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Adsorption behavior of the seleno‐amino acids viz. l‐selenomethionine (SeMet) and l‐selenocystine (SeCys) on the surface of Ag nanoparticles (NPs) was investigated by surface‐enhanced Raman scattering (SERS) and X‐ray photoelectron spectroscopy (XPS). The bare and functionalized Ag NPs were characterized by UV‐visible absorption, DLS, zeta‐potential measurements and TEM. The Raman spectrum supported by DFT computed spectrum of SeMet and SeCys suggested the existence of zwitterionic and diselenide (Se‐Se) forms in the crystalline state. The SERS study of SeMet and SeCys indicates that the zwitterionic and diselenide forms, respectively bind to the Ag NPs primarily through the Se atom. In case of SeCys, cleavage of the Se‐Se bond occurs on the Ag NPs surface. SERS results; thus, established the active anchoring sites involved in binding for both seleno‐amino acids and XPS analysis confirmed that Se atom was the most active coordinating site with minor involvement of the carboxylate and amino groups. The SERS study of the seleno‐amino acids showed the possibility of change in orientation of SeMet on the Ag NPs surface with alteration in concentration, while no variation in orientation was observed for SeCys. In this study, sensing of the SeMet and SeCys down to 100 nM level was also achieved. [ABSTRACT FROM AUTHOR]

Polymeric materials have been found to be ideal candidates for the synthesis of organic-inorganic nanomaterials. We have obtained Co3O4-decorated graphene oxide (GO) nanocomposites by a simple polymer combustion method. Polyvinyl alcohol (PVA) of two different molecular weights, 14,000 and 125,000, was used for the synthesis. The pristine sample was annealed at 300, 500, and 800°C. PVA has played an important role in the formation of GO and Co3O4 nanoparticles. Synthesized Co3O4-GO nanocomposites were characterized by X-ray diffraction, Fourier transform infrared, Raman, electron paramagnetic resonance, transmission electron microscopy, and vibrating sample magnetometry. Reflection peaks at 12° and 37° in an X-ray study confirm the formation of Co3O4-GO. Raman study validates the presence of GO in nanocomposites of Co3O4-GO. Room temperature ferromagnetism was observed in all annealed samples. The highest coercivity of 462 G was observed for 300°C annealed samples as compared with bulk Co3O4. On the basis of the results obtained, a mechanism of formation is proposed. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The catalytic effect of two different sizes of α-Fe2O3 nanoparticles synthesised using an electrochemical method was investigated on the thermal decomposition of ammonium perchlorate (AP) using differential scanning calorimetry as a function of catalyst concentration. The nanosized ferric oxide particles exhibited more of a catalytic effect on the thermal decomposition of AP than commercial α-Fe2O3 particles. A lowering of the high-temperature decomposition of AP by 59 °C was observed after mixing with 2 Wt per cent of α-Fe2O3 particles with the very fine size of 3.5 nm. The mixture produced a high heat release of 4.574 kJ/ g compared to 0.834 kJ/g of pure AP. The kinetic parameters were evaluated using Kissinger method. The decrease in the activation energy and increase in rate constant confirmed the catalytic activity of these nanoparticles. [ABSTRACT FROM AUTHOR]

Abstract: This report aimed to study the effect of CdS doping in TiO2 on the phase transformation of TiO2 from anatase to rutile using X-ray diffraction (XRD) and Raman spectroscopy. CdS-doped TiO2 nanocomposites have been prepared and characterized using Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). We have observed that contrary to bare TiO2, phase transformation of TiO2 from anatase to rutile is hindered when doped with CdS at high temperature. Raman spectroscopy is found to be more sensitive for detection of the surface of TiO2 as compared to XRD. [Copyright &y& Elsevier]

Present methods for the disposal of old and rejected ammunition carry high risk and are not environment-friendly. Various processes such as wet air oxidation, molten salt oxidation, hydro thermal oxidation, incineration, electrochemical reduction, biodegradation and other methods have limited use for decontamination and are not suitable for disposal of large quantities of explosives. Thus there is dire need to develop alternate method for safe disposal of rejected explosives which will be eco-friendly. In this paper we have attempted to combine two methods i.e. chemical treatment followed by biological/microbiological treatment. For this purpose we have selected Tri Nitro Toluene (TNT) as a model compound, which is used extensively in many types of ammunition. As reported previously from our laboratory the presence of nitro group from TNT was toxic to bacterial growth. By chemical treatment, nitro groups from TNT were converted into amine and mixed in soil for biodegradation. Our results suggest that after converting 'nitro groups' to 'amine groups' were much preferred by bacteria and faster mineralization is observed. Thus combined treatment to TNT as discussed in this study, showed much less phyto-toxicity and may have great potential to scale up the process for large quantities of explosive such as TNT.