scholarly journals Multifocal Flat Lens Using Thin Anisotropic Surface in Visible Light Spectrum

2022 ◽  
pp. 105185
Author(s):  
Jeong-Hyun Park ◽  
Jae-Gon Lee
Keyword(s):  
Visible Light ◽  
Light Spectrum ◽  
Anisotropic Surface ◽  
Flat Lens

scholarly journals Photocatalytic Activity and Characterization of Carbon-Modified Titania for Visible-Light-Active Photodegradation of Nitrogen Oxides

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Chun-Hung Huang ◽  
Yu-Ming Lin ◽  
I-Kai Wang ◽  
Chun-Mei Lu
Keyword(s):  
Visible Light ◽  
Carbon Number ◽  
Red Light ◽  
Matrix Material ◽  
Carbon Sources ◽  
Impregnation Method ◽  
Light Spectrum ◽  
Precursor Molecule ◽  
Visible Light Active ◽  
Carbonate Species

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.

scholarly journals A Modular, Self-Assembling Metallaphotocatalyst for Cross Couplings Using the Full Visible-Light Spectrum

2020 ◽  
Author(s):  
Susanne Reischauer ◽  
Volker Strauss ◽  
Bartholomäus Pieber
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Excited States ◽  
Catalyst System ◽  
Chemical Energy ◽  
Modular Approach ◽  
Nickel Catalysis ◽  
Light Spectrum ◽  
Dye Sensitized ◽  
Self Assembling

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>

Rutile TiO2(011)-2 × 1 Reconstructed Surfaces with Optical Absorption over the Visible Light Spectrum

2016 ◽  
Vol 8 (40) ◽  
pp. 27403-27410 ◽  
Author(s):  
Rulong Zhou ◽  
Dongdong Li ◽  
Bingyan Qu ◽  
Xiaorui Sun ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Visible Light ◽  
Light Spectrum ◽  
Rutile Tio2 ◽  
Reconstructed Surfaces

scholarly journals First Glimpse

1999 ◽  
Vol 121 (09) ◽  
pp. 68-70
Author(s):  
John DeGaspari
Keyword(s):  
Visible Light ◽  
Leading Edge ◽  
The Other ◽  
Light Spectrum ◽  
Substantial Cost ◽  
Infrared Band ◽  
Testing Protocol ◽  
High Level ◽  
To Receive ◽  
Very High

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.

scholarly journals The Influence of LightPath Length on the Color of Flame-Fusion Synthetic Ruby

2021 ◽  
Author(s):  
Bin Yuan ◽  
Ying Guo ◽  
Ziyuan Liu
Keyword(s):  
Visible Light ◽  
Light Source ◽  
Path Length ◽  
Color Difference ◽  
Light Path ◽  
Light Spectrum ◽  
Strong Absorption Band ◽  
Vis Spectroscopy ◽  
Path Lengths ◽  
New Perspective

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.

scholarly journals Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment

2016 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Dessy Ariyanti ◽  
Junzhe Dong ◽  
Junye Dong ◽  
Wei Gao
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Titanium Dioxide Nanoparticles ◽  
Wide Bandgap ◽  
Reaction Engineering ◽  
Photocatalytic Properties ◽  
Light Spectrum ◽  
Visible Light Range ◽  
Visible Light Photocatalytic

<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>

scholarly journals Modular, Self-Assembling Metallaphotocatalyst for Cross-Couplings Using the Full Visible-Light Spectrum

ACS Catalysis ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 13269-13274
Author(s):  
Susanne Reischauer ◽  
Volker Strauss ◽  
Bartholomäus Pieber
Keyword(s):  
Visible Light ◽  
Light Spectrum ◽  
Self Assembling
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