Search results for "Visible spectrum"

A study on the sensitivities of simulated aerosol optical properties to composition and size distribution using airborne measurements

2014

We present a flexible framework to calculate the optical properties of atmospheric aerosols at a given relative humidity based on their composition and size distribution. The similarity of this framework to climate model parameterisations allows rapid and extensive sensitivity tests of the impact of uncertainties in data or of new measurements on climate relevant aerosol properties. The data collected by the FAAM BAe-146 aircraft during the EUCAARI-LONGREX and VOCALS-REx campaigns have been used in a closure study to analyse the agreement between calculated and measured aerosol optical properties for two very different aerosol types. The agreement achieved for the EUCAARI-LONGREX flights is…

Multi-doped Brookite-Prevalent TiO2 Photocatalyst with Enhanced Activity in the Visible Light

2018

© 2018 Springer Science+Business Media, LLC, part of Springer Nature Abstract: Enabling solar and/or visible light-driven photocatalysis is a crucial step to access innovative applications in environmental science and sustainable energy. Titanium dioxide is the most used photocatalyst because of its low cost and toxicity, however it is also limitedly active under visible light irradiation due to its wide band gap. Among its polymorphs, brookite holds promising optoelectronic properties for visible light photocatalysis, which have to the best of our knowledge been limitedly exploited. Here, a C,S,N-doped brookite-based TiO2has been prepared via a rapid one-pot sol–gel synthesis. Besides subs…

Synthesis and photovoltaic performance of the porphyrin based sensitizers with 2H-[1,2,3]triazolo[4,5-c]pyridine and benzotriazole as auxiliary accep…

2017

Abstract Two novel zinc porphyrin dyes containing either benzotriazole or 2 H -[1,2,3]triazolo[4,5- c ]pyridine as auxiliary acceptors, respectively, were synthesized for dye-sensitized solar cells. These two auxiliary acceptors were firstly applied into porphyrin based dyes. The photophysical and electrochemical properties of the dyes were investigated. These two dyes show the whole visible light absorption when they are adsorbed on the TiO 2 film, which means that they are promising sensitizers for dye-sensitized solar cells. The absorption intensity of the triazolopyridine containing dye is higher than that of the benzotriazole containing dye, resulting in a better light harvesting. Thus…

Visible-Light Organophotoredox-Catalyzed Synthesis of Precursors for Horner-Type Olefinations

2018

Wavelength dependence of oxidative DNA damage induced by UV and visible light.

1997

DNA damage induced by UV radiation and visible light (290-500 nm) in AS52 Chinese hamster cells was analysed by an alkaline elution assay with specific repair endonucleases. Cells were exposed to extensively filtered monochrome or broad-band radiation. Between 290 and 315 nm, the ratio of base modifications sensitive to Fpg protein (i.e. 8-hydroxyguanine and formamidopyrimidines) and T4 endonuclease V (i.e. cyclobutane pyrimidine dimers) was constant (approximately 1:200), indicating that the direct excitation of DNA is responsible for both types of damage in this range of the spectrum. While the yield of pyrimidine dimers per unit dose continued to decrease exponentially beyond 315 nm, the…

Highly Efficient Electron Transfer in a Carbon Dot–Polyoxometalate Nanohybrid

2020

Using solar radiation to fuel catalytic processes is often regarded as the solution to our energy needs. However, developing effective photocatalysts that are active under visible light has proven to be difficult, often due to the toxicity, instability, and high cost of suitable catalysts. We engineered a novel photoactive nanomaterial obtained by the spontaneous electrostatic coupling of carbon nanodots with [P2W18O62]6-, a molecular catalyst belonging to the class of polyoxometalates. While the former are used as photosensitizers, the latter was chosen for its ability to catalyze reductive reactions such as dye decomposition and water splitting. We find the electron transfer within the na…

Cover Feature: Visible Light‐Induced Sulfonylation/Arylation of Styrenes in a Double Radical Three‐Component Photoredox Reaction (Chem. Eur. J. 38/20…

2019

Superatomic S2 Silver Clusters Stabilized by a Thiolate–Phosphine Monolayer: Insight into Electronic and Optical Properties of Ag14(SC6H3F2)12(PPh3)8…

2014

The electronic structure of two recently crystallographically solved, thiolate–phosphine protected silver clusters Ag14 and Ag16 are analyzed via density functional theory (DFT) and their optical excitations are analyzed from time-dependent DFT perturbation theory. Both clusters can be characterized as having the S2 free-electron configuration in the metal core, which is the first time such a configuration is confirmed for structurally known ligand-protected noble metal clusters. However, their different core shapes and ligand layer induce significantly different optical spectra. Performance of gradient-corrected DFT functionals is discussed and it is shown that the asymptotically correct L…

Visible‐Light‐Induced Cleavage of C−S Bonds in Thioacetals and Thioketals with Iodine as a Photocatalyst

2020

Rhodanine-based dyes absorbing in the entire visible spectrum

2017

A series of new broad-absorbing dyes based on rhodanine derivatives conjugated with triarylamines using Q5 a fluorene backbone was synthesized. Spectroscopic and electrochemical characterizations, along with theoretical calculations at the B3LYP/cc-pVDZ level, revealed interesting properties of the dyes, which make the dyes efficiently absorb in the entire visible spectrum.