Memory antibacterial effect from photoelectron transfer between nanoparticles and visible light photocatalyst

A novel visible light photocatalyst system was developed, consisting of palladium oxide (PdO) nanoparticles well dispersed on a nitrogen-doped titanium oxide (TiON) matrix. Clear evidence of photoelectron transfer between PdO nanoparticles and the TiON matrix was obtained for the first time. The optoelectronic coupling between PdO and TiON introduces enhanced photocatalytic bacterial disinfection under visible light illumination by electron trapping on a PdO nanoparticle, and a unique catalytic memory effect on bacterial disinfection due to the discharging of trapped electrons on PdO nanoparticles in the dark when the illumination is switched off. Thus, a unique robust catalytic disinfection system is created, which is driven by solar/visible light illumination, enables the continuous operation in day and night, and could be adapted to a broad range of environmental applications.