Ultrathin titanium oxide nanosheets film with memory bactericidal activity.

An ultrathin photocatalytic film of titanium oxide was fabricated using two dimensional (2D) titanium oxide nanosheets (TONs) as building blocks. The as-prepared film was found be able to store photoelectrons upon UV irradiation due to the reduction/oxidation of T4+ /Ti3+ on the 2D TONs. Post-illumination discharging of the stored electrons produced antibacterial radicals, and as a result, the as-prepared film showed memory bactericidal activity toward E. faecalis and E. coli in the dark.