Preparation of tungstophosphoric acid/cerium-doped NH2-UiO-66 Z-scheme photocatalyst: A new candidate for green photo-oxidation of dibenzothiophene and quinoline using molecular oxygen as oxidant

2021 ◽  
Author(s):  
Hanieh Fakhri ◽  
Ali Esrafili ◽  
Mahdi Farzadkia ◽  
Rabah Boukherroub ◽  
Varsha Srivastava ◽  
...  
Keyword(s):  
Visible Light ◽  
Molecular Oxygen ◽  
Oxidative Desulfurization ◽  
Tungstophosphoric Acid ◽  
High Ability ◽  
Photo Oxidation ◽  
Photocatalytic System

The goal of this study was to introduce an effective visible-light induced photocatalytic system with high ability of photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as...

scholarly journals Synthesis of Xanthones, Thioxanthones and Acridones by a Metal-Free Photocatalytic Oxidation Using Visible Light and Molecular Oxygen

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 974
Author(s):  
Alejandro Torregrosa-Chinillach ◽  
Rafael Chinchilla
Keyword(s):  
Visible Light ◽  
Molecular Oxygen ◽  
Blue Light ◽  
Photocatalytic Oxidation ◽  
Photo Oxidation ◽  
Metal Free

9H-Xanthenes, 9H-thioxanthenes and 9,10-dihydroacridines can be easily oxidized to the corresponding xanthones, thioxanthones and acridones, respectively, by a simple photo-oxidation procedure carried out using molecular oxygen as oxidant under the irradiation of visible blue light and in the presence of riboflavin tetraacetate as a metal-free photocatalyst. The obtained yields are high or quantitative.

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.

Visible Light Driven Degradation of Terephthalic Acid: Optimization of Energy Demand by Light Modulation Techniques

2020 ◽  
Vol 01 ◽  
Author(s):  
Diana Sannino ◽  
Vincenzo Vaiano ◽  
Olga Sacco ◽  
Nicola Morante ◽  
Luca De Guglielmo ◽  
...  
Keyword(s):  
Visible Light ◽  
White Light ◽  
Terephthalic Acid ◽  
Kinetic Constant ◽  
Fixed Bed ◽  
Light Modulation ◽  
Photocatalytic Reactor ◽  
Sinusoidal Modulation ◽  
Photocatalytic System ◽  
Modulation Techniques

Aims: The aim of this work was to investigate the impact of light modulation parameters on the degradation of terephtalic acid, an organic model pollutant, within a heterogeneous photocatalytic system under visible light. For this purpose, a fixed bed photocatalytic reactor, irradiated by white-light LEDs matrix controlled by a system for light dimming, was used. The bed consisted of a nitrogen-doped titania photocatalyst deposited on polystyrene pellets. Background: Wastewater containing TPA can be treated into conventional aerobic biological units. However, the mineralization of TPA is slow and inefficient and its presence influences negatively the biodegradation efficiency because this pollutant inhibits microbial growth. Nowadays innovative technologies named advanced oxidation processes (AOPs), such as heterogeneous photocatalysis with UV and visible light, ozonation, Fenton oxidation have gained popularity for effective organic destruction of TPA from wastewater. The heterogeneous photocatalytic oxidation process of the TPA under visible light is the most advantageous process in terms of both fixed and operating costs. Objective: In this work the successful application of light modulation techniques to degradation of TPA using a photocatalytic system with supported visible active photocatalysts (N-doped TiO2) immobilized on polystyrene pellets was reported. In particular, sinusoidal lighting has been used analyzing the influence of the period of oscillation and the amplitude of the light modulation on the reaction kinetics, in such a way as to minimize the times and energy costs for the process. Methods: To evaluate the influence of light modulation on the efficiency of the TPA removal, a discontinuous system composed by a Recirculating Photocatalytic Fixed Bed Reactor (RPFBR) irradiated by a matrix of white light LEDs was used. The flat geometry of photoreactor guarantees the efficient excitation of photocatalyst. An amount of 250 mL of aqueous solution with initial TPA concentration of 12.5 ppm was applied in the photocatalytic tests lasting 180 min of irradiation fixed or sinusoidal modulated. Results: The results show that the variation of the oscillation period of the sinusoidal modulation has a relevant influence on the photodegradation of TPA and a maximum value of the apparent kinetic constant, 0.0045 min-1 is found when the period of oscillation is 0.24 s. The sinusoidal modulation with optimal amplitude is that with current between 50-200 mA, that shows the highest value of the apparent kinetic constant, equal to 0.0046 min-1. The optimal sinusoidal modulation, as a consequence is with current between 50-200 mA and period of 0.24 s. From the data collected from the tests, it is possible to evaluate the energy cost necessary to obtain the reduction of 90% of the terephthalic acid in 1 m3 of polluted water for each modulation (E E/O ), and compare these values with other tests for TPA degradation reported in the literature. The internal comparison and with the three systems of literature showed the optima sinusoidal modulation of LEDs matrix permits a strong reduction the electrical energy consumption. Conclusion: Photocatalytic tests have demonstrated the improvement of the process energy efficiency using the light modulation technique . A further confirmation of the advantage of light modulation was obtained by comparing the energy costs required for the abatement of 90% of the terephthalic acid in 1m 3 of the photocatalytic system. Finally, a mathematical model for photocatalytic degradation of terephthalic acid within the recirculating fixed bed photocatalytic reactor, irradiated by white-light LEDs was developed.

