02200nas a2200229   4500008004100000022001400041245009100055210006900146260007300215300001400288490000700302520140100309653001401710653001501724653001901739653002201758653000801780100002401788700001901812700002201831856011701853       2008                        eng d  a0039-914000aControlled synthesis of ZnO from nanospheres to micro-rods and its gas sensing studies0 aControlled synthesis of ZnO from nanospheres to microrods and it  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a1315-13190 v753 a<p>1D ZnO rods are synthesized using less explored hydrazine method. Here we find, besides being combustible hydrazine can also be used as a structure-directing agent. The ratio of zinc nitrate (ZN) to hydrazine is found to control the morphology of ZnO. At lower concentration of ZN as compared with hydrazine the morphology of ZnO is found to be spherical. As we increase the hydrazine content the morphology changes from spherical (diameter similar to 100 nm) to the elongated structures including shapes like Y, T as well dumbbell (diameter similar to 40 nm and length similar to 150 nm). Interestingly for more than 50% of hydrazine ZnO micro-rods are formed. Such rods are of diameter similar to 120 mn having length of about 1 mu m for ZN to hydrazine ratio of 1:9, isolated as well as bundle of rods are seen in scanning electron microscopy (SEM). The X-ray diffraction (XRD) reveals the phase formation with average particle size of 37 nm as calculated using Scherrer's formula. The high-resolution transmission electron microscopy (HRTEM) is also done to confirm the d-spacing in ZnO. Gas sensing study for these samples shows high efficiency and selectivity towards LPG at all operating temperatures. Photoluminescence (PL) study for these samples is performed at room temperature to find potential application as photoelectric material. (C) 2008 Elsevier B.V. All rights reserved.</p>10aHydrazine10aLPG sensor10aNanostructures10aphotoluminescence10aZnO1 aNavale, Shalaka, C.1 aGosavi, S., W.1 aMulla, Imtiaz, S.  uhttps://library.ncl.res.in/content/controlled-synthesis-zno-nanospheres-micro-rods-and-its-gas-sensing-studies-002279nas a2200217   4500008004100000022001400041245007500055210006900130260006900199300001000268490000800278520153400286653001701820653001901837653002301856653001801879100001801897700001801915700001901933856010901952       2014                        eng d  a0254-058400aSynthesis and luminescence of graphene-nano calcium sulphide composite0 aSynthesis and luminescence of graphenenano calcium sulphide comp  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcSEP  a57-640 v1473 a<p>Graphene-nanocrystalline calcium sulphide has been synthesized using in-situ reduction of calcium salt and graphene oxide. Graphene oxide was prepared using Hummer's method. Surface morphology and crystal structure of samples were observed by transmission electron microscopy (TEM) and X-Ray diffraction (XRD). Ultra thin graphene and graphene oxide sheets with size ranging between tens to several hundreds of square nanometers are observed in TEM images. The TEM micrographs of G-CaS show that CaS particles are embedded in graphene sheets and the average particle size of CaS particles in the composite is less than 50 nm. The reduction in the intensity of various functional groups in FTIR spectrum also confirms the formation of graphene. The UV-Visible spectra of CaS shows absorption peak at 220 nm with a small shoulder at 250 nm whereas in G-CaS 220 nm absorption peak has reduced intensity and the shoulder at 250 nm has now shifted to 270 nm due to modification in the defect structure of CaS by graphene. CaS and G-CaS shows photoluminescence emission at 470 nm (lambda(exc.) = 375 nm) and 440 nm (lambda(exc.) = 350 nm) respectively, however emission intensity of G-CaS is relatively lower than CaS. Although the emission intensity is found to be lower than CaS, addition of CaS to graphene in G-CaS complex has made graphene luminescent. XPS spectra also indicate reduction of various oxygen containing functional groups in highly reduced graphene oxide and G-CaS. (C) 2014 Elsevier B.V. All rights reserved.</p>10aLuminescence10aNanostructures10apowder diffraction10aPrecipitation1 aSharma, Geeta1 aPatil, K., R.1 aGosavi, S., W.  uhttps://library.ncl.res.in/content/synthesis-and-luminescence-graphene-nano-calcium-sulphide-composite-0