scholarly journals Performance of Ag-TiO2Photocatalysts towards the Photocatalytic Disinfection of Water under Interior-Lighting and Solar-Simulated Light Irradiations

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Camilo A. Castro ◽  
Adriana Jurado ◽  
Diana Sissa ◽  
Sonia A. Giraldo
Keyword(s):  
Visible Light ◽  
Singlet Oxygen ◽  
Sorption Isotherms ◽  
Textural Properties ◽  
Bactericidal Effect ◽  
Oxygen Scavenger ◽  
Visible Light Absorption ◽  
Photocatalytic Disinfection ◽  
Interior Lighting ◽  
Inactivation Process

This paper reports the characterization and photoactivity of Ag-TiO2materials using different amounts of silver during the hydrothermal synthesis. Photocatalysts were characterized by means of TEM, XPS, XRD, DRS, and N2sorption isotherms to determine the textural properties. The photocatalyst's configuration was observed to be as anatase-brookite mixed phase particles with Ag partially oxidized aggregates on the TiO2surface, which increased visible light absorption of the material. Moreover, photoproduction of singlet oxygen was followed by EPR analysis under visible light irradiations following the formation of TEMPOL. Such photoproduction was totally decreased by using the singlet oxygen scavenger DABCO. Photocatalysts were tested towards the photocatalytic disinfection of water suing a solar light simulator and an interior-light irradiation setup. Results evidenced an increase in the photooxidative effect of TiO2, while dark processes evidenced that part of the inactivation process is due to the Ag-TiO2surface bactericidal effect and possible lixiviated Ag+.

Conjugated copolymer–photosensitizer molecular hybrids with broadband visible light absorption for efficient light-harvesting and enhanced singlet oxygen generation

2015 ◽  
Vol 3 (5) ◽  
pp. 973-976 ◽  
Author(s):  
Rongkun He ◽  
Ming Hu ◽  
Ting Xu ◽  
Chunxiang Li ◽  
Chuanliu Wu ◽  
...  
Keyword(s):  
Visible Light ◽  
Singlet Oxygen ◽  
Light Absorption ◽  
Light Harvesting ◽  
Visible Absorption ◽  
Visible Light Absorption ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Molecular Hybrids ◽  
Conjugated Copolymer

We have developed conjugated copolymer–photosensitizer molecular hybrids (PFBDBP–IPBP) with a strong, broad (from <400 nm to ∼700 nm) and continuous visible absorption.

Optical Properties of Photodynamic Therapy Drugs in Different Environments: The Paradigmatic Case of Temoporfin

2020 ◽  
Author(s):  
busenur Aslanoglu ◽  
Ilya Yakavets ◽  
Vladimir Zorin ◽  
Henri-Pierre Lassalle ◽  
Francesca Ingrosso ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Optical Properties ◽  
Photodynamic Therapy ◽  
Minimally Invasive ◽  
Visible Light ◽  
Cancer Treatment ◽  
Singlet Oxygen ◽  
Tumor Cells ◽  
Molecular Oxygen ◽  
Computational Tools

Computational tools have been used to study the photophysical and photochemical features of photosensitizers in photodynamic therapy (PDT) –a minimally invasive, less aggressive alternative for cancer treatment. PDT is mainly based by the activation of molecular oxygen through the action of a photoexcited sensitizer (photosensitizer). Temoporfin, widely known as mTHPC, is a second-generation photosensitizer, which produces the cytotoxic singlet oxygen when irradiated with visible light and hence destroys tumor cells. However, the bioavailability of the mostly hydrophobic photosensitizer, and hence its incorporation into the cells, is fundamental to achieve the desired effect on malignant tissues by PDT. In this study, we focus on the optical properties of the temoporfin chromophore in different environments –in <i>vacuo</i>, in solution, encapsulated in drug delivery agents, namely cyclodextrin, and interacting with a lipid bilayer.

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

Double Doping of NaTaO3 Photocatalysts with Lanthanum and Manganese for Strongly Enhanced Visible-Light Absorption

2019 ◽  
Vol 2 (10) ◽  
pp. 7518-7526 ◽  
Author(s):  
Hanggara Sudrajat ◽  
Mitsunori Kitta ◽  
Nobuyuki Ichikuni ◽  
Hiroshi Onishi
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Visible Light Absorption ◽  
Double Doping

Carrier Engineering of Zr-mediated Ta3N5 Film as Efficient Photoanode for Solar Water Splitting

2021 ◽  
Author(s):  
Xin Zou ◽  
Xueyang Han ◽  
Chengxiong Wang ◽  
Yunkun Zhao ◽  
Chun Du ◽  
...  
Keyword(s):  
Band Structure ◽  
Visible Light ◽  
Water Splitting ◽  
Light Absorption ◽  
Photoelectrochemical Water Splitting ◽  
Promising Candidate ◽  
Visible Light Absorption ◽  
Solar Water ◽  
Solar Water Splitting

Ta3N5 is regarded as a promising candidate material with adequate visible light absorption and band structure for photoelectrochemical water splitting. However, the performance of Ta3N5 is severely limited by the...

Tetragonal Tungsten Bronze Type Sn(II)-Based Quaternary Oxides: A New Type of Visible-Light-Absorbing Semiconductors for Photoelectrochemical Water Oxidation

2021 ◽  
Author(s):  
Yalong Zou ◽  
Jiabo Le ◽  
Yufeng Cao ◽  
Na An ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Visible Light ◽  
Water Oxidation ◽  
Tungsten Bronze ◽  
Complex Oxides ◽  
Tetragonal Tungsten Bronze ◽  
Visible Light Absorption ◽  
New Type ◽  
Hydrogen Fuels ◽  
Photoelectrochemical Water Oxidation ◽  
Pec Water Splitting

The attractive photoelectrochemical (PEC) water splitting for hydrogen fuels always desires new semiconductors which provide stronger visible light absorption with suitable band positions. Sn(II) complex oxides are expected to offer...

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