Photocatalytic degradation of persistent organic pollutants under visible irradiation by TiO2 catalysts sensitized with Zn(II) and Co(II) tetracarboxy-phthalocyanines
| Autor: | Ahmet Gül, Yaghub Mahmiani, Altuğ Mert Sevim |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Diffuse reflectance infrared fourier transform
Chemistry Infrared spectroscopy 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences Catalysis chemistry.chemical_compound Chlorobenzene Titanium dioxide Phthalocyanine Photocatalysis 0210 nano-technology Visible spectrum |
| Zdroj: | Journal of Porphyrins and Phthalocyanines. 20:1190-1199 |
| ISSN: | 1099-1409 1088-4246 |
| DOI: | 10.1142/s108842461650084x |
| Popis: | Photo-excitation under visible light has been an important step to acquire solar-driven TiO2 photocatalysts and dye sensitization has been used frequently to extend the optical response of TiO2 into the visible region. In the present work, new heterogeneous photocatalysts were prepared by anchoring carboxylic acid substituted Zn(II) and Co(II) phthalocyanines onto polycrystalline TiO2 surface and their photocatalytic activities were investigated. Due to covalent bonding of carboxy-terminated molecules onto TiO[Formula: see text]semiconductors, we synthesized symmetric 4-hydroxybenzoic acid-bearing metallophthalocyanines as dye sensitizer molecules. Heterogeneous composites having titanium dioxide and metallophthalocyanines anchored via CO–O–TiO2 bonds were characterized by using X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), and ultraviolet-visible diffuse reflectance spectroscopy. The optimum loading value of the dyes on TiO2 were 0.98 [Formula: see text]mol/g TiO2 for CoPc and 0.86 [Formula: see text]mol/g TiO2 for ZnPc, nearly independent of the amount of TiO2 used. These newly obtained heterogeneous photocatalysts were employed in the photocatalytic degradation of 4-chlorophenol(4-CP), chlorobenzene(CB) and 1,2,4-trichlorobenzen(TCB) in aqueous media under visible irradiation. Gas chromatography-mass spectrometry (GC-MS) was used for quantitation. The new photocatalysts showed excellent activities with visible-region irradiation in the photocatalytic degradation of persistent organic pollutants (POPs) as compared to the control experiments used with untreated TiO2 and the difference was attributed to the cooperation of the two elements, namely TiO2 and MPc. Experiments show that in two hours nearly complete degradation of POPs were observed. |
| Databáze: | OpenAIRE |
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