Photocatalytic degradation of methyl-red by immobilised nanoparticles of TiO2 and ZnO.
In this work, we report on the degradation of methyl-red (2-(4-Dimethylamino-phenylazo)-benzoic acid--C.I. 13020) under UV irradiation in the presence of nanosized ZnO and TiO2. Oxide nanocrystals with controlled size were synthesised by using non-hydrolytic approaches and tested for the photocatalysed degradation. The performances of the immobilised nanoparticles were compared with their commercial counterparts after immobilization onto a solid support. The influence of some experimental conditions, namely pH and dye concentration, were investigated by monitoring the dye decoloration spectrophotometrically. Several intermediate by-products were identified by HPLC-MS, showing that two different mechanisms were operative during the photocatalytic oxidation.
Comparelli
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Dipartimento di Chimica, Università di Bari, via Orabona 4, 1-70126, Bari, Italy. csilrc30@area.ba.cnr.it
Cozzoli
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Curri
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Agostiano
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Mascolo
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Lovecchio
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D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D003102:Colloids; D004396:Coloring Agents / Q000737:chemistry*; D013058:Mass Spectrometry; D036103:Nanotechnology; D010316:Particle Size; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification*
D003102:Colloids; D004396:Coloring Agents; D014873:Water Pollutants; C487942:methyl-red (2-(4-dimethylamino-phenylazo)-benzoic acid); C009495:titanium dioxide; D004124:p-Dimethylaminoazobenzene; D014025:Titanium