Incorporation of silver ions into ultrathin titanium phosphate films: In situ reduction to prepare silver nanoparticles and their antibacterial activity

Silver ions were incorporated into titanium phosphate ultrathin films by an ion-exchange process conducted at 50 degrees C and room temperature. The silver ions were dispersed homogeneously along the normal direction of titanium phosphate film, as confirmed by UV-vis spectroscopy and X-ray photoelectron spectroscopy. In situ reduction by NaBH4 produced silver nanoparticles embedded in titanium phosphate film. The particle size is dependent on the ion-exchange temperature, where a higher temperature leads to a larger particle size. The silver-ion-exchanged titanium phosphate films are effective in prohibiting the growth of Escherichia coli and, therefore, are expected to be used as antibacterial coatings.