@article { ISI:000228698900038, title = {PVA stabilized gold nanoparticles by use of unexplored albeit conventional reducing agent}, journal = {Materials Chemistry and Physics}, volume = {92}, number = {1}, year = {2005}, month = {JUL}, pages = {229-233}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Poly(vinyl alcohol) (PVA) stabilized gold nanoparticles have been prepared in aqueous medium using two different reducing viz.; hydrazine hydrate, a stronger reducing agent and sodium formaldehydesulfoxylate (SFS), a slightly weaker reducing agent. SFS is used for first ever time for reduction of gold metal salt. The PVA stabilized gold nanoparticles solutions are wine red to blood red coloured and are stable over a long period of time with no indication of aggregation. The solution shows strong visible light absorptions in the range of 520-540 nm, characteristics of gold nanoparticles. Powder X-ray diffraction patterns of freshly prepared films containing gold nanoparticles indicated particles size to be about 15 nm. Transmission electron microscopy (TEM) of a more than two-week-old sample revealed well-defined non-agglomerated spherical particles of about 50 nm diameter in solutions. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, electronic materials, Nanostructures, Polymer}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2005.01.016}, author = {Khanna, P. K. and Gokhale, R. and Subbarao, V. V. V. S. and Vishwanath, A. K. and Das, B. K. and Satyanarayana, C. V. V.} } @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:000256114400005, title = {Synthesis of oleic acid capped copper nano-particles via reduction of copper salt by SFS}, journal = {Materials Chemistry and Physics}, volume = {110}, number = {1}, year = {2008}, month = {JUL}, pages = {21-25}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Synthesis of oleic acid capped copper nano-particles has been carried out by use of sodium formaldehyde sulfoxylate (SFS) in aqueous medium. Nano-copper can be effectively coated with polyvinyl alcohol (PVA). Phase-pure nano-Cu can be obtained when water/acetone was used as aqueous medium. It is observed that the surface plasmon resonance (SPR) phenomena can be controlled during synthesis by the use of suitable reagent system, e.g. absorption band in presence of PVA can be blue shifted. As-prepared copper nano-particles were characterized by X-ray diffraction measurements (XRD), Scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), thermo gravimetric analysis (TGA) and Fourier transform infra-red spectroscopy (FTIR). XRD analysis revealed broad pattern for fcc crystal structure of copper metal. The particle size by use of Scherrer{\textquoteright}s equation was calculated to be about 20 nm. TGA revealed similar to 10\% weight loss due to the presence of surfactant. FTIR spectroscopy confirmed the presence of oleic acid around the particles. (c) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, electronic materials, metals, Nanostructure}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2008.01.013}, author = {Khanna, P. K. and Kale, Trupti S. and Shaikh, Mushtaq and Rao, N. Koteswar and Satyanarayana, C. V. V.} } @article { ISI:000262987800024, title = {Solid state synthesis and room temperature magnetic properties of iron phosphide nanoparticles}, journal = {Journal of Nanoparticle Research}, volume = {11}, number = {2}, year = {2009}, month = {FEB}, pages = {491-497}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Room temperature magnetic properties have been achieved for nano-crystalline iron phosphide synthesized from the direct solid state reaction of iron chloride and tri-octylphosphine (TOP). The magnetization continuously increased with higher magnetic fields, indicating a super-paramagnetic behavior. It is observed that room temperature magnetism is possible for the material showing antiferromagnetic nature at low temperatures. In the present synthesis, TOP acted as a source of phosphorus as well as a surfactant. X-ray diffraction (XRD) studies revealed that the black powder is a mixture of FeP and Fe(2)P. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed elongated as well spherical particles. Energy dispersion X-ray analysis (EDAX) confirmed a non-stoichiometric iron phosphide. Presence of TOP was confirmed by infra-red (IR) spectroscopy, and thermo-gravimetric analysis (TGA) indicated about 6\% wt. loss due to presence of organics.

}, keywords = {Iron phosphide, Semiconductors, Solid state reaction, synthesis, XRD}, issn = {1388-0764}, doi = {10.1007/s11051-008-9458-0}, author = {Singh, N. and Khanna, P. K. and Joy, Pattayil Alias} } @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:000291568100065, title = {Glycerol mediated low temperature synthesis of nickel nanoparticles by solution reduction method}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {11}, number = {6}, year = {2011}, month = {JUN}, pages = {5131-5136}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

Phase pure Nickel nano-particles were synthesized by in-situ generation of nickel hydrazine hydrate complex (Ni-HH) followed by its decomposition in an alkaline glycerol medium. The synthesis can be performed in an open beaker with or without the use of surface protective reagents. By using the present method, Ni nano-particles can be prepared in large scale. The black nano-powders so-obtained were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectroscopy and thermal analysis (TGA). XRD and SAED analysis revealed that the synthesized particles were pure crystalline nickel with FCC structure.

}, keywords = {Chemical Reduction, Nano-Particles, synthesis, Transition Metal, XRD}, issn = {1533-4880}, doi = {10.1166/jnn.2011.4142}, author = {Singh, Kalpana and Kate, Kunal H. and Chilukuri, V. V. Satayanarayana and Khanna, P. K.} } @article { ISI:000305039700151, title = {Sono-chemical synthesis of ZnO nano-particles and their application in hydrogen sulphide gas sensing}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {12}, number = {3}, year = {2012}, month = {MAR}, pages = {2791-2796}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Herein we describe synthesis of ZnO nanoparticles by using alkaline solution of ZnX2 (X = NO3, Cl) under ultrasound energy of 20 KHz. The reaction can be completed in about 1-2 hours. As prepared powders were analyzed by XRD measurement to find that the product is hexagonal phase pure ZnO. UV-Visible measurement of aq. solution showed absorption band at similar to 365 nm and photoluminescence (PL) indicated multiple bands in visible region due to deep traps owing to high temperature sintering. The hydrophilicity can be imparted by use of a suitable polyelectrolyte. Freshly prepared samples showed good dispersion in aqueous and alcoholic medium. The thick films derived from the ZnO nano-particles showed excellent sensing for hydrogen sulphide gas.

}, keywords = {Gas-Sensing, Sono-Chemical, synthesis, ZnO Nano-Particles}, issn = {1533-4880}, doi = {10.1166/jnn.2012.5732}, author = {Khanna, P. K. and Kate, Kunal and Dhanabalan, K. and Banerjee, Shaibal and Reji, Nedunnkandathil and Shinde, S. D. and Jain, G. H.} }