scholarly journals Antiviral Coatings as Continuously Active Disinfectants

2021 ◽  
Author(s):  
Luisa A. Ikner ◽  
Charles P. Gerba
Keyword(s):  
Titanium Dioxide ◽  
Free Radicals ◽  
Nucleic Acids ◽  
Visible Light ◽  
Quaternary Ammonium ◽  
Uv Light ◽  
Virus Transmission ◽  
Antimicrobial Surfaces ◽  
Bacteria And Fungi ◽  
Growth Of Bacteria

Antimicrobial surfaces and coatings have been available for many decades and have largely been designed to kill or prevent the growth of bacteria and fungi. Antiviral coatings have become of particular interest more recently during the COVID-19 pandemic as they are designed to act as continuously active disinfectants. The most studied antiviral coatings have been metal-based or are comprised of silane quaternary ammonium formulations. Copper and silver interact directly with proteins and nucleic acids, and influence the production of reactive free radicals. Titanium dioxide acts as a photocatalyst in the presence of water and oxygen to produce free radicals in the presence of UV light or visible light when alloyed with copper or silver. Silane quaternary ammonium formulations can be applied to surfaces using sprays or wipes, and are particularly effective against enveloped viruses. Continuously active disinfectants offer an extra barrier against fomite-mediated transmission of respiratory and enteric viruses to reduce exposure between routine disinfection and cleaning events. To take advantage of this technology, testing methods need to be standardized and the benefits quantified in terms of reduction of virus transmission.

Visible light inactivation of bacteria and fungi by modified titanium dioxide

2007 ◽  
Vol 6 (6) ◽  
pp. 642-648 ◽  
Author(s):  
Dariusz Mitoraj ◽  
Agnieszka Jańczyk ◽  
Magdalena Strus ◽  
Horst Kisch ◽  
Grażyna Stochel ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Bacteria And Fungi ◽  
Inactivation Of Bacteria

Preparation of visible light active S-doped TiO2 photocatalysts and their photocatalytic activities

2004 ◽  
Vol 49 (4) ◽  
pp. 159-163 ◽  
Author(s):  
T. Ohno
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Uv Light ◽  
Anatase Phase ◽  
Xps Spectra ◽  
Tio2 Photocatalysts ◽  
Chemically Modified ◽  
Tio2 Particles ◽  
Photocatalytic Activities ◽  
Visible Light Active

Although titanium dioxide photocatalysts having an anatase phase are a promising substrate for photodegradation of pollutants in water and air, their photocatalytic activities show only under UV light. To utilize solar light which has a large amount of visible light, the development of the photocatalysts whose activities show under visible light is one of the most important strategies. We have succeeded in synthesizing chemically modified titanium dioxide photocatalysts in which S (S4+) substitutes for some of the lattice titanium atoms. They show strong absorption for visible light and high activities for degradation of 2-propanol in aqueous solution and partial oxidation of adamantane in acetonitrile under irradiation at wavelengths longer than 440 nm. The oxidation state of the S atoms incorporated into the TiO2 particles is determined to be mainly S4+ from XPS spectra.

scholarly journals Preparation and Characterization of Copper, Iron, and Nickel Doped Titanium Dioxide Photocatalysts for Decolorization of Methylene Blue

2021 ◽  
Vol 50 (1) ◽  
pp. 135-149
Author(s):  
Jawed Qaderi ◽  
Che Rozid Mamat ◽  
Aishah Abdul Jalil
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Uv Light ◽  
Irradiation Time ◽  
Sol Gel ◽  
Light Response ◽  
Pure Tio2 ◽  
Necessary Condition ◽  
Doped Tio2 ◽  
Bet Analysis

The visible-light response is a necessary condition for titanium dioxide (TiO2) photocatalyst to function as a visible light active photocatalyst. This condition can be solved by investigation of the bandgaps and the optimization of doping levels of multivalency metal-doped TiO2. In this study, pure and Cu, Fe, and Ni-doped TiO2 photocatalysts were prepared by the sol‐gel method. The photocatalysts were characterized using XRD, FTIR, FESEM, EDX, N2 physisorption, and UV‐Vis spectrophotometry techniques. The XRD patterns of all pure TiO2 and Cu/TiO2, Fe/TiO2, and Ni/TiO2samples showed the dominant structure of the anatase TiO2 phase. The presence of functional groups at the interface of TiO2 particles was showed by FTIR. The FESEM analysis showed that the particle size of the prepared samples was uniform with spherical morphology. EDX results showed that TiO2 has successfully incorporated Cu, Fe, and Ni metals onto its surface. The BET analysis showed that the specific surface area of the doped samples increased with the amount of doping. The optical properties of all samples were carried out using UV-DRS measurements and their obtained bandgap energies were in the range of 3.22 - 3.42 eV. The pure TiO2 displayed more than 98% and 97% decolorization rates for MB solution at the end of irradiation time of 5 h under UV and visible light, respectively. Among the doped samples, 3 mol% Ni/TiO2 and Cu/TiO2 demonstrated the highest photocatalytic activity (97.65%) under UV light and 6 mol% Ni/TiO2 under visible light for MB (96.86%) decolorization.

