Effect of copper ion concentration and templating agent nature on the nano-Cu/TiO2 properties

Porous Cu/TiO2 films and powders were synthesized via the sol–gel technique. The photocatalytic and bactericidal properties of the samples, with varying copper (Cu) ion content (0.1–30%), were evaluated. The effect of the natural polymer template—Pluronic (P123) or PEG300—on the physicochemical characteristics of the materials in the presence of terpineol as a viscous solvent was also investigated. It is shown that Cu/TiO2 films exhibit high photocatalytic activity in the reduction process of Cr+6 ions to Cr+3 under the action of ultraviolet (UV) light. It is noted that the optimal concentration of Cu in the structure of photocatalytic active titanium dioxide (anatase) is in the range of 2.5–5%. Cu/TiO2 dispersions obtained using Pluronic (P123) demonstrate high bactericidal activity against gram-positive bacteria Staphylococcus aureus. The bactericidal activity of such composites correlates with the amount of Cu2+ ions released from the surface of the samples. In the case of Cu/TiO2 sample synthesized using PEG300, the desorption of Cu ions is insignificant (0.1%), suggesting Cu2+–polyethylene glycol (PEG) complex formation. The blocking of Cu ions due to complex formation may be responsible for the biocidal inactivity of the samples.