@article { ISI:000230375200016, title = {Synthesis of fine PbE (E = S, Se) powder from direct in situ reduction of sulphur or selenium}, journal = {Materials Chemistry and Physics}, volume = {93}, number = {1}, year = {2005}, month = {SEP}, pages = {91-94}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Lead sulphide and lead selenide have been prepared for the first time, by in situ reduction of elemental S or Se by using aqueous DMF or aqueous SFS as reducing agents and their reaction with lead acetate. The grayish-black powder has been characterized by powder XRD measurement, XPS and SEM/EDAX analysis. Powder X-ray diffraction pattern revealed that cubic PbE (E = S, Se) is formed with a little impurities of lead in case of PbSe. Slightly broader peaks in XRD measurement suggest small particles diameter in the powder. The particle size by using Scheffer{\textquoteright}s formula is found to be about 100 nm. Peaks due to free lead particles are observed in XPS and EDS (in case of PbSe) analysis and SEM analysis indicates agglomerated particles. (c) 2005 Elsevier B.V All rights reserved.

}, keywords = {Chemical synthesis, electronic materials, reduction, Semiconductor}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2005.02.025}, author = {Khanna, P. K. and Subbarao, VVVS and Wagh, M. and Jadhav, P. and Patil, K. R.} } @article { ISI:000239542900032, title = {Direct synthesis of nanocrystalline silver from the reaction between silver carboxylates and n-trioctylphosphine}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {6}, number = {7}, year = {2006}, month = {JUL}, pages = {2095-2102}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Neat n-Trioctylphosphine (TOP) has been used for the first ever time for reduction of silver nitrate and silver carboxylates (citrate, oleate, and myristate) under mild thermal reaction conditions. UV-visible absorption measurements of re-dispersible silver particles that were obtained by reduction of silver myristrate (product-IV) and silver nitrate (product-I) showed surface plasmon resonance absorption peak at 400 nm. The powder XRD pattern of fcc zero-valent silver resulted in diameters in the range of about 25-30 nm. TEM analysis showed particle diameter similar to that was observed by the XRD. FTIR spectroscopy revealed that the organics from the carboxylate group are retained by the nano-particles in case of product-IV however, presence of TOP is observed in product-I. It is found that when silver nitrate is reduced by TOP, spherical silver nano-particles with poor redispersity are formed but extended heating results in formation of long silver rods of micrometer size however, the re-dispersible nano-particles are easily formed when silver carboxylates are reduced by TOP.

}, keywords = {Chemical synthesis, Nanocrystalline, noble metal, XRD}, issn = {1533-4880}, doi = {10.1166/jnn.2006.339}, author = {Charan, Shobhit and Singh, Narendra and Khanna, P. K. and Patil, K. R.} } @article { ISI:000238050700006, title = {Synthesis of beta-Ag2Se from organo-selenium precursor and silver nitrate in DMF via simultaneous reduction of selenium and silver salt}, journal = {Materials Letters}, volume = {60}, number = {17-18}, year = {2006}, month = {AUG}, pages = {2080-2085}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Reaction of selenium powder and silver nitrate in aqueous N,N{\textquoteright}-dimethylformamide (aq. DMF) leads to formation of silver selenide. Similar reaction with cycloalkeno-1,2,3-selenadiazole an organic compound of selenium upon thermolysis, also produces silver selenide. It is believed that DMF activates selenium and reduces silver salt via in-situ generated hydrogen ion simultaneously. Slightly broadened X-ray diffraction pattern for pure beta silver selenide (beta-Ag2Se) was observed. Scanning electron microscopy (SEM) indicated that the agglomerated particles could be in the range of about 100 to 200 nm in dimension. EDAX analysis showed non-stoichiometric elemental ratio between silver and selenium. It is found that the weight percent of Ag is slightly higher than Se. However, free amorphous selenium is also detected by XPS analysis when the product is made by use of elemental selenium. Thermal analysis (TGA) revealed a small (4\%) weight loss due to the presence of organics or the solvent from the reaction medium. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, nano powder, noble metal chalcogenides, Semiconductor}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.12.079}, author = {Khanna, P. K. and Singh, N. and Charan, Shobhit and Patil, K. R.} } @article { ISI:000242469000012, title = {Unusual formation of nano-particles of CdO and Cd(OH)(2) from the reaction of dimethyl cadmium with DMF}, journal = {Materials Letters}, volume = {60}, number = {29-30}, year = {2006}, month = {DEC}, pages = {3492-3498}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

