Bactericidal Activity of Multilayered Hybrid Structures Comprising Titania Nanoparticles and CdSe Quantum Dots under Visible Light

Titania nanoparticle/CdSe quantum dot hybrid structures are a promising bactericidal coating that exhibits a pronounced effect against light-sensitive bacteria. Here, we report the results of a comprehensive study of the photophysical properties and bactericidal functionality of these hybrid structures on various bacterial strains. We found that our structures provide the efficient generation of superoxide anions under the action of visible light due to electron transfer from QDs to titania nanoparticles with ~60% efficiency. We also tested the antibacterial activity of hybrid structures on five strains of bacteria. The formed structures combined with visible light irradiation effectively inhibit the growth of Escherichia coli, Bacillus subtilis, and Mycobacterium smegmatis bacteria, the last of which is a photosensitive causative agent model of tuberculosis.

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Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.15.197 ◽

2019 ◽

Vol 15 ◽

pp. 2013-2019 ◽

Cited By ~ 1

Author(s):

Esther Nieland ◽

Oliver Weingart ◽

Bernd M Schmidt

Keyword(s):

Solid State ◽

Dft Calculations ◽

Visible Light ◽

Half Life ◽

Photophysical Properties ◽

Bathochromic Shift ◽

Halogen Bonding ◽

Building Blocks ◽

Partial Overlap

ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular building blocks both in solution and in the solid state in combination with neutral halogen bonding acceptors, such as lutidines. Therefore, we investigate the photochemistry of a series of azobenzene photoswitches. Upon introduction of iodoethynyl groups, the halogen bonding donor properties are significantly strengthened in solution. However, the bathochromic shift of the π→π* band leads to a partial overlap with the n→π* band, making it slightly more difficult to address. The introduction of iodine substituents is furthermore accompanied with a diminishing thermal half-life. A series of three azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations.

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Facile Low-Temperature Synthesis of Carbon Nanotube/ Nanohybrids with Enhanced Visible-Light-Driven Photocatalytic Activity

International Journal of Photoenergy ◽

10.1155/2012/682138 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

Yunlong Xie ◽

Huanhuan Qian ◽

Yijun Zhong ◽

Hangming Guo ◽

Yong Hu

Keyword(s):

Carbon Nanotubes ◽

Photocatalytic Activity ◽

Visible Light ◽

Chemical Precipitation ◽

Hybrid Structures ◽

Low Temperature Synthesis ◽

Temperature Synthesis ◽

Titanium Sulfate ◽

Visible Light Driven ◽

Degussa P25

We demonstrate a facile and novel chemical precipitation strategy for the accurate coating of TiO2nanoparticles on the surface of carbon nanotubes (CNTs) to form CNT/TiO2nanohybrids, which only requires titanium sulfate and CNTs as starting materials and reacts in the alkaline solution at 60°C for 6 h. Using this process, the as-prepared hybrid structures preserved the good dispersity and uniformity of initial CNTs. Furthermore, the CNT/TiO2nanohybrids show a broad blue luminescence at 469 nm and exhibit significantly enhanced photocatalytic activity for the degradation of rhodamine B (RhB) under visible-light irradiation, which is about 1.5 times greater than that of commercial Degussa P25 TiO2nanoparticles. It is believed that this facile chemical precipitation strategy is scalable and its application can be extended to synthesize other CNT/oxide nanohybrids for various applications.

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Fabrication of carbon microspheres@PbMoO4 core–shell hybrid structures and its visible light-induced photocatalytic activity

Catalysis Communications ◽

10.1016/j.catcom.2012.03.033 ◽

2012 ◽

Vol 24 ◽

pp. 85-89 ◽

Cited By ~ 11

Author(s):

Qingchun Chen ◽

Qingsheng Wu

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Hybrid Structures ◽

Core Shell ◽

Carbon Microspheres

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Coupling Ni-substituted polyoxometalate catalysts with water-soluble CdSe quantum dots for ultraefficient photogeneration of hydrogen under visible light

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2021.120893 ◽

2021 ◽

pp. 120893

Author(s):

Mo Zhang ◽

Xing Xin ◽

Yeqin Feng ◽

Junhao Zhang ◽

Hongjin Lv ◽

...

