TiO 2-mediated photocatalytic degradation of Orange II with the presence of Mn 2+ in solution (original) (raw)

Photocatalytic Degradation of Methyl Orange in Aqueous TiO2 Suspensions

Asian Journal of Chemistry, 2013

The degradation of methyl orange was studied using advanced oxidation process by exposed to UV irradiation in the presence of TiO2. TiO2 or UV light has a negligible effect when used alone. The effect of TiO2 dosage, initial pH of dye solution and the solution area exposed to UV light were studied. It is found that in the investigated range, degradation rate of methyl orange increases with the increase in TiO2 concentration and exposure area of solution. Acidic media is fvaourable to methyl orange degradation. The photodestruction of methyl orange is significantly inhibited by addition of KI as active holes scavenger at pH 2. However, the roles of •OH and H2O2 are increased gradually as the increase of initial pH value of dye solution.

Photocatalytic degradation of methyl orange with immobilized TiO2 nanoparticles: effect of pH and some inorganic anions

Physical and Chemical News

The photocatalytic degradation of Methyl Orange (MO) as a model pollutant compound was investigated using HPK 125W UV lamp as irradiation source, and titanium dioxide (TiO 2 ) immobilized on paper in batch reactor. The effect of pH and some inorganic anions such as Cl -, NO 3 -, SO 4 2-, CH 3 COOand HPO 4 2-, commonly present in real effluents, on the photocatalytic degradation was also studied. The photocatalytic degradation rate follows pseudo-first order kinetic with respect to (MO) concentration. The experimental results show that the photocatalytic degradation depends on the pH of the solution and is greater in acid medium. The presence of Cl -, SO 4 2-, NO 3 anions leads to an increase of the effectiveness of the photocatalytic degradation. However, the presence of HPO 4 2and CH 3 COOanions decreases differently the photocatalytic efficiency.

HIGHLY ACTIVE TiO2 NANOPHOTOCATALYSTS FOR DEGRADATION OF METHYL ORANGE UNDER UV IRRADIATION

This study describes the application of novel chemistry methods for the removal of dye by Nano structured titanium oxide (TiO 2 ) photo catalysts. Such materials can be applied in the development of efficient photo catalytic systems for the treatment of water. Nano crystalline TiO 2 was synthesized by Sol-Gel route using titanium tetraisopropoxide as a metal precursor. The catalysts were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR).Synthesized TiO 2 was related to anatase phase and crystalline structure was characterized by XRD. Cuboidal and uneven shape of TiO 2 nanoparticles were observed by TEM images. FTIR reveals the functional groups present in the synthesized TiO 2 nanoparticles. Thus synthesized TiO 2 nanoparticle was used for photo catalytic degradation of methyl orange. The photo degradation of methyl orange (MO) dye, is examined both under different dye concentration (10, 20, 30 and 40 ppm) and amounts of TiO 2 (5, 10, 15 and 20 mg / 10 ml). After 15W UV-365 nm irradiation for 3 h, ca. 99.9% of MO was degraded with addition of 20mg TiO 2 to solutions containing 40ppm dye. The photo degradation mechanism of the quinonoidal methyl orange using nanoparticles is low cost, eco-friendly and cost effective process in the removal of toxic dyes. KEY WORDS: TiO 2 nanoparticles, Photo catalytic degradation, Methyl Orange, XRD, TEM, FTIR

Current Research Paper Highly active TiO 2 nanophotocatalysts for degradation of methyl orange under UV irradiation Environmental Science Environmental Science

2015

This study describes the application of novel chemistry methods for the removal of dye by nano-structured titanium oxide (TiO 2) photocatalysts. Such materials can be applied in the development of efficient photocatalytic systems for the treatment of water. Nanocrystalline TiO 2 was synthesized by Sol-Gel route using titanium tetraisopropoxide as a metal precursor. The catalysts were characterized by X-ray diffraction (XRD), Transmission Electron Microoscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR). Synthesized TiO 2 was related to anatase phase and crystalline structure was characterized by XRD. Cuboidal and uneven shape of TiO 2 nanoparticles were observed by TEM images. FTIR reveals the functional groups present in the synthesized TiO 2 nanoparticles. Thus synthesized TiO 2 nanoparticle was used for photocatalytic degradation of methyl orange. The photodegradation of methyl orange (MO) dye, is examined both under different dye concentration(10,20,30 and 40 ppm) and ...

PHOTOCATALYTIC DEGRADATION OF ACID ORANGE II DYE ON SELECTED COMMERCIAL TITANIUM DIOXIDE CATALYSTS

Photocatalytic degradation of acid orange II dye in the presence of UV light was investigated using selected commercial TiO2 as photocatalysts. The objective of this study was to determine the rate of degradation of the model dye using selected commercial TiO2. The types of TiO2 used as photocatalysts in this study were P25 (Degussa), AVO1 (Precheza) and S7001 (Euro support). The oxides were immobilized on microscopic glass slides measuring 75 mm x 25 mm to form a uniform layer area 8.75 cm2. A four-hole position photoreactor and a UV panel reactor were used in batch mode during photocatalytic degradation. Source of UV light were fluorescent tubes that emitted light at 320-400 nm with a maximum wavelength being at 355 nm. A UV/Vis spectrophotometer (model Cecil 2020) was used to monitor the changes in dye concentration. Changes in concentration during irradiation was used to determine the rate of photcatalytic degradation of the dye. The efficiency of the three dioxides in photodgradation of the acid orange II dye was compared and the study revealed that AVO1 was the most efficient commercial TiO2 as a photocatalyst followed by P25 and S7OO1 was the least.

