scholarly journals RADIATION FORCES ON A CLUSTER OF SPHERICAL NANOPARTICLES IN VISIBLE LIGHT SPECTRUM

2017 ◽  
Vol 75 ◽  
pp. 99-109
Author(s):  
Aslan Nouri Moqadam ◽  
Ali Pourziad ◽  
Saeid Nikmehr
2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Chun-Hung Huang ◽  
Yu-Ming Lin ◽  
I-Kai Wang ◽  
Chun-Mei Lu

A variety of carbon-modified titania powders were prepared by impregnation method using a commercial available titania powder, Hombikat UV100, as matrix material while a range of alcohols from propanol to hexanol were used as precursors of carbon sources. Rising the carbon number of alcoholic precursor molecule, the modified titania showed increasing visible activities ofNOxphotodegradation. The catalyst modified with cyclohexanol exhibited the best activities of 62%, 62%, 59%, and 54% for the totalNOxremoval under UV, blue, green, and red light irradiation, respectively. The high activity with long wavelength irradiation suggested a good capability of photocatalysis in full visible light spectrum. Analysis of UV-visible spectrum indicated that carbon modification promoted visible light absorption and red shift in band gap. XPS spectroscopic analysis identified the existence of carbonate species (C=O), which increased with the increasing carbon number of precursor molecule. Photoluminescence spectra demonstrated that the carbonate species suppressed the recombination rate of electron-hole pair. As a result, a mechanism of visible-light-active photocatalyst was proposed according to the formation of carbonate species on carbon-modified TiO2.


Author(s):  
Susanne Reischauer ◽  
Volker Strauss ◽  
Bartholomäus Pieber

The combination of nickel- and photocatalysis has unlocked a variety of cross couplings. These protocols rely on a few photocatalysts that can only convert a small portion of visible light (<500 nm) into chemical energy. Many dyes that absorb a much broader spectrum of light are not applicable due to their short-lived excited states. Here we describe a self-assembling catalyst system that overcomes this limitation. The modular approach combines nickel catalysis with dye-sensitized titanium dioxide and can be used to catalyze various bond formations. <br>


2016 ◽  
Vol 8 (40) ◽  
pp. 27403-27410 ◽  
Author(s):  
Rulong Zhou ◽  
Dongdong Li ◽  
Bingyan Qu ◽  
Xiaorui Sun ◽  
Bo Zhang ◽  
...  

1999 ◽  
Vol 121 (09) ◽  
pp. 68-70
Author(s):  
John DeGaspari

The Next Generation Space Telescope (NGST) will incorporate leading-edge technology in construction, optics, and deployment. NGST will be composed of a large sunshield and lightweight mirror, which will be deployed in space. Both are depicted in this rendering by TRW Space and Electronic Group. Over the next two years, the teams, one led by Lockheed Martin Missiles & Space, Sunnyvale, CA, and the other led by TRW Space and Electronic Group in Redondo Beach, California, and including Ball Aerospace and Technologies Corp., Boulder, CO, will tackle some daunting engineering challenges. The new telescope will pick up where the Hubble telescope leaves off. Hubble observes objects that are still in the visible light spectrum. NGST will investigate objects that are much more distant in space and will need to be sensitive to the infrared band. The testing protocol is going to receive a very high level of attention during this upcoming phase one effort, because it is one of the substantial cost elements of a program of this nature.


2021 ◽  
Author(s):  
Bin Yuan ◽  
Ying Guo ◽  
Ziyuan Liu

Abstract Colorimetric studies of different light path lengths from a new perspective of UV-Vis spectroscopy. The corrected ultraviolet-visible light spectrum was used to calculate the color of flame-fusion synthetic ruby, and the influence of light path length and standard light source on the color of flame-fusion synthetic ruby was studied. The results show that the L*, C*, h° under the A light source are higher than those under the D65 light source. In the ultraviolet-visible light spectrum, the strong absorption band of Cr3+ at 545nm is the main cause of the color of the ruby. As the length of the light path increases, the absorption peak area at 545nm also increases, the lightness L* decreases, and the hue angle h° increases. The chroma C* first increases as the length of the light path increases, and then begins to decrease under the influence of the continuous decrease in lightness. The color difference ΔE*ab reaches the maximum when the light path length is around 10mm, and the standard light source has the greatest influence on the color difference ΔE*ab. As the length of the light path continues to increase, the influence of the standard light source on the color difference\(\)ΔE*ab decreases.


