Photocatalytic Decomposition of Organic Dyes Using a Rotating Cylinder System

2021 ◽  
Vol 21 (8) ◽  
pp. 4544-4552
Author(s):  
Young-Sang Cho ◽  
Sohyeon Sung
Keyword(s):  
Rate Constant ◽  
Organic Dyes ◽  
Outer Cylinder ◽  
Rotating Cylinder ◽  
Organic Dye ◽  
Photocatalytic Decomposition ◽  
Nanoparticle Dispersion ◽  
Batch Mode ◽  
Factors Affecting ◽  
Repeated Batch

In this study, a rotating cylinder system was used in the photocatalytic decomposition of organic dyes in aqueous medium for water purification. To this end, the titania nanoparticle dispersion was mixed with an organic dye solution under a rotating inner cylinder at controlled speed. The rate constant was adjusted by changing the speed of rotation to determine the optimal circulating velocity. Since nanoparticle dispersion is a secondary contaminant after wastewater treatment, the titania paste was deposited on the inner surface of the stationary outer cylinder to form a photocatalytic film. During repeated batch-mode operation, the deactivation of the deposited film was analyzed by measuring the rate constant as a function of time. Continuous operation was also used to remove organic dye in the water to study factors affecting the removal efficiency of methylene blue. Higher rotating velocity and slow feed rate facilitated the removal of contaminants via desorption of adsorbed dyes with adequate retention time.

Fabrication of Silica Microspheres Containing TiO2 or Aluminum Zinc Oxide Nanoparticles via Self-Assembly: Application in Water Purification

2020 ◽  
Vol 20 (11) ◽  
pp. 6738-6746
Author(s):  
Young-Sang Cho ◽  
Yeonghyun Lee ◽  
Jun Kyu Park
Keyword(s):  
Zinc Oxide ◽  
Water Purification ◽  
Self Assembly ◽  
Organic Dyes ◽  
Aqueous Dispersion ◽  
Photocatalytic Decomposition ◽  
Nanoparticle Dispersion ◽  
Micro Particles ◽  
Micro Reactors ◽  
Aluminum Zinc Oxide

In this study, silica micro-particles containing titania (TiO2) or aluminum zinc oxide (AZO) nanopar-ticles were synthesized using emulsion droplets as micro-reactors, for water purification application via photocatalytic decomposition of organic dyes. Towards this end, aqueous silicic acid solution has been emulsified with aqueous dispersion of TiO2 or AZO nanoparticles in a continuous oil phase to form tiny droplets, followed by subsequent self-assembly of the droplets via evaporation. The resulting composite microparticles were controlled to obtain a spherical or porous morphology by adjusting the concentration of the nanoparticle dispersion. As a demonstrative application, the resulting composite micro-particles have been used as photocatalysts for the removal of methylene blue under UV irradiation. In the case of silica microparticles containing AZO nanoparticles, the adsorption of organic pollutants combined with photocatalytic decomposition was found to be effective, and trace amounts of the pollutant remained after the removal process.

Dual-wavelength lasing from organic dye encapsulated metal–organic framework microcrystals

2019 ◽  
Vol 55 (24) ◽  
pp. 3445-3448 ◽  
Author(s):  
Yue Zhang ◽  
Haiyun Dong ◽  
Yuan Liu ◽  
Chunhuan Zhang ◽  
Fengqin Hu ◽  
...  
Keyword(s):  
Organic Dyes ◽  
Metal Organic Framework ◽  
Organic Dye ◽  
Dual Wavelength ◽  
Metal Organic ◽  
Organic Framework

Efficient and stable dual-wavelength microlasers are obtained by simultaneously incorporating two kinds of organic dyes into metal–organic framework microcrystals.

scholarly journals Effectiveness of photodecomposition of rhodamine B and malachite green upon coupled tricomponent TiO2(Anatase-Rutile)/ZnO nanocomposite

2013 ◽  
Vol 6 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Dongfang Zhang
Keyword(s):  
Malachite Green ◽  
Rhodamine B ◽  
Active Sites ◽  
Diffuse Reflectance Spectroscopy ◽  
Organic Dyes ◽  
Synergistic Effects ◽  
Sol Gel ◽  
Photocatalytic Decomposition ◽  
Photoluminescence Intensity ◽  
Tio2 Anatase

Abstract In this study, mixed phase ZnO-TiO2 nanocomposite consisting of hexagonal ZnO and anatase/rutile TiO2 has been synthesized via sol-gel process.The physical and photochemical properties of samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminscience spectra (PL) and and photocurrent action spectra techniques. In the case of minerlization of rhodamine B (RhB) and malachite green (MG) dyes, the coupled ZnO-TiO2 nanocomposite with the suitable band structure and the lowest photoluminescence intensity showed the best photodecolorization activity. Synergistic effects between the two oxides for photocatalytic decomposition of RhB and MG are proposed to elucidate the decolorization mechanism. The lifetime of electrons and holes was prolonged in the ZnO-anatase/rutile multiple-component system, which can enhance the light harvest and the ability of generating photo-induced electron-hole pairs of active sites, and the favorable electron-transfer properties in the coupled ZnO-TiO2 nanocomposite. Therefore, the as-prepared ZnO-TiO2 nanocomposite showed an excellent efficiency towards the removal of aqueous organic dyes and it is of certain significance for environmental photocatalysis.

scholarly journals Detection of Tumor Marker CA125 in Ovarian Carcinoma Using Quantum Dots