Photocatalytic degradation of methyl orange as a model compound

Journal of Photochemistry and Photobiology A-chemistry, 2002

Titanium dioxide (TiO 2 ) was used as a photocatalyst for the detoxification of water containing methyl orange (MO), which was used as a model compound. Solar radiation was used as an irradiation source. It was found that there was no degradation for the MO in the dark and in the presence of TiO 2 . Also no degradation was observed for MO when the solution placed under solar radiation but without TiO 2 . Several experiments were used to optimize the experimental parameters. In the first set of experiments variable amounts of TiO 2 were used with a fixed concentration of MO. It was found that 0.4% of TiO 2 gave the highest degradation rate constant, 0.619 h −1 . In the second set of experiments TiO 2 concentration was fixed at 0.4% and the MO concentration was varied, the highest rate constants was obtained when the concentration of MO was 4 × 10 −5 M and it was found to be 0.639 h −1 . The degradation became negligible in the presence of high concentrations of MO. The highest degradation rate was obtained at pH = 3 with a rate constant κ = 2.6683 h −1 , followed by that at pH = 9 where the calculated κ = 0.7585 h −1 .

Enhancing photocatalytic degradation of methyl orange by crystallinity transformation of titanium dioxide: A kinetic study

Water Environment Research, 2019

This work aimed to enhance the photocatalytic degradation of methyl orange (MO) by crystallinity transformation of titanium dioxide (TiO 2). In addition, the kinetic degradation of MO was determined. To transform its crystallinity, TiO 2 was synthesized using a sol-gel method and calcined at between 200 °C to 600 o C. Calcination at a temperature of 250 °C resulted in TiO 2 that showed the best performance, corresponding to MO removal of 87% ± 7%. MO removal by TiO 2 calcined between 250 °C to 400 °C was higher than for commercial TiO 2 powder (Sigma-aldrich) (62% ± 4%). TiO 2 with a small crystallite size and high anatase fraction enhanced the photocatalytic degradation of MO, while the specific Accepted Article This article is protected by copyright. All rights reserved. surface area and surface roughness seemed to play a minor role. The photocatalytic degradation of MO was NaCl-independent, while the photocatalytic activity increased with decreased pH. Reused TiO 2 showed similar photocatalytic degradation of MO compared with pristine TiO 2 , at 84 ± 2%. The oxidation kinetics of TiO 2 calcined at 250 °C were fitted to the Langmuir-Hinshelwood model (R 2 = 0.9134). The k r and K s values were 0.027 mgL-1 .min −1 and 0.621 L.mg −1 , respectively. Crystallinity transformation was a major factor in the enhancement of photocatalytic degradation of MO. Practitioner Points  Photocatalytic activity of TiO 2 depends on calcination temperature, pH and a number of UVC lamps.  TiO 2 with a small crystallite size and high anatase fraction enhanced the photocatalytic degradation of MO.

Photocatalytic Activity of Defective TiO2-x for Water Treatment/Methyl Orange Dye Degradation

Chemistry & Chemical Technology

This study is designed to highlight photocatalytic activity of TiO2 nanoparticles in methyl orange (MO) dye degradation. Titanium dioxide TiO2 nanopowder was synthesized by conventional sol-gel method and calcined in air atmosphere at different temperatures 350C, 550C and 850C. The prepared TiO2 nanoparticles then were subjected to a solid state reaction with calcium hydride (CaH2) at the same temperatures but calcined in argon atmosphere. X-Ray Diffraction (XRD) measurements used for phase and crystalline size identification showed that the obtained samples have the same TiO2 anatase phase, but the crystalline size decreased after reduction treatment. The electronic properties obtained via UV spectroscopy showed the decrease in calculated energy gap from 3.3 eV for prepared TiO2-550 to 2.65 eV for reduced TiO2-CaH2-550, which extend the absorption spectra toward visible light region. Energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM) measurements reveale...

Photocatalytic degradation of organic dyes in the presence of titanium dioxide under UV and solar light: Effect of operational parameters

Environmental Progress, 2005

The photocatalytic degradation of methylene blue and methyl orange have been studied in the presence of titanium dioxide powder illuminated with a 300-W UV lamp. The effect of hydrogen peroxide on the degradation process was also determined. It was found that the color removal efficiency was affected by the concentration of dye, amount of TiO 2 added, and the pH of the solution. The degradation of dyes obeys first-order kinetics, with the apparent first-order rate constant increasing with decreasing dye concentration. The rate constants were evaluated as a function of the concentration of dye, amount of TiO 2 , and pH.

Study effect of titanium dioxide on the photocatalytic degradation of methyl violet dye

IOP Conference Series: Materials Science and Engineering, 2019

The organic pollutant methyl violet dye photocatalytic degradation has been investigated using the UV irradiation and TiO 2 as a catalyst. The degradation process included the study of the initial dye concentration, light intensity, catalyst weight, the effect of intensity of light, and effect of temperature to approach the best conditions for the optimum photo-degradation efficiency of dye. The optimum photocatalytic degradation of methyl violet dye was at 0.15 g/100cm 3 of dosage mass of TiO 2 and 10 ppm of the dye. Photocatalytic degradation of methyl violet dye was at 9 mW/cm 2 light intensity. The percentage efficiency of degradation methyl violet dye equals 97.46%.