Synthesis of Co-doped TiO2 nanostructures for novel photo-catalytic coatings

Aggregates of cobalt doped TiO2 nanoparticles have been prepared through a sol gel method and annealed at 450°C and 550°C. The resulting aggregates were characterized with X-ray diffraction, Field emission scanning electron microscopy, scanning electron microscopy with energy dispersive X-ray analysis and Raman spectroscopy. Later the photocatalytic (PC) activity of the prepared samples was evaluated following the degradation of a solution of methylene blue containing the aggregated nanoparticles under UV (375-385nm) and green (525-535nm) light with a UV-Vis spectrophotometer. Experimental results show that varying the annealing temperature influenced the anatase/rutile ratio in the samples, however in all cases nanostructured particles aggregated to form micro-grains were observed. Furthermore the PC activity of the sample containing a majority of anatase was more active than the one containing both rutile and anatase, having a PC activity comparable to the commercial product and therefore suitable for use in PC coatings.