Vijayanagara Sri Krishnadevaraya University
Bellary, India
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Tan C.,Shaanxi Normal University | Zhu G.,Shaanxi Normal University | Hojamberdiev M.,Tokyo Institute of Technology | Lokesh K.S.,Vijayanagara Sri Krishnadevaraya University | And 4 more authors.
Journal of Hazardous Materials | Year: 2014

In this study, the doping effect of samarium on the structure, morphology, adsorption and photocatalytic performance of hexagonal ZnIn2S4 microspheres was studied. The photocatalytic activity of Sm-doped ZnIn2S4 microspheres was evaluated for the photodegradation of Rhodamine B (RhB) and methyl orange (MO) under visible light irradiation. The samples were characterized by XRD, SEM, XPS, UV-vis, TEM, and N2 adsorption-desorption analysis. The results show that the hexagonal ZnIn2S4 microspheres are composed of nanoplates growing along c-axis with the predominant negative-charged S plane. Compared with the photodegadation of MO dye, the negative-charged {0001} facets not only are beneficial for the adsorption of RhB by -N(Et)2 groups but also can accumulate the separation of photogenerated electrons and holes, enhancing photodegradation efficiency by direct-hole photocatalysis. Moreover, Sm is partially substituted for In in the crystal lattice for forming the doping energy level which promotes the separation of photoinduced electron-hole pairs and enhances absorption of visible light. Hexagonal 2% Sm-doped ZnIn2S4 microspheres with exposed {0001} facets resulted in higher photodegradation efficiency of RhB under visible light irradiation. © 2014.

Channagiri L.S.,GVK Biosciences Pvt. Ltd. | Reddy V.K.R.,Vijayanagara Sri Krishnadevaraya University
Der Pharma Chemica | Year: 2015

The Gewald Reaction is a synthesis of 2-aminothiophenes via a multi-component condensation between sulfur, an α-methylene carbonyl compound and an α-cyanoester. Green chemistry encourages the design of synthetic processes that minimize the use and generation of hazardous substances. The application of microwave assisted organic synthesis to conduct Gewald reaction has been demonstrated by the microwave assisted transformation of ethylcyanoacetate, cyclohexanone, anisidines and sulphur into 2-Amino-3-o/p-anisidyl-carboxamido-4,5,6,7-tetrahydro-benzo (b) thiophenes. The transformation has been confirmed by conventional synthesis.

Lokesh K.S.,Vijayanagara Sri Krishnadevaraya University | Adriaens A.,Ghent University
Dyes and Pigments | Year: 2015

The formation of a supramolecular electropolymerized film of a polymeric palladium phthalocyanine on a glassy carbon electrode is reported here. The film was obtained by cycling monomeric palladium tetraaminephthalocyanine in dimethyl sulfoxide in the potential range -0.5 to +1.0 V. The functionalized polymerized film on the electrode was characterized using Raman spectroscopy, X-ray photoelectron spectroscopy and electrochemical methods. A polymeric phthalocyanine film was shown to form by the oxidation of peripheral amino groups. It uniformly and completely covered the electrode surface. The modified electrode surface slightly blocked the reversible redox behavior of a redox probe owing to the thick polymeric film on its surface. The modified electrode showed a redox capacitance of 146 F g-1 at 0.27 V in 0.5 M sulfuric acid. © 2014 Elsevier Ltd. All rights reserved.

Venkoba Rao B.,Delkor Technik India Private Ltd | Kumar Velan H.,Delkor Technik India Private Ltd | Gopalkrishna S.J.,Vijayanagara Sri Krishnadevaraya University
Transactions of the Indian Institute of Metals | Year: 2016

Quite often researchers record key performance indices (KPIs) such as Ecart Probable i.e., Ep and separation density, ρ50, as function of particle size, rather than describing partition surface or associated efficiency curves for various size/size-class of particles of a separator. In this paper a study on how this information can be further utilized to visualize partition surface by reverse engineering KPI values is explained. The parameter estimation scheme proposed here is quite simple and can be easily implemented using spreadsheet approach. Also shown is a variance analyses of the parameters in representing partition surface, which indicates that parameters A and B contribute much more to overall variance of partition surface than parameters c and ρp. © 2015, The Indian Institute of Metals - IIM.

Liu Q.,Shinshu University | Lokesh K.S.,Shinshu University | Lokesh K.S.,Vijayanagara Sri Krishnadevaraya University | Chauvin C.,Shinshu University | Sugimoto W.,Shinshu University
Journal of the Electrochemical Society | Year: 2014

Model electrodes consisting of ruthenium oxide nanosheets coated on freshly cleaved highly oriented pyrolytic graphite (RuO2 nanosheet/HOPG) were prepared to investigate the electrostatic interactions between RuO 2 nanosheets and electrochemically dissolved Pt ions. The RuO 2 nanosheet/HOPG model electrode was dipped into a solution containing dissolved Pt ions generated by potential cycling a Pt working electrode in sulfuric acid electrolyte. Scanning tunneling microscopy revealed preferential adsorption of Pt ions on the nanosheets as island-like deposits, while no such deposits were observed on HOPG. This shows the strong electrostatic interactions between the positively-charged Pt ions and negatively-charged nanosheet. The calculated amount of Pt ions adsorbed was 0.93 x 106 atoms (im 2, which agreed with the theoretical saturated adsorption amount of Pt ion on RuO2 nanosheet of 0.96 x 106 atoms ( m 2 . All of the Pt ions could be electrochemically reduced to Pt nanoparticles showing activity toward the oxygen reduction reaction. © 2013 The Electrochemical Society. All rights reserved.

