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This article reviews and summarizes work recently performed in this laboratory on the synthesis of advanced transparent conducting oxide nanopowders by the use of plasma. The nanopowders thus synthesized include indium tin oxide (ITO), zinc oxide (ZnO) and tin-doped zinc oxide (TZO), aluminum-doped zinc oxide (AZO), and indium-doped zinc oxide (IZO). These oxides have excellent transparent conducting properties, among other useful characteristics. ZnO and TZO also has photocatalytic properties. The synthesis of these materials started with the selection of the suitable precursors, which were injected into a non-transferred thermal plasma and vaporized followed by vapor-phase reactions to form nanosized oxide particles. The products were analyzed by the use of various advanced instrumental analysis techniques, and their useful properties were tested by different appropriate methods. The thermal plasma process showed a considerable potential as an efficient technique for synthesizing oxide nanopowders. This process is also suitable for large scale production of nano-sized powders owing to the availability of high temperatures for volatilizing reactants rapidly, followed by vapor phase reactions and rapid quenching to yield nano-sized powder.

There are variety of effluents are dumped or directly discarded into atmosphere due to drastic industrialization which leads to damages in living organisms. To prevent many type of environmental defects our research group focused to synthesis material which degrades toxic substance like dyes with the help of ecofriendly synthesis. We have synthesized Tin oxide nanoparticles (SnO2 NPs) using aqueous extract of Catunaregam spinosa (C. spinosa) root barks. Bio-inspired synthesized SnO2 NPs were monitored by analytical characterization which inferred that SnO2 NPs resulted in shape of spherical, with size average of 47±2nm. Further bio-green synthesized SnO2 NPs were subjected to degrade toxic Congo red dye, which results in higher percentage of degradation with the K value of 0.9212 which obeys pseudo-first order reaction kinetics. This report said to be novel due to null report on SnO2 NPs synthesized from C. spinosa root bark aqueous extract which also stated to be simplest, cheaper and non-toxic while compare to other methods. Further to identify the metabolites which is present in the aqueous extract were identified through Gas Chromatography and Mass Spectrometry with methanol as a solvent results that 7-hydroxy-6-methoxy-2H-1-benzopyran-2-one contains higher area percentage of 67.47 with the retention time (RT) of 18.660., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this work, the biocompatibility and antibacterial activities of novel SnO2 nanowire coatings prepared by electron-beam (E-Beam) evaporation process at low temperatures were studied. The nanowire coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD) methods. The results of in vitro cytotoxicity and cell proliferation assays suggested that the SnO2 nanowire coatings were nontoxic and promoted the proliferation of C2C12 and L929 cells (> 90% viability). Cellular activities, cell adhesion, and lactate dehydrogenase activities were consistent with the superior biocompatibility of the nanowire materials. Notably, the nanowire coating showed potent antibacterial activity against six different bacterial strains. The antibacterial activity of the SnO2 material was attributed to the photocatalytic nature of SnO2. The antibacterial activity and biocompatibility of the newly developed SnO2 nanowire coatings may enable their use as coating materials for biomedical implants.

CZTS: Atlanta. A supercritical CO(2) continuous-flow reactor is employed to deposit micro- and nanoparticles of copper zinc tin sulfide (CZTS), a promising material for thin-film solar cells, onto a silicon wafer. The image shows a chemical map of deposited CZTS particles (scale bar: 15 μm), and a Raman spectrum with a peak characteristic of CZTS., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Nanocrystalline SnO(x) (x = 1-2) thin films were prepared on glass substrates by a simple chemical bath deposition method. Triethanolamine was used as complexing agent to decrease time and temperature of deposition and shift the pH of the solution to the noncorrosive region. The films were characterized for composition, surface morphology, structure and optical properties. X-ray diffraction analysis confirms that SnO(x) thin films consist of a polycrystalline structure with an average grain size of 36 nm. Atomic force microscopy studies show a uniform grain distribution without pinholes. The elemental composition was evaluated by energy dispersive X-ray spectroscopy. The average O/Sn atomic percentage ratio is 1.72. Band gap energy and optical transition were determined from optical absorbance data. The film was found to exhibit direct and indirect transitions in the visible spectrum with band gap values of about 3.9 and 3.7 eV, respectively. The optical transmittance in the visible region is 82%. The SnO(x) nanocrystals exhibit an ultraviolet emission band centered at 392 nm in the vicinity of the band edge, which is attributed to the well-known exciton transition in SnO(x). Photosensitivity was detected in the positive region under illumination with white light.

