Effect of atmosphere on recovery of diffuse reflection spectra of ZnO powder modified with nanoparticles upon irradiation in vacuum

2021 ◽  
Vol 115 ◽  
pp. 111038
Author(s):  
M.M. Mikhailov ◽  
A.N. Lapin ◽  
A.N. Sokolovskiy ◽  
S.A. Yuryev
Keyword(s):  
Diffuse Reflection ◽  
Reflection Spectra ◽  
Zno Powder

Preparation of Visible-Light-Responsive TiO2-xNx Photocatalyst by a Very Simple Method

2011 ◽  
Vol 383-390 ◽  
pp. 3188-3191
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang ◽  
Hai Peng Huang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflection ◽  
Ammonia Solution ◽  
Reflection Spectra ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Light Excitation

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.

Device for determining the diffuse-reflection spectra of various kinds of wood

2007 ◽  
Vol 74 (5) ◽  
pp. 351
Author(s):  
V. A. Anchukov ◽  
Yu. V. Ilyasov ◽  
G. G. Gorbunov ◽  
S. S. Gulidov ◽  
A. P. Lappo ◽  
...  
Keyword(s):  
Diffuse Reflection ◽  
Reflection Spectra

Effects of Sample Dilution and Particle Size/Morphology on Diffuse Reflection Spectra of Carbohydrate Systems in the Near- and Mid-Infrared. Part II: Durum Wheat

1993 ◽  
Vol 47 (6) ◽  
pp. 695-701 ◽  
Author(s):  
Jill M. Olinger ◽  
Peter R. Griffiths
Keyword(s):  
Particle Size ◽  
Durum Wheat ◽  
Near Infrared ◽  
Diffuse Reflection ◽  
Specular Reflection ◽  
Analytical Data ◽  
Reflection Spectra ◽  
Depth Of Penetration ◽  
Mid Infrared ◽  
Effective Depth

It is shown that reduction of particle size for ground durum wheat does not cause a concomitant decrease in the amount of specular reflection observed in the mid-infrared spectrum of the neat sample. Specular reflection can be reduced, but not completely eliminated, by dilution of the wheat in a nonabsorbing matrix such as KCl. The lack of dependence of mid-infrared diffuse reflection spectra of neat ground durum wheat on particle size is explained by the morphology of the surface of each particle and the low effective depth of penetration of mid-infrared radiation into particles of very high absorptivity. It is concluded that mid-infrared diffuse reflection spectra of wheats do not provide information characteristic of the overall composition of the wheat when the particle size exceeds a few micrometers, but that near-infrared diffuse reflection spectra will provide representative analytical data even when the particle size is large.

Infrared Spectroscopy of Surface Films and Powders Using a Metal Light Pipe (Experimental)

1987 ◽  
Vol 41 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Wilford N. Hansen ◽  
James F. Andrew ◽  
Galen J. Hansen
Keyword(s):  
Diffuse Reflection ◽  
High Sensitivity ◽  
Companion Paper ◽  
Thin Layers ◽  
Surface Films ◽  
Reflection Spectra ◽  
Reaction Cell ◽  
Light Pipe ◽  
Inner Surface ◽  
Adsorbed Layers

Light pipe infrared spectra of adsorbed layers and powders are shown. They are compared with specular external reflection, ATR, KBr pellet transmission, and diffuse reflection spectra. The resultant light pipe spectra are found to obey the predictions of the theory presented in the previous companion paper [Appl. Spectrosc. 41, 46–62 (1987)], including the high sensitivity and S/N predicted to be attainable. They are easy to obtain and to interpret. Only fractions of a milligram of sample are required in favorable cases. The light pipe is convenient as a reaction cell, allowing changing spectra to be followed in real time. In the previous paper were presented equations for absorption spectra of thin layers of material on the inner surface of a light pipe, in the infrared. In the present paper the equations are tested against experimental reality. These tests are a crucial verification of the theory.

scholarly journals Catalytic Activity of a Composition Based on Strontium Bismuthate and Bismuth Carbonate at the Exposure to the Light of the Visible Range

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
K. S. Makarevich ◽  
A. V. Zaitsev ◽  
O. I. Kaminsky ◽  
E. A. Kirichenko ◽  
I. A. Astapov
Keyword(s):  
Diffuse Reflection ◽  
Wide Band ◽  
Visible Range ◽  
Powder Materials ◽  
Reflection Spectra ◽  
Narrow Gap ◽  
Electron Hole ◽  
Organic Precursor ◽  
Molar Ratios ◽  
Semiconductor System

This paper presents the results pertaining to studying the properties of the photocatalytically active composition of strontium bismuthate SrBi2.70O5.05, SrBi2.90O5.35, and SrBi3.25O5.88 and bismuth carbonate (BiO)2CO3 in molar ratios 1/0.67, 1/0.56, and 1/0.37, respectively. These compositions are obtained through pyrolytic synthesis from organic precursor complexes of strontium and bismuth with sorbitol. It has been established that the synthesised powder materials absorb the light of the visible range up to 500 nm owing to the presence of a narrow-gap semiconductor strontium bismuthate. The presence of a wide-band semiconductor (BiO)2CO3 ensures an effective separation of electron-hole pairs. The diffuse reflection spectra (DRS) of compositions differ from the analogous spectra of a mechanical mixture of these semiconductor phases with the same composition, which allows one to assume the heterostructural structure of the semiconductor system. The same heterostructure is confirmed by the results of mapping. Catalytic particles that are synthesised at a temperature of 500°C containing 27 mass% (BiO)2CO3 (corresponding to SrBi2.9O5.35/(BiO)2CO3 = 1/0.56) have the greatest activity with respect to the photodecomposition of methylene blue (MB). The possibility of controlling the optical properties and photocatalytic activity of the composition is depicted due to the joint formation of the strontium bismuthate phase and the bismuth carbonate phase.

Preparation and Photocatalytic Activity of Titania Pillared Montmorillonite Doped with Boron

2011 ◽  
Vol 233-235 ◽  
pp. 519-522
Author(s):  
Qiu Yan Zhang ◽  
Xiang Feng Guo ◽  
Li Hua Jia ◽  
Xue Ju Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Diffuse Reflection ◽  
Sol Gel ◽  
Boron Doping ◽  
Reflection Spectra ◽  
Visible Light Region ◽  
Pillared Montmorillonite ◽  
Light Region ◽  
Gel Technique

Boron doping titanium pillared montmorillonite (B-Ti-mont) were prepared by the sol-gel technique using sodic montmorillonite (Na-mont) as a substrate. Several technics such as XRD, SEM, UV-vis diffuse reflection spectra were used to characterize the samples. The results showed that all of the samples were of anatase, the absorption in the visible light region was strengthened after doped with boron. The basic skeleton of montmorillonite did not change after doping. The photocatalyst with the boron mole content of 5% displayed the best photocatalytic performance.

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