Ultra-fast degradation of thiazine dyes in the presence of natural sunlight by coupling of titania with zinc oxide nanoparticles in the room temperature.

Semiconductor coupling is one of the best incredible ways to improve the photo-absorption range from UV to the visible region. Here, we prepared various proportions of titanium dioxide (TiO2) and zinc oxide (ZnO) and thus determined the best ratio suitable for photo-activated applications. Sol–gel synthesis method is used for the preparation of TiO2 and TiO2/ZnO nanoparticles. TiO2/ZnO composites are prepared in ratios 9:1, 8:2 and 7:3, respectively. HR-SEM micrograph reveals the conversion of surface morphology from rod to plate after addition of ZnO. The peak of photoluminescence spectra lies between 451 and 494 nm, which shows the photocatalyst can absorb photons in the visible region. The photocatalytic degradation of the samples was investigated using a model thiazine dye. The light medium used for the degradation is sunlight. UV spectroscopy results obtained from the sample TiO2/ZnO taken in the ratio 8:2 show an enhanced efficiency. The least absorbance was shown clearly with an efficient degradation of 95.11%. Photocatalysis procedure was repeated with the same photocatalyst up to five times, and dye degradation efficiency was not decreased. Durability of TiO2/ZnO paves the way for applications like anti-microbial activity, energy conservation and waste water treatment. [ABSTRACT FROM AUTHOR]