Yazar "Aida, Mohammed Salah" seçeneğine göre listele

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    CO2 sensing behavior of vertically aligned Si Nanowire/ZnO structures
    (Elsevier SCI LTD., 2021) Ocak, Yusuf Selim; Lamri Zeggar, Meryem; Genisel, Mustafa Fatih; Uzun, Nilufer Uslu; Aida, Mohammed Salah
    Metal oxide nanostructures are highly attractive for the fabrication of gas sensors due to their high surface-to-volume ratios. The design of novel structures has great importance to improve sensing behavior. Atomic layer deposited ZnO thin film on vertically aligned silicon nanowire (Si NW) arrays were used to understand the influence of etching time on CO2 sensing behavior of the SiNW/ZnO structure. The metal-assisted chemical etching method was used to realize SiNW arrays. The etching processes were performed for 5, 10, 30, and 60 min. The linear relationship between etching time and Si NW length was reported. 30 nm ZnO thin films were deposited on Si NWs by atomic layer deposition (ALD) method using diethyl Zinc and H2O as Zn and O-2 sources, respectively. The CO2 sensing properties of the SiNW/ZnO structures were examined at ambient temperature and low CO2 concentration. The testing measurement results reveal that the sensor realized on un-etched Si does not exhibit any sensitivity. While the SiNW/ZnO was sensitive to CO2, the sensor sensitivity increase with the etching time due to the increase in the specific reactive surface. Moreover, the realized sensors have a relatively low response and recovery times, in the range of 2-7 s, by comparison to the reported ones in the literature.
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    Influence of Seed Layer Surface Position on Morphology and Photocatalysis Efficiency of ZnO Nanorods and Nanoflowers
    (Hindawi Limited, 2020) Bourfaa, Fouzia; Boutelala, Abderhamane; Aida, Mohammed Salah; Attaf, Nadhir; Ocak, Yusuf Selim
    ZnO nanorods and nanoflowers were synthesized by a hydrothermal method via different surface substrate positions at 120°C for 3 h as a growth time. The influence of seed layer surface position on the growth of ZnO nanostructures was observed by the variation of ZnO morphologies from nanorods to nanoflowers. Both analyses XRD and EDS proved the pure wurtzite phase with high crystallinity quality and preferential growth along the c-axis. As displayed from the scanning of surface morphology through SEM, a large amount of ZnO nanorods and nanoflowers were deposited on the full substrate surface. Diverse ZnO photocatalysts were used to study the photodegradation of Methylene Blue (MB) dye by UV light. The organic dye MB was decolorized by the most efficient photocatalyst among the ZnO-tested nanostructures. The results showed an improvement of the degradability of this dye from 54% to 81% for ZnO nanoflowers compared to nanorods. Thus, ZnO nanoflowers are the best photocatalyst which have the high efficiency photodegradation and the large rate constant.