Ag promotion of TiO2-anatase disinfection capability: Study of Escherichia coli inactivation

In this report we investigate the promotion of the TiO2-anatase disinfection capability by addition of silver. Ag–TiO2 systems were prepared by two different methods, impregnation and photodeposition, and their anti-microbial properties analyzed as a function of the silver content using Escherichia coli as a benchmark microorganism. Both Ag–TiO2 series of samples display maximum photokilling activity for a 1 wt.% silver loading but behave very differently for higher silver loadings. The noble metal roles played on the E. coli inactivation and their physical grounds were analyzed by a multitechnique approach using XRD, and Raman, UV–vis and electron paramagnetic resonance (EPR) spectroscopies.