scholarly journals Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO2Immobilised on Ceramic Tiles

2011 ◽  
Vol 8 (2) ◽  
pp. 581-586
Author(s):  
P. N. Palanisamy ◽  
S. K. Kavitha
Keyword(s):  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Ceramic Tile ◽  
Azo Dye ◽  
Solar Irradiation ◽  
Ceramic Tiles ◽  
Comparative Efficiency ◽  
Photocatalytic Removal ◽  
Slurry Method ◽  
Better Than

The photocatalytic activity of TiO2immobilized on different supports; cement and ceramic tile, was studied to decolorize two commercial dyes. The catalyst was immobilised by two different techniques, namely, slurry method on ceramic tile and powder scattering on cement. The degradation of the dyes was carried out using UV and solar irradiation. The comparative efficiency of the catalyst immobilised on two different supports was determined. The photodegradation process was monitored by UV-Vis spectrophotometer. The catalyst immobilised on ceramic tile was found to be better than the catalyst immobilised on cement. Experimental results showed that both illumination and the catalyst were necessary for the degradation of the dyes and UV irradiation is more efficient compared to solar irradiation.

The Preparation of BiOCl Microspheres and its Photocatalytic Performance

2012 ◽  
Vol 487 ◽  
pp. 841-844 ◽  
Author(s):  
Xiao Chao Du ◽  
Wen Wen Zhao ◽  
Ya Wei Liu ◽  
Xiang Ping Huang ◽  
Feng Mao
Keyword(s):  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Photocatalytic Performance ◽  
Absolute Ethanol ◽  
Heating Method ◽  
Excellent Photocatalytic Activity ◽  
One Step ◽  
Better Than

The BiOCl microspheres photocatalyst was obtained by a one-step alcohol-heating method. The reactants were Bi(NO3)3•5H2O、TiCl3 and absolute ethanol, and the sample was synthesized at 100°C and calcined at 600°C. It then characterized by XRD, SEM, UV-vis DRS. The results showed that the sample was microspheres, having excellent photocatalytic activity that the sample could degradate more than 94% of RhB in 65 minites which is better than P25 under UV irradiation.

scholarly journals SnS2/TiO2 Nanocomposites for Hydrogen Production and Photodegradation Under Extended Solar Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Hydrogen Evolution ◽  
Environmental Remediation ◽  
High Performance ◽  
Degradation Mechanism ◽  
Solar Irradiation ◽  
Earth Abundant ◽  
Improved Performance ◽  
Chalcogenide Materials

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.

scholarly journals Biomimetic Synthesis, Characterization, and Evaluation of Fluorescence Resonance Energy Transfer, Photoluminescence, and Photocatalytic Activity of Zinc Oxide Nanoparticles

2021 ◽  
Vol 13 (4) ◽  
pp. 2004
Author(s):  
Udari Wijesinghe ◽  
Gobika Thiripuranathar ◽  
Haroon Iqbal ◽  
Farid Menaa
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Solar Irradiation ◽  
Zno Nps ◽  
Fluorescence Resonance

