A multifunctional biocide/sporocide and photocatalyst based on titanium dioxide (TiO2) codoped with silver, carbon, and sulfur

Autores: Hamal, D.B.|Haggstrom, J.A.|Marchin, J.L.|Ikenberry, M.A.|Hohn, K.|Klabunde, K.J.
Fuente: Langmuir
26 (4), 2805-2810
2010

Composite nanostructured samples of Ag (0.5-20%)/(C, S)-TiO2 were synthesized and characterized by EDX, XRD, FT-IR, UV-vis, BET, XPS, and zeta potential measurements. Photocatalytic and biocidal tests revealed that the amount of the codoped silver (Ag+) in (C, S)-TiO2 played a crucial, distinctive role in the photodegradation of gas-phase acetaldehyde as well as in the inactivation of Escherichia coli cells and Bacillus subtilis spores. Very interestingly, Ag/(C, S)-TiO2 nanoparticles (crystallite size <10 nm) have shown very strong antimicrobial properties without light activation against both E. coli (log kill >8) and B. subtilis spores (log kill >5) for 30 min exposures, compared with P25-TiO2. Thus, for the first time, we have demonstrated that titanium dioxide (an environmentally friendly photocatalyst) codoped with silver, carbon, and sulfur can serve as a multifunctional generic biocide as well as a visible light activated photocatalyst.