Keyword(s):

Quantum Dots ◽

Visible Light ◽

Water Soluble ◽

Cdse Quantum Dots

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In silico and in vitro approach of Allium cepa and isolated quercetin against MDR bacterial strains and Mycobacterium smegmatis

South African Journal of Botany ◽

10.1016/j.sajb.2019.04.019 ◽

2019 ◽

Vol 124 ◽

pp. 29-35 ◽

Cited By ~ 2

Author(s):

D. Sharma ◽

R. Rani ◽

M. Chaturvedi ◽

P. Rohilla ◽

J.P. Yadav

Keyword(s):

Allium Cepa ◽

Mycobacterium Smegmatis ◽

In Silico ◽

Bacterial Strains

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A Novel Route to Manufacture 2D Layer MoS2 and g-C3N4 by Atmospheric Plasma with Enhanced Visible-Light-Driven Photocatalysis

Nanomaterials ◽

10.3390/nano9081139 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1139 ◽

Cited By ~ 8

Author(s):

Bo Zhang ◽

Zhenhai Wang ◽

Xiangfeng Peng ◽

Zhao Wang ◽

Ling Zhou ◽

...

Keyword(s):

Visible Light ◽

Photophysical Properties ◽

Atmospheric Plasma ◽

Average Lifetime ◽

Bulk Materials ◽

Degradation Rates ◽

Excellent Photocatalytic Activity ◽

Visible Light Driven ◽

Ultrathin Nanosheet ◽

Gas Expansion

An atmospheric plasma treatment strategy was developed to prepare two-dimensional (2D) molybdenum disulfide (MoS2) and graphitic carbon nitride (g-C3N4) nanosheets from (NH4)2MoS4 and bulk g-C3N4, respectively. The moderate temperature of plasma is beneficial for exfoliating bulk materials to thinner nanosheets. The thicknesses of as-prepared MoS2 and g-C3N4 nanosheets are 2–3 nm and 1.2 nm, respectively. They exhibited excellent photocatalytic activity on account of the nanosheet structure, larger surface area, more flexible photophysical properties, and longer charge carrier average lifetime. Under visible light irradiation, the hydrogen production rates of MoS2 and g-C3N4 by plasma were 3.3 and 1.5 times higher than the corresponding bulk materials, respectively. And g-C3N4 by plasma exhibited 2.5 and 1.3 times degradation rates on bulk that for methyl orange and rhodamine B, respectively. The mechanism of plasma preparation was proposed on account of microstructure characterization and online mass spectroscopy, which indicated that gas etching, gas expansion, and the repulsive force of electron play the key roles in the plasma exfoliation. Plasma as an environmentally benign approach provides a general platform for fabricating ultrathin nanosheet materials with prospective applications as photocatalysts for pollutant degradation and water splitting.

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A Comprehensive Study on Light Signals of Opportunity for Subdecimetre Unmodulated Visible Light Positioning

Sensors ◽

10.3390/s20195596 ◽

2020 ◽

Vol 20 (19) ◽

pp. 5596

Author(s):

Sander Bastiaens ◽

Kenneth Deprez ◽

Luc Martens ◽

Wout Joseph ◽

David Plets

Keyword(s):

Visible Light ◽

Lower Cost ◽

Tracking System ◽

Low Cost ◽

Discriminative Feature ◽

Robust Model ◽

Significant Step ◽

Light Signals ◽

Signals Of Opportunity ◽

Comprehensive Study

Currently, visible light positioning (VLP) enabling an illumination infrastructure requires a costly retrofit. Intensity modulation systems not only necessitate changes to the internal LED driving module, but decrease the LEDs’ radiant flux as well. This hinders the infrastructure’s ability to meet the maintained illuminance standards. Ideally, the LEDs could be left unmodulated, i.e., unmodulated VLP (uVLP). uVLP systems, inherently low-cost, exploit the characteristics of the light signals of opportunity (LSOOP) to infer a position. In this paper, it is shown that proper signal processing allows using the LED’s characteristic frequency (CF) as a discriminative feature in photodiode (PD)-based received signal strength (RSS) uVLP. This manuscript investigates and compares the aptitude of (future) RSS-based uVLP and VLP systems in terms of their feasibility, cost and accuracy. It demonstrates that CF-based uVLP exhibits an acceptable loss of accuracy compared to (regular) VLP. For point source-like LEDs, uVLP only worsens the trilateration-based median p50 and 90th percentile root-mean-square error p90 from 5.3cm to 7.9cm (+50%) and from 9.6cm to 15.6cm (+62%), in the 4m × 4m room under consideration. A large experimental validation shows that employing a robust model-based fingerprinting localisation procedure, instead of trilateration, further boosts uVLP’s p50 and p90 accuracy to 5.0cm and 10.6cm. When collating with VLP’s p50=3.5cm and p90=6.8cm, uVLP exhibits a comparable positioning performance at a significantly lower cost and at a higher maintained illuminance, all of which underline uVLP’s high adoption potential. With this work, a significant step is taken towards the development of an accurate and low-cost tracking system.

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