The origin of room temperature (RT) ferromagnetism (

In this study, the effect of Sr-and Ni-doping on microstructural, morphological and sensing properties of ZnO nanorods has been investigated. Nanorods with different Sr and Ni loadings were prepared using a simple wet chemical method and characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL) analysis. XRD data confirmed that Sr-and Ni-doped samples maintainsthe wurtzite hexagonal structure of pure ZnO. However, unlikes Sr, Ni doping modifies the nanorod morphology, increases the surface area (SA) and decreases the ratio of I UV /I green photoluminescence peak to a greater extent. Sensing tests were performed on thick films resistive planar devices for monitoring CO and CO 2 , as indicators of indoor air quality.The effect of the operating temperature, nature and loading of dopant on the sensibility and selectivity of the fabricated sensors towards these two harmful gases were investigated. The gas sensing characteristics of Ni-and Sr-doped ZnO based sensors showed a remarkable enhancement (i. e. the response increased and shifted towards lower temperature for both gases) compared to ZnO-based one, demonstrating that these ZnO nanostructures are promising to fabricate sensor devices for monitoring indoor air quality.

Here we report an easy and rapid synthesis technique of wurtzite ZnO nano structures in the form of flowers, nano-rods and nano-tubes is achieved by a facile hydrothermal method. A growth mechanism is proposed based on series of temperature dependent experiments keeping other parameters during synthesis in the aqueous medium at optimized level. Pure ZnO results in nanorods while Sr doped ZnO material forms flower and tube like structures. The XRD and TEM investigations show that ZnO nanostructures possess good crystalline structures with growth direction along the c-axis of the crystal plane. Raman spectra confirms five phonon vibration modes for ZnO nanostructures at 99, 333, 382, 438 and 582 cm -1 and one more defect induced low intensity peak at 663 cm -1 for Sr doped ZnO. Ultraviolet-visible (UV-vis) spectroscopy shows the band gap energy of ZnO nanostructures decreases from 3.24 to 3.22 eV with the substitution of Sr in ZnO lattice. Photoluminescence spectra reveal existence of several defect states in all the samples. Defect intensity seems negligibly affected by the variation of growth temperature, whereas, Sr doping plays a major role in controlling oxygen and Zn related defects. I-V characteristics of the ZnO and Sr doped ZnO shows rectification behaviour of the Schottky diodes.The phase formation, composition and surface morphology of the ZnO and Zn0.98Sr0.02O films were investigated by X-ray diffraction (XRD, Bruker D8 Advance X-ray diffractometer) with Cu-Kα radiation (λ= 1.54 Å) and field emission scanning electron microscope (FESEM, Supra 55 Zeiss). Micro Raman scattering measurement of the samples were recorded using Labram-HR 800 spectrometer equipped with excitation radiation at wavelength of 488 nm from an argon ion laser

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In the present study partially reduced graphene oxide‐ Silver Nanocomposite (GO−Ag NC) was chemically synthesized by using graphene oxide as a precursor and simultaneously its antimicrobial property is studied. Results indicate growth inhibition of fungi belonging to phylum Zygomycota as well as several types of microbes grown under open environment at ambient conditions in Luria Bertani Agar medium. SEM and HRTEM images represent highly exfoliated rGO layers with Silver Nanoparticles embedded on rGO flakes indicating the formation of rGO−Ag Nanocomposite. XRD and Raman spectroscopy confirmed the formation of good quality GO flakes and rGO−Ag Nanocomposite. XPS confirmed intercalation of Graphite by Oxygen containing functional groups, confirming the oxidation of Graphite and corresponding changes in functional groups introduced by the inclusion of Ag Nanoparticles. FTIR and UV‐Vis Spectroscopy confirm the formation of good quality GO, rGO, rGO−Ag Nanocomposite. The behaviour of the silver ion release from the rGO−Ag NC was studied in an acidic solution.Comparative study to see the effect of GO, rGO and Ag Nanoparticles were also carried out on microbes. SEM images of fungi shows destruction of microbial cell membrane.