This paper presents generation of CdO and Cd(OH)(2) nano-particles from Dimethyl Cadmium in DMF. The CdO nano-particles were obtained instead of CdSe, even when the reaction was done in presence of 1,2,3-selenadiazole (the source of selenium) with Me2Cd in DMF (product-I). The direct reaction of Me2Cd in DMF also leads to formation of CdO (product-II). However, Cd(OH)(2) nano-particles were obtained when Me2Cd was refluxed in DMF for a few hours followed by reaction of H2S gas (product-III). The formation of Cd(OH)(2) was also established via decomposition Of Me2Cd:Et2O adduct (product-IV). Nano-particles of CdO and Cd(OH)(2) (product-I to product-IV) were characterized by X-ray powder diffraction (XRD), TEM and SEM/EDS measurements, FTIR, thermal analysis (TGA) and XPS analysis. The particle size of all the products as calculated by XRD patterns were in the range of about 20 nm. TEM images showed that the products are agglomerated clusters with the particles in the nano-meter regime. The synthesis however, is understood to be unusual as the reactions with selenium source and sulfur source should have generated the CdSe and CdS however, the end products were always found to be the product-I to product-IV (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, Nanoparticles, Semiconductor, XRD}, issn = {0167-577X}, doi = {10.1016/j.matlet.2006.03.054}, author = {Singh, Narendra and Charan, Shobhit and Patil, K. R. and Viswanath, A. K. and Khanna, P. K.} } @article { ISI:000250085300004, title = {One-step preparation of nanosized Ag-PdCo-powder and its alloy formation at low temperature}, journal = {Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry}, volume = {37}, number = {7}, year = {2007}, month = {SEP}, pages = {531-539}, publisher = {TAYLOR \& FRANCIS INC}, type = {Article}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

Nano-sized silver-palladium co-powder has been synthesized from silver nitrate-palladium chloride by wet chemical method. The present experimental conditions are applied for the first time for Ag-Pd co-powders wherein sodium formaldehyde sulfoxylate (SFS) has been used as an external reducing agent to simultaneously reduce respective metal salts. SFS reduces the metal salts at room temperature thus prevents formation of bigger particles of the respective metals in co-powder. Powder X-ray diffraction measurements ( XRD) and Transmission electron microscopy ( TEM) suggest the formation of nano-sized Ag-Pd co-powder with particle diameter in the range of about 25 nm. SEM shows that the powder morphology changes with temperature. Heat treatment of 90: 10 (Ag:Pd) composition showed shift in XRD peaks indicating alloy formation of Ag/Pd at lower temperature. Thick-films generated by use of the co-powder resulted in Ag/Pd alloy at about 500 degrees C as confirmed by the XRD. Thermal analysis showed that Ag/Pd co-powders initially gain the weight due to oxidation followed by the weight loss.

}, keywords = {alloy, Chemical synthesis, nano-powder, noble metal, Transition Metal}, issn = {1553-3174}, doi = {10.1080/15533170701563707}, author = {Khanna, P. K. and Singh, N. and Kulkarni, D. and Marimuthu, R. and Charan, Shobhit and Patil, K. R. and Jain, G. H.} } @article { ISI:000275170800011, title = {One-pot synthesis of oleic acid-capped cadmium chalcogenides (CdE: E = Se, Te) nano-crystals}, journal = {Journal of Nanoparticle Research}, volume = {12}, number = {1, SI}, year = {2010}, month = {JAN}, pages = {101-109}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Surface-capped CdSe and CdTe nano-crystals (NCs) have been synthesized using cadmium acetate, oleic acid and respective tri-octylphosphine chalcogenide (TOPE; E = Se/Te) in diphenyl ether (DPE). Well-dispersed CdSe particles showed two absorption bands at the region of 431-34 and 458-60 nm in optical absorption study. A band-edge emission resulted at 515 nm with an excitation energy of 400 nm, in its photoluminescence (PL) spectrum. Similarly, UV-visible absorption study of CdTe revealed an absorption band at \< 700 nm. The broadened X-ray diffraction (XRD) pattern showed that at higher reaction temperature cubic CdSe but hexagonal CdTe can be obtained with crystallite size of \< 10 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that agglomerated particles are of spherical nature. The inter-planar spacing in CdTe was measured to be 0.406 nm, a characteristic of (100) lattice plane in hexagonal CdTe. X-ray photoelectron spectroscopy (XPS) showed that CdSe NCs have better air stability stable than CdTe. Presence of organic moiety around the semiconductor particles was confirmed by infrared (IR) spectroscopy.

