Browsing by Subject "Photocatalytic efficiency"

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    Comparative study of optically activated nanocomposites with photocatalytic TiO2 and ZnO nanoparticles for massive environmental decontamination
    (S P I E - International Society for Optical Engineering, 2007) Tek, S.; Mutlugun, E.; Soganci, I. M.; Perkgoz, N. K.; Yucel, D.; Celiker, G.; Demir, Hilmi Volkan
    Nanocomposites that incorporate TiO2 and ZnO nanoparticles separately in three-dimensional solgel matrices through full chemical integration are prepared to perform highly efficient photocatalytic activities for applications of environmental decontamination. Spectral responses of photocatalytic TiO2 and ZnO nanoparticles exposed to UV activation for self-cleaning process were obtained as also their optical relative spectral efficiency curves from 270 to 370 nm in the UV regime. Our investigations of the optimal conditions to increase their spectral photocatalytic efficiencies resulted in remarkably high levels of optical recovery and efficiency.
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    Electrospun BiOI nano/microtectonic plate-like structure synthesis and UV-light assisted photodegradation of ARS dye
    (Royal Society of Chemistry, 2014) Babu, V. J.; Bhavatharini, R. S. R.; Ramakrishna, S.
    BiOI electrospun nanofibers were prepared by using PAN as a supporting polymer. Subsequent annealing at 500 °C for 5 h, with a ramp rate of about 5 °C min-1 in air, breaks the nanofibers down to tectonic plate-like nano/microstructures. The surface physical and chemical structural changes were then further characterized by FE-SEM, TEM, XRD and XPS. The results reveal that the morphology and crystallite size of BiOI vary strongly depending on the precursor concentration used in the synthesis method. These nanostructures were later employed for photocatalytic degradation of a synthetic textile dye, Alizarin Red S (ARS). The photocatalytic efficiencies were found to be about 93.34% after 100 min of UV-light (340 nm) illumination. Photocatalytic activity (PCA) performance depends on morphology and band alignment. All the compositions follow first order pseudo-kinetics, which was found to be 0.1197 min-1 for a doping concentration of 3%. The enhancement in photodegradation could be possibly by photocatalysis and a photosensitization phenomenon. This has been explained based on the band edge position. © the Partner Organisations 2014.