Visible-Light-Mediated Organoboron-Catalysed Metal-Free Dehydrogenation of N-Heterocycles Using Molecular Oxygen

2021 ◽  
Author(s):  
Lanfeng Wei ◽  
Yu Wei ◽  
Jinli Zhang ◽  
Liang Xu
Keyword(s):  
Visible Light ◽  
Molecular Oxygen ◽  
The Other ◽  
Metal Free ◽  
Other Hand

The surge of photocatalytic transformation not only provides unprecedented synthetical methods, but also triggers the enthusiasm for more sustainable photocatalysts. On the other hand, oxygen is an ideal oxidant in...

Visible-light-responsive lanthanide coordination polymers for highly efficient photocatalytic aerobic oxidation of amines and thiols

2021 ◽  
Author(s):  
Zhifen Guo ◽  
Xin Liu ◽  
Yan Che ◽  
Hongzhu Xing ◽  
Peng Chen
Keyword(s):  
Visible Light ◽  
Molecular Oxygen ◽  
Coordination Polymers ◽  
Aerobic Oxidation ◽  
Synthesis And Characterization ◽  
Lanthanide Coordination Polymers ◽  
Highly Efficient ◽  
Photocatalytic Reactions ◽  
Energy Issues

Development of visible-light-induced photocatalytic reactions using molecular oxygen as terminal oxidant is intriguing in view of the current environmental and energy issues. We report herein the synthesis and characterization of...

Visible light induced photo-oxidation of water. Formation of intermediary hydroxyl radicals through the photoexcited triplet state of perfluorophenazine

1997 ◽  
Vol 93 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Takayuki Kitamura ◽  
Hiroyuki Fudemoto ◽  
Yuji Wada ◽  
Kei Murakoshi ◽  
Mitsuhiro Kusaba ◽  
...  
Keyword(s):  
Visible Light ◽  
Triplet State ◽  
Hydroxyl Radicals ◽  
Photo Oxidation ◽  
Water Formation

The Oxidative Desulfurization of HDS Diesel: Using Aldehyde and Molecular Oxygen in the Presence of Cobalt Catalysts

2011 ◽  
Vol 29 (6) ◽  
pp. 626-632 ◽  
Author(s):  
T. V. Rao ◽  
P. M. Krishna ◽  
D. Paul ◽  
B. R. Nautiyal ◽  
J. Kumar ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Oxidative Desulfurization ◽  
Cobalt Catalysts
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