Upconverting particles in near-infrared light-induced TiO photocatalysis: towards the optimal architecture of upconverter/photocatalyst systems.

Preparation of highly active core-shell/hybrid materials based on up-converting particles combined with semiconductors for photocatalytic application usually requires sophisticated and multi-step synthesis procedures. We propose a new design of a highly efficient NIR-driven photocatalytic system composed of spatially separated thin films of upconverting NaYF:Yb,Tm particles (UCPs), and TiO. Several samples of UCPs were prepared in the form of thin films and suspensions, directly coated with a titania layer or mixed with P25.