Use of new quaternized water soluble zinc phthalocyanin derivatives for effective dye sensitization of TiO2

Abstract

This study consist the production of Q-ZnPc/TiO2 nanocomposites using two quaternized zinc phthalocyanine molecules as sensitizer using sol-gel procedure. Water soluble non-peripheral and peripheral zinc(II)-phthalocyanine compounds; namely (Q-ZnPc)(N) and (Q-ZnPc)(P;) have been specially designed to increase the polarity of the macrocycle. Geometric orientation and polarity are important parameters for production of effective dye-sensitized TiO2 nanocomposites. The enhanced photocatalytic properties have been tested for methylene blue (MB, 10 mg/L) and chromium (VI)(10 mg/L) ions as model pollutant compounds using UV light (>= 365 nm, 6 W) at 1 g/L catalyst mass. The nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). (Q-ZnPc)(P)/TiO2 has anatase crystal structure while (Q-ZnPc)(N)/TiO2 has amorphous character. These macromolecules seem to be effecting the orientation of the catalyst. Produced catalysts were so effective for both model pollutants that total degradation was achieved after 30 min exposure for Cr(VI) and almost 93.57% of MB was decomposed within 90 min exposure. Moreover, Cr(VI) removal% was extremely high even dark conditions.