Based on the sol-gel method, nanosized SnO2 material was prepared, and its structure and properties were studied by XRD, UV and Raman spectra. The XRD result indicated that the SnO2 particles had an ideal nanosize. The diameter of SnO2 particles increased with raising the temperature. The Raman spectrum indicated that the SnO2 nanometer material annealed at low temperature had a large number of O-empties. The UV spectra showed that the sample had stable absorption properties although the particle size changed greatly in the annealed range of 300-500 degrees C. These properties might be utilized in enhancing the performance of SnO2 gas-sensitive devices.

Crystalline nanobelts of ZnO and SnO2 were prepared from a thermal evaporation of oxide powders inside an alumina tube in the absence of catalysts. Typical dimensions of the nanobelt samples ranged from approximately 10 to 100 microns in length, 30 to 300 nm in width, and 6 to 30 nm in thickness. Room temperature Raman spectra were obtained on pressed mats of nanobelt samples and compared with the corresponding spectra of the starting oxide powders and bulk materials. Collectively, our Raman data indicated that the as-prepared nanobelt samples used in this study were oxygen deficient. Upon annealing at 900 degrees C in flowing oxygen for 1 h, the nanobelt samples exhibited Raman features that corresponded to those expected in respective bulk semiconducting oxides. The dimensions of the nanobelts were a bit too large to expect significant quantum size effects on the phonon structure similar to those observed in carbon nanotubes and short-period semiconductor superlattices.

Nanocrystalline Sn1-xInxO2 (0 < or = x < or = 0.2) has been successfully prepared by a solution chemical route. High-resolution transmission electron microscopy studies show that the average grain size of Sn0.8In0.2O2 heated at 310 degrees C, 500 degrees C, and 800 degrees C for 12 h is about 3-4 nm, 5-6 nm, and 7-10 nm, respectively. The corresponding values for pure SnO2 are 3-4 nm, 7-10 nm, and 50-90 nm, respectively. Powder X-ray diffraction and electron diffraction studies confirm the existence of solid solution only in the nanocrystalline state (the average particle size is in the range of 5-10 nm) with the solubility limited to 20% of In2O3. Indium ions stabilize the nanocrystalline nature of Sn1-xInxO2 (0 < or = x < or = 0.2) and prevent the grain growth by entering the SnO2 lattice. The thermal characteristics of nanocrystalline Sn1-xInxO2 (0 < or = x < or = 0.2) investigated by thermogravimetric (TG) and differential thermal analysis (DTA) show that the solid solution decomposes at 820 degrees C into SnO2 and In2O3, which is accompanied by a rapid crystal growth. The electrical conductivity and activation energy of Sn1-xInxO2 (0 < or = x < or = 0.2) undergo significant changes when the average grain size is less than or equal to 2 x the Debye length, LD.

This communication describes, for the first time, the growth of SnO2 nanoribbons by a controlled carbothermal reduction process. An analysis of the transmission electron microscopy image revealed that these nanoribbons have a well-defined shape, with a typical width in the range of 70-300 nm. In general, the nanostructured ribbons were more than 100 microns in length. The results reported here support the hypothesis that this ribbon-like nanostructured material grows by a vapor-solid process. This study introduces two hypotheses to explain the SnO2 nanoribbon growth process.