Government Lahiri College

Chhattisgarh, India

Government Lahiri College

Chhattisgarh, India

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Bajpai N.,Government E R R Pg Science College | Khan S.A.,Government College Seepat | Kher R.S.,Government E R R Pg Science College | Bramhe N.,Pandit Ravishankar Shukla University | And 2 more authors.
Journal of Luminescence | Year: 2014

Nanocrystalline tin oxide (IV) doped with Eu3+ has been synthesized by sol-gel technique. The prepared SnO2:Eu3+ nanoparticles were calcined and characterized by XRD, SEM, TEM and FTIR. The XRD analysis revealed well crystallised tetragonal rutile phase. Electron microscopy showed spherical morphologies with an average size of 15-20 nm. The thermoluminescence (TL) properties of SnO2:Eu3+ nanoparticles were investigated after γ-irradiation using 60Co source at room temperature. The TL glow curve showed variation in TL peak intensity as the concentration of dopant is changed. It has been found that TL response of linear in the range 0.5-2.0 kGy. This paper discusses about the optimal doping concentration of Europium in SnO2 nanoparticles and its dosimetric application has also been studied. © 2013 Elsevier B.V.


Tiwari A.,Government Lahiri College | Khan S.A.,Government College Seepat | Kher R.S.,Government E R R Pg Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Chandel A.L.S.,Government E R R Pg Science College
Luminescence | Year: 2016

Nanostructured polymer-semiconductor hybrid materials such as ZnS-poly(vinyl alcohol) (ZnS-PVA), ZnS-starch and ZnS-hydroxypropylmethyl cellulose (Zns-HPMC) are synthesized by a facile aqueous route. The obtained nanocomposites are characterized using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV/vis spectroscopy and photoluminescence (PL). XRD studies confirm the zinc blende phase of the nanocomposites and indicate the high purity of the samples. SEM studies indicate small nanoparticles clinging to the surface of a bigger particle. The Energy Dispersive Analysis by X-rays (EDAX) spectrum reveals that the elemental composition of the nanocomposites consists primarily of Zn:S. FTIR studies indicate that the polymer matrix is closely associated with ZnS nanoparticles. The large number of hydroxyl groups in the polymer matrix facilitates the complexation of metal ions. The absorption spectra of the specimens show a blue shift in the absorption edge. The spectrum reveals an absorption edge at 320, 310 and 325 nm, respectively. PL of nanocomposites shows broad peaks in the violet-blue region (420-450 nm). The emission intensity changes with the nature of capping agent. The PL intensity of ZnS-HPMC nanocomposites is found to be highest among the studied nanocomposites. The results clearly indicate that hydroxyl-functionalized HPMC is much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with PVA and starch. Copyright © 2015 John Wiley & Sons, Ltd.


Kurrey M.S.,Government Engineering College | Tiwari A.,Government Lahiri College | Khokhar M.S.K.,Guru Ghasidas University | Kher R.S.,Government Err Pg Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Journal of Luminescence | Year: 2015

Nanocrystalline YAG doped with Eu3+ and Nd3+ has been synthesized by a sol-gel technique. The prepared nanophosphors were calcined and characterized by XRD, SEM. The XRD analysis revealed well-defined cubic phase. Electron microscopy showed spherical morphologies with an average size of 15-20 nm. The thermoluminescence (TL) properties of as prepared nanophosphors were investigated after γ-irradiation using 60Co source at room temperature. It has been found that there is a prominent TL glow peak at 290-295 °C for the as prepared doped samples. The TL glow curve showed variation in TL peak intensity as the concentration of dopant is changed. Kinetic data and trap depth for the synthesized samples were calculated by a peak shape method. It has been found that TL response is nonlinear in the range 0.29-1.16 kGy. This paper discusses about the optimal doping concentration of Eu and Nd in YAG nanophosphors. © 2015 Elsevier B.V. All rights reserved.


Bajpai N.,Government E R R Pg Science College | Tiwari A.,Government Lahiri College | Khan S.A.,Government College Seepat | Kher R.S.,Government E R R Pg Science College | And 2 more authors.
Luminescence | Year: 2014

Highly pure SiO2 and SiO2:RE nanoparticles were synthesized by the sol-gel method. The morphological, structural and optical properties of the nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD results indicate that all the samples studied were free from impurities. SEM/TEM results indicate that the samples were well dispersed. Surface characterization of the nanocrystals by Fourier transform infrared spectroscopy has been carried out and the structure of surface-bound SiO2 based on spectral analysis is proposed. Thermoluminescence (TL) characteristics were investigated to study the influence of rare earth dopants (Tb, Ce, Eu, Dy) on SiO2 matrix subjected to 0.5 kG (1 h) γ-irradiation. Among these rare earth elements, Eu3+ was found to be the most efficient dopant for SiO2 showing maximum thermoluminescence intensity. SiO2:Eu0.5 seems to be a promising candidate for use as a TL dosimeter. Copyright © 2013 John Wiley & Sons, Ltd.


Tiwari A.,Government Lahiri College | Khan S.A.,Government College Seepat | Kher R.S.,Government E R R Pg Science College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
Luminescence | Year: 2014

ZnS nanoparticles stabilized by a carbohydrate-based matrix, hypromellose (hydroxypropyl methylcellulose) were prepared via a wet chemical method. The nanocomposite was characterized by X-ray diffraction, transmission electon microscopy and Fourier transform infrared spectroscopy. X-Ray diffraction patterns revealed a zinc blende structure. Thermogravimetric analysis suggested that polymer attached to the surface decomposes at 700°C. Absorption measurements were carried out and calculation of the diameter polydispersity index (DPI) suggests the formation of monodisperse nanoparticles. The optical properties of the as-prepared samples were studied by UV/vis spectroscopy and steady-state photoluminescence (PL) spectroscopy. The PL studies indicate the applicability of these nanoparticles as biocompatible sensors or luminescence markers in future. Copyright © 2013 John Wiley & Sons, Ltd.


