Diffuse reflectance spectra of zinc oxide and zinc oxide-peroxide mixtures. Titration with KMn04 revealed that this material contained only 54% by weight ZnOg (the remain- der being water and ZnO). A sample treated with a large excess of 30% hydrogen peroxide for one week, washed with alcohol and ether, and dried under P^Os for 24 hr resulted in 68% ZnOz. A similar two week treatment yielded
18/12/2018· The obtained results referred to ZnO wurtzite hexagonal structure in absence of other ZnO phases or any phases based on chromium. The obtained particles of the investigated samples are uniform rod-like shape with average diameter about 50 nm. The diffuse reflectance measurements exhibited the decrease in NIR reflectance with increasing Cr content.
18/2/2013· To understand wave diffuse reflection, consider a one-dimensional nanoscaled rough surface between ZnO and air in the context of the extinction theorem 12,13,14,15.Two length
1/6/2013· The diffuse reflectance spectra of the investigated samples were performed using a Shimadzu UV–vis–NIR 3600 spectrophotometer using integrating sphere attachments. 3. Results and discussion3.1. Optical properties of undoped and Fe-doped ZnO nanopowders3.1.1. Diffused reflectance: Theoretical background. When electromagnetic radiation in the UV/vis/NIR wavelength
Total and diffuse reflectance of the ZnO was measured over a wavelength range of 200–800 nm, using a . double-beam UV–Vis–NIR spectrophotometer (Cary 5 000, Varian) with a Cary 5000 Internal
15/8/2017· Fig. 11 illustrates the diffuse reflectance spectra of HGM/ZnO composite pigments with different ZnO loadings. The reflectance in the 400–700 nm increases with the increase of ZnO loading, which could be ascribed to the increase of ZnO coverage on hollow glass microsphere surface. Moreover, the reflectance of HGM/ZnO composite pigments in the visible region is higher than 0.9,
If reflection is nondiffuse, then the radiation intensities leaving any surface are functions of direction as well as surface location, and the analysis becomes immensely more complicated. 1 To make the analysis tractable, one may make the idealization that the reflectance, while not diffuse, can be adequately represented by a combination of a diffuse and a specular component, as illustrated
USE OF DIFFUSE REFLECTANCE SPECTROSCOPY FOR OPTICAL CHARACTERIZATION OF UN-SUPPORTED NANOSTRUCTURES 19 F (R1) is the so-called remission or Kubelka-Munk func- tion, where R1 = Rsample=Rstandard . In the parabolic band structure, the band gap Eg, and ab- sorption coefﬁcient ﬁ of a direct band gap semiconductor are related through the well known equation :
Optical properties of widely used semiconducting oxides namely; TiO 2, ZnO and ZrO 2 were investigated using diffuse reflectance spectroscopy (DRS). Prior to the optical absorption measurements, the structural purity of these samples was examined using powder x-ray diffraction experiments carried out on Indus-2 synchrotron source. It is observed that all the studied samples are structurally
The interaction of water with ZnO nanoparticles has been studied by means of diffuse reflectance infrared spectroscopy (DRIFTS) and ultra-high vacuum FTIR spectroscopy (UHV-FTIRS). Exposing clean ZnO powder to water at 323 K leads to both molecular and dissociative adsorption of H2O forming a number of hydroxyl species. All the OH bands are clearly identified by the adsorption of D2O showing
In similar work, Morales et al. used diffuse reflectance spectroscopy for powdered nanostructures for optical property measurements. In this study, investigation regarding the optical properties of powdered of ZnO doped with Bi 2 O 3 and TiO 2 at different sintering temperatures and times are discussed by using a UV-Vis Spectrophotometer attached to a RSA.
The interaction of water with ZnO nanoparticles has been studied by means of diffuse reflectance infrared spectroscopy (DRIFTS) and ultra-high vacuum FTIR spectroscopy (UHV-FTIRS). Exposing clean ZnO powder to water at 323 K leads to both molecular and dissociative adsorption of H 2 O forming a number of hydroxyl species. All the OH bands are clearly identified by the adsorption of D 2 O
The Diffuse Reflectance spectra showed the pure ZnO and Ag/ZnO photocatalysts have no significant difference in absorption in UV region, but rised of Ag loading increase the absorption in visible region. Photodegradation of 20 ppm methylene blue (MB) solution was used to evaluate the performance of Ag/ZnO photocatalysts on UV, visible and dark and was compared to pure ZnO. Loading Ag (1.7%
by the above route has pure ZnO phases. Diffuse reflectance analysis The UV-visible absorption spectra of the samples are shown in Figure 4. All the samples have a strong absorp-tion maximum below 400 nm. The absorption maximum of the samples calcined at 500°C and 700°C are shifted to higher wavelengths. This red shift can be attributed to the agglomerations in the samples . The band gap
Fig.2: UV-Vis diffuse reflection spectra of (a) ZnO/PW 12 /mordenite and (b) ZnO D= ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ − 0 0 1 ε ε ε ×100%, Lingling Wang, Miaoling Huang, Xiaolan Xie. Advanced Composites Letters, Vol. 19, Iss. 5, 2010 175 3.3. HRTEM and EDS ZnO/PW 12 /mordenite was studied by high-resolu-tion transmission electron microscopy (HRTEM) with selected-area electron diffraction
Kubelka-Munk transformed reflectance spectra of (a) reflectance spectra of ZnO/ZnFe 2 O 4 nanocomposite, (b) band-gap energy of ZnO, (c) Kubelka-Munk plot ZnO/ZnFe 2 O 4 nanocomposite (for sample Z3F as an example), and (d) diffuse reflectance UV-visible absorption spectra of calcined Zn-Fe-LDH nanostructure.
ZnO/g-C 3 N 4 was prepared by carrying out a simple one-step calcination process. The ZnO/g-C 3 N 4 composite was characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), transient photocurrent responses and photo-luminescence (PL
30/7/2020· Hello! I am trying to measure diffuse reflectances in solid samples in the UV-Vis region. The reference material is BaSO4. It has a reflectance of 100% in the visible region.
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