Owing to the development of nanotechnology, biosynthesis of nanoparticles (NPs) is gaining considerable attention as a cost-effective and eco-friendly approach that minimizes the effects of toxic chemicals used in NP fabrication. The present work reports low-cost phytofabrication of zinc oxide (ZnO) NPs employing aqueous extracts of various parts (leaves, stems, and inflorescences) of Tephrosia purpurea (T. purpurea). The formation, structure, morphology, and other physicochemical properties of ZnO NPs were characterized by ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS). UV–Vis spectral analysis revealed sharp surface plasmon resonance (SPR) at around 250–280 nm, while the XRD patterns confirmed distinctive peaks indices to the crystalline planes of hexagonal wurtzite ZnO NPs. TEM analysis confirmed the presence of spherical-shaped ZnO NPs with average particle sizes (PS) between 25–35 nm, which was in agreement with the XRD results. FTIR analysis revealed that phenolics, flavonoids, amides, alkaloids, and amines present in the plant extract are responsible for the stabilization of the ZnO NPs. Further, the hydrodynamic diameter in the range of 85–150 nm was measured using the DLS technique. The fluorescence resonance energy transfer (FRET) ability of biogenic ZnO NPs was evaluated, and the highest efficiency was found in ZnO NPs synthesized via T. purpurea inflorescences extract. Photoluminescence (PL) spectra of biogenic ZnO NPs showed three emission peaks consisting of a UV–Vis region with high-intensity compared to that of chemically synthesized ZnO NPs. The biosynthesized ZnO NPs showed photocatalytic activity under solar irradiation by enhancing the degradation rate of methylene blue (MB). Among the prepared biogenic ZnO NPs, T. purpurea leaves mediated with NPs acted as the most effective photocatalyst, with a maximum degradation efficiency of 98.86% and a half-life of 84.7 min. This is the first report related to the synthesis of multifunctional ZnO NPs using T. purpurea, with interesting characteristics for various potential applications in the future.

Bifunctional 4MBA mediated recyclable SERS-based immunoassay induced by photocatalytic activity of TiO2 nanotube arrays

2016 ◽  
Vol 18 (34) ◽  
pp. 23795-23802 ◽  
Author(s):  
Xiaolong Wang ◽  
Lu Zhou ◽  
Wei Lai ◽  
Tao Jiang ◽  
Jun Zhou
Keyword(s):  
Density Functional Theory ◽  
Photocatalytic Activity ◽  
Detection Limit ◽  
Uv Irradiation ◽  
Density Functional ◽  
Tio2 Nanotube Arrays ◽  
Tio2 Nanotube ◽  
Nanotube Arrays ◽  
Functional Theory ◽  
Low Detection Limit

We present a recyclable SERS-based immunoassay for CA19-9 with a low detection limit of 5 U mL−1. The linking between TiO2-NTs and 4MBA was destroyed by catalyzing 4MBA into 4-sulfobenzoate upon UV irradiation, which was clarified by UPLC/ESI-tqMS and density functional theory.

Degradation of an Azo Dye by Fenton Type Processes Assisted with UV Irradiation

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Natalija Koprivanac ◽  
Dinko Vujevic
Keyword(s):  
Uv Irradiation ◽  
Azo Dye ◽  
Dye Degradation ◽  
Degradation Products ◽  
Batch Reactor ◽  
Process Efficiency ◽  
Molar Ratio ◽  
Synthetic Dyes ◽  
Ambient Conditions ◽  
Treatment Methods

Organic synthetic dyes are widely produced and used today. Significant losses of organic and inorganic content occurs during the manufacturing and application of dyes and its discharge in the effluent presents a threat to the eco-systems due to general toxicity and resistance to destruction by biological treatment methods. Particularly azo dyes are of special environmental concern due to their degradation products such as aromatic amines, which are considered highly carcinogenic. So, dyes have to be removed from coloured wastewater before discharge. However, traditional treatment methods (adsorption, coagulation/flocculation) mainly transfer the contaminants from wastewater to secondary waste. Therefore, advanced oxidation processes seem to be sustainable and clean technology to decolorize and minimize organic dyes content from wastewater. In this paper, degradation of an azo dye C.I. Direct Orange 39 (DO39) using Fenton type processes (Fe2+/H2O2, Fe3+/H2O2and Fe0/H2O2) has been performed. The molar ratio of Fenton’s type reagents has been varied in the range of 1 : 5 up to 1 : 50 at 0.5 and 1.0 mM concentrations of iron salts and iron powder. Experiments have been conducted for two hours in a batch reactor with magnetic stirring, ambient conditions and pH 3. The process efficiency and formation of degradation by-products have been determined on the basis of results obtained by UV/VIS spectrophotometric, total organic carbon (TOC) and high performance liquid chromatography (HPLC) analyses. The optimal Fenton and Fenton ``like" processes parameters have been applied in the photo reactor, too. It has been observed that simultaneous utilization of UV irradiation with Fenton's and Fenton ``like" reagents increases the degradation of DO39 dye. Degradation of the dye in dilute aqueous solution follows pseudo-first order kinetics. The maximal decolourization of 20 mg L-1 DO39 in water of 93.2% and TOC degradation of 76.9% were obtained using Fe3+/H2O2= 1 : 5 molar ratio. The results indicate that the treatment of DO39 dye wastewater with UV/Fe3 +/H2O2 system was found to be the most efficient.