PubMed | Government E R R Pg Science College, Government Lahiri College, Government College Seepat and Rashtrasant Tukadoji Maharaj Nagpur University
Type: Journal Article | Journal: Luminescence : the journal of biological and chemical luminescence | Year: 2016

Nanostructured polymer-semiconductor hybrid materials such as ZnS-poly(vinyl alcohol) (ZnS-PVA), ZnS-starch and ZnS-hydroxypropylmethyl cellulose (Zns-HPMC) are synthesized by a facile aqueous route. The obtained nanocomposites are characterized using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV/vis spectroscopy and photoluminescence (PL). XRD studies confirm the zinc blende phase of the nanocomposites and indicate the high purity of the samples. SEM studies indicate small nanoparticles clinging to the surface of a bigger particle. The Energy Dispersive Analysis by X-rays (EDAX) spectrum reveals that the elemental composition of the nanocomposites consists primarily of Zn:S. FTIR studies indicate that the polymer matrix is closely associated with ZnS nanoparticles. The large number of hydroxyl groups in the polymer matrix facilitates the complexation of metal ions. The absorption spectra of the specimens show a blue shift in the absorption edge. The spectrum reveals an absorption edge at 320, 310 and 325nm, respectively. PL of nanocomposites shows broad peaks in the violet-blue region (420-450nm). The emission intensity changes with the nature of capping agent. The PL intensity of ZnS-HPMC nanocomposites is found to be highest among the studied nanocomposites. The results clearly indicate that hydroxyl-functionalized HPMC is much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with PVA and starch.


Tiwari A.,Government Lahiri College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Kher R.S.,Government E R R Science Pg College
Luminescence | Year: 2015

Mercaptoethanol (ME), mercaptopropionic acid (MPA) and L-cysteine (L-Cys) having -SH functional groups were used as surface passivating agents for the wet chemical synthesis of ZnS nanoparticles. The effect of the thiol group on the optical and photoluminescence (PL) properties of ZnS nanoparticles was studied. L-Cysteine-capped ZnS nanoparticles showed the highest PL intensity among the studied capping agents, with a PL emission peak at 455 nm. The PL intensity was found to be dependent on the concentration of Zn2+ and S2- precursors. The effect of buffer on the PL intensity of L-Cys-capped ZnS nanoparticles was also studied. UV/Vis spectra showed blue shifting of the absorption edge. © 2015 John Wiley & Sons, Ltd.


PubMed | Government Lahiri College, Rashtrasant Tukadoji Maharaj Nagpur University and Government E R R Science Pg College
Type: Journal Article | Journal: Luminescence : the journal of biological and chemical luminescence | Year: 2015

Mercaptoethanol (ME), mercaptopropionic acid (MPA) and L-cysteine (L-Cys) having -SH functional groups were used as surface passivating agents for the wet chemical synthesis of ZnS nanoparticles. The effect of the thiol group on the optical and photoluminescence (PL) properties of ZnS nanoparticles was studied. L-Cysteine-capped ZnS nanoparticles showed the highest PL intensity among the studied capping agents, with a PL emission peak at 455 nm. The PL intensity was found to be dependent on the concentration of Zn(2+) and S(2-) precursors. The effect of buffer on the PL intensity of L-Cys-capped ZnS nanoparticles was also studied. UV/Vis spectra showed blue shifting of the absorption edge.


Tiwari A.,Government Lahiri College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
RSC Advances | Year: 2016

ZnS has been one of the most investigated II-IV semiconductor materials, known for very interesting optoelectronic properties and its versatile applications in various fields. The transition from bulk to nano regime has brought forth some drastic changes in the optical properties of ZnS. In this review article, we have comprehensively discussed the surface passivation of ZnS nanoparticles by various polymeric ligands/matrix. Systematic investigation has been reported for state of the art synthesis and novel strategies for fabrication of ZnS nanocomposites have been discussed. A brief account of the pioneer works for ZnS has been described and their fundamental properties have been discussed. The characterization techniques in understanding the formation and stabilization of ZnS nanocomposites are highlighted. The article primarily focuses on the main features, synthesis techniques, and optical properties of polymer based ZnS nanocomposites. We have tried to cover recent application and developments in field of polymer based ZnS nanocomposites in biosensing, cell tagging, optoelectronic devices, heterogeneous catalysis, photocatalytic application etc. Overall this article provides an insight to optimize the synthetic routes and condition for better utilization of ZnS nanocomposites and provide an outlook to expand these applications to other areas, such as drug delivery, labeling, tracking agents, bioanalytical sensors, fluorescent probes, optics, information storage, and optoelectronics. © 2016 The Royal Society of Chemistry.


PubMed | Government Lahiri College
Type: Journal Article | Journal: Luminescence : the journal of biological and chemical luminescence | Year: 2014

ZnS nanoparticles stabilized by a carbohydrate-based matrix, hypromellose (hydroxypropyl methylcellulose) were prepared via a wet chemical method. The nanocomposite was characterized by X-ray diffraction, transmission electon microscopy and Fourier transform infrared spectroscopy. X-Ray diffraction patterns revealed a zinc blende structure. Thermogravimetric analysis suggested that polymer attached to the surface decomposes at 700C. Absorption measurements were carried out and calculation of the diameter polydispersity index (DPI) suggests the formation of monodisperse nanoparticles. The optical properties of the as-prepared samples were studied by UV/vis spectroscopy and steady-state photoluminescence (PL) spectroscopy. The PL studies indicate the applicability of these nanoparticles as biocompatible sensors or luminescence markers in future.

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