Amshumali M.K.,Vijayanagara Sri Krishnadevaraya University | Harvey M.D.,Virginia Polytechnic Institute and State University | Yee G.T.,Virginia Polytechnic Institute and State University
Synthetic Metals | Year: 2014

Four new vanadium-based coordination polymers that exhibit high magnetic ordering temperatures (Tc) have been synthesized. Magnetic measurements show that these polymers are soft ferrimagnets. The IR shows a reduced nitrile environment in these polymers, elemental analysis reveals that the compositions of the polymers are 2:1 acceptor to vanadium ratio. An electrochemical measurement of acceptors shows a weak correlation between T c and the redox potentials. Change in the dihedral angle of an acceptor with the substitution in a specific position of the phenyl ring alters the magnetic ordering temperature in these polymers. Calculated electron affinity and Mullikan spin densities on acceptors, either in the neutral or in the anionic form, shows no relationship with the observed trend in T c. These compounds are analogues to V[TCNE]2 complexes with varying degree of solvent of coordination. © 2013 Elsevier B.V.

Amshumali M.K.,Vijayanagara Sri Krishnadevaraya University | Arancibia V.,University of Santiago de Chile | Manriquez J.M.,University of Santiago de Chile | Chavez I.,University of Santiago de Chile
Canadian Journal of Chemistry | Year: 2013

A new fused ring compound, 2,6-dibutyl-4,8-dimethyl-1,5-dihydro-s-indacene (VII) (H2L), has been synthesized from 2,5-dimethyl-1,4- dibromomethylbenzene in almost quantitative yield. Two organomtallic binuclear complexes, [CpFe-L-FeCp] (1) and the mixed-valence compound [CpFe-L-FeCp] + BF- 4 (2), have been characterized by spectroscopic and electrochemical techniques. The cyclic voltammogram of 1 exhibits a potential difference of 668 mV between two redox peaks and the UV-vis-NIR spectra of compound 2 shows an intervalance charge transfer band at 1794 nm. The information gathered by these techniques indicates that the studied binuclear complex has strong interaction between the two metal centres. © 2013 Published by NRC Research Press.

Mungalimane A.,Vijayanagara Sri Krishnadevaraya University
Bulletin of the Chemical Society of Ethiopia | Year: 2014

Efficient synthesis of novel 6-(2-bromo-2-methyl propanoyloxy)hexyl phosphonic acid, dodecane di-phosphonic acid, 6-(thiophene-3-carbonyloxy)hexyl phosphonic acid, octadecyl phosphonic acid and such other derivatives are reported here. These derivatives have a potential application as tethers to nanoparticle surfaces that can promote efficient electron transfer process in solar energy conversion. © 2014 Chemical Society of Ethiopia.

Hanumanagoud H.,Vijayanagara Sri Krishnadevaraya University | Basavaraja K.M.,Vijayanagara Sri Krishnadevaraya University
Der Pharma Chemica | Year: 2013

The reaction of 7-methoxy-benzofuran-2-carboxylic acid hydrazide (2) with acetic anhydride gave the acetyl derivative 3, which underwent cyclisation by treatment with POCl3 yielded 4, with ethylchloroformate in methanol yielded 5 and with ethylchloroformate in dry benzene followed by POCl3 cyclisation resulted into 7 via the compound 6. On the other hand, the reaction of 2 with acetyl acetone, benzoyl acetone, and ethylacetoacetate resulted into pyrazoles 8, 9 and 10 respectively. All the new heterocycles have been characterized by elemental analysis, IR, 1H-NMR and GCMS spectral data. Further, these have been screened for antimicrobial, antioxidant, analgesic, anti-inflammatory and antipyretic activities. Compounds 5 and 7 exhibited encouraging results and remaining exhibited moderate activity.

Koodlur Sannegowda L.,Vijayanagara Sri Krishnadevaraya University | Reddy K.R.V.,Vijayanagara Sri Krishnadevaraya University | Shivaprasad K.H.,Vijayanagara Sri Krishnadevaraya University
RSC Advances | Year: 2014

Uniform and monodisperse copper nanoparticles have been synthesized using a cobalt tetraamino phthalocyanine macrocyclic complex as a stabilizer in a one-step process in inert atmosphere. The resultant nanoparticles are characterized by electronic absorption spectra, infrared spectroscopy, transmission electron microscopy and X-ray diffraction. The nanoparticles possess a relatively narrow size distribution. Copper nanoparticles have an average diameter of 2 to 3 nm with a spherical shape. When the copper particles are exposed to air, nanorod like structures of copper oxide nanoparticles are formed from tiny copper nanoparticles through a process involving slow oxidation of copper nanoclusters by the Ostwald ripening process and orientation attachment phenomena. In order to compare the electrochemical activity and efficiency of phthalocyanine capped copper and copper oxide nanoparticles, electrocatalytic reduction of oxygen was carried out. The copper nanoparticles showed better electrocatalytic activity than their oxide counterparts probably due to the blocking behavior of aggregated copper oxide nanoparticles. © 2014 The Royal Society of Chemistry.

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