Further, the ITO thin film was fabricated using sol–gel spin coating method. The surface morphology of the fabricated film was investigated using scanning electron microscopy images. For the study of humidity sensing, the thin film of ITO was exposed with humidity in a controlled humidity chamber. The variations in resistance of the film with relative humidity were observed. The average sensitivity of the humidity sensor was found 0.70 MΩ/%RH. In addition, we have also investigated the carbon dioxide (CO2) and liquefied petroleum gas sensing behaviour of the fabricated film. Maximum sensitivity of the film was ~17 towards CO2. Its response and recovery times were ~5 and 7 min respectively. Sensor based on CO2 is 97 % reproducible after 3 months of its fabrication. Better sensitivity, small response time and good reproducibility recognized that the fabricated sensor is challenging for the detection of carbon dioxide. © 2016, Springer Science+Business Media New York.
Structural analysis of nanostructured iron antimonate by experimental and quantum chemical simulation and its LPG sensing
(2014) Satyendra Singh; Vineet Gupta; B.C. Yadav; Poonam Tandon; Akhilesh Kumar Singh
In this paper structural, electrical, magnetic as well as liquefied petroleum gas (LPG) sensing properties of the synthesized ultrafine iron antimony oxide along with quantum chemical simulation have been reported. A detailed study of the structural analysis is presented including a thorough Raman spectroscopy and infra-red investigations. A detailed vibrational analysis of iron antimony oxide was performed by ab-initio Hartree-Fock (HF) and density functional theory (DFT) employing B3LYP exchange correlation functional with LanL2DZ and 6-311++G(d,p) basis sets. The observed spectral patterns were compared and assigned with fundamental vibrational frequencies showing an overall excellent agreement. X-ray diffraction along with Rietveld analysis was used to confirm the crystal structure, space group and crystallite size. The estimated value of minimum crystallite size was found 2 nm and confirmed by Rietveld and Vibrational spectral analysis. Scanning electron microscopy, Elemental mapping and Energy dispersive X-ray analysis were applied for surface morphology, elemental distributions and compositions of the material, respectively. The synthesized nanoparticles were used for the processing of gas-sensing device and the outstanding gas-sensing properties are accessible, proving the effectiveness of the whole process in advancing toward a new generation of gas-sensor. © 2014 Elsevier B.V.
Synthesis, Characterization of Nickel Ferrite and Its Uses as Humidity and LPG Sensors
(Springer New York LLC, 2016) Richa Srivastava; B.C. Yadav; Monika Singh; T.P. Yadav
Nanostructured nickel ferrites (sample B1 and B2) were synthesized by chemical precipitation method using two different precipitating agents; sodium and ammonium hydroxides. The samples were characterized by using powder X-ray diffraction, scanning and transmission electron microscopy techniques. The X-ray diffraction revealed the formation of nickel ferrite with lattice parameter a = 8.3 Å and the average crystallite sizes of the samples B1 and B2 were 50 and 15 nm respectively. Surface morphology of the sample B2 exhibited the higher number of adsorption sites in comparison to B1. Transmissions electron microscopy observations confirmed the formation of nanostructured nickel ferrite. Further the pellets, thick and thin films of materials B1 and B2 were prepared and investigated with the exposition of humidity and LPG. Maximum average sensitivity for humidity was formed as 53.74 MΩ/%RH. Also the maximum value of sensitivity was found 62.3 for 4 vol% of LPG. The results were found to be reproducible up to 96 % after 3 months. Response and recovery times for LPG sensing were found to be 220 and 250 s. Best sensitivity, less hysteresis, small activation energy and good reproducibility identify that fabricated humidity and LPG sensors (B2) are promising and challenging. © 2016, Springer Science+Business Media New York.
Titania prepared by ball milling: Its characterization and application as liquefied petroleum gas sensor
(Taylor and Francis Inc., 2015) B.C. Yadav; Satyendra Singh; T.P. Yadav
Present article reports the liquefied petroleum gas sensing of TiO2 obtained through ballmilling. Themilled powder was characterized by XRD, TEM, and UV-visible. Further the ball-milled powder was compressed into a pellet using hydraulic press. This pellet was investigated with the exposure of LPG. Variations in resistance with exposure of LPG to the sensing pellet were recorded. The sensitivity of the sensor was ? 11 for 5 vol.% of LPG. Response and recovery times of the sensor were ∼ 100 and 250 s. The sensor was quite sensitive to LPG and results were found reproducible within ±91%. Copyright © Taylor & Francis Group, LLC.