Author(s):  
Dessy Ariyanti ◽  
Junzhe Dong ◽  
Junye Dong ◽  
Wei Gao

<p>Titanium dioxide (TiO2) has gained much attentions for the last few decades due to its remarkable performance in photocatalysis and some other related properties. However, its wide bandgap (~3.2 eV) can only absorb UV energy which is only ~5% of solar light spectrum. The objective of this research was to improve the photocatalytic activity of TiO2 by improving the optical absorption to the visible light range. Here, colored TiO2 nanoparticles range from light to dark grey were prepared via aluminium treatment at the temperatures ranging from 400 to 600 oC. The modified TiO2 is able to absorb up to 50% of visible light (400-700 nm) and shows a relatively good photocatalytic activity in organic dye (Rhodamine B) degradation under visible light irradiation compared with the commercial TiO2. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 10th November 2015; Revised: 7th January 2016; Accepted: 7th January 20 </em></p><p><strong>How to Cite</strong>: Ariyanti, D., Dong, J.Z., Dong, J.Y., Gao, W. (2016). Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (1): 40-47. (doi:10.9767/bcrec.11.1.414.40-47)</p><p><strong>Permalink/DOI</strong>: <a href="http://dx.doi.org/10.9767/bcrec.11.1.414.40-47">http://dx.doi.org/10.9767/bcrec.11.1.414.40-47</a></p>


ACS Catalysis ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 13269-13274
Author(s):  
Susanne Reischauer ◽  
Volker Strauss ◽  
Bartholomäus Pieber

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 198 ◽  
Author(s):  
Shixiong Zhou ◽  
Tingting Shi ◽  
Zhihong Chen ◽  
Dmitri Kilin ◽  
Lingling Shui ◽  
...  

To explore the photocatalytic performances and optoelectronic properties of pure and doped bismuth oxyhalides D-doped BiOX (D = Ag, Pd; X = F, Cl, Br, I) compounds, their atomic properties, electronic structures, and optical properties were systematically investigated using first-principles calculations. In previous experiments, the BiOX (X = Cl, Br) based system has been observed with enhanced visible light photocatalytic activity driven by the Ag dopant. Our calculations also show that the potential photocatalytic performance of Ag-doped BiOCl or BiOBr systems is enhanced greatly under visible light, compared with other Pd-doped BiOX (X = Cl, Br) compounds. Furthermore, it is intriguing to find that the Pd-doped BiOF compound has strong absorption over the infrared and visible light spectrum, which may offer an effective strategy for a promising full spectrum catalyst. Indicated by various Mulliken charge distributions and different impurity states in the gap when Ag or Pd was doped in the BiOX compounds, we notice that all D-doped BiOXs exhibit a p-type semiconductor, and all impurity levels originated from the D-4d state. The charge transfer, optoelectronic properties, and absorption coefficients for photocatalytic activities among D-doped BiOX photocatalysts caused by the electronegativity difference of halide elements and metal atoms will finally affect the photocatalytic activity of doped BiOX systems. Therefore, it is significant to understand the inside physical mechanism of the enhanced Ag/Pd-doped BiOX photocatalysts through density functional theory.


Author(s):  
Ala' Fathi Khalifeh ◽  
Hasan Farahneh ◽  
Christopher Mekhiel ◽  
Xavier Fernando

Visible light communication (VLC) is a promising research topic that aims at utilizing the visible light spectrum for data communication, which in turn off-loads the heavily utilized wireless radio spectrum. VLC can take advantage of the increased use of light emitting diodes (LED) for lighting purposes in different fields, such as automotive headlights, traffic signals, advertising, aviation, and general lighting. Utilizing solid-state LEDs for lighting purposes not only saves energy but also can be used for data communication since LEDs can be easily modulated by switching the light on and off in frequencies above the human eye perception. This data can be transmitted in addition to the main lighting functionality of these devices. VLC is relatively easy to implement and safe, as it does not have potential side effects like the radio signals. As such, this new technology has a great potential for adoption in several applications. This chapter will briefly introduce the technology and discuss some potential indoors and outdoors applications.


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