}, keywords = {Chemical synthesis, photoluminescence, Semiconductors, Surface capping}, issn = {1388-0764}, doi = {10.1007/s11051-008-9581-y}, author = {Khanna, P. K. and Rao, K. Srinivasa and Patil, K. R. and Singh, V. N. and Mehta, B. R.} } @article { ISI:000281175500059, title = {Simple chemical co-precipitation/calcination route for the synthesis of simulated synroc-B and synroc-C powders}, journal = {Materials Chemistry and Physics}, volume = {123}, number = {2-3}, year = {2010}, month = {OCT}, pages = {695-699}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A simple chemical co-precipitation/calcination route was developed for the synthesis of simulated synroc-B and synroc-C powders using mostly nitrate salts as starting chemicals and 20\% ammonia solution as precipitant. In this route, a mixed solution containing Al-nitrate, Ca-nitrate, Ba-nitrate, zirconyl nitrate and titanyl nitrate in the molar proportion required for synroc-B is added to dilute ammonia solution to precipitate these cations in the form of their hydroxides at room temperature by maintaining pH approximate to 10.5 during precipitation. Formation of a major fluorite phase with minor amounts of anatase, rutile and hollandite phases is observed in the powder obtained after calcination in air at 750 degrees C. Multiphase crystalline synroc-B matrix containing hollandite, perovskite, zirconolite, and rutile phases is obtained after sintering the heat treated powder in the form of pellets at 1230 degrees C for 4h in air. Similarly, pure synroc-C phases with 14 and 20\% simulated waste loadings were synthesized following the same synthesis protocol. These pre-treated powders with a high surface area of similar to 25 m(2) g(-1) gave sintered ceramics having density of similar to 90\% for 14 and 20\% waste loadings. (C) 2010 Elsevier B.V. All rights reserved.

}, keywords = {Ceramics, Chemical synthesis, Oxides, Sintering}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2010.05.039}, author = {Potdar, H. S. and Vijayanand, S. and Mohaideen, Kamal Khaja and Patil, K. R. and Joy, Pattayil Alias and Madhavan, R. Raja and Kutty, K. V. G. and Ambashta, Ritu D. and Wattal, P. K.} } @article { ISI:000305112000030, title = {Novel microwave assisted sol-gel synthesis (MW-SGS) and electrochromic performance of petal like h-WO3 thin films}, journal = {Materials Research Bulletin}, volume = {47}, number = {7}, year = {2012}, month = {JUL}, pages = {1787-1793}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Use of domestic microwave oven is first time employed for chemical deposition of nanocrystalline hexagonal WO3 (h-WO3) thin films. Low cost precursors like sodium tungstate, hydrochloric acid, oxalic acid and potassium sulfate signifies cost effectiveness of this thin film fabrication route. Scanning electron microscopy images reveal formation of petal like nanodisks. A number of analytical techniques were used to characterize the WO3 petal like nanodisks, including X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX). X-ray photoelectron spectroscopy, FT-IR spectroscopy, Raman scattering spectroscopy, UV-visible spectrophotometry and cyclic voltammetry (CV). The X-ray photoelectron spectroscopic studies revealed 2.89 O/W atomic ratio. The electrical transport studies on WO3 thin films show semiconducting behavior with n-type semiconductivity. The value of determined coloration efficiency is 57.90 cm(2)/C. The mechanism of Li+ intercalation and deinercalation in h-WO3 matrix is proposed for enhanced electrochromism. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Chemical synthesis, Electrochemical properties, Oxides, photoelectron spectroscopy}, issn = {0025-5408}, doi = {10.1016/j.materresbull.2012.03.025}, author = {Kharade, Rohini R. and Patil, K. R. and Patil, P. S. and Bhosale, Popatrao N.} }