Photocatalytic degradation of AZO dyes by supported TiO2 + UV in aqueous solution

Chang, Zhu; Wang, Liangyan; Kong, Lingqian; Yang, Xi; Wang, Liansheng; Zheng, Shuilin; Chen, Feili; MaiZhi, Feng; Zong, Hong

doi:10.1016/s0045-6535(99)00487-7

Cited by 204 publications

(74 citation statements)

References 19 publications

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“…In addition, H 2 O 2 can modify the TiO 2 surface. This fact probably decreases its photocatalytic efficiency (Zhu et al 2000). In addition, in the presence of high concentration of peroxide, OH Á radicals preferentially react with the excess of H 2 O 2 .…”

Section: Effect Of Oxidizing Agentmentioning

confidence: 98%

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

2015

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Traditional chemical, physical and biological processes for treating wastewater containing textile dye have such disadvantages as high cost, high energy requirement and generation of secondary pollution during treatment process. The advanced oxidation processes technology has been attracting growing attention for the decomposition of organic dyes. Such processes are based on the light-enhanced generation of highly reactive hydroxyl radicals, which oxidize the organic matter in solution and convert it completely into water, CO 2 and inorganic compounds. In this presentation, the photocatalytic degradation of dyes in aqueous solution using TiO 2 as photocatalyst under solar and UV irradiation has been reviewed. It is observed that the degradation of dyes depends on several parameters such as pH, catalyst concentration, substrate concentration and the presence of oxidants. Reaction temperature and the intensity of light also affect the degradation of dyes. Particle size, BETsurface area and different mineral forms of TiO 2 also have influence on the degradation rate.

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Section: Effect Of Oxidizing Agentmentioning

confidence: 98%

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

2015

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“…The color of azo dyes is determined by the azo bonds and their associated chromophores and auxochromes. Azo bonds are the most active bonds in azo dye molecules and can be oxidized by positive hole or hydroxyl radical or reduced by electron in the conduction band 13 . The cleavage of -N=N-bonds leads to the decolorization of dyes, what was observed in the discussed experiment (Fig.…”

Section: Effect Of Tio 2 Structure On Photodegradation Rate Of Azo Dyesmentioning

confidence: 99%

Effect of calcination temperature on photocatalytic activity of TiO₂. Photodecomposition of mono- and polyazo dyes in water

Mozia

2008

Polish Journal of Chemical Technology

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The presented studies have focused on the influence of TiO 2 properties, such as crystalline phase, crystallite size and surface area, on the effectiveness of degradation of azo dyes in water under UV irradiation. Two monoazo dyes: Acid Red 18 (AR18, C 20 H 11 N 2 Na 3 O 10 S 3 ) and Acid Yellow 36 (AY36, C 18 H 14 N 3 NaO 3 S), and one polyazo dye Direct Green 99 (DG99, C 44 H 28 N 12 Na 4 O 14 S 4 ) were applied as model compounds. The photocatalysts were prepared from a crude titanium dioxide obtained directly from the production line (sulfate technology) at the Chemical Factory "Police" (Poland). The crude TiO 2 was calcinated in air for 1 -4h at the temperatures ranging from 600 to 800 o C. The BET specific surface area of TiO 2 decreased gradually with increasing the calcination temperature. The crude TiO 2 exhibited specific surface area of 277 m 2 /g. In case of the catalysts heated at 600, 700 and 800 o C contained primarily anatase phase (94 -97%), whereas the photocatalysts heated at 800 o C were composed mainly of rutile (97 -99%). The highest effectiveness of azo dyes degradation was obtained in case of the photocatalyst calcinated for 1h at 700 o C. The photocatalyst was composed mainly of anatase (97%) with crystallite size of 27 nm. The most effectively photodegraded was AR18, having the molecular weight of 640.4 g/mol. The most difficult to degrade was AY36 exhibiting the lowest molecular weight from all the dyes used (375.4 g/mol).

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“…Thus, resulting in decreased rate of photocatalytic degradation (Davis et al, 1994, Poulios andAetopoulou, 1999). Further, at higher dye initial concentration, the approach of the radiation photons to the catalyst surface is hindered and screened off, thereby, reducing the photocatalytic activity in the system (Epling and Lin, 2002;Zhu et al, 2000). Moreover, at the higher dye concentration, the number of collisions between dye molecules increases at the cost of required collisions between dye molecules and .…”

Section: Effect Of Phmentioning

confidence: 99%

Photo-catalytic Removal of Methyl Orange Dye by Polyaniline Modified ZnO using Visible Radiation

Melaku¹,

Yadav²,

Kebede³

2014

Sci. Technol. Arts Res. J.

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Article InformationPolyaniline modified zinc oxide (PANI/ZnO) nanocomposite was synthesized by in-situ polymerization process. The as-synthesized nano-ZnO, PANI and PANI/ZnO nanocomposite were characterized by X-ray diffraction (XRD), FT-IR, and UV-Vis spectroscopy. The UV-visible spectroscopy studies showed that the absorption peak for PANI/ZnO nanocomposite has a red shift toward visible wavelengths compared with the ZnO nanoparticles and PANI. Photocatalytic efficiency of PANI/ZnO nanocomposite was investigated for the degradation of methyl orange (MeO) dye as a model organic compound under Visible light irradiation. The photocatalytic activities of ZnO, PANI and PANI/ZnO nanocomposite were studied. The results showed that ZnO/PANI nanocomposite had greater photocatalytic activity than ZnO nanoparticles and PANI under visible light irradiation. According to these results, application of PANI as a shell on the surface of ZnO nanoparticles causes the enhanced photocatalytic activity of the PANI/ZnO nanocomposite. Influence of some operational parameters such as: amount of photocatalyst, pH of solution, and MeO dye initial concentration on the photodegradation reaction rate was investigated.The optimum values of pH and catalyst dose found to be 6 and 1.50 gmL -1 respectively. It was demonstrated that the photocatalytic degradation of MeO follows pseudo first-order kinetics. The PANI/ZnO nanocomposite photocatalysts have good photocatalytic stability and can be reused three times with only gradual loss of activity. Thus, the PANI/ZnO nanocomposites are efficient photocatalytic materials for degrading contaminated colored wastewater for reuse in textile industries under mild conditions.

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Photocatalytic degradation of AZO dyes by supported TiO2 + UV in aqueous solution

Cited by 204 publications

References 19 publications

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

Effect of calcination temperature on photocatalytic activity of TiO₂. Photodecomposition of mono- and polyazo dyes in water

Photo-catalytic Removal of Methyl Orange Dye by Polyaniline Modified ZnO using Visible Radiation

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Photocatalytic degradation of AZO dyes by supported TiO2 + UV in aqueous solution

Cited by 204 publications

References 19 publications

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

Effect of calcination temperature on photocatalytic activity of TiO2. Photodecomposition of mono- and polyazo dyes in water

Photo-catalytic Removal of Methyl Orange Dye by Polyaniline Modified ZnO using Visible Radiation

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Effect of calcination temperature on photocatalytic activity of TiO₂. Photodecomposition of mono- and polyazo dyes in water