@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.} }