The kinetics of Langmuir-Blodgett ZnO nano-film deposition for sensing electrodes (original) (raw)
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Zinc oxide (ZnO) nanostructures were electrodeposited onto ITO coated glass substrates from nitrate medium at different temperatures. The electrochemical deposition process was analyzed and the characteristics of the nanostructures were discussed. The electrochemical results showed that the deposition temperature had an important effect on the current density and the film morphology. From the Mott-Schottky measurements, the flat-band potential and the donor density for the ZnO nanostructure are determined. The morphological, structural and optical properties were studied by scanning electron microscopy (SEM), x-ray diffraction techniques (XRD) and spectrophotometer in the ultraviolet UV– visible region. SEM images demonstrated that the morphology of ZnO nanostructures depend greatly on the bath temperature. The XRD patterns revealed the formation of phase-pure ZnO nanostructure with hexagonal wurtzite phase. The optical transmittance spectrum gave a high transmittance of 82 % at low temperatures, and the optical band-gap (Eg) of the ZnO nanostructures was between 3.253.49 eV.
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Advanced Science Letters, 2014
ABSTRACT In this study, ZnO sharp edged grains were successfully anodized at room temperature by anodization of Zinc (Zn) sheet with 0.1 M oxalic acid as an electrolyte and Graphite as a counter electrode under the constant potential 10 V for 8 hr. Characterization was done by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Visible spectroscopy. The average crystallite size in a crystalline orientation of (101), (110) and (103) are in the range of 12–14 nm, which confirms the formation of Nanocrystalline nature of ZnO. The SEM images of the films show agglomerated sharp edged grains. The optical direct band gap value is measured using UV-Visible spectroscopy for annealed films, it is about 3.2 eV. It has been observed that angle of contact for pure Zn sheet, as deposited Zn(OH)2 film and annealed ZnO film goes on decreasing from 100°, 65° and 30° respectively. After anodization of nano crystalline ZnO on zinc substrate the contact angle completely transfer from hydrophobic to hydrophilic nature.