(70ea) Liquid Flame Spray Made Titania and Titania-Silver Nanoparticle Deposits Functionality as Photocatalyst for Organic- and Biofilm Removal

Titania and titania-silver nanoparticle deposits were made by Liquid Flame Spray technique (LFS). In LFS the liquid precursor is injected into a high temperature flame, where it will evaporate and nucleate to nanosize particles. The precursors were titanium(IV)ethoxide (TEOT) and silver nitrate (AgNO3) in ethanol solution. One-step and two-step methods were used for preparation of titania-silver deposits. The silver amount was 1 wt%. The deposits were collected in the flame zone on steel and glass surfaces and were analyzed by TEM, EDS, XPS and SAXS. The titania deposits consisted of porous nanosized titania agglomerates of primary particles (~10 nm). With silver addition, small spherical silver metal particles (~ 2 nm) were detected on the agglomerates. An increase in the photocatalytic activity was verified by stearic acid decomposition and biofilm removal using Deinococcus geothermalis as the model organism. The titania-silver deposit produced by one-step method has the highest potential as photocatalyst.

References

Keskinen, H., J.M. Mäkelä, M. Aromaa, J. Ristimäki, T. Kanerva, E. Levänen, T. Mäntylä and J. Keskinen, 2006, Effect of silver addition on the formation and deposition of titania nanoparticles produced by Liquid Flame Spray. In press, accepted for publication in Journal of Nanoparticle Research 12/2005.