Synthesis and characterization of silver-titania nanocomposites prepared by electrochemical method with enhanced photocatalytic characteristics, antifungal and antimicrobial activity

摘要

The paper deals with the synthesis of silver-titania (Ag-TiO2) nanocomposites with enhanced photocatalytic, antifungal and antimicrobial characteristics. Ag nanoparticles have been electrochemically deposited on the commercially available nano-TiO2powders involving the so-called “sacrificial anode” technique. The obtained nanocomposites were characterized by X-ray diffraction, XPS and Raman spectroscopy to get information on their composition and structure. Particle size distribution and stability of Ag-TiO2based colloidal solutions have been determined from dynamic light scattering andzetapotential measurements. The recorded UV–vis diffuse reflectance spectra evidenced the presence of an absorption band located in the range of 475–525nm and the presence of a tail as well, suggesting a better photocatalytic activity. The photoreactivity of the synthesized Ag-TiO2nanocomposite as well as the influence of Ag content were evaluated for the degradation of Orange II dye under UV irradiation (λ=365nm). The heterogeneous photocatalytic degradation rate follows pseudo first order kinetics. Antifungal and antimicrobial efficacy evaluation showed that the synthesized Ag-TiO2nanocomposites are significantly more active than pure titania.