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Sunkara V. Manorama

Bio: Sunkara V. Manorama is an academic researcher from Indian Institute of Chemical Technology. The author has contributed to research in topics: Nanocrystalline material & Nanoparticle. The author has an hindex of 37, co-authored 103 publications receiving 5294 citations. Previous affiliations of Sunkara V. Manorama include Centre for Cellular and Molecular Biology & Council of Scientific and Industrial Research.


Papers
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TL;DR: In this article, X-ray diffraction and transmission electron microscopy were used to characterize the structural properties of anatase nano-drone nano-dioxide and showed a blue shift in the absorption edge of the diffuse reflectance ultraviolet spectrum.

788 citations

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TL;DR: In this article, high crystalline zinc oxide (ZnO) nanoparticles have been synthesized by hydrothermal route at 120°C over a range of different time periods, and the synthesized nanoparticles are characterized for their phase and morphology by X-ray diffraction and transmission electron microscopy (TEM).
Abstract: Highly crystalline zinc oxide (ZnO) nanoparticles have been synthesized by hydrothermal route at 120 °C over a range of different time periods. The synthesized nanoparticles are characterized for their phase and morphology by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermogravimetric-differential thermal analysis (TG-DTA) follows the thermal changes accompanying the heat treatment and ultra-violet diffuse reflectance spectroscopic studies (UV-DRS) give a measure of the optical properties. Electrical properties of the synthesized nanoparticles are studied by AC impedance and DC conductivity measurement. The gas sensing properties were studied towards reducing gases like liquefied petroleum gas (LPG), ammonia, hydrogen, ethanol (EtOH), etc., and it is observed that the nanoparticles show high sensitivity to LPG and ethanol at relatively low operating temperatures. Pd incorporation results in a decrease in operating temperature by more than 100 °C, and improves the sensing characteristics in terms of response and recovery times.

281 citations

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TL;DR: Nickel ferrite, a p-type semiconducting oxide with an inverse spinel structure, has been used as a gas sensor to selectively detect chlorine in air as mentioned in this paper.
Abstract: Nickel ferrite, a p-type semiconducting oxide with an inverse spinel structure has been used as a gas sensor to selectively detect chlorine in air. This compound was prepared by two different routes namely, the citrate and co-precipitation method and sensor properties of the resulting compounds from both the methods were compared. X-ray diffraction was used to confirm the structure. The gas sensing characteristics were obtained by measuring the sensitivity as a function of various controlling factors like dopant, concentration of the dopant, operating temperature, concentration of the gas and finally the response time. The sensitivity to chlorine has been compared with that of other interfering gases. A probable explanation has been proposed to explain the selective sensitivity to oxidising gases like chlorine.

222 citations

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TL;DR: In this paper, an n-type semiconducting oxide material with cubic spinel (AB2O4) structure has been synthesized by the hydrothermal process with an average crystallite size of ∼11nm and surface area of 94m2g−1 and characterized by X-ray diffraction (XRD), thermogravimetric analysis, scanning electron microscopy (SEM) and transmission electron microscope (TEM), and Brunner-Emmett-Teller surface analyzer.

216 citations

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TL;DR: A facile route for Pd(0) immobilization on the surface of amine-terminated Fe3O4 and NiFe2O4 nanoparticles for a series of hydrogenation reactions is reported.

208 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, photo-induced superhydrophilicity was used on the surface of a wide-band gap semiconductor like titanium dioxide (TiO 2 ) for photocatalytic activity towards environmentally hazardous compounds.

4,241 citations

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TL;DR: This review presents an overview of silver nanoparticles (Ag NPs) preparation by green synthesis approaches that have advantages over conventional methods involving chemical agents associated with environmental toxicity.

3,290 citations

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TL;DR: A comprehensive analysis of the reported effects of dopants on the anatase to rutile phase transformation and the mechanisms by which these effects are brought about is presented in this article, yielding a plot of the cationic radius versus the valence characterised by a distinct boundary between inhibitors and promoters.
Abstract: Titanium dioxide, TiO2, is an important photocatalytic material that exists as two main polymorphs, anatase and rutile. The presence of either or both of these phases impacts on the photocatalytic performance of the material. The present work reviews the anatase to rutile phase transformation. The synthesis and properties of anatase and rutile are examined, followed by a discussion of the thermodynamics of the phase transformation and the factors affecting its observation. A comprehensive analysis of the reported effects of dopants on the anatase to rutile phase transformation and the mechanisms by which these effects are brought about is presented in this review, yielding a plot of the cationic radius versus the valence characterised by a distinct boundary between inhibitors and promoters of the phase transformation. Further, the likely effects of dopant elements, including those for which experimental data are unavailable, on the phase transformation are deduced and presented on the basis of this analysis.

2,570 citations

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TL;DR: In this paper, the authors present a review of the current approaches for the heterogeneous photocatalytic reduction of CO2 on TiO2 and other metal oxide, oxynitride, sulfide, and phosphide semiconductors.
Abstract: Rising atmospheric levels of carbon dioxide and the depletion of fossil fuel reserves raise serious concerns about the ensuing effects on the global climate and future energy supply. Utilizing the abundant solar energy to convert CO2 into fuels such as methane or methanol could address both problems simultaneously as well as provide a convenient means of energy storage. In this Review, current approaches for the heterogeneous photocatalytic reduction of CO2 on TiO2 and other metal oxide, oxynitride, sulfide, and phosphide semiconductors are presented. Research in this field is focused primarily on the development of novel nanostructured photocatalytic materials and on the investigation of the mechanism of the process, from light absorption through charge separation and transport to CO2 reduction pathways. The measures used to quantify the efficiency of the process are also discussed in detail.

2,273 citations