scholarly journals Surface modification of titanium dioxide nanotubes with sulfur for highly efficient photocatalytic performance under visible light irradiation

2018 ◽  
Vol 21 (3) ◽  
pp. 98-105 ◽  
Author(s):  
Ton Nu Quynh Trang ◽  
Le Thi Ngoc Tu ◽  
Co Le Thanh Tuyen ◽  
Tran Van Man ◽  
Vu Thi Hanh Thu
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Uv Light ◽  
Critical Role ◽  
Treatment Temperature ◽  
Chemical Components ◽  
X Ray ◽  
Transmission Electron ◽  
Tio2 Nts ◽  
Modification Of Titanium

In this paper, the surface of titanium dioxide (TiO2) nanotubes (NTs) was decorated with sulfur by impregnation procedure. The crystalline structure and morphology of the S-TiO2 NT hybrid catalyst were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The chemical components of S-TiO2 NT-1 sample were analyzed by energy dispersive X-ray (EDX). The results showed that sulfur impurities were incorporated into TiO2 crystal structure and decorated on its surface due to the heat treatment temperature used throughout the fabrication process. Moreover, its photocatalytic reaction was evaluated by change of adsorption intensity of methyl orange (MO) aqueous solution at wavelength of 467 nm. This work revealed that the sulfur loaded onto TiO2 NT nanostructures exhibited excellent photocatalytic efficacy for the degradation of the MO dye compared with pristine TiO2 NTs (93.12 ± 0.02% and 80.21 ± 0.04% MO degradation efficacy under UV light versus visible-light regime, respectively, after 180 minutes). This was mainly governed by sulfur ions modified on the surface of TiO2 NTs which played a critical role in promoting the separation rate of photo-induced charge carriers.  

Visible-Light Activated [2+2] Photocycloaddition Reaction Enabled Identification of Carbon-Carbon Double Bonds Position Isomerism in Structural Lipidomics

2020 ◽  
Author(s):  
Guifang Feng ◽  
Yanhong Hao ◽  
Liang Wu ◽  
Suming Chen
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Practical Importance ◽  
Side Reactions ◽  
Potential Health ◽  
Fundamental Interest ◽  
Unsaturated Lipids ◽  
Health Damage ◽  
Global Identification ◽  
Polyunsaturated Lipids

The photocycloaddition of olefins with carbonyls is of fundamental interest and practical importance in C=C bond location in unsaturated lipids. However, the traditional UV light activated [2+2] photocycloaddition reaction suffers side reactions and potential health damage. Here, we reported the first example of visible-light activated [2+2] photocycloaddition of anthraquinone with unsaturated lipids. This reaction showed great capability for locating the C=C bonds in various kinds of monounsaturated and polyunsaturated lipids by combining with tandem mass spectrometry (MS), such as fatty acids, phospholipids and glycerides. Based on this developed reaction, a workflow with liquid chromatography tandem MS method was developed for the global identification of unsaturated lipids in human serum, and 86 of monounsaturated and complicated polyunsaturated lipids were identified with definitive positions of C=C bonds. This approach provides new insights both on the photocycloaddition reactions and the structural lipidomics.

Green Synthesis of ZnO/Dy/NiO Heterostructures for Enhanced Photocatalytic Applications

2020 ◽  
Vol 1 (1) ◽  
pp. 30-36
Author(s):  
Shubha Jayachamarajapura Pranesh ◽  
Diwya Lanka
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Combustion Method ◽  
Hybrid Nanocomposites ◽  
Synthetic Dyes ◽  
Hybrid Nanostructure ◽  
Wide Range ◽  
Visible Light Active ◽  
Textile Industries ◽  
Photocatalytic Applications

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.

scholarly journals Visible Light Photochemical Reactions for Nucleic Acid-Based Technologies

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 556
Author(s):  
Bonwoo Koo ◽  
Haneul Yoo ◽  
Ho Jeong Choi ◽  
Min Kim ◽  
Cheoljae Kim ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Visible Light ◽  
Chemical Reactions ◽  
Chemical Biology ◽  
Photochemical Reactions ◽  
Reaction Conditions ◽  
Promising Tool ◽  
Recent Developments ◽  
Visible Light Driven

The expanding scope of chemical reactions applied to nucleic acids has diversified the design of nucleic acid-based technologies that are essential to medicinal chemistry and chemical biology. Among chemical reactions, visible light photochemical reaction is considered a promising tool that can be used for the manipulations of nucleic acids owing to its advantages, such as mild reaction conditions and ease of the reaction process. Of late, inspired by the development of visible light-absorbing molecules and photocatalysts, visible light-driven photochemical reactions have been used to conduct various molecular manipulations, such as the cleavage or ligation of nucleic acids and other molecules as well as the synthesis of functional molecules. In this review, we describe the recent developments (from 2010) in visible light photochemical reactions involving nucleic acids and their applications in the design of nucleic acid-based technologies including DNA photocleaving, DNA photoligation, nucleic acid sensors, the release of functional molecules, and DNA-encoded libraries.

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