Purification of titania nanoparticle thin films: Triviality or a challenge?

Although purification of titania nanoparticles is a very common process in laboratory practice the specific purification protocol is often chosen without scientific justification. In the present work the efficiency of three different and in laboratory practice widely used treatments is compared for removing organic contaminants from the surface of titania nanoparticles. The most effective purification treatment was annealing of nanoparticles below 400 °C: annealing at higher temperatures causes besides purification the growth of nanoparticles.