2004 ◽  
Vol 36 (10) ◽  
pp. 681-686 ◽  
Author(s):  
Hui-Zhi Wang ◽  
Hai-Yan Wang ◽  
Ru-Qiang Liang ◽  
Kang-Cheng Ruan
Keyword(s):  
Quantum Dots ◽  
Ovarian Carcinoma ◽  
Laser Power ◽  
Organic Dyes ◽  
Organic Dye ◽  
Continuous Illumination ◽  
Tissue Sections ◽  
High Intensity Laser ◽  
Different Types ◽  
Intensity Laser

Abstract Semiconductor quantum dots (QDs) offer several advantages over organic dyes in fluorescence-imaging applications, such as higher quantum yield, exceptional photostability, and a narrow, tunable, and symmetric emission spectrum. To explore whether QDs could specifically and effectively label tumor markers and be used in immunohistochemistry as a novel type of fluorescent probe, we used quantum dots with maximum emission wavelength 605 nm (QD605) to detect the ovarian carcinoma marker CA125 in specimens of different types (fixed cells, tissue sections, and xenograft piece). Additionally, we compared the photostability of QD signals with that of a conventional organic dye, FITC. All labeling signals of QDs were found to be more specific and brighter than those of FITC. Moreover, the QDs exhibited exceptional photostability during continuous illumination for 1 h by a high-intensity laser (Ar laser power 100 mW) at 488 nm, while the FITC signals faded very quickly and became undetectable after 24 min of illumination. These results indicate that QD-based probes can offer substantial advantages over existing fluorophores in many applications, and can be used effectively in immunohistochemistry as a novel class of fluorescent probes.

scholarly journals Multifunctional organic dyes: anion-sensing and light-harvesting properties of curcumin boron complexes

RSC Advances ◽  
2017 ◽  
Vol 7 (58) ◽  
pp. 36612-36616 ◽  
Author(s):  
Masahiro Tsuchikawa ◽  
Aya Takao ◽  
Takashi Funaki ◽  
Hideki Sugihara ◽  
Katsuhiko Ono
Keyword(s):  
Light Harvesting ◽  
Organic Dyes ◽  
Organic Dye ◽  
Anion Sensing ◽  
Organoboron Compounds ◽  
New Type ◽  
Boron Complexes ◽  
Natural Phenols

Organoboron compounds containing curcumin (i.e. natural phenols) were synthesised as a new type of multifunctional organic dye.

Metal–organic redox vehicles to encapsulate organic dyes for photocatalytic protons and carbon dioxide reduction

2016 ◽  
Vol 3 (10) ◽  
pp. 1256-1263 ◽  
Author(s):  
Hao Yu ◽  
Cheng He ◽  
Jing Xu ◽  
Chunying Duan ◽  
Joost N. H. Reek
Keyword(s):  
Carbon Dioxide ◽  
Organic Dyes ◽  
Carbon Dioxide Reduction ◽  
Organic Dye ◽  
Photocatalytic Reduction ◽  
Metal Organic

By encapsulation of an organic dye, a supramolecular nickel–organic macrocycle for the photocatalytic reduction of protons and CO2 has been reported.

scholarly journals SynActJ: Easy-to-Use Automated Analysis of Synaptic Activity

2021 ◽  
Vol 3 ◽  
Author(s):  
Christopher Schmied ◽  
Tolga Soykan ◽  
Svenja Bolz ◽  
Volker Haucke ◽  
Martin Lehmann
Keyword(s):  
Image Analysis ◽  
Organic Dyes ◽  
Calcium Influx ◽  
Glutamate Release ◽  
Automated Analysis ◽  
Time Lapse ◽  
Synaptic Activity ◽  
Automated Image Analysis ◽  
Batch Mode ◽  
Fluorescent Intensity

Neuronal synapses are highly dynamic communication hubs that mediate chemical neurotransmission via the exocytic fusion and subsequent endocytic recycling of neurotransmitter-containing synaptic vesicles (SVs). Functional imaging tools allow for the direct visualization of synaptic activity by detecting action potentials, pre- or postsynaptic calcium influx, SV exo- and endocytosis, and glutamate release. Fluorescent organic dyes or synapse-targeted genetic molecular reporters, such as calcium, voltage or neurotransmitter sensors and synapto-pHluorins reveal synaptic activity by undergoing rapid changes in their fluorescence intensity upon neuronal activity on timescales of milliseconds to seconds, which typically are recorded by fast and sensitive widefield live cell microscopy. The analysis of the resulting time-lapse movies in the past has been performed by either manually picking individual structures, custom scripts that have not been made widely available to the scientific community, or advanced software toolboxes that are complicated to use. For the precise, unbiased and reproducible measurement of synaptic activity, it is key that the research community has access to bio-image analysis tools that are easy-to-apply and allow the automated detection of fluorescent intensity changes in active synapses. Here we present SynActJ (Synaptic Activity in ImageJ), an easy-to-use fully open-source workflow that enables automated image and data analysis of synaptic activity. The workflow consists of a Fiji plugin performing the automated image analysis of active synapses in time-lapse movies via an interactive seeded watershed segmentation that can be easily adjusted and applied to a dataset in batch mode. The extracted intensity traces of each synaptic bouton are automatically processed, analyzed, and plotted using an R Shiny workflow. We validate the workflow on time-lapse images of stimulated synapses expressing the SV exo-/endocytosis reporter Synaptophysin-pHluorin or a synapse-targeted calcium sensor, Synaptophysin-RGECO. We compare the automatic workflow to manual analysis and compute calcium-influx and SV exo-/endocytosis kinetics and other parameters for synaptic vesicle recycling under different conditions. We predict SynActJ to become an important tool for the analysis of synaptic activity and synapse properties.

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