Photocatalytic activity of erbium-doped TiO2 nanoparticles immobilized in macro-porous silica films

A macro-porous silica film served as mechanical support to immobilize TiO2 nanoparticles, which were doped with erbium. The films and the nanoparticles were prepared by sol–gel route. The nanoparticles exhibited photocatalytic activity under visible light. We obtained a degradation rate of methylene blue that followed first order kinetics. The sensitization of the nanoparticles to visible light was attributed to a red shift in the band-gap of the TiO2 due to the addition of erbium ions.