F. T. Thema

Elucidation of photocatalysis, photoluminescence and antibacterial studies of ZnO thin films by spin coating method

The ZnO thin films have been prepared by spin coating followed by annealing at different temperatures like 300°C, 350°C, 400°C, 450°C, 500°C & 550°C and ZnO nanoparticles have been used for photocatalytic and antibacterial applications. The morphological investigation and phase analysis of synthesized thin films well characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence (PL), Transmission Electron Microscopy (TEM) and Raman studies. The luminescence peaks detected in the noticeable region between 350nm to 550nm for all synthesized nanosamples are associated to the existence of defects of oxygen sites. The luminescence emission bands are observed at 487nm (blue emission), and 530nm (green emission) at the RT. It is observed that there are no modification positions of PL peaks in all ZnO nanoparticles. In the current attempt, the synthesized ZnO particles have been used photocatalytic and antibacterial applications. The antibacterial activity of characterized samples was regulated using different concentrations of synthesized ZnO particles (100μg/ml, 200μg/ml, 300μg/ml, 400μg/ml, 500μg/ml and 600μg/ml) against gram positive and gram negative bacteria (S. pnemoniae, S. aureus, E. coli and E. hermannii) using agar well diffusion assay. The increase in concentration, decrease in zone of inhibition. The prepared ZnO morphologies showed photocatalytic activity under the sunlight enhancing the degradation rate of Rhodamine-B (RhB), which is one of the common water pollutant released by textile and paper industries.

Structural, Optical, Morphological and Microbial Studies on SnO2 Nanoparticles Prepared by Co-Precipitation Method

Nanoparticles of tin oxide (SnO2) powders were prepared by co-precipitation method at 500 °C, 700 °C and 900 °C temperature. The sintered SnO2 nanoparticles, structural, optical, magnetic, morphological properties and microbial activity have been studied. XRD studies reveals that sintered powder which exhibits tetragonal crystal structure and both crystallinity as well as crystal size increase with increase in temperature. The morphological studies reveal randomly arranged grains with compact nature grain size increases with sintering temperature. The compositional analyses of SnO2 nanoparticles have been studied using X-ray photoelectron spectroscopy analysis. The optical band gap values of SnO2 nanoparticles were calculated to be about 4.3 eV in the temperature 500 °C, comparing with that of the bulk SnO2 3.78 eV, by optical absorption measurement. Room temperature M-H curve for pure SnO2 nanoparticles exhibits ferromagnetic behaviour. The tin oxide nanoparticles are acted as potential candidate material for bacterial and fungal activity.

INFLUENCE OF KILO-ELECTRON-VOLT OXYGEN ION IRRADIATION ON STRUCTURAL, ELECTRICAL AND OPTICAL PROPERTIES OF CdTe THIN FILMS

In this paper, effect of oxygen (O+) ion irradiation on the properties of polycrystalline cubic structure CdTe thin films has been investigated. CdTe thin films were irradiated with O+ ions of energy 80keV at different fluence ranging from 1×1015 to 5×1016 ion/cm2 at room temperature. At 1×1015 ion/cm2 O+ ions fluence, the CdTe structure was maintained while XRD peaks of cubic phase were shifted toward lower angles. At 5×1016 ion/cm2 O+ ions fluence, cubic structure of CdTe thin films was transformed into hexagonal structure. In addition, electrical resistivity and optical bandgap were decreased with increasing O+ ion beam irradiation.

Surface modification and oxidation of vanadium thin film using femtosecond laser

X-beam imaging of mice utilizing a colloid arrangement of Au nanoparticles that were covered with silica and hence surface-adjusted with carboxymethylcellulose (CMC) (Au/SiO2/CMC) was acted in this work. The silica-covering for Au nanoparticles and the amination for silica-covered particles were at the same time acted within the sight of the Au nanoparticles with a size of 17.9 nm, which were set up by decreasing Au particles (III) with sodium citrate in water at 80°C and by surface-changing the Au nanoparticles with (3-aminopropyl)- trimethoxysilane, by a sol-gel measure utilizing tetraethylorthosilicate, (3-aminopropyl)- triethoxysilane, water and sodium hydroxide (Au/SiO2-NH2). The surface alteration of Au/SiO2-NH2 particles with CMC was performed by essentially adding CMC with carboxyl gatherings that respond with an amino gathering to the Au/SiO2-NH2 molecule colloid arrangement. The as-arranged the Au/SiO2/CMC molecule colloid arrangement was concentrated by centrifugation for estimations utilizing figured tomography (CT). Figure 1 shows a photo of the concentrated molecule colloid arrangement and a conveyance electron microscopy picture of the Au/SiO2/CMC particles in the concentrated colloid arrangement. Most particles contained a solitary center of the Au nanoparticles. Their molecule size was 67.4±5.4 nm. A CT estimation of the Au/SiO2/CMC molecule colloid arrangement with an Au convergence of 0.043 M was as high as 344±12 Hounsfield units (HU). This worth compared to 8.0×103 HU/M as for the Au fixation, which was bigger than that of Iopamiron 300, a business X-beam contrast specialist. Mouse tissues were imaged following infusion of the Au/SiO2/CMC molecule colloid arrangement.