scholarly journals Modelling Porosity Permeability of Ceramic Tiles using Fuzzy Taguchi Method

2018 ◽  
Vol 16 (1) ◽  
pp. 1111-1114
Author(s):  
Abdullah Hulusi Kokcam ◽  
Özer Uygun ◽  
Mehmet Fatih Taskin ◽  
Halil Ibrahim Demir ◽  
Zeynep Demir
Keyword(s):  
Taguchi Method ◽  
Product Development ◽  
Ceramic Tile ◽  
Fuzzy Numbers ◽  
Experiment Design ◽  
Quality Development ◽  
Triangular Fuzzy Numbers ◽  
Ceramic Tiles ◽  
Factors Affecting ◽  
Taguchi Experiment Design

AbstractTaguchi experiment design in quality development studies, is an approach to engineering that supports research and development, product design and product development activities by enabling fewer trials of experiments to determine the best combinations of inputs that affect the outcome. In this study, the factors affecting the porosity were studied in a firm that produces ceramic tile. There were 6 factors considered to be important in total and 2 levels in each factor. L8 orthogonal array were used during the experiment design, which proposes 8 experiment types with different factor levels. The results of the experiments were analyzed so that important factors were determined. Significance of factors were tested by ANOVA and 4 of them were found to be significant. These factors were fuzzified by assessing the factors using linguistic expressions and then triangular fuzzy numbers. A model with 4 inputs and 1 output was built and 34 rules were generated for this model. The developed model was shown to be a useful approach in modeling the porosity permeability of ceramic tiles.

scholarly journals Antimicrobial polymers: Antibacterial efficacy of silicone rubber–titanium dioxide composites

2016 ◽  
Vol 51 (16) ◽  
pp. 2253-2262 ◽  
Author(s):  
Betiana Felice ◽  
Vera Seitz ◽  
Maximilian Bach ◽  
Christin Rapp ◽  
Erich Wintermantel
Keyword(s):  
Photocatalytic Activity ◽  
High Risk ◽  
Uv Irradiation ◽  
Silicone Rubber ◽  
Light Exposure ◽  
Antibiotics Resistance ◽  
Antibacterial Efficacy ◽  
Risk Environments ◽  
Antibacterial Polymers ◽  
High Risk Environments

Control and reduction of microorganism infections in high-risk environments is up to date a challenge. Traditional techniques imply several limitations including development of antibiotics resistance and ecotoxicity. Then, polymers functionalized with photocatalyts arise as a promising solution against a broad spectrum of microorganisms found at, e.g. sanitary, food, and medical environments. Here, we present silicone rubber–TiO2 composites as novel antibacterial polymers. Four different types of composites with different TiO2 contents were produced and analyzed under UV irradiation and dark conditions in terms of particle distribution, chemical composition, photocatalytic activity, wettability, and antibacterial efficacy against Escherichia coli. Under UV irradiation, antibacterial sensitivity assay showed a 1000 times reduction of colony forming units after 2 h of light exposure so that the antibacterial ability of silicone–TiO2 composites was proved. Photocatalytic activity assessment suggested that reactive oxygen species induced by photocatalytic reaction at TiO2 particles are the main cause of the observed antibacterial effect. Scanning electron microscopy indicated no topographical damage after UV exposure. In addition, chemical analysis through Raman and X-Ray photoelectron spectroscopies demonstrated the stability of the silicone matrix under UV irradiation. Hence, the current work presents silicone–TiO2 composites as stable nonspecific antibacterial polymers for prevention of infections at multiple high-risk environments.

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